CX3PYRIGHT DEPOSIT THE MANUFACTURE OF LEATHER: ^ BEING A DESCRIPTION OF ALL OF THE PROCESSES FOR THE TANNING, TAWING, CURRYING, FINISHING, AND DYEING OF EVERY KIND OF LEATHER; INCLUDING THE VARIOUS RAW MATERIALS AND THE METHODS FOR DETERMINING THEIR VALUES ; THE TOOLS, MACHINES, AND ALL DETAILS OF IMPORTANCE CONNECTED WITH AN INTELLIGENT AND PROFITABLE PROS- ECUTION OF THE ART, WITH SPECIAL REFERENCE TO THE BEST AMERICAN PRACTICE. TO WHICH ARE ADDED COMPLETE LISTS OF ALL AMERICAN PATENTS FOR MATERIALS, PROCESSES, TOOLS, AND MACHINES FOR TANNING, CURRYING, ETC. (3 , BY / 1 -y^ CHARLES THOMAS DAVIS. ILLUSTRATED BY THREE HUNDRED AND TWO ENGRAVINGS, AND TWELVE SAMPLES OF DYED LEATHERS. DEC 10 18i4 PHILADELPHIA: HENEY CAEEY BAIRD & C 07^ INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, No. 810 WALNUT STREET. A LOXDOI^ : SAMPSON LOW, MARSTON, SEARLE & RIVINGTON, CROWN BUILDINGS, 188 FLEET STREET. 1885. &- ^'^y 5 Copyright by CHAKLES THOMAS DAVIS, 1884. COPl'RIGHT BY HENRY CAREY BAIRD & CO. 1884. ^.W^ COLLINS, PRINTER. PREFACE Considering the importance of the leather industry, it seems strange that up to the present time it should in technical literature have been so much neglected. There is not in England nor is there in America a single current book broadly treating all the branches of this subject, and the object of the present volume is fully to explain the details of manufacturing all kinds of leather in common use, and produced from hides and skins by the agency of the usual tanning substances. The author has not been satisfied to make use of the matter found in obsolete books, but has preferred to present a view of the state of the art as it to-day exists in the United States. The tools, machines, and in fact nearly all the mechanical appliances illustrated in the present treatise are of American origin, and in common use in the numerous tanneries and leather-finishing shops of the country. The collection, compilation, and collation of the vast amount of technical and detailed information attainable relating to the various processes, and to the construction of the numerous ma- chines herein described, have required almost herculean labor. But the work has been greatly aided by many of the leading tanners and curriers of the United States, who have not only placed at the author's disposal every opportunity for personal observation, but have promptly and courteously responded to IV PREFACE. his letters when containing requests for information. It is doubtful if such facilities as have been extended to him would be granted to a like professional writer on technical subjects in any other country in tlje world. The enormous development of American leather manufactur- ing industries is a source of much congratulation. There are of course in this manufacture, as in all others, times of depression, but the natural facilities for obtaining the raw material, the great ingenuity of our people, and the steady increase in the export demand, added to the large home consumption of leather, are certain to keep the United States in the position of the leading leather-producing country of the world. The invention and employment of a large number of mechan- ical appliances have done much to stimulate and cheapen leather production in the times just passed, and those manufacturers who have clung to the old-fasliioned metliods of tanning and finishing leather by hand have found their business absorbed by more enterprising firms. Sucli results were only natural, and it is therefore in the future very desirable that those now in the business should keep fully abreast of the improvements in the art. When a machine or process has, after fair trial and investigation, proved to be an improvement upon old methods, it is simply suicidal to a busi- ness not to employ it. Every new method or contrivance is not necessarily an improvement: but the success of small tanners and curriers in the future lies solel}^ in the discrimi- native adoption of labor-saving machines and time-saving processes. It is among those who j)roduce leather on a small scale that many chemical experiments in depilating, bating, and tanning could be conducted without serious loss or inconvenience, and it is urgently recommended that in the future more attention be given to this subject than it has received in the past. Every PREFACE. V process or machine used in leather manufacture that has been patented in the United States since 1790 to the close of the year 1883 is mentioned in this work. Ten volumes of the size of the present one would not have been sufl&cient to describe them all in full, but a printed copy of any patent issued since the year 1866 will, on receipt of twenty -five cents, be sent by the Com- missioner of Patents to any address in the postal union. The patents issued prior to 1866 require to be copied in manuscript, and are therefore charged for by the United States Government according to the number of words contained in them. Thus there is by means of the present volume placed at the disposal of any person who desires it, an opportunity to become fully acquainted with every step and improvement in leather manu- facture made in the United States during nearly a century. The author desires to acknowledge the assistance which he has received from Dr. Thomas Antisell, Mr. John P. Chapman, and Prof. Benjamin S. Hedrick, examiners in the United States Patent Office, all of whom have most kindly and willingly aided him in many ways. The numerous and valuable lists of patents contained in this volume could not have been perfected but for the facilities which the above-named gentlemen have extended. Prof. William H. Seaman, assistant examiner, early mani- fested his interest in the work, and his suggestions from the first have proved valuable. Col. Weston Flint, and his assistants in the scientific library of the United States Patent Office, have also greatly aided the author in his researches, and to them also he desires to ac- knowledge his indebtedness. To the enterprising publishers of this volume much credit is due. They have most kindly responded to every suggestion of the author, and have cooperated with him in every particular, sparing neither time, labor, nor expense. VI PREFACE, The chernistr}'- relating to leather, skin, and tannins has been compiled from the best German and French authorities, and due credit is given for all such matter in the proper places in the volume. It is earnestl}^ hoped by the undersigned that his long labors will not prove unfruitful, and that many persons will be bene- fited by his work. CHARLES T. DAVIS. < 1114 Pennsylvania Avenue, Washington, D. C, Nov. 22, 1884. CONTENTS. PART I. CHAPTER I. HJDES AND SKINS — THE VARIETIES OF HIDES AND SKINS USED FOR LEATHER — REMOVING HIDES AND SKINS FROM ANIMALS — SELECTING HIDES AND SKINS — FRAUDULENTLY INCREASING THE WEIGHT OF HIDES — PRESERVING HIDES — LIST OF AMERICAN PATENTS FOR PRE- SERVING HIDES-^COMMERCIAL CLASSIFICATION OP HIDES. PAGE Historical facts relating to the use of Hides and Skins of Animals . 33 Early facts in regard to flocks and herds as given in the Old Testament . 34 Cattle breeding in the United States ; the Empii-e of Nature divided into three Kingdoms — Mineral, Vegetable, and Animal ; their con- nection with the Leather Industry ; the Mineral Kingdom ; the Vege- table Kingdom . . . . . . . . . . . 35 The Animal Kingdom ; the Skins which are applicable to the Manu- facture of l^eather ; Historical facts regarding the Manufacture of Leather 86 Surmises as to the manner of the origin of the Art of Tanning . . 37 Varieties of Hides and Skins used for Leather ; Classification of Tanned Leather and of the parts of Hides ; Hides, Kips .... 38 Skins ; Mammiferous Animals, and their application to the wants of Man ; the Common Ox — its Flesh, Horns, Cartilages, Bone, Hair, etc. ; Glue ; Effect of the improvement of the Breed of Cattle on their Hides 39 Hides from UnimproAred Breeds preferred by the Tanner ; Cattle-Skins the chief source of supply for Tanneries ; whence procured and the Characteristics of those from the Various Countries . . . .40 Heavy Hides and Medium Weight Hides, Calf-Skins, Sheep- Skins, I^amb-Skins whence derived, and Varieties of Leather which they produce . . . . . . . . . . . .41 Sheep and Lamb- Skins, the next in impor'_tance to Ox Hides as sources of Leather ; the value of a Breed of Sheep for the Tanner in inverse proportion to its value as Wool ; Some of the uses of Sheep and Lamb Skins; Goat Skins .......... 42 Horse Hides, and the Skins of the Ass, Zebra, Quagga, etc. ; Horse Leather and the importance of this Industry ; Seal- Skins . . .43 Vm CONTENTS. VAGE Hog-Skins, Dog-Skins, Porpoise- Skins, Hippopotamus, and Elephant Hides ; Alligator Skins, the Alligator Leather Industry in the United States ; Characteristics and Uses of Alligator Leather ... 44 Kangaroo-Skins and the Leathers which they produce ; Buffalo Hides, Deer-Skins, Shark and Rhinoceros Skins, AValrus Hides ; Removing Hides and Skins from Animals ........ 45 Directions urgently recommended in Flaying Hides and Skins ; Import- ance of these dii'ections ......... 46 Selecting Hides and Skins; the Hides of Oxen, Bulls, and Cows; the Hides of Animals dying of disease ; Criteria for guiding the purchaser in distinguishing the quality of Hides and Skins . . . .47 Hides of Animals dying from contagious diseases should be rejected or handled with great care ; danger of handling such Hides ; Poisoning by Bacterium, AntTirax producing Malignant Carbuncles : Disinfecting I'anneries and other places where Skins are stored ; Importance of thorough Cleansing of the Store-room ...... 48 Fraudulently increasing the Weight of Hides by the employment of Sul- phuric Acid ; Tests for the Detection of this Fraud ; Preserving Hides ; Mode of Salting ; Delane's Method the one generally employed . 49 Quantity of Salt required; Glauber's Salt for Salting Hides; Other Materials for Preserving Hides ; Moret's Composition for Impregnating Hides and Skins and Preserving them so as to be capable of being unhaired by a simple immersion in water ...... 50 The Preparation and Application of Moret's Composition . . .51 Advantages claimed for Moret's Composition ; Rock's Liquid for Curing Hides 52 Sabath6 and Jourdan's Process ; Napier's Process, Sacc's Process, Wickersheimer's Process ......... 53 List of all Patents issued by the Government of the United States of America for Preserving Hides from 1790 to 1883 inclusive ; Commercial Classification of Hides ; Dry Flint ; Dry Salted ; Green Hides . . 54 Green Salted Hides ; Part Cured Hides ; Damaged Hides ; Glue Stock ; Branded Hides ; etc. . . . . . . . . .55 CHAPTER IL SYNOPSIS OF THE HISTORY OF TANNING — COMMERCIAL VARIETIES OF LEATHER. Synopsis of the History of Tanning ; Conditions upon which an Art must rest in order to improve ; Facts in reference to the history of Leather derived from the Old Testament ....... 5C Colored Leather described by Ezekiel as early as 593 B. C. as in use by Babylonians, Chaldeans, Pecods, Shoas, Koas, and all the Assyrians ; Testimony of Herodotus in regard to the use of Leather; Early use CONTENTS. IX PAGE of Leather by the Greeks, Phoenicians, Germans, and Britons ; Testi- mony of Homer and Hesiod ........ 57 Early expressions regarding the use of Leather ; the legend of St. Crispin ; the names of the early discoverers and improvers of the Processes of Tanning Leather ; Discoveries of MacBride (1768), Seguin (1 795), and Banks (1801); MacBride's Process of Raising by Sulphuric Acid; Seguin's Method by which Hides and Skins were Tanned in a shorter time, and Banks's discovery of the Tanning Property of Terra Japonica (Catechu) 58 The English discovery of the Art of Varnishing Leather ; the introduction of the art of preparing AVater-Proof Leather by Ballamy, Von Hilde- brandt, Edward, and others ; Little done by science in regard to the Improvement of the Art of Tanning ; Great improvements made in Apparatus, especially in the United States ..... 59 Skill not force, Chemical Knowledge not steam power, which in the future must cheapen and accelerate the Process of Tanning ; our in- ventors must aim to be good Chemists, as well as good Mechanics ; Room for inquiry after Tanning Materials and as to the Hide itself and its Structure .... ...... 60 The System of Tanning or Tawing by means of Chromium Compounds by Dr. Heinzerling in Germany ....... 61 The claims of Dr. Heinzerling as to the meritorious and original features of his Process ; Experiments of David Kircaldy, London, on Bark- Tanned and Chrome Leather ; Advantages which seem to be offered by the Chrome Process . . . . . . . • .62 Localities in which Dr. Heinzerling's Process, is in use ; Not yet full}' passed critical stages of practical experiment ; Commercial varieties of Leather ; Characteristic properties of Leather ; Leather Chemic- ally considered .......... 63 Tawing and the class of Skins to which it is applied ; Tawing practised by the Romans ; Introduced into Hungary in the 1 2th Century ; Chamois Dressing invented in Hungary ; the Hungarians celebrated in early times for their White Leather ; French and Dane's Leather made from Lamb and Goat- Skins for the manufacture of Kid Gloves . 64 Red or Bark Tanning the oldest Method of Tanning ; Leather similar to Morocco and Cordovan made by the Ancient Orientals ; Persian and Babylonish Leather ; the art of making Leather brought from Asia into Europe ; the Turks, Russians, and Hungarians, the most cele- brated Tanners in the first centuries of the Christian era ; Cordovan, Morocco, Shagreen, and Russia Leather ...... 65 The Morocco Leather Industry in the United States ; Decline of the Morocco and Chamois Leather Industries in Russia; the Tanning- Industry in Russia . . . . . . . . . .66 Shagreen and Russia Leather . . . . . . . .67 X CONTENTS. Hungarian Leather ; Parchment ; Artificial Parchment ... 68 The use of Parchment, and where most hirgely produced ; Alum Leather ; JBazil ; BufF Leather ; Chamois, Shammy, or Shamoy Leather ; Enamelled Leather . . . . . . . . . .69 Enamelled Leather first manufactured in the United States in Newark, N. J. ; Fair Leather ; Juncten ; Japanned, Patent and varnished Leathers first made in the United States at Newark, N. J.; Oil Leather; Roan; Russet; Saffian Leather ; Mogador Leather ; Skiver . . 70 Split Leather ; Wash Leather ; Whang ; White Leather or Tawed Leather; List of names applied to Leathers in Commerce . . 71 Artificial Leather and its uses ; Vegetable Leather . . . .7? Artificial Leather produced in Boston, Mass.; Importance of the Leather Industry in the United States ........ 73 ^ CHAPTER IIL STATISTICS OF THE TANNING INTERESTS IN THE UNITED STATES. Statement of the number of Tanneries in the United States ; Capital ; Hemlock and Oak Bark used ; Hides and Skins Tanned and the total value of products for the year 1880 . ... . . .74 The leading States engaged in this Industry . . . . . .76 Increase of Tanneries in Virginia, Tennessee, and other Southern States ; Exports and Imports of Leather ; the Leather Industry in Italy . 77 The Leather Industry of the United States rivals those of England, Germany, and Austria, and our exports should be largely increased ; Objections of English Tanners to our Leather ..... 78 Imports and Exports of Hides, Skins, Bark for Tanning, Cutch, and Gambir, Tallow, Fish Oils, etc., into and out of the United States for the twelve months ending June 30, 1882, and June 30, 1883, respec- tively ; Number of Leather Currying Establishments in the United States and their product in 1880 ; Importance of this Industry in Massachusetts . . . . . . . . . . .79 Table of the Leather Currying industry of the twelve leading States, representing nine-tenths of the whole business ..... 80 CHAPTER IV. EXAMINATION OE LEATHERS. Importance of the determination of the value and quality of Leather by chemico-technical examination; Marquis's Method — 1. Determination of fat and resin . . . . . . . . . .81 2. Determination of Lime in Leather. 3. Determination of the Tan- ning constituents : Method proposed by Heinzerling ; Determination of AVater ; Percentage of Ash ; Importance of determining the amount of Lime in Leather . . . . . . . . . . 82 • CONTENTS. XI PAGE Percentage of Fat . . . . . . . . . .83 To determine the Sebaoie Acid ; Determination of Nitrogen ; Plan pro- posed by Muntz; Barrentrapp-Will Method ; Cori'in, formulae of Reimer 84 Tanning Substance. 1. Tannic Acid ; Defects of Marquis's Method for determining Tannic Acid ; Mittenzweig's Method. 2. Mineral Con- stituents ; Determination of Mineral Materials in Mineral Tanned Leathers of Knapp and Heinzerling ; Examination of the cutting sur- face of leather, as a criterion ; Behavior of Tanned Leather toward boiling water as a test . . . . . . . . " . 85 Determination of means used to increase the weight of Leather ; Detec- tion of Adulterations, such as Glucose, added for this purpose ; Physi- cal methods of testing Leather ........ 86 I. Change in volume and ability for resisting water ; Table of Dr. Hein- zerling in regard to the comparative resisting qualities of Tanned Leather and Heinzerling' s Mineral Tanned Leather . . . .87 Results shown by the Table ; IL Testing the strength of Leather ; AVeiner's Apparatus . ... . . . . . 89>' Tables showing the strength of a Skin in different places ... 91 PART II. CHAPTER Y ANIMAL SKIN. The Raw Products with which the Tanner has to deal — 1. Hides and Skins. 2. Tanning Materials ; the construction of Animal Skin ; the Ejjidermis and its Composition ........ 93 The Epidermis does not combine with Tannin, and is, therefore, useless to the Tanner ; the Corium or Leather Skin ; the Quality of the Leather dependent upon the thickness, flexibility, and strength of the Corium ; Coriin ; Illustration showing an enlarged Transverse Section of the Skin 94 Chemical Process in the production of Glue ; Skin slowly and completely dried in the air can be kept for a long time ; Decomposition of Moist Skins ; Preservation of Skins with Salt, . or Immersed in Strong Brine ; the Chemical and Morphological Constitution of Skins as shown by RoUet and Reimer ......... 96 Modes of Preparing Coriin ; to obtain perfectly pure Coriin free from an admixture of Cell Elements . . . . . . .97 Behavior of Coriin toward different Substances ; Liming contliuied too long gives poor weight ; Composition of Coriin ; Connective Tissue Substance and the Intercellular Substance, the difference between . 98 Xll CONTENTS. PAGE To prepare Connective Tissue Substance ; Behavior of Connective Tis- sue Substance towards various other Substances .... 99 The Swelling Property of Skin Fibre 100 CHAPTER VT. VEGETABLE TANNING MATERIALS. Section I. Tannix or Tannic Acid ; Tannin or Tannic Acid ; Great variety of Plants in which Tannic Acid occurs . . . .100 The different varieties of Tannin, their Chemical and Physical behavior, and whence derived .......... 101 Classification of Tannic Acids by E. Wagner into physiological and pathological Tannic Acids ; -whence these Tannic Acids are derived ; Wagner's views on the Subject of Leather Tanned with the respective Tannic Acids ; our knowledge of the different Tannic Acids still in- complete ; Principal obstacles to a determination of the Nature of Tannic Acids 102 Gallotannic Acid — Tannin of the Xut-gall ; Discovered by Lewis in the Eighteenth Century; Pelouze's Process for its Examination; Appa- ratus of Robiquet and Boutron . . . . . . . . lOo Process of Mohr for the Exhaustion of Gall-nuts . . . . .104 Appearance and Qualities of the Tannin ; Domine's Process for the ex- haustion of Gall-nuts ; Separation of the Tannic Acid by the Aqueous Solutions of Sulphuric and Hydrochloric Acids, etc. ; Melting and de- composition of Tannin ......... lOS Behavior of Tannin under various conditions ; Tannin considered by Sti'ecker a Glucoside . . . . . . . , .106 More recent Experiments prove Tannin not to be a Glucoside ; Experi- ments of Rochleder and Kawalier ; Liebig on the Transformation of Tannin into Gallic Acid by means of Potash and thence into Carbonic and Pyrogallic Acids ; Behavior of Tannin toward various Substances 107 Jmpure Tannin Substances modify themselves when kept in contact with the Air ; Constituticni of Gallotannic Acid ; Experiments of Strecker and Schriff ; Conclusions of SchrifF; Schriff's formula of Tannin . 108 The new formula of Tannin confirmed ; Tannomelanic Acid ; how ob- tained ; Tannopinic Acid . . . . . . . . .109 Tannoxylic or Ptufitannic Acid ; Quercotannic Acid ; Properties and Behavior of Quercotannic Acid. . . . . . . .110 Quercus Red ; Quercus Bitter or Quercin . . . . . .111 Querphlobaphene ; Phloroglucin ; Protocatechuic Acid ; Pyrocatechin ; the property in Tannic Acid of forming insoluble combinations with Alkaline Salt ; loss of Tannic Acid in using Hard Water ; Fermenta- tion of Tannic Acid by Fungi - and P'erments ; Filtering of Water through exhausted Tan ; Researches of Sclmlze in regard to the Tan- nic Acid yielded by Oaks of different ages . . . . .112 CONTENTS. Xlll PAGK Tannic Acid generally present in the Roots, Barks, and Branches of Trees ; Tannic Acid a Brimary product of Vegetable Life ; Action of the different Tannic Acids toward the Corium or Leather Skin ; Tan- nic Acid which when heated forms Byrogallic Acid, furnishes Leather less capable of resisting Water than Tannic Acid yielding Pyrocatechin ; Influence of Extractive Substances upon the value of a Tannic Acid; Influence of Resins, Pectine Substances, etc. . .113 Spxtion IL Vegetable Tanning Materials .... 113 Rutea ; Kino ; African Kino, Malabar or East Indian Kino ; Kino very rich in Tannic Acid ; Garabier, its percentage of Tannin high ; Cate- chu or Terra Japonica ; its Constituents, Qualities, and Adulterations; the Leather produced from Catechu ; Gall-nuts — the richest in Tan- ning of all Tanning materials, their formation and qualities . .114 Green Galls ; European Galls ; Chinese Gall-nuts ; the countries in which Gall-nuts are produced ; Rove or Bassora Gall-nut . . .115 Sumach ; different varieties of Sumach found in Commerce — Sicilian, Italian, Spanish, Tyrol, French, and American Sumachs . . .116 Swedish Sumach ; the Tannic Acid contained in the Sicilian Sumach according to Stenhouse identical with Gallotannic Acid ; Tannic Acid of Old Sumach ; Leather prepared with Sumach possesses but little capacity of resisting Water ; Valonia ; Qualities of Leather prepared with Valonia ; Divi-divi ; Qualities of Leathers Tanned with divi-divi ; Tannic Acid of divi-divi ; Myrobalans . . . . . .117 Bublah ; Logwood ; Fustic ; Weld ; Larch Bark ; Fir Bark ; Hemlock Bark; Qualities of Hemlock Bark . . . . . . .118 American Hemlock Extract; Oak Barks; Walnut Bark; Lombardy Poplar Bark; Elm Bark 119 Horse-chestnut Bark ; jEsculotannic Acid ; qualities, constitution, and behavior of ^li^sculotannic Acid ; Horse-chestnut Extract ; AVillow Bark 120 Alder Bark ; Beach Bark ; Protaceae Barks ; Snouba Bark ; Scorza Rosa; Ratanhy Root 121 Avens Root ; Tormentil Root ; Sassafras Root ; Live Oak Wood ; Que- bracho ; Mimosa . . . . . . . . . . 122 Table showing the percentage of Tannin contained In the various Tanning- materials determined according to different methods . . . .123 Results of more recent examinations of various substances containing Tannin, according to Fraas . . . . . . . .124 Tanning materials used in most countries only such as are there produced in great abundance ; the Tanning materials used in principal countries ; Practical experiments show that there is a considerable difference in the quiintity of the various Tannins absorbed by the Skin; Table of the quantities of Tannin required, according to Anthon, for the con- version of each one pound of Skin into Leather .... 125 XIV CONTENTS. PAGE Table of Experiments ; Experiments by Kester showing the increased weight of Hides after Tanning ........ 126 Tables of Experiments of Prof. Miintz and Dr. Schon regarding the ab- sorption of different Tannins by the Skin, and of the removal of resi- nous extractive substances in Leather Tanned with different Tannins ; Conclusions of Miintz and Schon regarding the value of Leather . 127 Tables showing the results of the experiments of Miintz and Schon on the percentages of Skin and Tannin in various kinds of Leather, as well as of Glue, Tannin, and Nitrogen in Leather perfectly dry and free from all soluble substances . . . . . . . . 1 28 Table of the number of pounds of Leather free from Resin obtained from < 220 pounds of Dry Skin ; Results to be deduced from these Experi- ments as to the quantities of different Tannins absorbed by Skins . 129 CHAPTER YII. MINERAL AND ARTIFICIALLY PREPARED TANNING SUBSTANCES. Section I. Mineral Tanning Materials ; Use of Mineral Tanning materials in very early times ; Principal Mineral Substances to be con- sidered — 1. Alum, Aluminium Sulphate, and Aluminium Acetate. 2. Chromates and Chromic Oxides. 3. Ferric Salts. 4. Common Salt ; Aluminium Sulphate; Preparation, qualities, and characteristics . 130 Aluminium Sulphate in Tanning ; Alum ; Preparation, qualities, and characteristics . . . . . . . . . . .131 Iron Alum ; Manganese Alum ; Chromium Alum ; Alum in Tanning ; Aluminium Acetate ; Preparation, (jualities, and characteristics . 132 Chromium Salts ; Potassium Bichromate in Tanning ; Preparation, qualities, and characteristics ........ 133 Sodium Bichromate ; Calcium Bichromate ; Strontium and Barium ; the Neutral Alkaline Chromates; Chromium Alum, its use in Tanning ; Chromic Sulphate . . . . . . . . . .134 Ferric Salts ; Recommendation of Ferric Salts for Tanning by D' Arcet in the last century; Patent of Bordier in 1842 ; Experiments of Pro- fessor Knapp on Tanning with Ferric Salts; Knapp's L-on Soap; Common Salt, its use in Tanning . , . . . . .135 Section II. Artificially Prepared Tanning Substances; Jen- nings's Artificial Tanning Material . . . , . . .136 Sky's Tanning Material; Lees's Artificial Tannin; an Artificial Tannin formed by heating a solution of Resins and Camphor with Sulphuric Acid 137 The Classes to which the different Artificial Tannins belong . . . 138 CONTENTS. XV CHAPTER VIII. CHEMICAL EXAMINATION OP VEGETABLE TANNING MATERIALS. PAGE Method of determining the Tannic Acid ; Substances found by Gerber in a solution of the inner layer of Oak Bark ; Davy's Volumetric method of analysis .......... 139 Miintz and Rampercher's Apparatus for Filtering Tanning Liquor under pressure ............ 140 Fleck and Wolf's Method; Persoz's Method 141 Wildenstein's Colorimetric Method ; Fehling's Method modified by G. Muller 142 Satisfactory results secured from the last-named method according to Gauhe and Hallwachs ; Lippowitz employs Isinglass in place of White Glue for precipitation of the Tannic Acid in the Felling-Miiller Method; Carpene-Barbieri's Method ...... 143 Gerland's Method ; Jeans's Method ; Hammer's Method . . . 144 Table of the relation between the Specific Gravity and the Percentage of Tannic Acid, intended to facilitate calculations when Hammer's Method is employed; Franz Schulze's modification of Hammer's Method . 145 Salzer on Schulze's modification ; Observations on the manner of exe- cuting Hammer's Method ......... 146 Special Areometers which can be used to advantage with Hammer's Method; Mittenzwei and Terreil's Method 147 Manner of executing this method . -, . . . . . . 148 Hallwachs states that the results of this method are too high ; Grassi's Method 150 Wagner's Method 151 Biichner's Remarks on Wagner's Method . . . . . .152 Neubauer's Criticisms on Wagner's Method ; Clark's modification of Wagner's Method . . . . . . . . . .153 Loewenthal's Method modified by Neubauer ; Details of the execution of this method . . . . . . . . . . .154 Making the Titre . .156 Loewenthal's modification of his method; Kathreiner on the manner of executing Loewenthal's Method ....... 157 Results of experiments by Kathreiner on the Tannic Acid in Tanning materials ............ 158 Recommendations of Kathreiner ; Examination of Oak Bark . . 159 Practice of Neubauer and Kathreiner . . . . . . .160 Results obtained by Cech and Neubauer . . . . . .162 Comprehensive comparison of the results obtained by the above-described methods . . . . . . . . . . . .163 Table by Hallwachs showing the difTcrence in the percentage of Tannic Acid determined according to the methods of Fehling, Muller, Loewen- thal, Hammer, Fleck, and Mittenzwei . . . . ... 164 XVI CONTENTS. CHAPTER IX. WATER. PAGE Section I. General Remarks Concerning Water . . .165 Determination of the qualities of Water for Tanning purposes . . 1(36 The effects of Hard and Soft Watei's when used for Soaking, Cleansing, and Washing the Hides ; Eitner's Experiments regarding the effects of inorganic constituents of Water upon the depilated Skin ; Comparative effects of Hard and Soft Waters in Swelling or Plumping Hides ; tem- perature of Water for Preparing Hides . . . . . .167 Importance of a Uniform Temperature in the Water used in a Tannery ; Supply of Water to a Tannery . . . . . . . .168 Section II. Methods for Determining the Constituents of Water; Qualitative Examination of Water ..... 169 Clark's Process of Determining the Hardness of Water by Soap Solu- tion ; Mode of Execution of Clark's Process according to Faisst and Knauss . . . . . . . . . . . .170 Determination of total Hardness . . . . . . . ^ . 1 ? 1 Determination of permanent Hardness . . . . . . .173 PART HI. CHAPTER X. BARK — THE NATURE OF BARK — TOOLS USED IN BARKING — ROSSING BARK — LIST OP AMERICAN PATENTS FOR BARK-ROSSING MACHINES PREPARING BARK FOR TRANSPORTATION LIST OF AMERICAN PATENTS FOR PREPARING BARK FOR TRANSPORTATION. The Nature of Bark ; the Epidermis . . . . . . .174 Davy's Examination of the Epidermis of the Bamboo, the Sugar Cane, etc. ; the Parenchyma ; the Epiphloeum ; the Mesophlceum ; the Lieber or Endophloeum ; the Cortical Layers ; the Alburnum or Sap-wood . 1 75 Peeling the Bark and the most convenient time for it . . . .176 Davy on the comparative amounts of Tannin in Oak Bark cut in the Spring and Fall ; Influence of seasons and place at the time of Bark- ing in the richness of Tannin ; Tools used in Barking . . .177 Daigneau's Contrivance for Cutting Bark preparatory to Peeling . .178 Rossing Bark . . . . . . . . . . .181 List of all Patents for Bark Rossing Machines issued by the Government of the United States of America from 1790 to 1883 inclusive; Pre- paring Tanned Bark for Transportation ; Process 'of William H. Smith, of Chicago, Illinois . . . . . . . . . .182 CONTENTS. XVll PAGE List of all Patents for Methods and Machines for Packing Tan Bark for Transpoi'tation issued by the United States of America from 1790 to 1883 inckisive 183 CHAPTER XL GRINDING, CUTTING, CRUSHING, AND CONVEYING TAN BARK — LIST OF AMERICAN PATENTS FOR BARK MILLS. Si-.CTiON I. Grixding, Cutting, and Crxishing Tan Bark; Importance of the Grinding and Leaching of Bark ; Prime Require- ments of a good Bark Mill . . . . . . . .184 Some of the peculiarities of the present Bark Mills ; Improvement of the Troy or Starbuck Bark Mill ; the Horizontal Cylinder Breaker Bark Mill manufactured by C. Weston & Sons, Salem, Mass. . . . 185 Mosser's Safety Coupling Device for Bark Mills .' . . , .186 Barber's Bark Mill 188 Thompson's and Johnson's improved Bark Mill . . . . .190 List of all Patents for Bark Mills issued by the (Government of the United States of America, from 1790 to 1883 inclusive. . . . .19.5 Process for preparing Tan Bark for use, which consists in crushing the Dry Bark and reducing it to thin Hakes by passing it between rollers under heavy pressure after it has been ground; Holbrook's Machine for breaking up the cellular structure of Bark . . . . .197 Section II. Improved Bark Conveyer; Zane's Bark Conveyer . 200 CHAPTER XII. LEACHING TAN BARK — THE KINDS OF LEACHES EMPLOYED — BUILDING ROUND LEACHES — PILLING AND RUNNING THE SPRINKLER LEACHES — THE '^ BARKOMETER" — PURIFYING EXTRACTS OF BARK — OBTAIN- ING TANNIC ACID IN ACICULAR FORM LIST OF AMERICAN PATENTS FOR PROCESSES AND APPARATUSES FOR LEACHING AND MAKING EX- TRACTS OF TAN-BARK. Section I. The Kinds of Leaches Employed ; Best Method of Leaching or Extracting Tannin from Tan Bark long sought for ; the Lixiviation commonly conducted by one of three methods ; the Sprink- ler Leach invented by Allen and AVarren ...... 203 The forms, materials, and modes of constructing Leaches ; Apparatus for the Automatic Distribution of Fluids for Leaching, and to render the distribution uniform .......... 204 Leach with the Allen and Warren Hanging Sprinkler attached . . 208 Section II. Building Round Leaches . . . , . 209 Rule by which to find the capacity in cubic feet of a Leach of any size; Table showing the capacity of Round Leaches of many sizes . .212 The Supply Tank of a Leach ; a Round Tank the cheapest and most durable; Straining the Liquors going to the Leaches . . . 213 B XVlll CONTENTS. PAGE A Supply Tank in -which both direct and exhaust steam are used . . 214 liegulating the Sprinklers ; Diiferent modes of heating the Tank . .215 Making and working of box suitable for exhaust steam . . .216 Regulating the supply of exhaust steam ; Wooden Conductor to Leaches, described and illustrated . . . . . . . . .218 Section III. Filling and Running the Leaches . . . 219 Liquor denser than Water is inferior Leaching Fluid ; the quantity of Liquor yielded by a cord of Ground Hemlock Bark, when Water is used as the Leaching Fluid ........ 221 Yields of Oak and Chestnut Barks ; Using old or weak liquors for the Leaching Fluid ; the best way to concentrate the strength without '• doubling ; Temperature of the liquor when it commences to run from the leach ; the strongest liquors obtained with the least heat . . 222 Amount of liquor yielded under certain conditions ; Gum in liquors ; Time required for Leaching by Hot-water Method ; Advantages of Allen and Warren's System when it is desired to take from the Bark the larger portion of its Tannin with the use of little or no heat ; the liquors obtained by this system very clear and pure . . . . 223 Sizes and arrangement of Leaches . . . . . . . 224 On the amount of Ground Bark obtained from a cord of Bark as pur- chased . . . . . . 225 Section IV. The Barkometer ....... 226 Section V. Purifying Extract of Bark ; Bradley's Apparatus for the removal by precipitation of the resinous gums and floating par- ticles of Bark from the extract emanating from Leach Tubs . .227 Essential elements of this process; Description of Bradley's Apparatus; McKenzie's Screw form of Evaporator ...... 230 Section VI. Obtaining Tannic Acid in Acicular Form ; Holtz's Apparatus for improvement in the production of Tannic Acid 232 List of all Patents for Processes and Apparatuses for Leaching and making extracts from Tan Bark issued by the Government of the United States of America from 1790 to 1883 inclusive . . . 235 PART IV. CHAPTER XIII. WASHING AND SOAKING HIDES AND SKINS — PROCESSES FOR SOFTENING HIDES, SKINS, AND PELTRIES — LIST OF AMERICAN PATENTS FOR COMPOUNDS FOR SOFTENING HIDES — PROCESS FOR PLUMPING BEFORE DEPILATING. Section I. Washing and Soaking; Soaking of Green Hides and Dry Hides; Selecting Hides according to size, variety, thickness, and condition . . . . . . . . . . . .237 CONTENTS. XIX PAGE Injuries which result to Hides in Soaking ...... 238 Hammond's Process of Soaking Hides with Saltpetre or Nitrate of Potassa; Principle upon which this manner of Soaking is based; Practical details of the process ........ 239 Advantages claimed for this process ....... 240 The practice of Soaking small Hides or Kips in foul bloody water ; Soft- ening by Sweating ; Softening Imported Salted Hides ; a difference in the practice of different .Tanners in Soaking ; Dry Hides Soaked longer and handled oftener than Green Hides . . . . .241 Soaking Hides after being worked in the Hide Mill ; the practice in some parts of Prance of Soaking Dry Hides in Lime-water . . . 242 Soaking Dry Hides in Running Water ...... 243 Section II. Processes for Softrnixg Hides, Skins, and Pel- tries; Softening Dry Hides, Skins, and Peltries by Soaking them in the waste water from Gas Works ....... 243 Advantages claimed for this system ; Barron's process .... 244 Berry's Process for Softening Hides . . ■ . . . . 24.'> List of all Patents for Softening Hides issued by the Government of the United States of America from 1790 to 1883 inclusive . . . 246 Section III. Process for Plumping before Depilating, and THE Treatment op Hides or Skins with an Acid Solution before Liming, for thk Removal of Salt or other Mat- ters ; Ely's Process for Plumping Hides before Depilating; Practical details of the process . . . . . . . . .246 Advantages claimed for Ely's Process . . . ■ . . . . 249 CHAPTER XIY. HIDE MILLS — LIST OP AMERICAN PATENTS FOR HIDE MILLS — LIST OF AMERICAN PATENTS FOR BREAKING HIDES. The Softening of Dry Hides and Skins in the Hide Mill after removal from the Soaks ; Difference in the forms of Hide Mills for the various branches of Leather Manufacture; Practice of the Morocco 1'anners at Lynn, Mass., and other parts of Xew England .... 250 Practice of the Morocco Tanners of Philadelphia, Pa. . . . .2.51 Hide Mills in common use ; the Hide Mill Invented by Wm. Edwards of Northampton, Mass., in 1812; Edwards's invention of the contrivance for rolling Sole Leather ; the Idea of a Hide Mill primarily due to the Fulling Machine ; great antiquity of the Fulling Process ; Detailed description of a Hide Mill ........ 959 Friend and Annable's improvement in connec^tlng the Pitman which actu- ates the Beaters In Hide Mills, with detailed description . . . 253 Mill for Softening Hides and Fulling Cloth, with detailed description . 256 Middleton's Hide Mill, with detailed description 258 XX CONTENTS. PAGK List of all Patents for Hide Mills, issued by the Government of the United States of America from 1790 to 1883 inclusive . . . 260 List of all Patents for Breaking Hides, issued by the Government of the United States of America from 1790 to 1883 inclusive . . . 261 CHAPTER XY. PROCESSES AND COMPOUNDS FOR DEPILATING HIDES AND SKINS — THE LIMING PROCESS — OTHER DEPILATORY COMPOUNDS AND PROCESSES DEPILATING BY SWEATING — THE COLD SWEATING PROCESS — THE WARM SAVEATING PROCESS — OBSOLETE METHODS OF DEPILATING — LIST OP AMERICAN PATENTS FOR COMPOUNDS FOR DEPILATING HIDES AND SKINS. Section I. The Liming Process ; Depilation generally done by the use of Lime ; Objections to the Liming Process . . . .261 Harshness and Brittleness imparted to Leather by Liming ; Restoration of Suppleness to Leather by Bating ; Some of the inconveniences of the Liming Process . . . . . . . . . .262 Eflbrts to Substitute Other Agents ; Preparation of Hides for Liming . 263 Precautions to be taken in Liming ; Treatment of Calf-skins in the Limes ; Salted Calf-skins 264 Replacing Lime in Depilating by Acid Liquors requires judgment ; Lime Vats ; Liming SjDlit Hides ; Determination of the Quantity of Lime in a Vat .......... 265 The number of Vats in a Series ; the use of Old Limes ; the time em- ployed for Liming ; the Keel for Handling in the Lime Vats ; Stein- mann's Apparatus for Handling Hides in the Lime Pits, detailed description ........... 266 Study's Rotary Rack for Liming Hides ...... 269 Section. II. Other Depilatory Compounds and Processes ; Robinson's Process ; Ward's Process ...... 269 Wilson's Process; Carter and Keith's Process; De Montoison's Pro- cess ; Head's Process ; Banks's Process of Depilating with Steam in a Tight Room or Vat 270 Eaton's Process of Depilating by the use of Soda Ash, Caustic Lime, Monosulphuret of Potassium, Hard Soap and Soft Water . . 271 Schlosser's Composition for Depilating Green and Dry Hides with Nitrate of Potassa, Chloride of Sodium, Sulphuric Acid and Tartaric Acid . 272 Adler's Compound consisting of Sulphuretted Hydrogen Gas in connec- tion with Lime, Soda Ash, etc., as a Dejiilatory and for the purpose of Swelling Hides 273 Henry's Compound of Potash, Lime, Salt, and Sulphur, and Charcoal for Depilating . . . . . . . . . . . 274 Siebel's Application of "Refuse Gas-lime" as a Depilatory; Proposal of Boettger to use as a Depilatory Lime that had served for Purifying Gas . 275 CONTENTS. XXI • PAGE Watteau's Compound of Double Sulphate of Sodium and Calcium for Depilating; the Patents of Brainard, Claus, and Lynds • . . 276 Anderson's Process of Depilating with Cha,rcoal ..... 277 Maynard's Method for Depilating by the employment of Lime in Water, ' together with Sulphurous Acid ; Mower's Process of the combination of Lye from Wood Ashes or Potash, and Lime which has been treated by the Gas generated by Sulphuric Acid ; Sulphuret of Lime and Water, for Unhairing Hides and Skins, and for Pulling Wool . .278 Advantages claimed for this Process ....... 280 Tinnerholm's Process of Depilating and Removing Grease, with a com- pound of Water, Lime, Soda Ash, Saltpetre, and Flowers of Sulphur ; Advantages claimed for this Process . . . . . .281 Foley's Process of Softening, Plumping, and Depilating Hides and Skins through the employment of Sulphide of Barium, in solution . 282 Advantages claimed for this Process ; Patents for the use of Sulphide or Sulphuret of Calcium for Depilating; Use of Sulphide of Calcium for this purpose in Europe and America ; Action of Sulphur com- bined with Lime .......... 283 Depilating with a compound of Water, Burnt Oolite, and Muriatic Acid ; BoUman's Process of Depilating with a mixture of Water, Lime, and Blood .......... 284 Advantages claimed for this Process ; Proposed Bating mixture of Blood and Ammonia . . . ... . . . . . . 285 Laure's Process of Depilating with Water in an open vessel . . . 286 Advantages claimed for this Process ; Process of Depilation by Sul- phuret of Calcium and Soda . . . . . . . .287 Potash, Lime, and Orpiment as a Depilatorj^ ; Boettger's Pi'ocess of Depilating by the Hydrosulphate of Lime ; Preparation of the Hydrosulphate of Lime . . . . . . . . ' . 288 Boudet's Process of Depilation by Caustic Soda ..... 290 Section III. Depilating by Sweating; Cold Sweating Process much used in New York, New Hampshii'e, and Northern Pennsyl- vania 291 Mason's Building for Sweating Hides and Skins, with detailed de- scription ............ 293 Advantages claimed for this Building . . ..... 295 Care to be observed in Sweating Hides ...... 296 The Warm Sweating Process largely employed in Germany and other parts of Europe . . 298 Sweating Fresh Hides . . .' 299 Section IV. Other Methods of Depilating now nearly obso- lete ............ 300 Raising by Sour Tan Liquor ........ 301 XXll CONTENTS. PAGE Raising by Yeast ; List of all Patents for Compounds for Depilatino; H'des and Skins issued by the Government of the United States of America from 1790 to 1883 inehisive ...... 302 CHAPTER XVI. UNHAIRING AND FLESHING — UNHAIRING BY THE HAND PROCESS rr-ESHlNG BY THE HAND PROCESS — SOAKING HIDES AFTER FLESHING UNHAIRING AND FLESHING BY MACHINERY LIST OP AMERICAN PATENTS FOR UNHAIRING AND FLESHING MACHINES. Section I. Unhairing by the Hand Pkocess ; the Beam House ; ■with the forms of Beams employed; the German form of Beam and Stand used in Tawing Establishments, and the Unhairing Knife ; Practical details of the Unhairing Process . . . . .304 Section II. Fleshing by the Hand Pkocess ; the Fleshing Tools 308 Section III. Soaking Hides after Fleshing .... 311 Soaking Hides in a Steeping Cistern after Fleshing, as practised in Ger- many and France ; how long should the hides soak after Fleshing, and what indicates their readiness for Scouring ? . . . .312 Section IV. Unhairing and Fleshing by Machinery ; the Un- hairing of Hides and Skins by Machinery now an accomplished fact 313 Larrabee's Unhairing Machine with detailed description . . . 314 Tapley's Unhairing Machine with detailed description . . . .318 McDonald's Unhairing Machine with detailed description . . . 322 McDonald's improvement in Feed Rolls for Unhairing Machines . . 325 Taylor's Machine for Unhairing, Fleshing, and Working Hides and Skins, with detailed description ....... 327 Janson's Machine for simultaneously Unhairing and Fleshing Hides and Skins, with detailed description ....... 330 Roberts and Lenox's Fleshing, Slating, and Striking Out Machine . 332 List of all American Patents for Unhairing Machines issued by the Government of the United States of America, from 1790 to 1883 inclusive ............ 333 List of- all Patents for Fleshing Machines issued by the Government of the United States of America, from 1790 to 1883 inclusive . . 334 CHAPTER XVII. BATING AND FINAL PREPARATION FOR THE OOZE — BATING COMPOUNDS LIST OP AMERICAN PATENTS FOR BATING COMPOUNDS. Section I. Bating and Final Preparation for the Ooze ; Various synonymous terms used for Bating ; Use of the Bate ; the period in which the Hides remain in the Bating Solution . . .335 .CONTENTS. XX 111 PAGE Dung Bates ; Employment of Hydrochloric Acid for Dissolving Lime, as shown by MacBride in 1774 ; Carbonate of Ammonia employed by Warrington in 1841 ; Sugar used by Trumbull in 1847; Other sub- stances used ; Objections to the present method of Bating . . 336 Bating as usually accomplished by placing the Hides or Skins in a Vat, with a circular tight bottom, over which vat is a revolving paddle- wheel ; the England wheels used for agitating the Bate Liquor illus- trated and described ; the Scouring Slicker . . . . .337 Final Soaking before placing the Hides in the Ooze ; Lampert's Machine for Working Hides, with detailed description ..... 338 Section II. Bating Compounds ; ZoUick offer's Process of Bating with Muriate of Ammonia, either alone or in combination with hen's, pigeon's, or dogs's dung ......... 341 Another Process of Zollickoffer ........ 342 Advantages claimed for this process ; Parkins's Bating Compound of Carbolic Acid, Muriate of Ammonia, and Alum .... 343 Vickers and Holmes's Composition for Bating, consisting of a mixture of Sulphuric Acid with the Lime Liquor in which the Skins have been already treated for removing the Hair ...... 344 Stack's Compound for Bating, consisting of Bran, Oil of Vitriol, and Salt 345 McMurtrie's Bate of Glucose and Dried Sour Cheese ; Maynard's Bating Compound of a l^iquor composed of Water impregnated with Sulphur Dioxide, which has previously been employed in Soaking and Soften- ing Hides 346 Advantages claimed for this Compound ...... 347 Mullen's Process; Adamson's Process; Vast quantities of dilute phos- phoric acid formed in glue factories ; Siiderberg's Process . . 349 AVilson's Process; Wells's Process ; Tucker's Process ; Swan's Process 350 Turley's Process; List of all Patents for Compounds for Bating Hides and Skins issued by the Government of the United States of America, from 1790 to 1883 inclusive 351 PAKT y. CHAPTER XVIir. HANDLING AND PLUMPING. Section I. Handling ; Old and New Methods of Handling . 352 Connecting the Sides which are to be Handled with the Reel ; the Hand Reel; the Rocker Handler; England's Handling Apparatus with de- tailed description .......... 353 England's Paddle Wheels for Handling ; the Vats in which these wheels revolve ; motion of the wheels ........ 355 XXIV CONTENTS. PAGE Lenorth of time and speed at which to run these wheels ; Arrangement of the wheels ; Methods of Handling now obsolete in this country, but still used in Europe .......... 356 Handling by placing the Stock in a large Revolving Drum ; Gorsiine's Handling Apparatus ; Steinmann's Apparatus for Handling Hides in the Lime-pits ........... 357 List of all Patents for Tanners' Vats, Agitators, and Handling Appliances issued by the Government of the United States of America, from 1790 to 1883 inclusive .......... 358 Section IL Swelling ok Plumping 359 Plumping by means of Sour Liquor; Botchford's Process for Distilling Sour Liquors ........... 360 Plumping by means of Sulphuric Acid ; Introduction of this system by David MacBride, 1773 361 CHAPTER XIX. LAYING AWAY. Leather not a Chemical Combination of the Animal Substance with the Tanning Substance ; Knapp's Experiments; Deductions to be drawn from these Experiments . . . . . . . . .364 Lay-away Vats for Sole leather Hides ; Manner in which the Stock is laid away . . . . . . . . . . . 365 The number of Layers, and period for each Layer . . . .366 Practice for difi'erent kinds of Leather . . . . . . .367 CHAPTER XX. SPLITTING LEATHER. The Cellar of an Upper-leather Tannery, with Arrangement of Machines, and the manner in which the Power is supplied ; View in the Tannery of Thomas E. Proctor, Peabody, Mass 368 Splitting Machine invented by Alpha Richardson, 1831 ; Early inven- tion of Seth Boyden, Newark, N. J. ; Richardson's Union Splitting Machine ; Belt-knife Splitting Machine of Flanders and Marden ; Facilities afforded by these Machines . . . . . .369 Practical Working of the Union Splitting Machine . . . .370 A Modification of this Machine; Enos's Attachment to prevent injury to those working at the ordinary Splitting Machines, with detailed description . . . . . .. . . . .371 McDonald and Begg's Leather Splitting Machine, with detailed de- scription . . . . . . . . . . . .375 The Belt-knife Splitting Machine 3 78 Cummings'sLnprovement in Belt-knife Splitting Machines, with detailed description ........... 380 List of all Patents for Leather Splitting Machines issued by the Govern- ment of the United States of America, from 1790 to 1883 inclusive . 383 CONTENTS. XXV PAET VI. CHAPTER XXI. SCOURING. PAGE The Tools used in the Hand Method of Scouring Leather . . . 385 The Lockwood Automatic Leather Scouring and Setting Machine, with detailed description .......... 386 Improvements in this Machine on that patented by the same Inventor in 1876 391 The Holmes's Scouring, Setting, and Hide Working Machine, with detailed description . . . . . . . . . .392 Holmes's Improved Scouring Machine Parts . . . . .396 The Fitzhenry Leather-dressing Machine ; Details of the latest Im- provements . . . . . . . . . . .398 Burdon's Machine, with detailed description . . . . .401 Daheney's Table for Leather Scouring Machines, with detailed descrip- tion 405 List of all Patents for Scouring and Setting Machines issued by the Gov- ernment of the United States of America, from 1790 to 1883 inclusive 407 CHAPTER XXII. STUFFING LEATHER — HAND STUFFING AND STUFFING WHEELS — STUF- FING AND CURRYING COMl'OUNDS — MACHINE FOR REMOVING GREASE FROM LEATHER — LIST OF AMERICAN PATENTS FOR STUFFING APPA- RATUSES AND FOR STUFFING AND CURRYING COMPOUNDS. Section I. Hand Stuffing and Stuffing Wheels . . . 408 Stuffing Wheels ; First Stuffiing Wheel patented in this country invented by L. W. Fiske ; Peed and Winchester's Stuffing Wheel with de- tailed description .......... 409 Carl's Stuffing Wheel, with detailed description . . . . .412 List of Patents for all Apparatuses for Stuffing and Greasing Leather issued by the G"bvernment of the United States of America, from 1790 to 1883 inclusive . . . . . . . . . . 414 Section II. Stuffing Compounds ; Andrews's Compound . . 415 Merrill's Compound . . . . . .. . . .416 Williams's Compound, Glycerole of Egg . . . . . .417 Thayer's Compound . . . . . . . . . .418 '' B. S Oil" for Stuffing Compounds, Dewees and Green's Patent Process with B. S. Oil 419 List of all Patents for Compounds for Stuffing Leather issued by the Government of the United States of America from 1790 to 1883 inclu- XXVI CONTENTS. PAGE sive. List of all Patents for Compounds for Currying Leather issued by the Government of the United States of America from 1790 to 1883 inclusive 420 Section IIL Machines for Removing Grease from Leather; Perkins's Machine for Removing Grease from Leather, with detailed description ........... 421 List of all Patents for Machines for removing Grease from Leather issued by the Government of the United States of America from 1790 to 1883 inclusive . 422 CHAPTER XXIII. WHITENING LEATHER. French Pattern of Whitening Slicker; Beam now generally employed in Currying Shops; Common form of Curriers' Knives . .^ . 423 Clements's Leather Whitening Machine, with detailed description . 424 Smith's Leather Whitening and Buffing Machine, with detailed descrip- tion 428 List of all Patents for Curriers' Slickers issued by the Government of the United States of America, from 1790 to 1883 inclusive. List of all Patents for Curriers' Knives, and for Machines for Sharpening Cur- riers' Knives, issued by the Government of the United States of America from 1790 to 1883 inclusive. List of all Patents for Machines for Whitening, Buffing, and Shaving Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive . . 430 CHAPTER XXIV. BOARDING AND GRAINING BY MACHINERY. Advantages which have arisen from the introduction of Boarding and Graining Machines . . . . . . . . . .431 Coogan's Boarding and Graining Machine, with detailed description . 432 Hovey's Boarding and Graining Machine, with detailed description . 434 Coogan's Machine for Boarding and Graining Morocco, as improved by G. W. Baker ^. , . 438 JAst of all Patents for Machines for Boarding and Graining Leather, issued by the Government of the United States of America from 1790 to 1883 inclusive .......... 439 CHAPTER XXV. BLACKING LEATHER. Section I. Blacking and Smutting Appliances; The two forms of Blacking Brushes in common use ....... 440 Bachelder's Leather Blacking, Coloring, and Dressing Machine, with detailed description . . . . . . . . . .441 CONTENTS. XXVll PAGE Bryant's Machine for Smutting Leather, witli detailed description . 447 List of all Patents for Apparatuses for Blacking Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive ............ 449 Section II. Blacking Compounds, Hayward's Flesh Blacking 449 Shaw's Compound for Finishing Upper Leather ..... 450 Putnam's Composition for Finishing Split Leather. List of all Patents for Blacking Compounds for Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive . . . 451 CHAPTER XXVI. MACHINES FOR GLASSING OR POLISHING, PEBBLING, FINISHING, ROLLING LEATHER, ETC. . 454 . 458 . 460 . 462 . 463 . 464 ing, Finishing, Glass- Glass Slick 3r for Glassing by Hand ....... 453 Martin's Machine, with detailed description . Friend's Machine, with detailed description . Hildreth's Machine, with detailed description Baker's Improved No. 4 Glazing Machine Baker's Ponj'-Glazing Machine Overhead Glazing .Machines ; Knox's Machine List of all Patents for ISIachines for Stoning, Polisl ing, Glazing, Flinting, Creasing, and Dicing Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive ............ 465 List of all Patents for Machines used for Pebbling Leather, issued by the Government of the United States of America, from 1790 to 1883 inclu- sive ; List of all Patents for Machines for Rolling Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive ............ 467 CHAPTER XXVII. MACHINES FOR MEASURING LEATHER. Leather Measuring Machines invented in the United States since 1877 ; Winter's Leather Measuring Machine ...... 468 Williams, Moore, and Hurlburt's Leather Measuring Machine, Avith detailed description .......... 469 Sawyer's Leather Measuring Machine, with detailed description . . 473 List of all Patents for Machines for Measuring the Areas of Hides, Skins, and Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive 480 XXVUl CONTENTS. PART Vll. CHAPTER XXVIII. SOLE LEATHER. PAGE Section I. General Remarks ; What is sought to be Combined in the Manufacture of Sole Leather ; Oak-tanned Sole Leather ; The Astrin- gent Principle of Oak and Hemlock Bai'ks 481 " Hemlock Non-acid," and Hemlock Acid Leather; The Varieties into which Sole Leather is divided in this Country — Hemlock, Oak Slaughter, Oak Texas Hide, Union Slaughter ..... 4'82 Process of making Oak Slaughter Sole Leather at Luraj', Virginia . 483 Section H. Tanning and Finishing Oak Slaughter Sole Leather ........... 483 Rolling Machine generally Employed for Rolling Sole Leatlier . . 485 Section IH. Tanning Inside Sole Leather . . . . 486 Section IV. Bleaching Hemlock Tan, and Union Tan Leather, Similar to Oak Tanning ; Process of E. W. Phillips 488 Section V. Artificial Sole Leather; Pollock's Process for mak- ing Artificial Leather from Scraps and Waste . . . . .489 Practical details of the process . . . . . . . .490 Chemical Reaction which takes place in the process . . . .491 CHAPTER XXIX. heavy upper leather — tanning and finishing the " side" and "split" — removing extractive matter from tanned leather — PROCESS for water-proofjng, dubbing, and whitening upper leather — improvement in tan presses. Section I. Tanning and Finishing the " Side" and " Split ;" AVhat are included under the head of Upper Leather ; the Hides and Skins from which Upper Leathers are produced .... 492 Machinery now largely employed in the production of Leathers . . 493 Whence Hides are generally imported into the United States ; Whence the supplies of Bark are obtained, and how purchased ; Preparation of the Hides ; Placing the Hides in the " Soaks ;" Splitting into Sides ; Placing in the Hide Mill ; Placing in clear cold Water . . . 494 Removal of Hides to the "Limes;" Machine commonly employed in Salem, Mass., for unhairing ; the Drenching Wheels and Wash Wheels ; the Hide Worker ; Tanning ...... 495 The Sides of Leather as hung over the poles in the Drying Yard, and showing a view of the Shops . . . . . . , . 496 CONTENTS. XXIX PAGE Finishing the Sides . . . , . . . . '. .49 7 The various Machines and processes used ...... 498 Interior of the Finishing Room of an Upper Leather Manufactory, with the Pasting Tubs and Tables, Horses for receiving and moving the Leather, and the Bhicked and Pasted Sides suspended from Hooks in the Ceiling Racks; Finishing the Split; Head's Process for Soaking, Liming, Tanning, Blacking, and Gumming Hides intended for Upper Leather ............ 500 Section II. Removing Extractive Matter from Tanned Leather; Plumer and Kernans's Process for Removing Extractive Matter from Tanned Leather ........ 503 Section III. Processes for Water-proofing, Dubbing, and Whitening Upper Leather; Rady's Process for Water-proofing, Dubbing, and Whitening Upper Leather, and giving it a "Satin Finish" 504 Treating Boots, Shoes, and Harness by tliis process ; Sponhouse's Method for Manufacturing Water-proof Leather ... . . . . 505 Section IV. Improvements in Tan Presses ; Holmes's Tan Press; 507 Daniels's Tan Press ; Weston's Tan Press, with detailed description 508 CHAPTER XXX. GRAIN, SPLIT, AND BUFFED LEATHERS — TANNING AND FINISHING GRAIN, SPLIT, AND BUFFED LEATHERS — COMPOUNDS FOR PRODUCING IMITATION OF GRAIN AND MOROCCO LEATHERS. Section I. Tanning and Finishing Grain, Split, and Buff Leathers ; the above varieties of Leather produced in large quan- tities in this country ; the Bark and Hides used ; Details of the processes . . . . . . . . . . . .511 Unhairing by Machinery . . . . . . . . .512 Finishing Grain Leather . . . . . . . . .515 Finishing Buff Leather . . . . . . . . .516 CHAPTER XXXI. GERMAN HARNESS LEATHER VACHE LEATHER — MACHINE BELT LEATHER GREASED WITH TALLOW. The Hides used for these varieties; Handling the Hides . . .518 Preparation of Vache Leather; Details of the process . . . 519 Machine Belt Leather Greased with Tallow ...... 522 Currying the Tallowed Leather ........ 523 XXX CONTENTS. CHAPTER XXXII. MOROCCO LEATHERS. PAGE Section T. Tanning and Finishing Imitation of French Kid ; Brushed Kid ; Straight-grained Goat, Pebbled Goat, and Oil Goat ; What is understood by Morocco ; from what Skins Moroccos ai-e prod uced ; Commercial Classification of Morocco Leather in this Country ; Classification of Goat-skins employed in this Country for the Manufacture of Morocco Leather ...... 524 Glove Calf and Glove Sheep ; Whence the Skins are obtained for the Manufacture in the United States ; Tanning Material usually em- ployed ; Preparing the Skins ; Lime Vats in a INiorocco Tannery . 5^5 The Quantity of Skins treated at one time in large Morocco Tanneries ; Practical details .......... 52G Tanning ; Tan Tubs in a Morocco Factory ; Manner in v?hich the Skins are attached to the Spigots, and method by which the Skin Bags are filled with Sumach l^iquor ; Baker's Vat or Tank with Feeding Pipe, etc., with detailed description . . . . . . . .527 Apparatuses of Dr. Turnbull, Patented 1844, and of Dudley and Brooks, Patented 1834 . 529 Striking out and Drying ; the Drying Loft in a Morocco Factory, show- ing the Skins hung on Hooks on the Racks ..... 530 Finishing Imitation French Kid ; Finishing Room in a Morocco Fac- tory 531 Finishing Brushed Kid ; Finishing Straight-grained Goat ; Drying Loft in a Morocco Factory with the Skins spread out ..... 532 The Finishing Room in which the Skins are Rolled and Glazed ; the Graining Board .......... 534 Finishing Pebbled Grain Goat ; Finishing Oil Goat .... 535 SkctionII. Tanning Apparatuses for Goat- and Shekp-Skins; Warner's Apparatus for Tanning Goat- and Sheep-skins, with de- tailed description .......... 530 Walters's Filling Cup for Morocco Manufacturers, with detailed descrip- tion 539 Hand Method of Tanning Morocco ....... 541 Tanning Morocco in a Combined Wheel and Vat ; Halsej-'s Apparatus with detailed description . . . . . . . . .542 Section III. Puttinc; Out Machines for Morocco; Vaughn's Machine for Putting Out Skins ; Hoffman's Putting Out Machine, with detailed description . . . . . . . . . . 545 List of all Patents for Putting Out Machines and for Leather Fluffing and Grounding Machines issued by the Government of the United States of America from 1790 to 1883 inclusive ...... 550 CONTENTS. XXXI PAGE List of all Patents for Machines for Evening or Making Leather of Uni- form Thickness issued by the Government of the United States of America from 1790 to 2 883 inclusive ...... 551 Section IV. Compounds for Producing Lmitation of Grain OR Morocco Leather ; Smith's Compound ..... 551 Process for Finishing Lower Grades of Leather similar to Morocco, the Invention of Tice and O'Connell ....... 552 CHAPTER XXXIII. TANNING AND FINISHING SHEEP-SKINS. Section I. Tanning and Finishing Sheep-skin Fleshers for Linings, Bindeks, and Skivers; Importance of this branch of In- dustry ; the Sheep-skins used ........ 555 Exterior of a Sheep-skin Tannery with the Slat Openings into the Dry- ino- Lofts for the Free Admission of Air ; Tanning Vats in a Sheep-skin Tannery ; Drying Lofts in a Sheep-skin Tannery .... 556 Finishing Department of Sheep-skin Tannery, where the Skins are Rolled, Glassed, or Pebbled by Machines ; Dressing Sheep-skin Fleshers for Glove Bindings ; Hart's Process ....... -557 Section II. Improved Methods for Dressing and Tawing Sheep-skins; Manassee's Method for Tawing Sheep-skins . . 558 Hibbard's Process for Preparing and Tanning Sheep-skins . . . 559 Hesthal's Process for Dressing Sheep-skins, etc. ..... 560 Section III. Artificial Sheep-skins for Linings ; Evans's Imi- tation Sheep-skins .......... 561 CHAPTER XXXIY. LACE LEATHER. Lace Leathers and their Mode of Preparation ... . 563 Junior's Methods of Manufacturing Lace Leather . . . . 565 Quick Tanning Process for Lace and Whip Leather by Bartenbach and Richter; Loescher's Method for Manufacturing Lace Leather . . 567 Coupe's Stretching Machine, with detailed description .... 568 Tidd's Softening Machine, with detailed description .... 570 CHAPTER XXXT. HORSE LEATHER FOR FOOT-WEAR. Origin and History of this Industry ....... 572 Details of the Process of Manufacture . . . . . • .573 XXXU CONTENTS. CHAPTER XXXVL RUSSIA LEATHER — THE MATSfUEACTURE OP RUSSIA LEATHER RUSSIAN METHOD OF PREPARING AND APPLYING THE MORDANT AND DYE — MANUFACTURE OF BIRCH OIL — ARTIFICIAL RUSSIA LEATHER. PAGE Section I. The Manufacture of Russia Leather; Uses to which this Leather is applied .... .... 574 Russia Leather at the Centennial Exhibition ; Pi-ocess of Manufacturing this Leather as conducted in the United States ..... 575 Dyeing the Leather, Black or Red ; Mordant ..... 576 Graining the Hides ; Towein's Graining Machine ..... 578 Section II. Manufacture of Birch Oil ..... 578 Processes for Distilling this Oil ; Fischerstroern's Method . . . 579 Grouvelle and Duval-Duval's Process; Payen's Experiments; Distill- ing Apparatus ........ ... . 580 Products obtained by the Distillation ....... 581 Section III. Artificial Russia Leather; "Rubber Cloth," " Enamelled Cloth," and "Leatherette" ...... 581 Freely's Method .......... 582 CHAPTER XXX VII. ALLIGATOR LEATHER. Purposes for which this Leather is used ; the Alligator Skins . . 582 Tanning and Finishing the Skins ........ 583 CHAPTER XXXYIIL PATENT, JAPANNED, OR ENAMELLED LEATHER. The Hides for this Leather and whence obtained ; the Material cm- ployed for Tanning .......... 585 Details of the Operation ; the Bate Stone ; the Vats with Revolving Wheels 586 Stretching ; Oliver and Howell's Frame for Stretching Leather, with detailed description .......... 588 Compounds for Finishing Japanned or Enamelled Leather ; their Com- position and Application ......... 590 Pumicing ............ 591 Varnishing and Drying; Merrill's Process for Boarding the Leather; Hoey's Process for renewing the surface of Japanned Leather; Pre- paring the cut surface of Split Leather for manufacturing Japanned or Enamelled Leather 592 •CONTENTS. XXXin Patterson's Method for forming an Artificial Grain on the Hide after it has been buffed or split ......... 59.'! Japanned Leather in imitation of Alligator Skin, Merritt's Process . .594 Substitute for Patent Leather ; List of all Patents for Methods for manu- facturing Enamelled, Japanned, and Patent Leathers, issued by the Government of the United States of America from 1790 to 1883 inclu- sive ........'.... 595 List of all Patents for Apparatus for Stretching Jjeather issued by the Government of the LTnited States of America, from 1790 to 1883 inclusive ............ 596 PART VIII. CHAPTER XXXIX. TANNING PROCESSES. Large number of Processes invented for facilitating the Tanning of Leather ; but few of value ; Precautions to be taken in adopting new- Processes ; Most of the Leather Tanned in the United States Tanned by one of three methods . . . . . . . . .597 Tanning Processes : Snyder's; German's; L-ving's; Hibbard's . . 598 Fulton's; Enos's ; Keeler's ; Wattles' s ; Gould's .... 599 Hatchs's; Daniels's; Kennedy's ....... 600 Noble's • 601 ' Garge's; Page's . . . . . . . . . " . . 602 Robinson's ............ 603 Wyeth's 604 Pickard's ; Wheelock's ......... 605 Kidder's; Jenkins's . . . . . . . . . 600 Ruemelin's Tan Vat, with detailed description ..... 607 List of all Patents for Processes for Tanning Leather, issued by the Gov- ernment of the United States of America, from 1790 to 1883 in- clusive 609 List of all Patents for Processes, Employing Apparatus for Tannino- Leather, issued by the (xovernment of the L) nited States of America, from 1790 to 1883 inclusive 614 I^ist of all Compounds and Materials for Tanning and also for Tawing Leather, and for Preparing Raw Hides, that are especially claimed or mentioned in any Patent issued by the Government of the United States of America, from 1790 to 1883 inclusive .. .. .. .616 C XX XIV CONTENTS. CHAPTER XL. TANNING AND CURRYING HIDES AND SKINS WITH THE HAIR AND PUR ON. PAGE Pingree's Processes ; Johnson's Process ...... 620 Coe's Process ; Cai-ter and Keith's Process ...... 621 Tanning and Coloring Beaver, Otter, and any other Skins with the Fur or Hair on ; Bugh's Method . .622 The Preparation of the Tan Liquor ....... 628 To Color Furs ; Method and Machine for Dyeing the Wool on Sheep- skins ; Jack's Apparatus for Dyeing the AVool on Sheep-skins, with , detailed description .......... 624 CHAPTER XLI. MINERAL TANNING. What is understood by Mineral Tanning; Attempts to Substitute Mineral Substances for Vegetable Tannin made more than a hundred years ago; Ashton's Patent for Tanning with Ferric Salts, 1794 . . 626 Bordier's Patent for Converting Hides into Leather by means of Mineral and Earthy Substances, especially Ferric Sulphate, 1842; Molac and Triedel's Patent, 1855 627 Knapp's Patent, 1861; Pfanhauser's Patent, 1864; Process of Cavalin, the first use of bichromates . . . . . . . .628 All of the foregoing processes abandoned ; Fresh Impetus given to the subject of Mineral Tanning by Knapp in 187 7 ; Knapp's Process of Tanning Avith Ferric Salts, with detailed description . . . 629 Heinzerling's Method of Tanning with Chromates, etc. ; Heinzerling's Patents obtained in the United States in 1880 and 1881 ; Detailed description of Heinzerling's Process ....... 633 Comparative Experiments of Dr. J. Clark, of Glasgow, as to the Solu- bility of the Tannin in Chrome and other Leathers .... 636 Quantity of Potassium Bichromate withdrawn from different kinds of Leather Tanned by Heinzerling's Process, and treated in different modes ; Tannin withdrawn from English Tanned Leather by similar modes of treatment . . . . . . . . . .637 Conclusions of Dr. Clark ; Tables giving the results arrived at, at two English Experimental Stations as to the Stretching Capacity of Chrome and Tan Leathers ........ 688 Aluminium Tanning ; Method of Dr. Putz, of Passau ; List of all Patents for Employing Mineral Substances for Tawing Hides and Skins, issued by the Government of the United States of America, from 1790 to 1883 inclusive 641 CONTENTS. XXXV CHAPTER XLII. TAWING — FRENCH OR ERLANGER METHOD OF TAWING — DANISH GLOVE LEATHER — JENNINGS'S METHOD OF TAWING — DEFECTS OF ALU MED VARIETIES OF LEATHER — MANUFACTURE OF OIL OR CHAMOIS LEATHER — PRELLER'S METHOD OP TAWING — KLEMM'S OIL LEATHER. PAGE French or Erlanger Method of Tawing ; this method employed in the Manufacture of Soft Leather for Gloves, originally a French Industry brought to a high degree of perfection in Germany and Austria ; Qualities demanded in such Leather ....... 642 Buying and Preserving the Raw Skins . . . . ... . 643 Damage by Moths .......... 645 Best means of getting rid of Moths ....... 646 Manner of working the Skins ; Dilference between the Ordinary and the French Methods ; Work of Tawing according to the French or Er- langer Method ; How Divided : 1. Soaking and Rinsing . . . 647 2. Liming and Depilating ......... 648 3. Treatment in Bate of Dog Excrements . . . . . . 649 Washing Wheel for Fulling used in Germany and France ; Preparing the Bate 650 The manner of using the Drum for Fulling Machine . . . . 651 Treatment of the Skins after the removal from the Bate or Fulling Drum; 4. Branning . . . . . . . . . 652 Precautions to be observed ; 5. Tawing ; the Object of this Operation ; Various Tawing Pastes ......... 653 The Object of using a Tawing Paste, such as plays a prominent part in the Manufacture of French Glove Leather . . . . .657 Experiments of Knapp in regard to Tanning and Tawing . . . 660 6. Finishing; Polishing with a Polishing Steel or Agate Roller . . 661 Polishing Roller kept Hot by a simple device . . . . .662 The use of Flat Irons instead of Polishing Rollers ; Glazing of inferior qualities of Leather before Smoothing . . . . . .663 Glazed or Glac6 Leather ; Aikins's Method of working Lamb-skins into Glove Leather ........... 664 Watts's Method of working the Skins of Lambs, Goats, and Dogs into Glove Leather 666 Main's Process of Finishing Alumed Leather ..... 667 Danish Glove Leather .......... 668 Jennings's Method of Tawing . . . . . . . .669 The Theory of this Method . .672 The object of adding Zinc Filings or a soluble Zinc Salt to obtain a higher degree of Whiteness ; Tawing by Jennings's Method more constant than by the ordinary process, and the Leather resists the action of Water better ; the cause of this ; defects of Alumed varie- XXXVl CONTENTS. PAGE ties of Leather ; either natural ones or result from Storing or the man- ner of Working . . . . . . . . . .673 Injury to which Skins are liable in Branning . . . . .675 How to prevent this evil ; defect technically called " Shading" . . 676 ])efect of what is called Rotten or Burned Leather ; investigations on this subject, and remedy proposed by Prof. Knapp . . . .677 Manufacture of Oil or Chamois Leather ...... 679 The Heads under which the Operations in making this Leather may be divided ; Depilation and Frizzing ....... 680 First Jiming ; Stretching and Scraping, upon the Flesh Side, and partly upon the Grain Side ; Second Liming ; Branning . . . 6§1 Fulling in the Oil ; the Oil to be used . 682 Fulling the most important and delicate Operation in Oil Tawing ; Test of the Skins being sufficiently Oiled . . . . . . . 683 Heating the Skins ; Finishing and Dressing ...... 68.5 Stretching L-on . .687 Bleaching and Pumicing Chamois Leather for Gloves ; to obtain the Shade of Buff Leather for Pantaloons, Gloves, etc. ; to clean dirty Leather 688 Twisted Leather; Preller's Method of Tawing; the Animal and Vege- table substances and the Salt used . . . . . . . 689 The Composition of the Mixture ; Treatment of the Skins . . . 690 Drying; the Leather prepared according to Preller's Method called " H B Crown;" the weight of Leather Tanned by Preller's Process yielded by 220 pounds of Green Hide ; Superior strength of Preller's Leather . . . . . . . . . . . .691 Purposes for which Crown Leather is adapted ; Time required for mak- ing Leather by Preller's Process ; Capacity of Crown I^eather to re- sist Water ; Behavior of Crown Leather Boiled in Water ; Softness of Crown Leather .......... 692 The Theory of Pi-eller's Process; Preparation of Klemm's Oil Leather; Manner of preparing the Hides ; Tanning ..... 693 Subsequent Treatment; advantages of this Process; Prof. Reusch's Ex- periments in regard to the strength of this Jjcather ; Coloring, Greas- ing, and Finishing ; this process corresponds in many points with Preller's, and does not differ materially from the more rational methods of the manufacture of Glac6 Leather ...... 694 Prof. Fehling's Experiment with Klemm's Leather ; Dr. F. Knapp's Process of Tanning with Salt Solutions and Soap Baths ; Details of this process ........... 695 Character of the Leather obtained ; the nature of the process ; Advan- tages upon the score of economy ....... 696 White Glazed Leather of great Softness and Suppleness obtained by Knapp by Macerating thorouglily cleansed Skins of Lambs and Goats in Saturated solution of Stearine in Spirit of Wine .... 697 CONTENTS. XXXVll PAET IX. CHAPTER XLIII. DYEING LEATHER. PAGE Section I. General Remarks; Light the source of all Color; the "Spectrum" ........... 698 The Primitive Colors (J99 The importance of the Art of Dyeing ; Chemistry and its relation to Dyeing ; in composing shades, only in fact, the three Primary Colors are at disposal — Red, Yellow, and Blue ; the limitless combinations into which these Coloi's can enter ; the part which Water plays in these modifications and combinations ; Water for the Dyer what the White Color is for the painter ; Modifications of Color caused by the use of Water 700 A "graduated line of color, " and a "modified color;" Examination and Dissection of a Spectrum showing twelve colors in it ; producing these twelve colors Avith Red, Yellow, and Blue .... 7^1 'JMie measure for a Leather Dyer is what Scales and Weights are to the Chemist ; the effects of mixing certain proportions of Dye Stuffs of different colors . . . . . . . . . . . 702 An illustration of the transition of colors through their countless modifi- cations by a so-called Color-ball ; the circle of normal colors ; the " category" of a color ; the category not identical with shades . . 703 Shades 704 Section II. Mordants; Acids ....... 705 Mineral Acids; Sulphuric Acid ........ 706 Nitric Acid ; Hydrochloric Acid . . . . . . . .707 Organic Acids ; Acetic Acid ; Oxalic Acid ...... 708 Citri(> Acid and Tartaric Acid ; Bases ; Potassium Hydrate and Sodium Hydrate 709 Ammonia ; Lime . . . . . . . . . .710 Salts; Sulphates; Ferrous Sulphate or Green Vitriol . . . .711 Cupric Sulphate or Blue Vitriol ; White Vitriol or Zinc Sulphate ; Aluminium Sulphate ;* Alum . . . . . . . .712 Chromium Alum . . . . . . . . . . .713 Nitrates ; Ferric Nitrate ; Lead Nitrate ; Chlorides ; Sal Ammoniac ; Ferric Chloride ; Stannous Chloride or Tin Salt ; Stannic Chloride- Tin Composition or Physic ........ 714 Common Salt or Sodium Chloride ; Acetates ; Ferric Acetate ; Alumi- nium Acetate . . . . . . . . . . .715 Plumbic Acetate ; Cupric Acetate or Verdigris . . . . .716 XXXVIU COiSTTENTS. PAGE Tartrates ; Potassium liitartrate or Crude Tartar ; Carbonates ; Potas- sium Carbonate or Potash . . . . . . . .717 Sodium Cai'bonate; Potassium Bichromate ; Lead Chromate . "718 Yellow Prussiate of Potash or Potassium Ferrocyanide ; Red Prussiate of Potash or Potassium Ferriccyanide . . . . . .719 Soaps ............. 720 Section III. Mechanical Work of Dyeing Alumed Leather AND Directions eor Preparing and Applying Various Vege- table Dyes; Dyeing the Skins upon the Flesh Side . . . 721 Dyeing the Skins upon the Grain Side ; Dyeing by Dipping . . 723 Dyeing by Painting ; by the Grenoble Method ..... ?24 The English Method 725 French Method 726 Light-Leather Brown . . . . . . . . . .729 Olive; Mi-fonce Brown; Bottle Green; Method of Brushing the Dye Liquor on the Skins ......... 730 French Knee Contrivance for "Boarding" or Softening and Overletting the Skins . . . . . . . . . . .732 % Section IV. Receipts for Various Vegetable Colors, and FOR Coloring Leather WITH Mineral Pigments . . . 732 Dark Brown ; Light Brown ; Olive Brown ; Catechu Brown ; Catechu Gray-Brown ; Coffee Brown ; Dark Green ; Olive Green ; Light Olive- Green ; Picric Green ; Lemon Color ...... 733 Quercitron Yellow ; Barberry Yellow ; Rust Yellow ; Orange ; Violet ; Mixed Brown ; Sap Green ; Nankin Yellow ; Dai'kBlue; Red . 734 A-lazarine Red ; Scarlet ; Red ; Dark Gray ; Iron Gray ; Black ; Min- eral Pigments . . . . . . . . . . . 735 Sky Blue ; Brown ; Chrome Yellow . . . . . . . 736 Section V. Dyeing Chamois or Oil Leather .... 736 Madder Red; Preparing the Skins ; Mordanting; the Madder Bath . 737 Giving the Dyed Skins more Lustre ; Blue in all Shades by Dyeing in the Indigo Vat ; Green ......... 738 Yellow; Brown; Black 739 Section VI. Dyeing with Aniline Colors and the Methods OF their Preparation ; Aniline Color especially suitable for Color- ing I^eather . . . . . . . ■ . . . . 740 Oil or Chamois Leather Dyed in the same manner as Alumed Leather with Aniline Colors ; Aniline Colors for Parchment Dyeing ; Aniline Violet; Perkins's Violet ; Parisian Violet ; Hofmann's Violet ; Rosa- niline Violet ........... 741 Dahlia; Aniline Blue; Bleu de Paris; Bleu de Lyon; Ordinary Ani- line Blue ; Aniline Green ; Aldehyd Green ..... 742 CONTENTS. XXXIX Ethyl Rosaniline Green ; Emeraldine ; Aniline Yellow ; Ordinary Ani line Yellow; Zinaline ; Chrysaniline ; Aniline Red . Aniline Brown ; Havana Brown ; Bismarck Brown ; Aniline Black Lucas Aniline Black . . . . Coralline ; Azuline .......... Phenol Brown ; Naphthalene Colors ; Dinitro-Naphthalene Section VII. Dyeing SuxMach-tanned Skivers with Aniline CoLOKS ; Samples of Leather Dyed by some of the following ReceijJts No. I. Methylene Blue O, Patented No. II. Azobenzole Fast Crimson RR, Patented; No. III. Naphthol Yellow L, Patented ; No. IV. Leather Brown .... No. V. Victoria Green; No. VL Dark Rose Pink B ; No. VII Orceine B .......... No. VIII. Orange BR ; No. IX. Bismarck Brown R . No.X. Fast Brown; No. XI. Soluble Blue R ; No. XII. Fast Red R, Patented No. XIII. Brilliant Green ; No. XIV. Russia Green ; XV. Rose Bengal ........... No. XVI. Scarlet, No. 2; No. XVII. Nankeen Brown; No. XVIII Dark Nankeen Brown ........ Section VIII. Dyeing Russia and Morocco Leathers with Aniline Colors ; Eitner's Directions for the Use of Aniline Colors, prepared by the Aniline Manufacturing Company, of Berlin Russia Leather Red G Light ; Russia Leather Red GR medium ; Russia Leather Red R Dark ; Dyeing Skins ; Producing the Odor of Russia Leather ; Production of Yellow and Yellowish-brown Shades . Dyeing Leather Golden Orange ; Production of the Reddish Shade of this Group of Colors ; A Pure Orange ; A Half Dark-pale Blue, so- called Marine Blue ; Pale Blue with a Pure Blue Shade; Dark Blue ; A Beautiful Bright Green ........ Violet Color; Convenience of using Aniline Colors; Martin's Yellow for Pure Yellow. Tones ; Orange Tones of the Redder Shade; The Intermediate Shades from Pure Yellow to the Reddest Orange; How the Dyeing is accomplished ........ Impai'ting a Lustre to Harness Leather; To give Leather Sti-aps at the same time a Color and a Lustre with Orange Fat Color 74o 744 745 746 747 748 749 750 751 752 754 754 755 •56 (57 r58 CHAPTER XLIY. COMPOUNDS FOR COLORING AND POLISHING LEATHER. A Black consisting of an Ammoniacal Solution of Shellac, and the Aniline Color knoAvn as " Pourrier's D Blue Aniline" . . . 758 Protochloride of Iron in Solution as a Basis for Black for Skins ; Pre- paring Raw Hides and imparting Black, Maroon, and Purple Colors . 759 xl CONTENTS, PAGE An Intense Black, etc., prepared from Aniline Colors, mixed with Alcohol, etc ■ 761 Black Staining Compound for concealing defects in Leather and for applying to Pocket-books, composed of Aniline Colors, Naphthaline, etc 762 Compound for imparting a lustrous Black Gloss to Leather ; Dyeing Leather, containing Tannic or Gallic Acid, Black, by subjecting it to the action of a Vanadic Compound ....... 764 Gilding and Ornamenting Leather for Suspender Ends, etc. ; Gilding Leather ; Bronze Dressing for Leather . . . . . .76.5 Aniline Bronze Colors of Various Shades applicable to Jjeather . . 7<66 Producing upon Leather Various Shades of Light Brown and Darker Colors by the Combination of Oxalic Acid, Salt of Tin, and Potash, with Nut-gall and Sulphate of L'on . . . . . . .767 Coloring Leather with Aniline upon a Starch Surface and jjroducing an appearance similar to Marbled Paper ...... 768 Forming a Solution for Staining Tawed Leather, consisting in mixing Clay, Water, Common Salt, Sulphuric Acid, Brewer's Yeast, Alum, Hemlock Extract, and Terra- Japonica . . . . . .769 Preparing, Coloi-ing, and Polishing Light Skins for Car Seats, Trunk Covers, etc. . . . . . . . • . . .770 Composition of Glycerine, Resinous and other Substances atfording a Base for imparting a High Polish to Jjeather ; Composition for Polishing, Water-proofing, and Coloring Leather . . . . . .771 Polish for Leather used for Bags, Satchels, etc. . . . . .772 Coloring partly Tanned Hides and Skins by the employment of a Bath of Tin, Acid and Water, and Turmeric ; Compound for Changing the Color of Leather, especially the Color of the Soles of Boots and Shoes 773 Compound for Whitening Leather . . . . . . .774 List of all Patents for Compounds for Polishing and Coloring Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive .775 Index . . . . . . . . . . . . .777 THE MANUFACTURE OF LEATHER. PART I. CHAPTEE I. HIDES AND SKINS — THE VARIETIES OF HIDES AND SKINS USED FOR LEATHER — REMOVING- HIDES AND SKINS FROM ANIMALS — SELECTING HIDES AND SKINS — FRAUDULENTLY INCREASING THE WEIGHT OF HIDES — PRESERVING- HIDES — LIST OF AMERI- CAN PATENTS FOR PRESERVING HIDES — COMMERCIAL CLASSI- FICATION OF HIDES. From a very early period the hides and skins of animals have been doubtless much employed to contribute, first, to the neces- sities, next to the comforts, and finally, to the luxuries of man, being easily obtainable and adapted for shelter, apparel, and for a large number of articles of general utility. The origin of their use is more likely to be traced to moun- tainous than to low and warm districts, as in the first the animal food was desirable, and warmer clothing more necessary than in the latter, where man originally lived, between the tropics, under wide-spreading and protecting palm-trees, where food came spontaneously from the earth, and clothing was neither used nor requisite, and was not employed until circumstances finally compelled him to gradually migrate towards the poles. Then, as necessity has always been the mother of invention, mankind acquired sufficient knowledge to select the tender por- tions of plants and form them into clothing, and when they 3 34 THE MANUFACTUEE OF LEATHER. reached greater altitudes and colder districts to slaughter ani- mals, using the flesh for food, and the hides for shelter or cloth- ing, and, appreciating the use of plants, agriculture was prac- tised, and for the same reason animals were valued and the breeding of them received much attention. This branch of industry was carefully cultivated ; but, accord- ing to the economy of nature, mammiferous animals, as a class, seem destined from earliest times to have preserved a constant equilibrium in the number of animated beings that at all periods have held their existence on the surface of the earth. The quarrel between Laban and Jacob, in 1739 B. C, gives us an insight into the manner of conducting the cattle business, and the class of animals that were considered profitable. The same disposition to make contracts and then to seek to break them was just as common then as now. Laban, for a consideration of service, sold to Jacob a certain interest in the sheep and other animals, and then, when he saw that the pur- chaser was getting the best of the agreement, he changed 'it, and again he found that he was the sufferer. Jacob was the shrewdest cattle-trader of history, and was more forbearing than is the custom now, as he allowed Laban to change his inte- rest ten times in their dealings before he took his part of the cattle, camels, asses, and other chattels, and departed secretly from the Syrian, turning his back on the East, and his face towards Beersheba, which he had left about twenty-one years previously. In 1918 B'. C, when Abraham and Lot went up out of Egypt into the south, we are told in the thirteenth chapter of Genesis that they were both rich in cattle, in silver, and in gold. After reaching Bethel, because the land was not large enough to con- tain their vast herds, and also on account of the strife between the herdsmen of their separate cattle, the same as the "cow- boys" of our plains to-day, they divided. Lot journeyed east- ward, and chose the watered and rich plains of Jordan, and pitched his tents near Sodom. Nothing seemingly pleases the herdsmen or " cow-boys" of the present time so much as to be convenient to a wicked city, and doubtless those in Lot's employ were gi'eatly elated at being HIDES AND SKINS. 35 SO near to Sodom and Gomorrah. Human nature has been the same in all ages; the wicked delight to dwell in iniquity; it is their life, their happiness. After the departure of Lot the plain of Marare was selected by Abraham, and the land further than he could see in all directions was his. In our own day we have great ranches, containing enormous herds of cattle, distributed through Texas, Colorado, New Mexico, Southern California, and other portions of the coun- try; but for extent of territory and number of animals it is not probable that there are any to compare with the possessions of either Abraham or Lot. From the omission of the census to include the business of the retail slaughtering establishments in its statistics, and from the manner in which the exports of cattle are recorded at the ports of exit, it is not possible to form an accurate estimate and classificatioli of the annual production in this country; but as cattle-breeding is one of our principal industries, it is important to that interest, as well as to that of tanning, that some such record and classification should be made. In accordance with the universal assent of mankind, the em- pire of nature has been divided into three kingdoms : — 1. Mineral. 2. Yegetable. 3. Animal. With each of these we shall have more or less to do; of the first in the preparation and use of mineral tannins, the second of vegetable tannins, and of the third the hides and skins of the mammalia order of animals. The mineral kingdom comprises all substances which are without those organs necessary to locomotion, and the due per- formance of the functions of life. They are composed of the accidental aggregation of particles, which, under certain circum- stances, take a constant and regular figure, but which are more frequently found without any definite conformation. The vege- table kingdom covers and beautifies the earth with an endless variety of form and color. It consists of bodies organized, but destitute of the power of locomotion. They are nourished by 36 THE MANUFACTUEE OF LEATHER, means of roots; they breathe bj means of leaves; and propagate by means of seed, dispensed within certain limits. The animal kingdom consists of sentient beings, that enliven the external parts of the earth. They possess the power of voluntary mo- tion, respire air, and are forced into action by the cravings of hunger or the parching of thirst, by the instincts of animal pas- sion or by pain. The skins of the most important of the mammalia class of animals, and the alligator of the fish family, are all with which we shall have to do of the six classes into which Linnaeus li L. Jourdan, ^ Paris, France. 59.251 Oct. 30, 1866 H, Napier, Elizabeth, N. J. 75,794 March 24, 1868 L, S. Robbins, New York, N. Y. 86,808 Feb. 9, 1869 J. P. Bridge, Boston, Mass. 112,285 Feb. 28, 1871 A. Rock, New Orleans, La. 118,746 Sept. 5, 1871 A. Rock. New Orleans, La. 171,177 Dec. 14, 1875 F. L. C Sacc, Neufchatel, Switzerland. 246,260 Aug. 23, 1881 J. Wickersheiraer, Berlin, Germany. 281,287 July 17, 1883 J. L. Moret, Paris, France. COMMERCIAL CLASSIFICATION OF HIDES. All hides sold in the American market are classified as dry flint, dry salted, green, green salted, and part cured. Dry fiini is a thoroughly dry hide that has not been salted. Dry salted is a thoroughly dry hide, having been salted while green. Green hides are those which are sent in just as they come from the animal after being slaughtered. ' The first American patent system was founded by act of April 10, 1790, and it is a source of great regret that no well-preserved history of Airierican inven- tions dating from that time is in existence, and that no classified list of models which were in the Patent Office at the time of the fire in 1836 can be obtained. The earliest date that can be reached is January 21, 1823, and that is only par- tially complete. After the fire in 1836, the United States Government adver- tised for the patents which had been issued prior to the conflagration, and in this way numerous copies of the earlier patents were secured. This explana- tion is necessary in order to make plain the reason why certain of the numerous lists of patents in this volume contain some patents dating from 1836, and other of the lists contain patents dating from a much earlier period. HIDES AND SKINS. 55 Green salted are those that have been salted and are thoroughly cured. In green salted hides and skins, those which weigh less than 8 pounds are called deacons ; 8 to 14 pounds, calf ; and 14 to 25 pounds, if they are plump, kip ; bat if they are thin and poor they are called runners or murrains, and are sold at two-thirds the price of good kip ; all weighing in excess of 25 pounds are called hides. Green salted hides are understood to be thoroughly cured, free from salt, dirt, meat, water, horns, tail bones, and sinews, and before being weighed all such substances are removed, or a proper reduction is made from the weight. Part cured hides are those that have been salted, but not sufficiently long to be thoroughly cured. All stag, tainted, aod badly scored, grubby, or murrain hides are called damaged, and must go at two-thirds price, unless they are badly damaged, when they are classed as glue stock, aad sell at a much lower figure. When hides are branded a deduction of about ten per cent, is made on all of them. In dry hides there are other kinds of damaged, such as sun- burned, weather-beaten, or moth-eaten. 56 THE MANUFACTURE OF LEATHER. CHAPTEE II. SYNOPSIS OF THE HISTORY OF TANNING — COMMERCIAL VARIETIES OF LEATHER. SYNOPSIS OF THE HISTORY OF TANNING, An art may continue for a time slowly progressive, bat can- not reach its highest point until its limit be precisely defined. An excellent means by which to improve an art consists in ex- plaining its origin and progress and in pointing out the end to be attained, and the bounds within which it must be confined. Without this precaution, we exhaust ourselves in single and un- connected researches, without reference to each other, and the knowledge which we acquire is dissipated and loses in force as it recedes from the common focus. A small number of principles and a great mass of conclusions; this is the history of all arts, all sciences. The principles must rest upon reliable facts derived from experience and observation ; but neither a compiler nor an author can render all conclusions and explanations. The principles are not numerous and are easy of comprehension, but the conclusions arising from them are innumerable, and lucidity is only to be achieved by placing them in order under the general laws to which they respectively be- long, and, therefore, a judicious classification is requisite. "We will first give nearer data upon the origin and development of our system of tanning, and subsequently consider minutely and singly each step in the tanning, currying, and finishing of leather, and the different methods and systems in our tanneries at home and abroad, keeping constantly in view the statistics of the foreign leather trade and manufacture as compared with our own. We beg to go back some centuries in history, and we will be convinced that the products of our trade were known in the time of Moses; for at that period leather carpets were already SYNOPSIS OF THE HISTOEY OF TANNING. 57 used in tents; these we may at present still meet with among the Arabs, Colored leather seems to have been common, for Ezekiel speaks of fine red leather, which was probably our splen- did red morocco. In 593 B. C, in describing the brilliant dresses and horse har- ness of the Babylonians, the Chaldeans, Pekods, Shoas, Koas, and all the Assyrians with them, girded with girdles upon their loins, clothed most gorgeously, all of them captains and rulers, great lords and renowned, riding upon horses, the trappings of which were replete with rich and beautiful colors, Ezekiel con- veys some idea of the grandeur which prevailed and the brilliant color of the dyed leather in use at the time he was prophesying the ruin of the two great kingdoms. Leather was also used in the remotest ages by the Israelites as a material to write upon, for they used strips made of leather for this purpose. Accord- ing to the testimony of Herodotus, the ancient lonians wrote their annals upon sheep-skin, and the ancient Persians, likewise, according to Diodorus of Sicil}^ Herodotus also tells us that the ancient Libyans wore leather clothing; the Ichthyophagists on the banks of the Araxes dressed themselves in seal-skins, and in the time of Alexander the wild inhabitants of Geodrosia used the hides of animals for clothing and covered their dwellings with leather. For many years leather was used by the Greeks in the con- struction of ships; especially by the Phoenicians, who originally inhabited an arid, sandy corner of the earth, between the Eed Sea and the Mediterranean, where the soil was not favorable to the growth of timber, and they were obliged to supply its place by covering their boats, constructed of willows woven together, with leather or hides, which even thus early were subjected to a certain amount of dressing. The ancient Germans, also, who lived on the sea-coast, and the original Britons, equally possessed this custom. Homer praises the splendid half boots of Agamemnon, and Hesiod recommends leather shoes lined with fur. Homer has perpetuated the name of a tanner who showed kindness to the beggar poet, and now after passing undying through the ages gone, we are charmed by his lines to-day, which 58 THE MANUFACTURE OF LEATHER. are in praise of his friend, and of good cheer for the working- men who were employed in the tannery which he so frequently visited, and where he was at all times well received. That the preparation or tanning of hides was discovered cen- turies ago, and that the leather produced was employed for the same purpose as at present, is shown by the following old pro- verb, which is a proof that leather shoes were already worn at that time, viz. : " We must vot steal leather to give away shoes in God's name.'''' This refers to the legend of St. Crispin, who stole leather to make shoes out of it for the poor. In the old form,of speech, "To draw frovi the leather^'''' signified to draw the sword. In low Saxon the same expression signifies to undress. What- ever may be the facts, it is to be presumed that the most ignorant, races of antiquity, whose chief occupation was the chase, pos- sessed the knowledge of giving a certain preparation to the raw animal hides to protect them from decay, and to render their necessary clothing convenient. They were certainly driven to invention by necessity, and thus the origin of the art of tanning was probably the work of accident, like the invention of most of the other arts. To them, consequently, must the invention of the art of tanning leather be ascribed, although it must be con- ceded that this art owes its proper cultivation and perfection to more recent ages. Such is the synopsis of the historical origin of our leather trade ; but the gradual development and progress of technical tanning have been promoted and assisted by many, and among the most zealous are MacBride, St. Real.^ Proust.^ Hermstadt, Vauquelin, Ghaptal, Seguiii^ Desmond^ Von Meidinger^ AiJcin, and others. Attempts have been made to discover new methods by which hides and skins could be better tanned, and in a shorter space of time, than by the usual mode of treatment. In the year 1768 MacBride discovered the process of raising with diluted sulphuric acid (1 part acid to 400 parts water). Later great attention was attracted to the system of quick tanning, discovered in 1795 by Seguin, by which hides and skins were tanned in much less time than formerly. This new process was tested by experts, and found to be partially good and partially deficient. In 1801, Banks discovered the tanning SYNOPSIS OF THE HISTOEY OF TANNING. 59 property of Terra Jcqwnica (Catechu), Since that time tannin has been discovered in a great number of plants, which will be enumerated in another chapter. The English discovered, in the last century, the art of var- nishing leather, which was soon after imitated in Grermany with complete success. Ballamy, Von Hildebrandt, Edward, and others introduced the art of preparing water-proof leather. Science has not done its duty in regard to the improvement of the art of tanning. There have been steps taken in the sav- ing of labor, which are of great importance ; but in all the long years that have passed since the union of tannin and gelatine was first demonstrated how little progress we have made ! At first it did seem to promise immediate results ; but failure has succeeded failure, and the fruit which should have resulted has not fully appeared, and all because of a lack of chemical know- ledge. If the production of tanneries has been increased and the time of their work shortened, it is owing not to the introduc- tion of new principles and to scientific theorizing, but to the use of improved apparatus for facilitating old processes. Take away our bark and hide-mills, improved leaches and vats, hand- ling and stuffing appliances and other improved constructions, our splitting, scouring, boarding, whitening, polishing, pebbling, and other modern mechanical inventions, and our steam-power so economically derived from the use of spent tan for fuel, turn us out of doors to work among the rude contrivances of a centur}^ past, and would the result of our labor show an extra- ordinary gain either in time or quality over that of our predecessors ? The modern appliances, of which American tanners are so justly proud, and in which they lead the world, are certainly ingenious and highly praiseworthy, and having taken a deep interest in all classes of mechanical improvements, that have been perfected by my countrymen, and upheld them before all nations, I would not for one moment be understood as depre- ciating their importance, or in the least to slight the intelligent enterprise of which they are the offspring. 60 THE MANUFACTURE OF LEATHER. But it is skill, not force, chemical knowledge, not steam- power, which is principally in the future to accelerate and cheapen the process of tanning ; and the sooner the trade acts on this conviction, which every day's experience ought to strengthen, the better. If our present machinery can be super- seded by the discovery of more effective and economical methods, it will furnish cause for congratulation and none for mourning. Our inventors must aim to be good chemists as they are already good mechanics. With the analytical taste of the French and the Germans superadded to their great ingenuity and energy, what results might not be expected from their studies ? The field to be ex- plored is a broad one. Long as the art of tanning has been known to the world, not one step in its chemical practice seems to be complete. There is still room for iaquiry after tanning materials, and still a doubt whether tannin, or what is equiva- lent to tannin, may not be produced in quantity by artificial means. Especial attention is invited to all the vegetable, mineral, and artificial tannins which are to be hereafter described, not for experiments that have no knowledge of chemistry to direct them, but for those who are willing to acquire a thorough knowledge ^of any one of the materials themselves, and then supplement it with that of the chemical combinations which it is capable of forming. In this way only can further satisfactory progress be made, or the result of our experiment be of value. The hide itself should be examined and analyzed at every stage of its manufacture. Its structure cannot be too minutely scrutinized ; its preliminary preparation is a problem ; the nature of gelatine is a study ; the manufacture of ooze, simple as it appears, is not uniform ; the proper consistency and strength of the liquor are yet to be graduated and fixed. Most of all, the union of the tannin and the gelatine in the interior fibres is to be critically observed and facilitated by every possi- ble means. The object is, of course, to produce leather in less time and at less cost than heretofore. To these remarks the tanner will probably reply that he has neither taste, time, nor means to employ in chemical experi- SYNOPSIS OF THE HISTORY OF TANNING. 61 ments. But if this be so, he can at least join his brethren and endeavor with them to eft'ect, by concerted action, that which it may be impossible for a single individual to accomplish. It is worth while to inquire whether our associations might not advantageously employ educated chemists to unlock for them the secrets of nature. There is no denying that our pathway to success winds up the hill of science. If we cannot travel it alone, we should secure guides, and accept whatever assistance is at hand. Of late some attention has been given in Europe to a system of tanning or tawing by means of chromium compounds patented by Dr. Christian Heinzerling, a German chemist. The oxidiz- ing power of chromate salts, and the deoxidizing effect of which organic matter has upon these salts, have long been recognized, and the knowledge of this action and counter- action has led to many attempts in the past to use chromates in tanning, but which have proved unsuccessful. It is now strongly claimed that the difficulties have been overcome by Dr. Heinzerling's process, which consists practically in the use of bicarbonate of potash, chloride of potassium, or chloride of sodium, and sul- phate of alumina. These are mixed together in one large stock- tank, from which the compound is drawn by means of a system of piping communicating with each pit, the quantity required to make the necessary strength of liquor; this at first, as in tanning with bark, is very weak ; but every few days it is sys- tematically strengthened, according to the thickness of the hides being tanned. The amount of chromatic acid ordinarily used amounts to from about 2| to 5 per cent, of the weight of the leather produced, and as the chromatic acid is not expensive the cost of the leather is greatly reduced. Light skins, such as sheep-skins and calf-skins, are tanned in less than one week, ox and buffalo hides in about two weeks, and walrus hides, more than two inches in thickness, in six weeks. After being tanned the hides, which at this stage are of a yellowish tint, like sumach-tanned leather, are dipped in chlo- ride of barium, which converts the soluble chromates on the surface into the insoluble chromate of barium. If any particu- 62 THE MANUFACTURE OF LEATHER. lar shade of color is desired, it is then put on, and in general the hides are colored like ordinary leather. After being colored the leather is allowed to get nearly dry, when it is immersed in pure parafl&n wax and resin dissolved together in certain proportions. These materials with chloride of potassium, or chloride of sodium, and sulphate of alumina, aid in giving the necessary substance weight, and waterproofing to the leather. The hides are afterwards dried and brushed clean by suitable machinery, and when so finished the leather in appearance dif- fers but slightly from ordinary leather. Dr. Heinzerling claims as the meritorious and original fea- tures of his process the combined use of chromate compounds and fatty matter. The stuffing with fat or paraf&n of chrome leather, he main- tains, in the first place, reduces chromic acid to chrome oxide ; and secondly, the oxygen thus liberated in the substance of the hide oxidizes the fatty into acid bodies, which, uniting with the chrome oxide, forms a third insoluble compound mordanted in the fibre of the leather, rendering it at once supple and water- proof. Leather thus made has been reported by Mr. David Kircaldy, London, as very considerably stronger than the best bark-tanned leather he was able to procure. After steeping samples of it in cold water for six days, it has been found that the total quan- tity of tanning material extracted amounted to from .Ol-i to .135 per cent., while first-class bark-tanned leather treated in a similar way yielded 6.79 per cent. By boiling chrome leather in water for one-half hour, the loss ranged from .005 to .054 per cent. The .process seems to offer the means of utilizing classes of hides, such as sheep-skins, and very heavy hides, as those of the walrus, hippopotamus, etc., in a way that has not heretofore been found practicable by other processes. Sheep-skins in chrome tanning do not require to be pured and freed from their oleaginous constituents, and when finished by this process are no longer porous, but waterproof. COMMERCIAL VARIETIES OF LEATHER. 63 They can be shaved and whitened like calf-skins, and it is claimed that they may be used for shoe purposes. Dr. Heinzerling's process is at work in various localities throughout Germany. For the United Kingdom and British colonies the patent rights have been acquired by the Eglinton Chemical Company of Glasgow, who, as manufacturers of bichromate of potash, have an indirect interest in the general development of the system. Although the method has not yet fully passed the critical stages of practical experiment, the products appear to be gain- ing the favor of men of great experience; and should the sys- tem fully meet the expectations of its originator and promoters, it cannot in the end fail to greatly cheapen many useful classes of leather. Dr. Heinzerling's system will be enlarged upon in the proper chapters of this work, in fact, his own language will be used, and no pains spared to fully describe his whole system of tan- ning. COMMERCIAL VARIETIES OF LEATHER. In the present section all the leathers known to commerce will be enumerated and slightly described, and the methods of their manufacture enlarged upon in the succeeding chapters of the work. The art of tanning is that by which animal hides and skins are converted into leather, a product possessing certain charac- teristic properties, being manageable and elastic after drying, as well as imputrescible, differing entirely from those of the original material, and eminently adapting it to the varied and useful pur- poses for which it is employed. These properties are of a physical nature, and varying with the kind of hide or skin employed, and the modifications of the process which it undergoes. Chemically considered, however, leather proper, whatever its kind, while not accurately speaking a chemical combination, is a compound of tannin and gelatine, possessing the all-desirable requisites of durability, pliability, inalterability, insolubility in 64 THE MANUFACTURE OF LEATHER. water, and great power of resisting the action of cliemical re- agents, but of tliis subject we shall have more to saj hereafter. When mineral or earthy substances are used as the leather- making agents, the result is a compound of gelatine with the base employed, and is more or less indestructible, according to the nature of the material and the circumstances under which the combination takes place. Tawing embraces the preparation of leather by the action of mineral or fatty substances on hides and skins. The system of tawing is principally applied to thin and light skins of sheep, lambs, kids, and goats ; although in former times much leather was tawed for military belts, machine belts, etc.; for most light purposes, however, sumach-tanned or similar leathers are now usually considered to be much more durable, as well as applicable. By tawing a white, pliant leather is obtained with alum, salt, chromium compounds, fats, etc. This method was practised by the Eomans, for we read in Isidore of calcei (shoes) called allutse because the skin was soft- ened with alum, and the Eomans derived it from Africa. It appears to have been introduced into Hungary before the twelfth century. This leather is used principally by glovers and harness-makers. In Hungary, also, not long after the invention of tanning, cha- mois dressing was invented. In this method neither bark nor alum is employed ; the leather is simply dressed by rolling and other powerful operations, first with bran, and subsequently with animal fat (train oil). In order that the fat may the better penetrate, the grain side is cut away with sharp instruments. For this reason chamois leather is rough or velvety on both sides. The Hungarians were, in ancient times, especially celebrated for their white tanned leather, which was imitated in France as long as three hundred years ago. In chamois leather, the most famous is the fine, white, shining French and Dane's leather (made from lamb and goat-skins), from which the so-called kid gloves are made. The inconvenience of raw hides, and their roughness and hardness preventing their adaptation to the body, awoke reflec- tion ; men sought to discover the causes of these defects, as well COMMERCIAL VARIETIES OF LEATHER. 65 as the means of remedying them, and thus arose with a gradual progress towards perfection the art of converting the raw hide into leather and for clothing, which mode of preparation is now called tanning. With an increase of population and wealth the greater became the demand for the necessities of civilization and luxury, and thus forced and attracted by necessity and gain, many experi- ments were made with a view to the improvement of tanning, until those excellent inventions were attained which have brought tanning to its present state of development. In these experiments the principal properties of tanned leather were kept in view. Attention was paid to the preparation of the hide so as to render it pliant and more impervious to moisture. The oldest method of tanning is red or bark tanning, or that in which, in addition to the wooden and iron scraping and rub- bing instrument used in the preparation or improvement of the hide or skin, lime-water, and astringent extracts from oak and other kinds of bark, or from other vegetable substances, are employed. It is called red tanning because the tanning sub- stances always contain more or less coloring matter, which dye the leather a more or less reddish color. The ancient orientals understood the art of preparing not only common leather, but even good, and often finely colored varieties, similar to our Morocco and Cordovan. Persian and Babylonian leather has been celebrated for many centuries back, as has been shown. Such leather was brought from Asia into Europe, first into Turkey, Prussia, and Hungary, and thence later to Grermany, Holland, England, France, Spain, etc., and these countries learned subsequently to manufacture leather themselves. In the first centuries of Christianity, the Turks, Eussians, and Hungarians were the most celebrated tan- ners; subsequently England, the Netherlands, and Spain en- deavored to equal them. Among fine leathers of foreign origin. Cordovan, Morocco, Shagreen, and Russia leathers have been especially famous. Cor- dovan, a soft, small-grained, colored leather, had already been prepared by the ancient Orientals. Its name is derived from the Spanish city of Cordova, where it was probably fii^&t iatro- QQ THE MANUFACTURE OF LEATHER. duced into Europe, and where, for a long time afterwards, it was chiefly manufactured. It. enjoyed a great reputation in the eleventh century, when the most distinguished persons wore shoes of Cordovan leather. The French name for shoemaker, "(7or(ioww{er," appears also to be derived from this leather. The best qualities have been made in Constantinople, Smyrna, and Aleppo. The best known German Cordovan is the Bremen variety. From the gradual improvement of Cordovan was engendered Morocco^ called also Turkish and Spanish leather, a still hand- somer leather than Cordovan. This beautifully colored and brilliant leather has been most excellently manufactured in Morocco, in the Levant, in Asiatic and European Turkey, in Krim Tartary, in Aleppo and Smyrna, and in the Island of Cyprus, and very well also in Eussia, Poland, Hungary, and Spain, but especially in England, France, Holland, Switzerland, and Germany (in the latter country at Offenbach on the Main, and Calin, in Wurtemberg). Morocco leather manufacture has been developed to a great extent in our own country, and with us the leading place for its production is Philadelphia, Pa., Newark, N. J., ranking next ; but Wilmington, Del., and Lynn, Mass., are also produc- ing it in large quantities. In contrast to our advancement in this line of production, the past fifteen years has witnessed the gradual but now complete destruction of not only Morocco, but also chamois leather man- ufacture in Eussia, although in other branches of tanning the value of productions has for the same period increased nearly 250 per cent., and the number of tanneries at the present time is not less than 3800 in Eussia. Tanning is one of the most widely spread and best developed of Eussian industries, being represented in fifty-nine of the sixty Eussian governments, and working up in 1879 more than 7,000,000 hides (43,000 poods) and 741,000 goat and lamb skins, the latter being dressed more largely in the governments of Valadimir, Odessa, Vologda, and Kasan. Russia's wealth in fur-bearing animals, together with climatic conditions, rendering furs a matter of necessity, have given the COMMERCIAL VARIETIES OF LEATHER. 67 trade of dressing these skins a development beyond that of other countries, and it is very much to be regretted that the branch of furriers proper had not been included in the statistics. Shagreen (in Turkish, Sagri, and Persian, Sagre) is chiefly celebrated for its hardness and strength, and for the peculiarity of the grain side, which appears as if covered with globular granules; it is also of eastern origin. The best shagreen has been made in Persia, Constantinople, Algiers, and Tripoli. The production of the small globular granules on the grain side was for a long time kept secret. We were first informed many years since by the celebrated traveller, Pallas, that they were produced by stamping the hard seeds of the wild orach [Ghe- nopodium album) into the hide, spread on the ground ; the seeds were afterwards knocked out and the hide scraped on the indented side and soaked in water for two days, in order to raise bulbs where the indentations existed. There is another descrip- tion of shagreen totally different, made from fish skin, called /?s/i- skin shagreen ; it is used for covers, wood polishing, etc. Russia leather is a strong and pliant leather, generally red or black, with a peculiarly penetrating odor, owing to the peculiar smell of oil of birch, and was undoubtedly invented by the ancient Bulgarians. It is only within comparatively late years that we have learned the mode of preparing this leather. Among other things, we first perceived that the peculiar odor arose from the birch oil which was rubbed into the leather. Inuften^ the German name of this leather, is derived from the Bulgarian word '•'•Jufti^'' a pair, as the Bulgarians, when they colored hides, always sewed them together by pairs in the form of a bag, with the grain side inwards ; the coloring liquor was then poured in and the hides kept in motion. The best Eussia leather has been made in various Eussian and Lithuanian provinces. But so rapidly has our own country developed the production of Eussia leather that we are manufacturing about all the leather of this kind which we consume, Philadelphia and Newark being with us the chief places for its manufacture, Eussia leather was formerly much employed in this country for bookbinding ; but its use for this purpose has been aban- doned by our principal librarians, and its place superseded by Y^ 68 THE MANUFACTUEE OF LEATHEE. red-colored Morocco for this purpose. The Eussia leather bind- ings on the books would decay, and finally possess no greater strength than so much common brown paper. In the English libraries, the climate being more moist than with us, the use of Russia leather for bookbinding is still continued to a moderate extent, as the destruction is not so rapid as with us. Hungarian Leather. — The art of dressing leather upon the so-called Hungarian method, was first brought from Senegal, in Africa, and made known to us in the middle of the sixteenth century by one Buscher, the son of a tanner in Paris. At that time leather was common in Hungary, and that dressed there was very highly esteemed. In the year 1584, two German tanners named Lasmagne and Aurand came to Neuchatel in Lorraine, where they worked at their trade ; from thence they went to St. Diziers, in Champagne, and finally to Paris, where they prepared very good leather. In this process mineral salts are substituted for vegetable extracts. The hides are first treated with a mixture of alum and common salt, by which a portion of the sulphate is con- verted into the chloride of aluminum, the hides being kept supple by an excess of salt. The fleshing and scraping processes are proceeded with as in the ordinary modes of tanning, but the hair is removed by shearing instead of liming. The first alum bath usually contains alum 7 pounds, salt 4| pounds, water 8 gallons, for each hide of 85 pounds weight. The whole process of the manufacture of Hungarian leather will be described later in a separate chapter. Parchment was known long before the invention of paper; for sheep and goatskins were used to write upon in the time of Herodotus. The name is derived from the city of Pergamus, in Asia Minor, where it was excellently manufactured. The best parchment is prepared from calfskin, and inferior qualities from sheep, goat, ass, and pig skins. The fine virgin ■parchment is made from the skins of new-born lambs. Artificial parchment, which was invented in England, consists of linen, cloth, or paper, which is tightly stretched, and then a paste composed of gypsum, white lead, powdered lime, water, COMMEECIAL VARIETIES OF LEATHER, 69 and parchment glue, is laid on with a brush four times ; it is then smoothed with pumice-stone, and lastly steeped in a bright oil varnish. The use of parchment is not extensive; beyond the ordinary purposes it is sometimes used for deeds, for printing, for diplomas, for organ bellows, and for sieves, and in England for sounding boards in stringed musical instruments. In Germany it is principally manufactured at Bentheim and Schuttorf in Hanover, and also in Augsburg, Nuremberg, Breslau, and Dantzic. Holland, England, and France manufacture excellent parchment. Alum leather is produced by tanning or tawing the skins white by a solution of alum or salt, and it is the same leather which has been before mentioned as Hungarian leather. Bazil is sheep-skin dyed with bark and used for making slippers, Buff leather is so named from the huffe or wild bull of Poland and Hungary ; it was used for armor, and tanned soft and white, and in Europe it is yet used for sabre belts and cartridge boxes. Chamois^ shammy, or shamoy leather was originally prepared from the skin of the chamois^ but the skins of other goats, and even of sheep, are now dressed in the soft manner, and furnish skins for carriages, polishing, for gloves, and other purposes. Enamelled leather is leather split to the required thickness, and then subjected to two operations; the first to render it impermeable to the varnish, and the other to coat it with varnish. The hides used are those of kip, calf, ox, or horse, and are rubbed on the grain or flesh side with three coatings of boiled linseed oil mixed with ochre or ground chalk, and dried after coating. The surface is then pumiced, treated ^with the same material of a thinner quality in several applications. Succes- sive layers of boiled linseed oil, and of this oil mixed with lampblack* and turpentine spread on with a brush, are laid over the thus prepared surface. The surface which has become black and shining, is varnished with copal and linseed oil con- taining coloring matter, which will be explained at length in the chapter on patent and enamelled leathers. The leather is curried expressly for this purpose, and particu- 70 THE MANUFACTUEE OF LEATHER. ]ar attention is observed to keep it as free from grease as pos- sible. It is sometimes used for boots and shoes, but most largely for carriage upholstery and similar purposes. It was first manufactured for carriage tops by David Crockett, of New- ark, N. J. Previous to this, oil-dressed leather, presenting the appearance of harness leather, was used for this purpose. Fair leather is subjected to a bleaching process and. is then finished in the color imparted by the bark, and is not speci- fically colored. Juncten is a name by which Eussia leather is sometimes called. Japanned, patent^ and varnished leathers are usually the same as enamelled leather, and the first made in this country was in 1818, by Seth Boyden, of Newark, N. J. Oil leather is curried in oil, the usual medium being fish-oil, with or without potassa, which is employed in alternation with drying. Fulling, graining, and pummelling are employed, fol- lowed by coloring, stretching, and surfacing. Roan is a leather made from sheep-skins in imitation of Morocco, except the grain, and is used for bookbinding. Russet is leather finished except the coloring and polishing, the tanned hides being stored in this condition in order to be com- pleted in any desired manner, as the future demand may suggest. Saffian leather derives its name from Saffi or Asfee, as it is called by the natives properly, and anciently Soffia, which is a city of great antiquity belonging to the province of Abda, and was built by the Carthagenians near Cape Cantin. This leather is produced from goat-skins, and is but a sub- name for Morocco. Another leather made near Saffi, in Morocco, is the Mogador leather, whicli is also a sub-name for Morocco leather, and derives its name from Mogador the capital of the fertile Moorish province of Haba. Large quantities of goat-skins are exported from Mogador, which are mostl}^ brought there by caravans from Timbuctoo and the Soudan. Quite a large amount of Morocco leather is produced at Mogador, chiefly of that rich yellow color of which slippers are so universally made. Shiver is a thin split of leather used for hat linings, sales-cases for jewelry, etc. COMMERCIAL VARIETIES OF LEATHER. 71 S-plit-leather is that which has been split in a machine for sepa- rating the grain from the flesh side. Sometimes it is done to lighten a leather, and at other times to make two thicknesses, both of which are utilized. Wash-leather is a skin soft-dressed and suitable for polishing, and for making specie-bags, pantaloon and overcoat pockets, also for cleaning metals, plate, and highly-polished articles. Whang is a tough leather made from the skins of calves, dogs, ground-hogs, etc., and is used for bag-strings, whip-crackers, belt lacings for machinery, and other occasional purposes. White-leather is the same as tawed-leather ; the process leaving the leather white, differing thus from that tanned by ooze. In commerce the following names are applied to leather: — Alligator-leather. Alum-leather. American-leather. Backs. Band-leather. Bazil. Belt-leather. Bindings. Bridle-leather. Bronze-leather. Buckskin-leather. Buffalo. Buff-leather. Butts. Calf-skin. Card-leather. Chamois-leather. Collar-leather. Cordovan-leather. Curried-leather. Deer-skin. Dog-skin. Dyed-leather. B nibossed-leather. Enamelled-leather. Fair-leather. Flint-leather. Glove-leather. Goat-skin. Grain-leather. Green-hides. Harness-leather. Hides. Hog-skin. Hungarian-leather. Juncten. Kangaroo-leather. Kid. Kip. Luce-leather. Lamb-skin. Legging-leather. Lime-leather. Linings, Morocco-leather. Maroquin. Oil-leather. Pad-leather. 72 THE MANUFACTURE OF LEATHEE. ParcTiment. Patent-leather. Eein-leather. Eaw-hides. Roan. Rough-tanned-leather. Rasset-leather. Russia-leather. Saddle-leather. Saffian. Salted-hides. Seal- skin. Shagreen. Sheep-skin. Shoe and Boot-leather. Sides. Skins. Skirting. Skivers. Sole-leather. Split-leather. Stamped-leather. Striped-leather. Sweat-leather. Tawed-leather. Toppings. Trunk-leather. Upper-leather. Varnished-leather. Wash-leather. Waxed-leather. Welt-leather. Whang. White- leather. Artificial leather is produced by various processes. According to the Bonneville method it is made from leather cuttings, shav- ings and parings, by reducing while in a dry state to powder, which is then mixed with a solution of India-rubber, with or without a solution of gum-lac, or of marine glue, to a suitable consistency. When partially dried, which process is effected by straining on wire cloth, or perforated metal, the sheets or slabs of artificial leather are pressed between rollers, and, if required, are orna- mented with any suitable designs. This kind of leather is now largely employed for covering cheap and medium-priced trunks, the squares, diamonds, circles and other ornamentation being impressed upon it in the manner which has been mentioned- Artificial leather is also made for soles and heels of shoddy shoes by pasting thin skivings together and passing them be- tween rollers. Messrs. Spill & Co., of Stepney, in 1860, matured the manu- facture of a substance which they termed vegetable leather^ and resembled leather-cloth in being an application of caoutchouc COMMERCIAL VARIETIES OF LEATHER. 73 to a woven ground-work or back ; but naphtha also took part in its preparation, and it possessed other peculiarities. Thej produced it in pieces 50 yards long by IJ yards wide, and thereby rendered it applicable to many purposes for which hides or skins of real leather would be too small. They varied its thickness to any desired degree by changing the number of cemented layers, and many qualities of leather were imitated in it at one-third the cost. The vegetable leather was much used in making carriage and horse aprons, soldiers' belfs, buckets, harness, book-covers, and other articles, a large number of which are now produced from Avhat we call rubber cloth. The Evans Artificial Leather Co., of Boston, Mass., are pro- ducers of various grades and colors of artificial leather, which is employed by boot, shoe, carriage, furniture, pocket-book, suspender, glove, jewelry-box, and trunk manufacturers. There is not the least room for doubt that in the United States the leather industry ranks second in importance only to agri- culture, when the amount of capital and the labor employed in all its branches are considered. It ranks among the leading half dozen human industries in many portions of Europe; but it is doubtful if even in England it holds the same relative po- sition that it does in our own country. In England the iron, cotton, and woollen interests are so very large, and on the continent of Europe the average consumption of leather among the populations is much less than in the United States. Among the inhabitants of all other parts of the world be- sides the United States and British North America, the British islands, eastern and southern Europe and Australia, the produc- tion of leather is, comparatively speaking, very small, and that which is produced is of an inferior quality. The hides and skins exported from the excluded sections form a most important item in the stock from which leather is made in the countries which have been named, and the value of the hides and skins, other than furs imported by this coun- try, for the year ending June 30, 1883, was $27,640,030, as is shown in Chapter III. 74 THE MANUFACTURE OF LEATHER. CHAPTER III. STATISTICS OF THE TANNING INTERESTS IN THE UNITED STATES. The number of tanneries in the United States, the capital invested, amount of hemlock and oak-bark used, number "of hides and skins tanned, and the total value of all products is given in the following table, which is based on the year 1880, and includes the States and Territories. The State possessing the largest number of tanneries being placed first, and the others following, according to their relative number of tanneries. The table does not include the consumption of cutch, gambler, sumach, or other tannins, excepting oak and hemlock barks, either vegetable or mineral. The imports of foreign materials are shown in the table of imports and exports in this chapter. It will be noticed that in the table, the State of Pennsylvania is credited with the greatest number of hides tanned, while the State of Massachusetts is credited with tanning the largest num- ber of skins. The reason for the latter being the enormous quantities of goat-skins used in the manufacture of Morocco leather, and sheep-skins consumed for linings, bindings, and skivers. TANNING- INTERESTS IN THE UNITED STATES. 75 Estab- states and Terri- lish- Capital. Hemlock Oak Hides. Skins. Total value toi'ies. ments. bark. bark. of products. ■ No. Dollars. Toas. Tons Number. Number. Dollars. United States. 3105 50,222,054 1,101,526 353,245 11,773,171 19,936,658 113,348,336 Pennsylvania, 642 15,608,635 379,069 122,550 2,970.680 635,280 27,042,068 New York, 386 11,710,415 334,048 6,624 2,503.855 4,171,290 23,652,366 Ohio, 302 2,022,990 5,775 42,274 456,015 434,732 4,357,273 Virginia, 163 658,973 69 11,661 125,438 30,628 1,011,830 Tennessee, 147 470,075 15 15,085 159,524 66,909 1,504,660 Massachusetts, 133 2,712,130 107,324 74 1,625,344 5,724,897 13,556,721 North Carolina, 133 183,659 29 6,154 83,661 20,750 367,920 Indiana, 105 653,349 1,856 18,633 152,375 57,602 1,266,653 Georgia, 94 143,441 30 115 1,561 4,284 West Virginia, 93 515,855 '"'33 16,987 150,317 50,713 1,451,528 Maine, 83 2,459,700 93,406 180 879,160 2,202,158 7,100,967 Alabama, 82 86,876 11 3,591 44,308 15,073 212,-545 California, 77 1,746,750 103 22,066 254,624 1,314,215 3,738,723 Wisconsin, 73 1,697,825 36,806 134 327,524 239,581 4,324,433 Michigan, 66 1,081,489 21,139 1,20.5 184,011 341,793 2,029,653 Kentucky, 63 1,741,430 31,107 211,097 213,840 2,511,960 Maryland, 63 802,343 "'75 24,733 137,617 286,250 1,468,591 New Jersey, 55 1,810,050 11,332 14,675 369,667 1,783,647 6,748,094 New Hampshire, 53 603,450 34,968 281,490 404,341 2,315,616 Vermont, 53 433,300 12,264 125,232 176.250 1,084,503 Illinois, 34 2,220,114 50,762 "137 395,030 1,486,570 5,402,070 Mississippi, 34 37,690 22 1,650 21,020 9,225 106,260 South Carolina, 28 42,675 1,605 20,967 4,705 73,597 Texas, 28 31,850 825 10,920 9,616 63,750 Missouri, 26 137,850 l",639 3,190 41,419 152,313 435,072 Oregon, 16 36,465 573 240 8,961 5,916 65,767 Utah, 13 43,200 322 81 5,046 4,952 47,267 Connecticut, 11 50,600 472 916 11,950 24,625 146,750 Iowa, 10 14,575 108 2,470 12,025 43,974 Louisiana, 10 9,300 270 3,412 13,280 28,470 Arkansas, 6 7,683 222 2,450 330 12,300 Minnesota, 6 32,450 1,724 16,716 7,046 111,000 Rhode Island, 4 368,600 7,375 106,777 368,000 Colorado, 3 16,700 4,100 15,'ioo 55,800 Delaware, 3 2,800 *130 1,400 195 7,000 Idaho, 2 1,850 "'35 400 475 2,216 Kansas, 2 1,167 20 '""70 980 150 7,452 Washington, 2 14,250 210 2,400 900 27,000 Dist. Columbia, 1 9,500 '"30 115 1,561 4,284 From this table, whicli is based on the census of 1880, it would appear that the average amount of capital invested in each tannery is $16,170, the odd dollars and cents being omitted in this calculation, as well as in the three which immediately follow. 76 THE MANUFACTUEE OF LEATHER. This average is largely exceeded in some portions of the country, the seven States possessing the largest average amount of capital invested in each tannery, rank as follows: — 1. Illinois $65,300 2. New Jersey .52,090 3. New York . . 30,340 4. Maine 29,630 5. Pennsylvania 24,320 6. California ... . . . . .22,670 7. Massachusetts 20,400 The average annual total value of products in each of the tanneries in the United States is $36,500; but this is also largely exceeded in the States which have just been mentioned. The rank of the seven leading States (in the average total value of products) in proportion to the number of tanneries established in each State, is as follows : — 1. Illinois $158,580 2. New Jersey 104,510 3. Massachusetts 101,930 4. Maine . . 85,550 5. New York . . 61,010 6. California 48,420 7. Pennsylvania 42,100 The business of tanning in this country is profitable (in pro- portion to the capital invested) in the leading States, in the order in which they will now be named: — - 1. Massachusetts. 2. Illinois. 3. Maine. 4. California. 5. New York. 6. New Jersey. 7. Pennsylvania. The profits should be larger in the State of Massachusetts than in any of the others, the business annually done being about as 5 to 1 to the capital invested; Illinois, Maine, and Cali- fornia about 2| to 1 ; New York and New Jersey being scarcely 2 to 1; while Pennsylvania does not average more thaii If to 1. TANNING INTERESTS IN THE UNITED STATES. 77 Since the census of 1880, a large number of sole leather tanne- ries have been located in Virginia, Tennessee, and other South- ern States, some being to supply the home demand for this variety of leather, and others are entirely devoted to manufac- turing leather for export. The imports and exports of leather should be closely inves- tigated. For the twelve months ending June 30, 1882, our exports of leather exceeded our imports by $618,403, and for the twelve months ending June 30, 1883, the trade was against us to the amount of $1,811,131. Such changes are too sudden. There are many places in Europe to which our tanned leather could be exported with profit, but which are neglected. Take, for example, the exports of the United States to Bremen. In 1878 we exported from the United States to Bremen tanned leather to the value of $149,604, and in 1879 to the value of $234,503, showing a gain of $84,699, which has been increasing each year, but not to the extent which is possible. The condition of the leather industry of Italy should invite the attention of American manufacturers and dealers to what could easily be made a profitable market for their products. Although the manufacture of leather is carried on in all the Italian provinces, the product is by no means equal to the wants of the nation, and a large deficiency has annually to be supplied from other countries. This importation is mainly from France, Great Britain, Ger- many, and Austria-Hungary, and more recently, to a limited extent, from India. Leather from the United States has found its way at times, during the past twelve years, into the Italian markets, but in small quantities, and has been principally our hemlock-tanned sole leather, which was re-shipped from Germany. The number of the tanneries in Italy at the close of 1879 was 1316, divided among sixteen provinces. The tanneries are mostly small, but water and steam power are used in many of them. The following table shows the importation of raw hides and leather into Italy, from 1869 to 1879, both years inclusive : — I 78 THE MANUFACTUEE OF LEATHER. Raw hides. Leather. Qaiutals. Qiiuitals. 1869 ....;.. 129,103 13,188 1870 98,876 10,552 1871 ....... 113,743 11,505 1872 127,202 11,705 1873 181,434 11,423 1874 136,761 12,165 1875 141,752 13,535 1876 . . . . , . . 139,262 16,350 1877 . . 134,987 15,376 1878 106,621 15,719 1879 . . . . . . . 126,178 15,733 Under tlie tariff" of May, 1878, the duty on importation of sole leather is $4.82, and calf-skins $5.79 per quintal, which is 220.46 pounds. It was highly desirable that the United States should have been largely represented in Germany at the Leather Exhibition, which commenced June 15, 1881, and continued for three months, at Frankfort-on-the-Main. In the staple of leather our own country now rivals like manu- factures of even England, Germany, and Austria, and no oppor- tunity should be lost to so advertise this fact to all the world. On account of the cheapness of hemlock bark and other tan- ning materials in this country, as well as of a generally better class of hides used in the manufacture of leather, our great convenience of position for obtaining the raw materials from South America, the superior labor-saving machinery employed in tanning, and the low rates for freight to Liverpool, there is no reason why our exports of sole and other leathers to Great Britain and the Continent should not be at least twice as large as they now are. The English tanners have raised all kinds of objections to our leather, they loudly sound extravagant praises of their home products, and let not the slightest opportunity pass to cry down ours; they say that all our leathers are only colored, and are not tanned, that they will not last one-half as long in wear as their home products. When, in fact, oar sole and upper leather is of better stock, and Avill wear one-fourth longer than three- TANNING- INTERESTS IN THE UNITED STATES. 79 fourths of that prodaeed in England, even if we do not lime and tan so long. The following table shows our imports and exports of hides and skins, bark for tanning, cutcli and gambir, tallow, fish oils, etc., for the twelve months ending June 30, 1883, as compared to the twelve months ending June 30, 1882 : — 12 months to June 30. Imports of hides and skins other than fur Exports " Iinports in excess of exports Imports of leather .... Exports : 1883. Morocco and other fine $385,825 Leather, sole and upper 6,038,097 1SS3. ]SS2. $27,640,030 $27,841,126 1,220,158 1,449,737 Imports in excess of exports in 1883 Imports for 12 months to June 30, 1882 Excess of exports over imports to June 30, 1882 Imports of bark for tanning Exports " " Excess of imports over exports Imports of cutch and gambir Exports of tallow Imports " Excess of exports over imports Exports of whale and other fish oils Imports " " " Excess of exports over imports 1882. $687,638 7,059,906 26,419,872 8,235,053 6,423,922 26,391,389 7,747,544 2 . e30 1882 1,811,131 343,998 87,528 256,470 997,536 3,248,749 3,399 3,245,350 115,490 76,553 7,029,041 618,403 490,588 97,442 393,046 784,232 2,647,515 5,522 2,641,993 420,730 103,020 38,837 317,710 At the close of 1880 the number of leather-currying estab- lishments in the United States was 2319, the number of sides of leather curried was 12,464,299, and the number of skins, 10,655,606, and the total value of all curried products was $71,351,297. Nearly one-third in value of the whole currying business of this country is done in the State of Massachusetts, which ex- ceeds in this line the combined products of New Jerse}^, Penn- sylvania, and New York. 80 THE MANUFACTUEE OF LEATHER. More than nine-tenths of the whole currying business of this country is done in the twelve States which will be shortly enu- merated : — The following table shows the twelve States which have been mentioned, the number of establishments in each, the capital invested, the number of sides of leather and skins curried, and the total value of the products in each State, that having the greatest value of products being placed first; and the others following in relative importance, the table being based on the year 1880. Establish- Sides of Total value of ments. Capital. leather. Skins. products. Massachusetts, 194 $4,308,169 4,951,562 5,178,609 23,282,775 New Jersey, 56 1,983,746 818,804 1,703,316 8,727,128 Pennsylvania, 455 2,570,969 1,272,931 404,874 7,852,177 New York, 185 1,720,356 1,048,581 639,772 6,192.002 Wisconsin, 61 1,299,425 734,800 582,451 4.496,729 Ohio, 251 1,089,075 632,615 256,054 3,886,627 Maine, 34 510,900 518,850 232,552 2,612,350 Illinois, 18 537,786 251,660 431,920 2,391,380 New Hampshire, 37 351,850 435,450 339,466 2,161,734 California, 63 427,350 266,054 466,450 2,001,850 Indiana, 93. 381,552 276,760 37,lsl 1,461,776 Michigan, 44 256,311 161,308 63,351 996,932 EXAMINATION OF LEATHERS. 81 CHAPTER lY. EXAMINATION OF LEATHERS.^ The determination of the value and quality of leather by a chemieo-technical examination has heretofore been perhaps more neglected than that of any other product of industry and commerce. The consumer or dealer either does not examine the leather at all, but buys his supply from a well-known tan- nery, or judges it solely by the cut, flexibility, and weight. Although it cannot be denied that an, expert may rely on exter- nal marks, it must nevertheless be admitted, that these leave us in the dark in man}'- points as regards the value of leather. "We need, for instance, refer only to the varying percentage of w^ater in the different varieties, according to the time they have been stored, to prove the importance of a method of testing based upon measure and weight. Unfortunately no thorough examinations in this direction have thus far been made by competent experts, and the litera- ture in regard to this matter found in chemieo-technical works is very meagre. Marquis,^ who undertook a chemical examina- tion of different varieties of leather, made use of the following process: — Marquis's Method. 1. Determination of fat and resin. — An accurately weighed quantity of leather is cut into small pieces, which are thoroughly dried in an exsiccator, and then three times in succession digested with ether. After distilling off the latter, the matrass, the weight of which has been previously determined, is weighed together with the residue it contains. 1 Bolley's Technologie, 35 (Bd. vi. 4). 2 Pharmac. Zeitschr. fiir Russland, Jalirg. 4, Heft 10, S. 389 ; cf. Zeitschr. fur analyt. Cliemie, 1866, S. 236. 6 82 THE MANUFACTUEE OF LEATHEE. The mixture, consisting of fat and resinous substances, is treated with cold alcohol to separate the resinous constituents from the fat. This method of determining the fat cannot be an accurate one, since, besides fat, other substances, for instance tannic acid, are dissolved by the ether. 2. Determination of lime in leather. — 6.211 grammes of shredded leather are burned to ashes in a platinum crucible, the ash is treated with hydrochloric acid, the solution fil- tered, and the filtrate sufficiently washed out with water. The lime is precipitated from the filtrate with ammonium hydrate and ammonium oxalate. The precipitate is washed and dis- solved in nitric acid. The oxalic acid in the solution thus ob- tained is determined by solution of potassium mangauate, and the lime calculated from the quantity of potassium manganate used. Marquis found between 1 and 3 per cent, of lime in the dif- ferent samples. 3. Determination of the Tanning Constituents. — Heinzerling proposes the following method: — Determination of Water. — 10 grammes of sole or upper leather in the form of small cubes are dried in a dry current of air at 170° to 190° F. until a decrease in weight is no longer observed. It is best to use for this purpose such an air-bath as is shown in Fig. 1. The cubes of leather, contained in a tube expanding in the centre and running to a point in front, are placed in the air-bath and dried. Percentage of Ash. — 5 grms. of leather are heated in a porce- lain or platinum crucible until all coal is burned. Should this be difficult to effect, some ammonium nitrate is carefnlly added in order to accelerate the process. The ash is weighed and calcu- lated in the usual manner. In case the percentage of ash is very high (7 to 10 per cent.), so as to arouse the suspicion of the leather having been made heavy with inorganic substances, the ash is qualitatively tested by the ordinary analytical process and the admixtures, such as chlorides of barium or calcium, which may be found, determined in freshly weighed leather. As lime in leather exerts an injurious influence upon its EXAMINATION OF LEATHER. 83 durability, causing, especially, brittleness in upper leather, it is of the utmost importance to learn the percentage of that substance. For this purpose the residue obtained from a determined quan- tity of leather is dissolved in hydrochloric acid, the solution Fisf. 1. diluted with distilled water and filtered. The filtrate is boiled with a few drops of nitric acid and compounded with solution of ammonium hydrate and sal-ammoniac to separate the iron and alumina. The lime is precipitated as calcium oxalate with ammonium oxalate, and weighed as calcium carbonate or caus- tic lime. Members of the fifth group represented in the hydro- chloric solution of ash must of course be previously removed. Percentage of Fat. — As many varieties of leather are exces- sively greased with fat, in order to increase the weight, it is of interest to determine the percentage of fat. For this purpose 5 to 10 grms. of shredded leather are, according to Caillelet, placed in a small matrass and boiled in a 6 to 8 per cent, solution of soda or potash lye for some time, in order to saponify all animal and vegetable fats. By compounding the soap solution with hydrochloric acid, the free sebacic acids are separated upon the surface of the fluid. 84 THE MANDFACTUEE OF LEATHER. To determine the sebacic acids, they are dissolved in 20 or 30 cubic centimeters of oil of turpentine. The fluid, together with the fat solution, is placed in a graduated tube and by reading the volume of the layer of oil of turpentine containing the sebacic acids in solution, the quantity of the latter is obtained from the increase in volume of the oil of turpentine. If, for instance, 20 c.c. of oil of turpentine have been used and the volume of the solution of oil of turpentine and sebacic acid amounts to 26 c.c. the amount of sebacic acids will, by subtraction, be found to be 6 c.c. The weight of the sebacic acids is obtained by multiplying the cubic centimeters found with the specific gravity. These methods of determining the fat, although not entirely accurate, are sufficiently so for technical purposes. Determination of Nitrogen. — As the cleansed leather skin shows a considerable percentage of nitrogen, Miintz has pro- posed to determine the percentage of nitrogen in leather, in order to draw from it a conclusion in regard to the chemical composition of leather. The method is available for tan-leather as well as mineral-leather. 0.6 to 1 grm. of leather rasped or finely shredded is mixed with a large quantity of soda-lime and placed in a tube of con- siderable length and the nitrogen determined as ammonium according to the Barrentrapp- Will method. . As the bubbles of ammonium of a larger molecular weight form also combina- tions with platinum chlorine, to avoid errors, the platoso-am- monium chloride obtained by precipitation with platinum chloride must not be weighed as such and the nitrogen calculated from it, but the precipitate should be heated in a porcelain crucible and the percentage of nitrogen calculated from the metallic platinum obtained (1 equivalent of platinum = 1 equivalent of nitrogen). Coriin, a small quantity of which occurs in the skin, has ac- cording to Reimer^ the formula Cj^H^gNj^Oij containing con- sequently 28.3 per cent, of nitrogen. The membranous tissue of which the raw skin chiefly consists, has the formula C,jH^NjOg and contains 30.3 per cent, of nitrogen. Suppose .the .skin contains 4 to 6 per cent, of coriin, the EXAMINATION OF LEATHER, 85 quantity of nitrogen may be taken in round numbers as amounting to 30 per cent. If, therefore, an analysis should show 15 per cent, of nitrogen in a variety of leather, the latter con- tains 50 per cent, of skin substance and 50 per cent, of other substances such as water, tanning materials, fats, etc. Tanning Substance. 1. Tannic Acid. — A knowledge of the quantity of tanning material contained in a variety of leather is of more scientific than practical interest. An accurately tested method of establishing the quantity of tannic acid in tan-leather is riot yet known. Marquis's method, as already mentioned, has many defects. Other methods require a separation of the tannic acid from the animal fibre, which can scarcely be effected without decomposition of the latter. Mittenzweig's method is the only one worthy of a thorough test. 2. Mineral Constituents. — The tanning materials in mineral tanned leather, ferric salt in Knapp's process, and alkaline chromates, chromium salts and aluminium combinations in Heinzerling's, can be readily determined, after destruction of the fibre tissue, by the usual analytical process. The cutting surface is generally taken as a criterion by which to judge whether leather is thoroughly tanned. It should be uniform throughout the entire mass and show no dark stripes on the sides nor in the centre. The cutting surface of leather not thoroughly • tanned presents an unequal appearance, dark stripes occurring on the side as well as in the centre. The behavior of tan-leather towards boiling water has also been made use of to determine whether the leather has been thoroughly tanned. By heating in water to the boiling point a thin piece of leather not sufficiently tanned, it swells up considerably, and becomes transparent and tough like pig skin, only the thoroughly tanned places remaining opaque and of a coffee-brown color. Such leather, when rubbed between the fingers, is soft and sticky. The decoction obtained from leather insufficiently tanned is generally already turbid on cooling, has a yellow to pale-brown color, and on evaporating the fluid after cooling some gelatine remains behind. Thin strips of thoroughly tanned leather, when boiled in water, 86 THE MANUFACTURE OF LEATHER. shrink considerably, become opaque and of a coffee-brown color, and brittle when rubbed between the fingers after cooling. The decoction obtained from thoroughly tanned leather is transparent and of a reddish -brown color and, when evaporated to the consistency of sj^rup, shows no sign of gelatinizing. Determination of Means used to Increase the Weight of Leather. — It is frequently the case in modern times, especially in Germany and Great Britain where tanning material is high that, in order to obtain greater weight, a concentrated solution of banum chloride, aluminium chloride or grape-sugar isNnot only applied to the flesh side of tanned sole and upper leather, but the entire product is sometimes saturated with it. The detection of these adulterations of leather is not very difficult. Digest the leather in lukewarm water for a few hours, acidulate a part of the resulting aqueous solution with nitric acid and test it with nitrate of silver for chloride, and another part of the solution with sulphuric acid for barium salt. Ammonium hydrate is used as a reagent for aluminium salts. Precipitates are formed when any of these substances are pre- sent. The chloride of silver soon darkens on exposure to light, while the precipitate of alumina produced with ammonium is very voluminous. If only a small degree of turbidity occurs during these reactions, no adulteration has taken place. The de- tection of grape-sugar is somewhat more difficult, as the tanning material, for instance tannin, passing into solution yields, on splitting, grape-sugar, which must be taken into consideration. The leather is digested in lukewarm water for some time and, in order to precipitate all the tannic acid contained in the solu- tion, some cupric acetate is carefully added. The solution is then filtered and when a precipitate is formed, some Fehling's copper solution is added, and the whole boiled for twelve to fif- teen minutes. A strong separation of cuprous oxide is a proof of the leather having been weighted with grape-sugar. Physical Methods of Testing Leather. If it is only desired to test the quality of leather, this can be directly ascertained by the following methods: — EXAMIN"ATION" OF LEATHER. 87 I, Change in Volume and Ability for resisting Water: — As the ability for resisting water may be considered one of the principal properties of leather, the variety which absorbs water the most slowly and in the least quantity, must evidently be considered as possessing qualities which should testify highly in its favor. The following table, on page 88, can be understood without further explanation. It was compiled by Dr. Heinzerling, and has been admitted into the present work in order to invite atten- tion to his manner of tanning or rather tawing ; hoping that it may eventually be perfected by some of our American inventors into a generally acceptable process, and that whatever objection there may now be to the leather thus economically produced may in the course of time be overcome. The manner of tanning leather by this process will be considered in a subsequent chapter. THE MAISTTFACTURE OF LEATHER. .Sf a m CO m lO r-i c4 cq c4 ; t^ (M 11= I— I oc o 9.5 a a ® w P. a tu 1 1 ) (M r^ to t^ Tt T}< T}( ^ o ^' i.5S : oD t~- oi : c4 rt to ; ^ CO "^ M P< (N CO CO CO = 5 i ?= g a s b^ a •- c cs ^ &i V> CO ' O O CO I— ( T— I 1—4 CM ^ o in oi TJH CO O i^ O u a5 o; a sh a a o " '^ ^ o in :o Tf (jjCO I-H LiJwH, Journ. Prac. Chern., cvii. 464; H. Schiflf, Deutsch. Chem. Gesel., 1871, 231 and 9G7. VEGETABLE TANNING MATERIALS. 109 The new formula of tannin is confirmed by the analysis of the tetracetic derivative formed by the action of the acetic anhy- dride on the tannin, C,^Hg(C2H30)409, a colorless body, crystalliz- ing in peaks, having the form of cauliflower, hardly soluble in water, soluble enough in boiling alcohol, and not reacting any longer on ferric salts. Concentrated sulphuric acid converts it in rufigallic acid at 212° F. Eufigallic acid should be the anhydride of tannin or of gallic acid and should answer to the formula Cj^HgOg. According to all these results, it is probable that vegetables containing tannin under the formof apolygallic glucoside are very alterable and of which a portion v/ould remain undecomposed in ordinary tannin. Tannomelanic Acid. — According to Biichner, tannomelanic acid is obtained, as a product of the decomposition of ordinary tannin, by a prolonged ebullition of a solution of gallotannate of potash. The tannin is dissolved in a boiling solution of carbonate of potash of a density of 1.27, as long as there is any eftervescence ; then the liquid is kept boiling until a testing quantity, increased with acetic acid, remains limpid after cooling. It is supersaturated with acetic acid, and it is .evaporated to a dry state by means of steaming. The residue is exhausted by alcohol, which dissolves some acetate and some gallate of potash. The residue is dissolved in water and the solution is mixed with acetic acid and acetate of lead, which causes a precipitation of tannomelanate of lead under the form of a brown-black powder. The composition of this acid appears^ to be represented by the formula CgH^Og, and its formation at the expense of the gallic acid would be explained by the equation G^'K^O^+O—Q^Jd.^ + CO, + H,0. Tanno'pinic Acid. — Eochleder and KaAvalier^ give this name to a derivative of tannin which is found towards spring in the needles of the Scotch pine. The alcoholic extract distilled after adding water, furnishes an aqueous liquor from which some resin has separated. This liquid is precipitated by fractioning ' Biichner, Am. Chem. u. Pharm., liii. 373. 2 Wiener Akadem. Ber., xxix. 22. 110 THE MANUFACTURE OF LEATHER. with neutral acetate of lead. The precipitate is dissolved with weakened acetic acid, the solution is precipitated with basic acetate of lead, and the precipitate suspended in water is decom- posed bj sulphuretted hydrogen. The hot aqueous solution of this acid oxidizes rapidly in the air. The authors named give it the formula C28H3oO,g(?). Tannoxylic or Rufitannic Acid. — Product of the oxidation of gallic acid under the influence of alkalis. To obtain it, dissolve some tannin, cold, in a moderately con- centrated solution of potash ; the liquid is left to itself, in don- tact with the air, until it has taken a dark red-brown tint, then precipitated with acetate of lead ; the tannate of lead mixed with the tannoxylate is taken out by means of hot acetic acid ; the insoluble residue is treated hot with a mixture of alcohol and sulphuric acid. A dark red solution is thus obtained, of which the acid is taken by distillation of the alcohol, under the form of an amorphous brown-red mass. Its composition ap- pears to answer to the formula C^H^^Og. There would be pro- duced at the expense of the gallic acid^ by addition of oxygen Many of the other tannic acids, which have thus far not been thoroughly examined, show properties corresponding more or less in their behavior. We will here consider somewhat closer the quercotannic acid as being highly important to the tanner. This was formerly considered as identical with gallotannic acid, but it differs materially in its composition, properties, and products of decomposition. Stenhouse showed conclusively that quercitannic acid, on decomposition Avith sulphuric acid, does not give gallic acid, nor pyrogallic acid, when subjected to dry distillation. The chemical formula of quercotannic acid is according to Grahowsky^ and Oser^ CguHjoOj,. It forms a yellow brown amorphous mass readily soluble in water and alcohol ; the aqueous solution is precipitated with sulphuric acid in red- ' Buchner, Am. Chem. Pharm., liii. 369. 2 Wiener Akadem. Ber., 1867, Ivi. 387. 3 Wiener Akadem. Ber., 1876, Ixxii. 165, und Handwoerter buch der Chem., Bd. ii. VEGETABLE TANNING MATERIALS. Ill brown flakes. With solutions of glue, tartar emetic, and quinine, it gives precipitates like gallotannic acid. It changes ferric chloride into a deep black fluid, which is colored red bj an addition of sodium carbonate. Quercotannic acid is easily oxidized by exposure to the air, especially when in alkaline solution ; 100 grms. of the acid absorb 12.8 grms. of oxygen. By boiling with dilute sulphuric acid quercotannic acid (Gj^ Hgi.O],) is resolved, with absorption of water, into quercus red,^ Cj^HjgOg, and sugar, CgHj^Og (Oser^). According to Grabowsky quercus red is Cj^Hj^O^, the difference appearing to be due to the temperature and duration of decomposition or the quantity of acid used. Quercus red is a red amorphous body insoluble in water and ether, but soluble in water and ammonia. Water precipitates it from an alcoholic solution, and acids from an ammoniacal solution. Quercotannic acid in aqueous solution compounded with cinchonin acetate gives a precipitate with the formula Cj^H^^lSr, 0{Q^^Jd^^? In washing the precipitate it is not insoluble in water but dissolves more readily in acetone. This solution is precipitated with solution of barium acetate in acetic acid.^ Besides quercotannic acid, oak bark contains quercus hitter or quercin as Gerber^ terms it. It is a crystallizable bitter sub- stance which Gerber obtained from a decoction of bark pre- pared with milk of lime after precipitation with potassium carbonate and evaporation. The small white crystals possess no odor and a very bitter taste. They dissolve in thirteen parts of cold water, but more readily in warm, and also in aqueous but not in absolute alcohol, and in ether and oil of turpentine. From hot hydrochloric acid or acetic acid they crystallize with- out change, but are colored by nitric or sulphuric acid. ■ The well-known fact that oak-tanned leather on coming in contact with acids, turns red, may be traced to this. 2 Wiener Academ. Ber., 1876, Ixxii. 165. 3 Wiener Akadem. Ber., 1876, Ixxii. 165. * Handwoeterbuch der Chemie, Bd. ii. 1046 ; Berzelius's Jahresber., xxiv. 635. 112 THE MANUFACTURE OF LEATHER. We will here mention the quevphlohai^jhene^ which resembles quercus red, and which is prepared by treating bark completely- extracted with water with ammonium, and precipitating with hydrochloric acid. Its composition corresponds to the formula C^^Hg^Oj., or nearly Cj^Hj^O^. Querphlobaphene dissolved in as little ammonium as possible gives with calcium chloride or barium chloride as precipitates: Cj^H^^Oj^Ca, or CjoHj^Oj^Ba. By fusing this body with potassium hydrate, it yields phloroghicin and protocatechuic acid, and sometimes a small quantity of pyrocathechin.^ The property of tannic acid of forming insoluble combinations with earthy alkaline salts is of practical importance in tanning. By the use of hard water a loss of tannic acid may be caused by the formation of insoluble barium or lime combinations with the tannic acid. As the loss thus caused is by no means a small one, it is recommended for tanneries using very hard water to purify it before leaching the bark.^ A further property of tannic acid deserving consideration is that it can be brought into fermentation by fungi and ferments. In tanneries where scrupulous cleanliness is not the rule, it is frequently the case that the edge of the ooze vats is covered with a rank fungous vegetation. Many tanners cannot know that these fungi decompose tannic acid into acetic acid, lactic acid, etc., or they would surely be more careful to remove this foul matter. Only since we have acquired the knowledge how to deter- mine tannic acid analytically, has it been found that plants may contain very varying quantities of tannic acid in their separate parts, or in the different stages of their development.^ 1 Wiener Akadem. Ber., 1867, Ivi. 387. 2 Aniial. der Chemie u. Pharinacie, cxlv. 1. 3 In many tanneries the water is filtered through exhausted tan, whicli though quite suitable, is rather a laborious method. Tlie small quantity of tannic acid still contained in the tan precipitates the lime and magnesia salts of the water. The principal objection to this method of purifying the water is that organic acids such as acetic, lactic, propionic acids, etc., may get into tlie water, and that by using such water for leaching fresh tan a decomposition of tlie tannic acid may be caused by the ferments. * Through researches made by Schulze (Dingler's Polyt. .Journal, clxxxii. 158), it was found that oaks twenty-four to thirty years old yield tan containing a very VEGETABLE TANNING MATERIALS. 113 In perennial plants the roots, barks, and brandies of most trees contain tannic acid, as frequently do also the leaves, folli- cles, and fruits of bush-like and tree-like plants, especially when full-grown. Tannic acid was formerly supposed to be the pro- duct of a commencing process of decomposition of the cell substance, and its formation a peculiar decomposing process of the cell membrane, but recent researches have proven that tannic acid is in most cases a primary product of vegetable life, as shown by its frequent occurrence in young plants while yet in the first stage of development. The action of the different tannic acids towards the coriura or leather skin varies greatly. Observations of practical men have shown that vegetable substances the tannic acid of which, when heated, forms pyro- gallic acid, furnish leather less capable of resisting water, and consequently less suitable for the consumer, than tannic acids which, when heated, yield pyrocatechin. The extractive substances, such as coloring matter, resins, pectine, and pectic acid, organic acids, sugar, etc., exert a material influence upon the value of a tannic acid. The coloring matter, for instance, may injure the appearance of the leather, and the resins and other extractive substances the quality. The influence exerted by resins, pectine substances, etc., has unfortunately been but little studied by chemists, and the judg- ment of this matter is limited. Section II. Vegetable Tanning Materials. But few of the large number of vegetables containing tannic acid are used in tanning, though in modern times the number has been largely increased by diligent researches m-ade with a view to obtain cheaper tanning materials. We shall here briefly discuss the most important tanning high percentage of tannic acid, while that from oaks eighty to one hundred and twenty years old contained far less. But the percentage of tannic acid in tlie younger trees varies frequently so much, that that contained in the older ones may often be as large as in the younger trees. 114: THE MANUFACTURE OF LEATHER, materials, first mentioning the inspissated vegetable juices which are imported. Rutea is the inspissated juice of Rutea formosa^ and is only used for tanning in the northwest of India. Kino is the inspissated juice of Pterocarpus erinaceus and onarsupium. Kuraerous varieties of kino are known in com- merce, though the principal ones are those coming from Africa and Malabar. The African kino, which is the best, and but seldom found in commerce, is the inspissated juice of Pterocaiyus erinaceus. The Malabar or East Indian kino is derived from Pterocarpus marsapium^ a tree indigenous to After India, Malabar, and Ceylon. Both varieties of kino are very rich in tannic acid, that of the latter being identical with gallotannic acid, it yielding, on heating, pyrogallic acid. On account of its high price, and the disagreeable red color it imparts to the leather, this tanning material is but little used. Gambier is an extract from the leaves of Uncaria yamhir. It forms cubical pieces -^ to ^ inch thick of a light and dark rust or sometimes gray color, which float upon water and are very friable. Gambier is slightly soluble in cold water, but readily in hot. Its percentage of tannin is quite high. Catechu^ or terra jap)onica^ is the dry extract from the core wood of a mimosa, Acacia catechu^ growing in the East Indian islands. Its principal constituents are : Catechin, a brown substance which can be precipitated from its solution with glue, and cate- chutannic acid, which appears to be formed from the catechin by exposure to the air. It colors ferric oxide green, and gives a green-black precipitate with ferric salts. A judgment of the value of catechu is formed by its external color, hardness, taste, solubility ia spirit of wine, etc. Genuine catechu melts upon the tongue, while non-genuine sticks to it. Adulterations with blood, sugar, etc., can be detected by the characteristic odor of these admixtures when burnt. The leather produced with catechu is not of a particularly good quality, it being of a dark color, permeable to water, spongy, and at the same time hard. Gall-nuts are the richest in tannin of all tanning materials. They are morbid excrescences of the leaves and young branches VEGETABLE TANNING- MATERIALS. 115 of Quercus infectoria^ Oliv., formed by the puncture of gall-flies {Cynips gallse tinctorta), belonging to the Hymenoptera^ for the purpose of depositing their eggs. As the latter develop, excres- censes called galls or gall-nuts are formed on the jDunctured places by the exudation of sap and enlargement of the cells. The larvae which are inclosed in the galls are supported by the juices of the plant until they become perfect insects, when they perforate the gall and escape. When this happens the excres- cense loses much of its astringent principle and becomes lighter in color and finally entirely white, while if collected before the entombed insect is completely developed the galls are of a dark to blackish color, and much richer in tannin. The latter are known in commerce as green ycdls^ and come from Aleppo, Smyrna, and Mesopotamia. Gall-nuts are also imported from Cypria^ Karamania^ etc., though they are not so good as the Aleppo galls, with which they are sometimes mixed. European galls, formed by the puncture of other species of gall-flies of other varieties of oaks, are not so good as the Aleppo galls. They come from the Morea, Italy, Hungary, and Istria. Gallotannic acid is, as previously mentioned, the most accurately known. OaUs (Knoppern) formed by the puncture of a gall-fly {Cy- nips quercus calycis) in the young fruits of Quercus pedunculata. They are principally collected in Hungary, Dalmatia, and Sla- vonia, and contain, besides a small quantity of gallic acid, much tannin closely resembling gallotannic acid. The percentage of tannin amounts, according to Mueller, to as much as 50 per cent. Chinese Gall-nuts form irregular roundish bulbs of the size of a hazel or walnut, which inclose the insect. Their rind is smooth and felt-like, of a gray or reddish color, and very thin, and consequently fragile. They show no vegetable structure, but a dense, brilliant, resinous fracture, and are said to be de- rived from a species of sumach. They are much in dem.and on account of their high percentage of tannin, which, according to Mueller, amounts to as high as 65.5 per cent. Rove. — The article known by this name, which is brought 116 THE MANUFACTURE OF LEATHER. into commerce ground and pressed in bricks, is the so-called Bassora gall-nut, and is found in Persia and Asia Minor. It is principally exported by way of Smyrna. It contains about 27 per cent, of tannic acid. Mixed with oak or fir bark, it is, according to Eitner, well adapted for tanning sole leather. Sumacli consists of comminuted leaves, stems of blossoms, and branches of several Rhus species, such as Rhus coriaria^ R. co- tinus, R. glahrum, R. canadense, R. iyjphinum^ R. pentaphyllum^ Arbutus uva ursi, Coriaria mystifalia. The following varieties are found in commerce : — Sicilian Sumach., from Rhus coriaria^ is the most valued. It is divided into two qualities, the best being of a, greenish -yellow color, while the inferior variety is of a more rusty-yellowish color, and has less smell and less tannic a«id. Italian Sumach, which is also derived from Rhus coriaria, is a dirty-green powder. It is far inferior in tanning capacity to the Sicilian variety, it being besides frequently adulterated with sondro leaves. Spanish Sumach. — Three varieties of this occur in commerce, viz: Malaga, or Priego, Malino, and VaUadolid, the last two be- ino" of less value than the first. l^yrol Sumach, the odor of which resembles that of oak bark, is derived from the leaves and stems of Rhus cotinus. Like the Italian and Sicilian sumach, it is frequently adulterated w^ith fig leaves. French Sumach (from Coriaria mystifolia). There are four varieties : Fauvis, Redoul, Donz^re, and Pudis sumach, the last two being less liked than the others. The " Tezera''' sumach, used by the Arabs for tanning morocco leather, is derived from Rhus pentaphillum. American Sumach is derived from Rhus canadense and R. glah- rum. Large quantities of it are used in the United States, nearly all the morocco manufacturers mixing it with an equal quantity of Sicilian sumach to form the tanning liquor, which is forced through the goat skins by hydrostatic pressure. Sumach is also used in tanning buffed leather. Large quantities of American sumach are shipped from Georgetown,, I). C, and Alexandria, Va. VEGETABLE TANNING MATERIALS. 117 Swedish Sumach is prepared from the leaves of the bear-berry {Arbutus uva-ursi). It is not yet definitely determined whether all the different varieties of sumach contain the same or different kinds of tannic acid, though the latter is the most probable. The tannic acid contained in the Sicilian sumach is, according to Stenhouse,* identical with gallotannic acid. In old sumach, the larger portion of the tannic acid has been converted into gallic acid and sugar. Leather prepared with sumach possesses but little capacity for resisting water, and is therefore principally used for the uppers of ladies' fine shoes, book-binding, portfolios, pocket-books, linings, bindings, skivers, etc. Valonia is the acorn-cup of Quercus seyilops^ prickly-cupped oak, a tree growing in abundance in the islands of the Grecian Archipelago, The tannic acid of valonia is not known in a pure state, as it always contains gallic acid. The use of valonia has recently much increased in Europe, it being especially em ployed, mixed with oak tan, for sole-leather in the last two spreadings of the hides in the binders. Leatlier prepared with valonia, is said to be harder and« less permeable to water than that made with oak bark, its weight being also increased. The price of valonia which contains a considerable percentage of tannic acid, is low compared with that of tan, and it is much used by English tanners. Divi-divi consists of the dried pods of a bush {Csesalinnia coriaria) indigenous to South America. Leather tanned with the extract becomes very soft and spongy, and on exposure to the air assumes a more or less brown to brown-red color. The extract of the divi-divi pods is also brought into commerce. The tannic acid differs from the gallotannic acid, and, when heated, does not yield, like the latter, pyrogallic acid. Myrohalans^ the dried fruit of Terminalia chebula^ is princi- pally collected in India. The fruits exported by way of Cal- cutta are of a roundish shape, gray-black color, and hard and astringent. They contain, principally in the husk, a consider- 1 Dingl. Polyt. Journ. clxv. 150. 118 THE MANUFACTURE OF LEATHER. able quantity of gallic acid, which, according to Stenhouse, dif- fers so far from gallotannic acid as not to yield, on boiling with dilute sulphuric acid, gallic acid, but a reddish-brown sub- stance insoluble in spirit of wine. Myrobalan is used in Europe in tanning as an addition to oak bark. Buhlah is the husk of the fruit of Acacia hamhtila. It comes from India, and contains considerable tannic acid. Of the other foreign materials containing tannic acid, which, on account of their high price, etc., are more extensively used in dying and coloring than tanning, we will mention : — Logivood^ which is derived from Hsematoxylon carri'peacliionu.ra^ a Csesalpina growing wild in Yucatan and some of the West Indies. Fustic^ obtained from Moms tinctoria. It contains a peculiar tannic acid, moritannic acid, or macherin, which on heating yields pyrocatechin. It is only used for coloring leather. Weld [Reseda luteola) is a plant belonging to the Resedacese, which grows wild in all European countries, though it is occa- sionally cultivated in Southern France and Germany, The following barks are also made use of in tanning, although not so extensively as hemlock and oak barks : — Larch hark {Larix Europsea). — This bark yields a material relatively poor in tannin. It contains, according to Dav}'^, 1.6 to 2 per cent, of tannic acid. The bark is used in England and Ireland for tanning sheep-skins. Fir barh [Pinus ahies) is principally used in Europe, in Austrian, Bavarian, Hanoverian, and Upper Svvabian tanneries. It is claimed to be especially adapted for " plumping," or the so-called preparatory swelling and tanning of hides. Hemloch bark is obtained from Abies Canadensis. The baric is light, has a somewhat balsamic odor, and a slightly astringent taste. The tannin is colored green by ferric salts, and brown by potash lye. It is the most important tan- ning material in America, where it is much used for tanning both sole and upper leathers, two-thirds of all sole and upper leathers produced in the United States being tanned with it. This variety of leather has been only lately appreciated in many VEGETABLE TANNING MATERIALS. 119 portions of Europe, and our exports of this variety of leather are constantly increasing, but, as has been stated, not so rapidly as they ought to do considering its wearing qualities and its cheapness, A mixture of hemlock bark and oak gives a very serviceable leather, termed " union tannage." An extract of hemlock bark goes into the European markets under the name of American hemlock extract^ and it is also em- ployed in portions of this country where bark is scarce. It is chiefly prepared from thick bark, since the greatest yield of tannin is, according to Eitner, obtained from the rind, and not from the pulp, an analysis of the latter showing 7.7 per cent, of tannic acid, and of the former 11.3 per cent., while the entire bark yielded 10.1 per cent. Oak harks, from Quercus monticola of Michaux, rock chestnut oak, and Q. tinctoria, yellow-barked oak, are the most esteemed for tanning purposes in the United States. The best is the first-named variety, and the prime quality is derived from the Blue Ridge, which is the most easterly ridge of the Allegheny Mountains. The principal tanneries using rock' chestnut-oak bark are located in the State of Yirginia, the western portions of the Carolinas, and in Tennessee ; the bark in the latter State being derived from the Cumberland Mountains. In tanning it is used unmixed, and gives a beautiful " bloom ;" the sole leather produced with it being always in demand for both home con- sumption and for export. The bark of the yellow-barked oak is in tanning commonly mixed with red-oak bark, as the color which the former yields when used alone is objectionable. The inner bark of the Q. tinctoria is the quercitron of dyers. The barks of the Q. alha, white oak, and Q. rubra, red oak, are not esteemed in tanning, the first being poor in tannin and the second imparting an undesirable color to the leather. Walnut hark from Juglans reyia gives a very soft leather, but can only be obtained in small quantities. Lorahardy poplar hark gives a light-brown leather with an odor resembling that of Russia leather. Elm hark, from Uhnus campestris, is especially used in Norway for manufacturing the beautiful Norwegian glove leather. V 120 THE MANUFACTURE OF LEATHER. Horse-chestnut bark from jEscuIus hippocastunum. The bark of this tree contains a tannin which is colored intensely green by ferric oxide. Besides the tannin, which is also found in other parts of the tree, the bark contains fraxin, fraxetin, ses- culin, sesculetin, and aesculetin hydrate, a small quantity of a peculiarly yellow crystalline body and a pectine substance which is decomposed into formic acid, oxalic acid, and protoca- techuic acid by boiling potash. The leaves of the horse chest- nut^ contain also tannic acid, wax, a variety of rosin (C^gHg^O,^) and a resinous substance (Cj^H^gO^) possessing a peculiar odor of frankincense. The young leaves and buds contain a peculiar tannin to which Rochleder has applied the term '■'■ pjhyllocitannic acidr JEsculotannic Acid? — Different kinds of tannic acid are found in the horse chestnut, sesculotannic acid (G^gHg^Oj^)- occurring, according to Rochleder, in the bark, leaves, flower-buds, ripe and unripe seeds, roots, and the trunk. In a pure state it forms an almost colorless amorphous powder readily soluble in water, spirit of wine, and ether. By the action of the air and alkali, or substances containing oxygen, such as chromic acid, it is decom- posed into a brown body having the constitution CjgH220j3. Fusing with potash changes ^esculotannic acid into phloroglucin and proto-catechuic acid. Ferric chloride colors the tannic acid green. An aqueous extract of the bark comes into commerce under the name of " horse-chestnut extract^ The percentage of tannic acid in the extract varies according to its specific gravity. It is at present much used in Germany and other portions of Europe as an addition in oak-bark tanning, and is said to give good leather. It is considerably cheaper than quercotannic acid. Willoio Baric. — The following are the principal willow barks used in tanning: Salix alba, S. arenaria, S.fragilis, S. piayura^ etc. There is not much difference in the value of the barks, though it is claimed that barks containing salicin, as for instance that of S. purpurea, are not so good as others. The amount of 1 Rochleder Wiener Akadem., liv. 24 bis 48 ; 236 bis 254 ; 604; 607 bis 657. 8 Ibid., liv. 607. VEGETABLE TANKING MATERIALS. 121 tannin varies from 6 to 16 per cent. In Russia willow bark is used for tanning Russia leather, and in Sweden and Norway for preparing the well-known Swedish glove leather. The tannic acid 'contained in willow barks colors ferric salts green, and, when treated with dilute sulphuric acid, yields sugar and possi- bly gallic acid, though this is donbtful. Alder Barh contains a high percentage of tannin, amounting, according to Gassincourt, to 36 per cent. Beech hark from Fagiis silvatica mixed with oak bark may be used as a substitute for the latter, but the resulting product is of an inferior quality. It contains, according to Davy, 2 per cent. of tannin, and besides a peculiarly red matter and a substance with an odor of vanilla. Proiaceee Barks. — The trees from which this bark is obtained are indigenous to the Cape and Australia. The principal ones are the Protea conocarpa (knotted tree) and Banksia serrata. The tannin of the latter imparts a beautiful violet-blue color to solutions of ferric salts, while that of the first colors iron- green. Both give a brown color with potash lye. jSnouha Bark. — The Aleppo fir [Pinus halepensis) yields two important tanning materials, namely, the snouba bark, and the scorzarosa. The first is the inner bark of the tree freed entirely from the rind, and comes from Tunis and Algiers. The scorza rosa is the rind of the same tree, obtained in Southern Italy, and especially in Sicily, from the living trees in a very rational manner, so that the flesh of the bark remains intact, and produces, like the cork tree, new bark, which is periodically taken ofi". Snouza bark contains 25 per cent, of tannin, and sco?-za rosa 13 to 15 per cent. The tannin colors ferric salts green, while it becomes brown by an addition of potash lye. Batanhy root is obtained from Krameria triandra., which grows in Peru. The root comes into commerce in a comminuted state, and is very rich in tannin, which is extracted with water, and theresulting solution used as an addition in tanning. The pro-, portion of tannin is, according to Peschir, as much as 42.6 per cent. It corresponds, according to A. Rabe,^ with the formula 1 Pharm. Zeitung f. Russland, xix. 577. 122 THE MANUFACTURE OF LEATHER. CgoHjoOg, It is not a glucoside, and passes, by the splitting off of H2O, over into ratanhy red CjoH^gO,,. Avens root, from Geumi urhanum, contains, according to Trommsdorff, up to 41 per cent, of tannin. Solutions of it have occasionally been used as an addition in tanning. Tormentil root and Sassafras root show a still higher percent- age of tannin, the first containing, according to Gassincourt, 16 per cent, of it, and, according to Reinsch, up to 58 per cent. Both roots being very expensive are not often used for tan- ning. The wood of the Algarohia glandulosd of Gray, m.esquite oah, and Q. virens, live oah, contains much tannin in its entire mass, and is very successfully used in America in place of tan. Quebracho is obtained, according to a communication by C. Donath,^ in the province of Santiago from Aspido^Derma que- hracho. It is brought into commerce in blocks with a reddish- brown appearance upon the cutting surface. It costs about $2.75 per 100 lbs., and is said to contain about 20 per cent, of tannin. Before use it is cut into small pieces, which are ground to a fine powder by disintegrators. G. Fraude^ found in the bark of the wood an alkaloid to which he has applied the term aspidospermin G^^^^^O^, or Cg^H^gNgOg. Miintz and Schon claim that, by tanning with quebracho, good leather and weight are obtained. Mimosa. — Besides these the following tannins, the names of which we will only mention, have been proposed and occasion- ally used : Barks of Butea frontosa and Butea gibsonis, both indigenous to the West Indies; fruits of Balsamoharpon brevi- folium.^ bark of Eucahji:)tus ; Pangue, a root growing in India ; Pitnica granatum, etc. We have in the following compiled — ' Dingl. Polyteclni. Journal, ccxxxi. 451. 2 Ber. d. deutsch. cliem. Ges. 1878, 2189 ; Diugl. Polyteclni. Journal, ccxxxii. 92. ' Engl. Patentberichte, 1875, Ramsbaclier, Masurer. VEGETABLE TANNIKG MATERIALS. 123 The Percentage of Tannin contained i7i the various Tangling materials determined according to different methods. cent, according to Davy. Davy. Vauquelin. Solly. Guibonrt. Fehling. Bley. Fehling, Roder. Fehling. Peschier. Gmelin. Fehling. Fehling. Davy. Davy and Geiger. Esenbeck. Fehling. Davy. Davy. Davy. Davy. Gassinconrt. Gassinconrt. Fontenelle. Davy. Fontenelle. Fontenelle. Davy. Davy. Davy. Davy. Davy. Riggers. Gassinconrt. Gassinconrt. Gassinconrt. Gassinconrt. Davy. Gassinconrt. Gassinconrt. Gassinconrt. Reinsch. Bombay catechu . 55 per Bengal " . 44 " Kino . . 75 " Buted gum . 73.2 " Aleppo nut-galls . 65 ' Gerberzeitung, 1881, No. 32. 128 THE MANUFACTURE OF LEATHER. alcohol, after whicli they dried the leather completely, and calculated from this the quantity of tannin absorbed. The experiments gave the following results: — Table III. Hemlock leather contained in Sumach leather " " Fir leather " " Quebracho leather " " Chestnut leather Oak-bark leather Leather in a la garouille . Oak bark (3 years in the pit) By calculating the above table to 100 parts of skin, we obtain the following figures : — Table IV. Parts of skin. Parts tannin. . 43.91 29.23 45.10 29.70 46.70 42.60 48.70 36.70 52.56 44.08 53.36 41.16 54.19 35.13 56.30 39.00 100 parts of skin contain pure tannin — As hemlock leather' . 64.2 pe r cent. " sumach leather' .... . 61.2 " fir bark leather ^ .... . 90.8 " quebracho leather . . . . 75.3 " chestnut leather .... . 85.2 " oak-bark leather . . . . . 76.9 " a la garouille^ . 64.8 " oak bark (3 years in the pit) . ■ . 70.2 The percentage of glue, tannin, and nitrogen in leather per- fectly dry and free from all soluble substances, calculated from Table III., should be as follows : — Table Hemlock Sumach . Fir bark Quebracho Chestnut Oak A la garouille Oak (3 years in the pit) V. Glue. Tannin. Nitrogen 60.40 39.96 10.88 60.40 39.60 11.00 52.50 47.50 9.56 57.10 42.90 10.40 53.97 46.30 9.79 55.87 44.13 10.24 60.40 39.60 10.94 58.75 41.25 10.65 1 The figures for hemlock, sumach, and fir bark leather, given in the " Ger- berzeitung," are wrong. They should be 66.5 per cent, for hemlock, 65.8 for sumach, and 91.2 for fir bark. ^ A la garouille is probably a variety of leather obtained by mixing the bark of Daphne Laureola with Quercus. VEG-ETABLE TAJSTNIISTG MATERIALS. 129 Bj calculating from Table Y. liow many pounds of leather free from resin are obtained from 220 lbs. of dry skin, we obtain the following figures : — Table VI. Hemlock 365.2 lbs. Quebracho 380.6 " Chestnut 407 " Oak 374 " a la garouille ........ 363 " The last table shows that leather tanned with hemlock and a la garouille absorbed the least tannin. Leather tanned with hem- lock is solid, while that tanned with a la garouille appears soft. Miintz and Schon raise the question why equal quantities of tannin give such different results, and answer that in tanning with hemlock a certain quantity of resinous substances are introduced into the interior of the leather which cannot be removed by washing with ether and alcohol, and make the fibre brittle. Leather tanned with chestnut bark and quebracho furnishes, it is claimed, as good a quality as that with oak bark, and at the same time a greater increase in weight. As the tannin con- tained in these materials costs scarcely half as much as oak tannin, the use of chestnut and quebracho would be of advantage. Miintz and Schon also draw attention to the fact that leather tanned with oak bark kept three years in the pit contained, after washing with ether and alcohol, 2 per cent, less tannin than that tanned with oak bark two years in the pit. Tiiis phenomenon, they say, may possibly be caused by the skins differing in their interior condition and possessing a greater or smaller absorbing power. The question whether a skin by continued remaining in the tanning material can absorb larger quantities of tannin, Miintz and Schon answer by saying : " The skin does not absorb an unlimited quantity of tannin ; there comes the moment of satu- ration." In the opinion of these two chemists the quality of the leather is not improved by its remaining for a long time in the pit.^ ^ For portions of the matter in this chapter the author desires to acknowledge his indebtedness to the Dictionnaire de Chimie Pure et Appliquee, Wurtz, and to Bolley's Technolgie 35 (Bd. vi. 4), Lederbereitung, Heinzerling. 9 130 THE MANUFACTUEE OF LEATHEE. CHAPTER YII. MINEEAL AND AETIFICIALLY PEEPAEED TANNING SUBSTANCES.^ Section I. Mineeal Tanning Mateeials. The use of mineral tanning materials dates back to very re- mote times, since history teaches us that the Saracens used alum and aluminium salts for tanning skins. These substances were in fact for a long time the only tanning materials employed for preparing leather, a series of other mineral substances for tan- ning having been only recently introduced as a substitute for vegetable substances. The principal mineral substances we have to consider are : — 1. Aliim^ aluminium sulphate^ and aluminium^ acetate, 2. Ghromates and chromic oxides. 3. Ferric salts. 4. Common salt. Aluminium Sulphate. Neutral aluminium sulphate (AI23SOJ is prepared either by treating clay or bauxite with concentrated sulphuric acid, or from cryolite. In an anhydrous state it contains 30 per cent, of alumina and 70 per cent, of sulphuric acid. With eighteen equivalents of water it crystallizes into octahedrons, or at a temperature of 32° F. into hexagonal rhombohedrons. Alu- minium sulphate is soluble in double its weight of water. A solution prepared with the assistance of heat separates, on cooling, crystalline lamina of aluminium sulphate (Al23SO^ + ISHgO). It is found in commerce in a nearly pure state, the best qualities containing only traces of iron, but from 0.5 to 2 1 Bolley's Teclinologie, 35 (Bd. vi. 4), Lederbereitung, Heiiizerling. MINERAL TANNING SUBSTANCES. 131 per cent, of free sulphuric acid/ which is frequently injurious when the salt is to be used for tanning purposes. The presence of free sulphuric acid may also be detected by adding to a solu- tion of aluminium sulphate some logwood tincture. The solu- tion, if free acid is present, will be colored brown-yellow, and deep violet, if it is neutral. To make aluminium sulphate con- taining free sulphuric acid available for tanning purposes, add to a solution of it 1 to 2 per cent, of zinc chips, the solution of which will be attended by a violent development of hydrogen. By the free sulphuric acid combining with the zinc, zinc sul- phate is formed. An excess of zinc is dissolved with formation of zinc sulphate and separation of basic sulphate of alumina. Instead of zinc chips 1 to 2 per cent, of sodium carbonate may be used. Aluminium sulphate, known in commerce as concentrated alum, is used in tanning as a substitute for alum. The skin absorbs, according to Knapp, up to 27 per cent, of it, which is removed by washing with water. Alum (Al^3SO, + K2S04+24H20), is formed by the combina- tion of aluminium sulphate with alkaline sulphates. It is read- ily prepared by mixing solutions of the two sulphates. In evaporating the fluid, the alum crystallizes out. Potash-alum and ammonia-alum dissolve with difficulty, they requiring 18.4 parts of cold water and 7.5 parts of boiling water, while soda- alum dissolves readily. From a hot saturated solution, the alum separates in octahedrons, and from alkaline solutions in hexadrons. The last variety is called in commerce cubic alum, and, being nearly free from iron, is valued more highly than the former. Alum has at first a sweetish taste which changes into an astringent. By heating it loses graduall}'' its water of crys- tallization, becomes anhydrous, and is converted into the so- called burned alum. Ferric sulphate, manganous sulphate, and chromium sulphate, which are isomorphous with aluminium, ' To test aluminium sulphate for free sulphuric acid, compound, according to Edward Donath, a solution of it at an ordinary temperature with a few drops of potassium iodide and potassium bichromate and add a little bisulphate of carbon. If free acid is present the iodine is liberated and the bisulphide of carbon, on shaking, assumes a beautiful violet color. 132 THE MANUFACTUKE OF LEATHEE. form also double salts when combined with potassium, sodium, or ammonium sulphate. The resulting combinations are called iron alum, chromium alum, and manganese alum. Instead of alumina they contain ferric oxide, chromic oxide or manganic oxide. They crystallize in the same form, and contain an equal quantity of water of crystallization : — Iron alum = Pe,3SO, + K2SO,+ 24Hp. Manganese alum = Mn2'3S04 4-K2S04+24H.p. : Chromium alum= G^ 3S0, + K,SO, + 24:Rp. If several of these alums in solution are present in one fluid, the crystals separating from it contain the different bases in varying quantity. It is due to this circumstance that alumina alum contains frequently iron alum, which it is often impossible to remove even by repeated recrystallization. In tawing and in mineral tanning potash-alum is principally used. For a complete saturation the skin tissue absorbs, according to Knapp, 7 to 8 per cent, of alum. The tanning properties of alum are principally due to the alumina salts it contains. In absorption by the skin tissue, the alum, according to Knapp and Kaimer, is split, the aluminium sulphate or basic aluminium sulphate precipitating upon the fibre, while the potassium sulphate remains in the liquid. In the presence of common salt in aqueous solution, the alum, according to Knapp, is not converted into aluminium chloride and sodium sulphate. Iron and chromium alum act upon the skin tissue in the same manner as aluminium alum. Aluminium acetate (Al26(OC2H30)) is prepared by dissolving alumina in acetic acid or compounding lead acetate with aluminium sulphate or alum. Heating during the process should be avoided. Experiments have lately been made in using aluminium acetate in place of aluminium sulphate or alum. It does not separate, it is claimed, in a crystalline form in the skin, and the leather tanned with it does not become spotted, as is frequently the case in tanning with alum. The tanning with this salt is more solid than with alum, since the aluminium acetate decomposes more or less in the leather by the formation of basic salts or free alumina. MINERAL TANNIKG SUBSTANCES, 133 A further advantage claimed for aluminium acetate is the absence of free sulphuric acid, which is split off from the aluminium sulphate and exerts a very injurious influence upon the leather. Chromimn Salts. Experiments have only been made within the last three or four years to use chromates mixed with alumina salts for tanning in place of vegetable substances. The most important for this method of tanning is the potas- sium hichromaie from Avhich all other chromic salts and com- pounds of chromium used for technical purposes are derived. The salt is chiefly manufactured in three large establishments in England, from whence it is sent to all parts of Europe and partly to America. It is made by roasting a mixture of finely powdered chrome iron-stone with potassium carbonate upon the hearth of a reverberatory furnace for several hours with con- stant stirring of the mass. The chromium oxide is oxidized to chromic acid, the latter combining with the potassium to potas- sium chromate. The ferric oxide contained in the chrome iron- stone is separated as such. After thorough oxidation the roasted mass is lixiviated with water, whereby potassium chro- mate, a small excess of potassium carbonate and a few impurities, such as potassium silicate, pass into solution. The liquid is allowed to clarify by standing, and, after decanting, is evapo- rated if necessary, and the neutral potassium chromate con- verted into potassium bichromate by adding the required quantity of sulphuric acid. The potassium bichromate forms large bright garnet-red trichinic crystals. It is soluble with difficulty in cold water. 20 parts of water at 32° F. dissolve 1 part of tlie salt. 11.8 " " " 50 " " 1 " 7.65 " " " 68 " " 1 " " 1.18 " " " 140 " " 1 Potassium bichromate is very sensitive. With glue, gelatine, gum, etc., it forms combinations which, after exposure to light, are insoluble in water, its employment in photography for 134 THE MANUFACTURE OF LEATHER. preparing pigment or carbon pictures depending upon this property. It precipitates itself upon the skin fibre, and partly pene- trates it. Taken internally it has a poisonous effect like most metallic combinations. Placed repeatedly upon excoriated or sore places it produces running ulcers, which are, however, soon healed by washing with lead vinegar. It colors the sound cuticle yellow without destroying it. In pulverizing potassium chromate care must be had not to allow the powder to enter the nostrils as it produces violent itching and severe spells of sneezing. Sodium bichromate is more soluble in cold water than potas- sium bichromate, but as it crystallizes with difficulty and does not form an article of commerce, it is but little used. Calcium bichromate, strontium,' and barium are soluble in water, while the neutral chromate of calcium, strontium, and barium are soluble with difficulty, the barium salt, which forms a well-known art color, being almost insoluble in water. Lead salts give with chromic salts insoluble precipitates which are used as painters' colors. The neutral alkaline chromates are yellow, readily soluble in water, and can be used in place of the alkaline bichromates, but beino; dearer than the latter offer no advantag-e. Chromium alum is the most important of the chromium salts thus far introduced in tanning. It is prepared by mixing chromium sulphate with alkaline sulphates. It crystallizes from the fluid in octahedrons. In speaking of alum, it has been mentioned that chromium alum acts upon the fibre in the same maimer as aluminium alum, but the tanning of leather prepared with aluminium alum being, as we will see later on, more perishable on exposure to water than that of leather prepared with chromates, the latter are pre- ferred. Chromic sulphate (CrjoSOJ is obtained by reducing chromic acid to chromic oxide, and dissolving in sulphuric acid. It is soluble in water, giving to the latter an emerald-green color, and has the same tanning effect upon the skin fibre as aluminium sulphate. MINERAL TANNING SUBSTANCES. 135 Ferric Salts. Tanning with ferric salts was already recommenced in the last century by D'Arcet. Bordier, in 1842, obtained a patent for tanning by means of ferric sulphate obtained by oxidizing ferrous sulphate. In modern times Knapp has attempted to reintroduce in practice the method of tanning with ferric salts. The ferric .sulphate used by him is also prepared by oxidizing ferrous sul- phate with nitric acid, the latter being added to a solution of the former until eServesceace ceases and all the ferrous oxide is converted into ferric oxide. After the cessation of the first effervescence ferrous sulphate is again added until effervescence ceases, the object of this addition being to reduce any excess of nitric acid used. The resulting basic ferric sulphate solution should be of a syrupy consistency, and contain chiefly basic ferric sulphate and a small excess of ferrous sulphate. Prof. Knapp says that only basic ferric sulphate prepared in the above manner is adapted for tanning on account of its amorphous condition and beautiful brown-yellow color and the indecomposableness of its aqueous solution in boiling. The commercial basic ferric sulphate, according to Knapp, does not give a syrupy solution, is of a much darker color, and the aque- ous solution is decomposed by boiling. This ferric salt is, according to Knapp, abundantly absorbed by the skin tissue and effects a complete tanning of the skin fibre. It is claimed that the salt absorbed by the skin cannot be removed by treating with water. By precipitating a soap solution with the above basic ferric sulphate. Prof. Knapp prepares an iron soap which is a com- bination of ferric oxide with sebacic acids. This, to complete the tanning process, is mechanically fulled into the skin, either by itself or mixed with fat solutions or emulsions. Comraon Salt occupies an important place in tanning. It serves, as has been previously mentioned, on the one hand for preserving skins, and on the other to accelerate the tanning process in tawing 136 THE MANUFACTUEE OF LEATHER. and mineral tanqing. As regards its occurrence, preparation, etc., nothing need be said. The salt found in commerce is either rock salt or that ob- tained from salt springs or sea-water, the latter being known as common salt. Both varieties contain varying quantities of admixtures, the principal being the sulphates of magnesia, lime, or gypsum, and the chlorides of calcium and magnesium. Common salt prepared from sea-water contains the most im- purities, the principal being magnesium chloride, magnesium sulphate, calcium chloride, etc. The salt obtained from rock salt by recrystallization being the purest is especially adapted for use in tanning. In using common salt in tawing and mineral tanning, admix- tures of magnesium chloride and calcium chloride are especially injurious as they absorb water from the air, i. e., they are hygroscopic. When salt containing these admixtures is used for tanning the leather produced with it absorbs water from the air and becomes moist. Section II. Artificially Prepared Tanning Substances. Many attempts have been made to substitute artificial tan- ning substances for those of a vegetable or mineral origin occurring iti nature. Although they have thus far not been introduced in practice we will briefly describe the manner of preparing them. Jennings patented in 1848 an artificial tanning material pre- pared in the following manner: Dense black peat is thoroughly dried and pulverized, and treated with 10 to 20 per cent, of concentrated nitric acid gradually added. The mass becomes hot in a short time and evolves yellow-red vapors of nitrous acid, the escape of which is partly prevented by covering the apparatus. When the action of the nitric acid has ceased, six to ten times the quantity of water of acid used is added, and the whole heated for a few hours with frequent stirring, the object of heating being to accomplish the solution of the tannin formed by the action of nitric acid. In order to use peat re- MINERAL TANNING SUBSTANCES. 137 cently cut, it must be heated with steam to 176° to 212° F. before treating with nitric acid. The tannin dissolved in the fluid is freed from the coloring matter bj adding a few per cent, of stannous chloride and boiling for a few minutes. The coloring matter is precipitated, after which the clear super- natant fluid is decanted off. Aluminium sulphate and common salt can also be used for precipitating the coloring matter. The skins to be tanned are immersed for a few hours in the tanning solution and frequently moved, and then placed for a few hours in an alkaline carbonate solution and also frequently moved, when they are replaced in the tannin solution, next in the alkaline solution, and so on until they are completely tanned. Sky manufactures a similar tanning material (Wagner's Jahresberichte, 1867, 666). Lees patented in 1858 the following method of preparing artificial tannin. The heavy oils obtained in the dry distillation of coal or bituminous shale are treated with concentrated sul- phuric acid until a carbonaceous, resinous mass is obtained. To accelerate the action of the sulphuric acid upon the oily mass, the mixture of sulphuric acid and oil is indirectly heated with steam. The resulting black, pitchy mass is boiled with nitric acid and then compounded with ammonia, or ammoniacal liquor or some other alkali, until the acid is neutralized. An excess of alkali must be avoided, as it exerts a dissolving effect upon the pitchy mass. Lees calls the resulting product mine- ral tan. For tanning it is dissolved in water, and the skins are allowed to remain in intimate contact with the solution for some time, after which they are finished in a solution of alum or other salts. Another kind of artificial tannin is formed by heating a solu- tion of resins and camphor with sulphuric acid.^ After some time the mass becomes black. By adding water a black pow- der is separated, the alcoholic extract of which on being evapo- rated leaves behind the artificial tannin. The chemical nature ' Muspratt, iii. 106. 138 THE MANUFACTURE OF LEATHER. of the tannins obtained by these processes can only be conjec- tured, since they have not been scientifically examined. The tannins obtained by treating peat, brown coal, coal, etc., with nitric acid are very likely nitro-combinations of the aro- matic series and possibly closely related to picric acid, for it is well known that by the action of nitric acid upon a series of organic substances yellow nitro-combinations are formed which are frequently considered as picric acid. Picric acid^ in aqueous or alcoholic solution converts the skin into leather, but is not used in practice on account of its high price. The tannins obtained by the action of sulphuric acid upon resins and. camphor may possibly be sulpho-combinations of organic bodies, such as are frequently produced by sulphuric acid. CHAPTER VIII. CHEMICAL EXAMINATION OF VEGETABLE TANNING MATERIALS. Most tanners determine, even at the present time, as has been done for hundreds of years, the quality of the tanning material by its appearance, taste, and odor. While with some experience it may be possible by these means to distinguish good bark from a bad article, they offer no guide for the finer distinctions in value. That an absolutely accurate method of determining the tannic acid in the various tanning materials is wanting even at the present day, may be explained by the fact that, with the excep- tion of gallotannic acid, we know next to nothing, in a chemical respect, of the different tannins. As regards the properties and mode of distinguishing the tannins occurring in the various vegetable tanning materials, we refer to what has been stated in Chapter YI. • Picric acid, C6H2(N02)3HO, is obtained by the action of nitric acid upon phe- nol, indigo, benzole, silk, wool, resins, etc. It forms pale yellow crystalline lamina, and is soluble with difficulty in water, but readily in ether or spirit of wine. EXAMINATION OF VEGETABLE TANNING MATERIALS. 139 Method of Determining the Tannic Acid. The quantity of tanning matters contained in the different astringent products used in industry has a valuable practical importance and a large number of methods have been proposed to reach this result in the most rapid and accurate way possible. The areometer (tan-meter) is an instrument which has been used for some time to obtain an idea as to the strength of the tann- ing liquors, and the percentage of the bark. The percentage of tannic acid is estimated from the greater or smaller specific gravity of the aqueous solution of a determined quantity of tan- ning material. The richer the aqueous solution in tannic acid, the higher its specific gravity. This method furnishes inaccu- rate results, since the bark, according to its age and the soil upon which it is grown, contains varying quantities of other substances soluble in water, which affect the specific gravity of an aqueous solution. The following substances occur, according to Gerber, in an aqueous solution of the inside layer of oak bark: — Tannin , 8.05 Gallic acid 1.59 Sugar Extractive substances ^ ....... 8.33 Malic acid Rosin •1 6.31 Fat > Gum 5.60 Quercus red . . . . . . . . .2.34 Pectic acid 6.77 Davy first indicated a volumetric method founded on the precipitation of the gelatine with the tannin. To the aqueous extract of a known weight of astringent matter is added an ex- cess of a solution of gelatine or isinglass (1 part of isinglass for 6 parts of the astringent solution). The precipitate gathered on the filter, washed, dried, and weighed, represents -^-^ of its weight in tannin. The results thus obtained are very weak, as the precipitate of tannate of gelatine always passes partially through the filter. According to Mliller, this inconvenience may be obviated by the use of a solution of gelatine containing some alum. In that case the precipitate separates completely, 140 THE MANUFACTURE OF LEATHER. and Fehberg has even been able to found, on the use of alumi- nated gelatine, a process of volumetric denomination. The nor- mal solution contains 10 grms. of air-dried gelatine per litre and 3 grras. of alum. This liquor is titrated by means of a solution of pure tannin containing 2 grms. per litre. It is evident that this process can only be applied to the tan- nins which precipitate gelatine ; but, as they are also those that enter into the composition of tanning matters, this restriction does not diminish the value of the process. One can judge of the termination of the reaction when a small quantity, taken for trial from the clear liquor and put in a testing vessel, does not sensibly become troubled by the gelatine or tannin. Miintz and Rampercher^ filter the tanning liquor under pres- sure through a moistened skin from which the hair has been removed, and weighed while dry. By drying the skin later on at 212° F. they learn from the increase in weight the amount of tannic acid contained in the solution. They have constructed a small apparatus shown in Fig. 6. The lower part serves as a support for a piece of prepared skin. When the apparatus is to be used, the upper part, which is provided with a long arm, is connected with the lower by means of clamp screws- The space between the piece of skin and the helmet of vulcanized rubber is sufficiently large to hold 100 c,c. of tanning liquor, the specific gravity of which has been previously determined by the areometer. The brass cover on the side is then screwed down tightly, and the liquor forced down upon the skin, which absorbs all the tannic acid, by the pressure of the perpendicular screw upon the rubber helmet. The water and other substances of the solu- Fis. 6. 1 Comptes rendus, Ixxix. 380, and Ding. Polyt. Journ., ccxiv. 74. EXAMINATION OF VEGETABLE TANNING MATERIALS. 141 tion run off into a glass vessel, and are tested as to their specific gravity with the areometer, the percentage of tannic acid being shown by the difference between the two gravities. This apparatus is said to answer the purpose very well. It recommends itself at any rate by its simplicity and the quick- ness with which a determination of the tannic acid can be exe- cuted. Fleck and Wolf's^ method is based upon the precipitation of the tannin with a solution of cupric acetate, 100 parts of cupric oxide= 130.4 of tannic acid (WolP). Persoz's method. — Risle Bennat^ describes a process by Persoz, according to which the tannic acid is precipitated with stannous chloride solution, and its percentage estimated by measuring and comparing the precipitate, several measuring cylinders graduated into y^ of parts being used for the purpose, A solution of tannic acid of a determined percentage is prepared by dissolving 10 grms. of dry pure gallotannic acid in water and diluting the solution to one litre. The stannous chloride solution is prepared by dissolving 8 grms, of stannous chloride and 2 grms. of sal ammoniac in 1000 c.c. of water. To deter- mine the tannic acid, for instance in barks, 10 grms. of the latter are boiled in half a litre of water for half an hour. The decoction is filtered and the residue washed out with sufficient hot water to make the total quantity of the fluid equal to 1 litre. 100 c.c. of this solution are brought into the measuring cylin- der by means of a pipette and slowly compounded with 100 c.c, of the stannous chloride solution. After settling for ten or twelve hours the amount of precipitate is read off" from the scale of the cylinder. A comparative experiment being made at the same time with the normal solution mentioned above, by adding to 100 ' Wagner, Jaliresbericlite, 1861, 625, 2 According to Pavesi aud Rotondi 145 parts of tannic acid (Berichte der deutsch, chera. Ges, 1874, 590), Schiff explains these differences by the use of tannic acids of varying purity. By using pure tannic acid (t. e., digallic acid Cj^HigOg) 100 parts of cupric oxide would, according to »ScA;/7', correspond to 136 parts of tannic acid. 3 Zeitschr. f. analyt. Chemie, 1863, 287. 142 THE MANUFACTUKE OF LEATHEE. c.c. of it, a like quantity of stannous chloride solution, the per- centage of tannic acid can be readily determined from the relative volumes of the two precipitates. If, for instance, 50 c.c. of precipitate are obtained with the normal tannic acid, and only 7 c.c. with tiie test fluid, the percentage of this substance, 7 X 100 if 10 sfrms. were contained in 1 litre, would be = 14 per , ' 50 ^ cent. Grauhe advises especial care that the difference in the volumes of the precipitates is not too great. The extracts of the tanning materials should, if necessary, be concentrated, or the test acid diluted. The fluids must, of course, stand at an equal height in the cylinders. To enable persons not possessing graduated cylinders to avail themselves of this method, Risle Bennat proposes the determi- nation of the precipitate, previously washed out and dried hy gravimetric analysis. By heating the precipitate with ammo- nium nitrate pure stannic oxide is obtained. The percentage of tannic acid is found by subtracting the amount of stannous oxide calculated from the stannic oxide (100 SnOg correspond to 89.33 SnO) from the previously found weight of the pre- cipitate of stannous tannate. This method may be recommended for technical purposes, especially in cases where gallic aciel occurs with tannic acid. Wildenstein^s^ colorimetric method is based upon the coloring which strips of paper saturated with ferric citrate assume when dipped in a fluid containing tannic acid. Wildenstein claims that the percentage of tannic acid can be estimated by com- paring the depth of the coloring with an empirically obtained color-scale. Fehliny's method^ modified hy G. Muller? — This is based upon the precipitation of the tannic acid with titrated aluminated solution of glue. To prepare the glue solution 10 grms. of white bone glue are soaked in distilled water, and, after swelling, dissolved by moderate heating, 25 grms. of alum are then added ' Zeitschr. fur aiialyt. Chemie, 1863, 137. 2 Liebig and Kopp Jahresberichte, 1853, 683. 3 Ding. Polyt. Journ., I. 51 to 69. EXAMIXATIOX OF VEGETABLE TANNING MATERIALS. 143 and the whole diluted to 1 litre. The titre of the glue solution undergoing quick alteration, it must every time be re-established to the normal tannin solution. 0.2 grm. of dry gallotannic acid requires for complete precipitation 22.7 c.c, 1 c.c. of this glue solution corresponding consequently to 0.0088 grm. of tannic acid. 5 grms. of the bark to be tested are boiled three or four times in 50-60 c.c. The resulting solution is filtered and diluted with water to 500 c.c. To 50 or 100 c.c. of this solution, glue solution is added from a burette, with constant stirring, until all the tannic acid is precipitated. The stirring is done, according to Hallwachs, with a glass tube open on both ends, with which, in the same manner as with a pipette, a sample is taken from the supernatant fluid and placed upon a small filter. To the filtered sample a drop of glue solution is added by allowing it to remain suspended in the upper part of the tube, which is held obliquely, and then rinsing it carefully with distilled water into the sample fluid. If the latter remains clear, the reaction is finished, but if it becomes turbid, the filtered sample and the filter are returned to the test fluid and more glue solution added to the latter from a burette. This is carefully continued until a small sample gives no turbidity with tannic acid nor with glue solution. Should turbidity be caused by tannic acid, an excess of glue solution has been added, neces- sitating a repetition of the test. Satisfactory results are, according to Gauhe* and Hallwachs,^ obtained by this method, but, on account of the tedious manner of execution, it is not suitable for easily making many determin- ations of tannic acid. In place of white glue, Lippowitz^ uses isinglass for precipitat- ing the tannic acid. According to his statement 1 grm. of insinglass dried over sulphuric acid precipitates exactly 0.75 grm. of tannic acid, a solution of 1.333 grms. of isinglass sufficing consequently for the precipitation of 1 grm. of tannic acid. Carpene-Barhieri's method is based upon the precipitation of the tannic acid with an ammoniacal solution of zinc acetate. ' Zeitschr. f. analyt. Chemie. 2 Gewerbeblatt f. d. Grosshergogtli, Hessen, 1845, 51 w. 52. ^ Wagner .Jahresberichte, 1861, 624. 144: THE MANUFACTUEE OF LEATHER. One-tliird of the precipitated fluid is evaporated by boiling. The precipitate obtained is filtered, washed with hot water, and dissolved in dilute sulphuric acid. The insoluble substances are separated from the solution by filtering, and the filtrate tritrated with solution of potassium manganate. Kathreimer,-^ on subjecting this method to a closer examination, found the results obtained by it to be inaccurate. Gerland's me^/iorZ^ is based upon the precipitation of the tannic acid with tritrated solution of tartar emetic. Hallwachs^ and Koller,^ who have already had control of this method, are of the opinion that an accurate determination of the tannic acid can in no case be attained with Gerland's method. Jeans' s^ method of determination is based upon the action of tannic acid and gallic acid to fix, in the presence of sodium carbonate, a propor- tional quantity of iodine. The extractive substances of oak bark, it is claimed, exert no disturbing influence whatever. If, be- sides tannic acid, gallic acid is present, two tritrations are required, one direct and the other indirect, after the tannic acid has been removed by means of animal skin or gelatine. Kathreiner, who tested this method, con- siders it as very tedious and requiring too much time. A further evil is the quick alteration of the titre of the iodine solution. K. Ilammer^s method^ is based upon prin- ciples coming closest to the true conditions in tanning, and furnishes, if in any way accurately executed, good corresponding results. Hammer determines the specific gravity of the fluid containing the tannic acid by means of a picnometer (Fig. 7) or, Fi>. 7. Ill PiciK'iufter. 1 Dingl. Polyt. Journal, ccxxvii. 489. 2 Chem, News, 1863, 54, Zeitschr. f. analyt. Chemie, 1863, 419. 3 Dingl. Polyt. Journ., clxxx. 50. * Neiies Jalirbncli fiir Pharmacia, xxv. 206. 6 Bei-icht d. deutscli. Chem. Gesellsch. 1877, 730. " Journal f. prakt. Chemie, Ixxxi. 156. EXAMINATIOISr OF VEGETABLE TANNING- MATERIALS. 145 an areometer, wliich indicates the specific gravity to 1.0409. Next he precipitates the tannic acid from the fluid with especi- ally prepared animal skin, and determines the specific gravity after precipitation. The difference in the two specific gravities is in proportion to the percentage of tannic acid. To facilitate the calculation of the latter, the following table is used from which the relation between the specific gravity and the percentage of tannic acid of varying concentration can be seen. Per cent, of Specific gravity Per cent, of Specific gravity Per cent, of Specific gravity tannic acid. at 59° F. tannic acid. at 59° F. tannic acid. at 09° F. 0.0 1.0000 1.7 1.0068 3.4 1.0139 0.1 1.0004 1.8 1.0072 3.5 1.0140 0.2 1.0008 1.9 1.0076 3.6 1.0144 0.3 1.0012 2.0 1.0080 3.7 1.0148 . 0.4 1.0016 2.1 1.00S4 3.8 1.0152 0.5 1.0020 2.2 1.0088 3.9 1.0156 0.6 1.0024 2.3 1.0092 4.0 1.0160 0.7 1.0028 2.4 1.0096 4.1 1.0164 . 0.8 1.0032 2.5 1.0100 4.2 1.0168 0.9 1.0036 2.6 1.0104 4.3 1.0172 1.0 1.0040 2.7 1.0108 4.4 1.0176 1.1 1.0044 2.8 1.0112 4.5 1,0] 80 1.2 1.0048 2.9 1.0116 4.6 1.0186 1.3 1.0052 3.0 1.0120 4.7 1.0190 1.4 1.0056 3.1 1.0124 4.8 1.0194 1.5 1.0060 3.2 1.0128 4.9 1.0198 1.6 1.0064 3.3 1.0132 5.0 1.0202 Franz Schulze^ has modified this method by adding 10 grms. of white glue to a concentrated solution of sal ammoniac and diluting to 1 litre by a further addition of pure solution of sal ammoniac. 10 grms. of gallotannic acid are, in the same man- ner, dissolved in concentrated sal ammoniac and the solution diluted to 1 litre. The addition of sal ammoniac is claimed to facilitate the settling of the precipitate. The bark extract is saturated with sal ammoniac, and, after compounding with a teaspoonful of white sand or glass powder, the glue solution is gradually added, with constant stirring, until the formation of the precipitate is more and more plainly observed. The nearer the point of saturation is approached, the quicker, by allowing ' Dingl. Polyt. Jour, clxxxii. 155, bis 158. 10 146 THE MANUFACTURE OF LEATHER. the mixture to stand quietly, is tlie sediment shown, until the precipitation takes place inside of half a minute, and the fluid appears clear. Salzer,^ who tested Schulze's method, remarks that with some experience it is easily and quickl}?- executed, but as the precipi- tate, though separating itself readily, floats on top if the fluid contains too much sal ammoniac, he recommends the use of a less concentrated solution of sal ammoniac. In executing Hammer's method, it must first of all be ob- served, that the tannic acid to be determined, is obtained frbm the substance in as concentrated a solution as possible, because if the difference in the specific gravities is greater before and after precipitation, the error of observation is smaller. 20-30 grms. of the substance are boiled with 50-60 c.c. of water for 30 to 40 minutes, the water lost by evaporation being con- stantly replenished, and then completely exhausted with five to six times the quantity of hot water, and filtered. The clear fil- trate is weighed and reduced to a round number of 350 to 400 grms. After cooling, the specific gravity of the fluid is deter- mined either with the picnometer or the areometer, all precau- tions required for such operations being of course used. Sufficient test fluid to fill the picnometer or a cylinder in which the areometer is to be immersed is weighed off in a matrass which may be either dry or previously rinsed out with fluid containing tannic acid, and then four times the quantity of tannic acid, found by a preliminary determination from the specific gravity, of unhaired animal skin is added. The latter is best prepared in the following manner : A piece of skin pre- pared for tanning by freeing it from hair, lime, etc., is placed in running water for several hours, then stretched upon a clean board, and after drying converted into powder with a coarse rasp. The powder can be kept in a hermetically closed flask for some time. Before use it is soaked in cold water for a short while, then thoroughly pressed out in a linen cloth between the hands to prevent the adhering water from changing the specific ^ Zeitschr. f. analyt. Chemie, 1868, 70. EXAMINATION OF VEGETABLE TANNING MATERIALS. 147 gravity of tlie fluid containing tannic acid. After adding the skin powder to the fluid, the matrass is closed and shaken for some time. An approximate weighing of the fluid and skin powder only is required. After the precipitate has settled, the supernatant fluid is poured off" through a fine cloth either directly into the measuring cylinder or into the picnometer, and the specific gravity determined. Special areometers have been constructed for practical use, which show directly the quantity of tannic acid by the differ- ence in the specific gravity. The graduation of this areometer is according to degrees or per cents. Suppose a solution of tan- ning material shows before precipitation 5.5 per cent, and after precipitation 1.5 per cent., the amount of tannin would be 4 per cent. But if the percentage of tannin is to be calculated from the specific gravity found by means of the areometer or picnometer, the following example may serve for an illustration : — 30 grms. of bark have been exhausted with 850 grms. of water. The specific gravity which was 1.01 at 59° F., indicated 2.5 per cent, of tannin. After precipitation with skin powder and filtering, the specific gravity was 1.006=1.5 per cent, of tannin. The difference between the two determinations beiuo; 1 per cent., the fluid is a 1 per cent, one, and the 350 grms. con- sumed contained 3.5 grms. of tannin. As the latter were con- tained in 30 grms. of bark, the calculation (30 : 3.5 : : 100 : x) gives 11.66 per cent, as the amount of tannin contained in the bark. Mittenzioei^ and TerreiVs^ method is based upon the well- known property of tannic acid and allied substances to absorb, when in alkaline solution, oxygen. The quantity of tannic acid is calculated from the amount of oxygen absorbed in the pres- ence of potash, and they use for the determination a graduated testing tube of special form and arrangement. 1 Journ. f. prakt. Chemie, Ixi. 61. 2 Coinptes rendus, Ixxviii. 790. 14:8 THE MANUFACTUKE. OF LEATHEE. Fi?. 8. This method, which, according to the statements of the authors, is also adapted to the determination of ferrous oxide, manganesous oxide, and indigo, is executed in the following manner : — The air in a flask having a capacity of 1 litre (Fig. 8) communicates with the atmos- phere by means of the bent glass tubes h and c, the upper part of the latter narrowing to 1.5 to 1 millimeter. The connection of Jhe two glass tubes is effected by means of a moderately long rubber tube provided with a compression stopcock. The tubes pass into the flask through a hole in the cork, or, better through a rubber stopper. Before commencing the operation, the air in the flask and all fluids to be used should have the same temperature as the working room, one of 59° F. being the best. The flask A is then filled with 200 c.c. of 8 to 5 per cent, solution of potash or soda lye to which is added 1 grm. of tannic acid wrapped lightly in paper. After placing the cork firmly in the flask, the compression stopcock is opened for a moment in order to place the inclosed air under the pressure of the atmosphere, the absorption of oxygen being facilitated by frequent shaking. An increase in the temperature of the flask Fiff. 9. is prevented by wrapping a cloth around the hand. After shaking the flask several times, water is drawn in through, the aperture c?, of the pipe c, from a weighed beaker glass />, by opening the compression stopcock / (Fig. 9). examhstatiojst of vegetable tanning materials. 149 The experiment is finished when, after frequent shaking, no more absorption takes place. The grammes of water entering the flask from the beaker glass which are found from the difference in the weight of the beaker glass before and after the operation, indicate the number of cubic centimeters of oxygen absorbed, which can be readily reduced to a temperature of 32° F. and 29.922 inches pressure by the well-known formula. 1 grm. of tannic acid and 1 grm. of gallic acid absorb, according to Mit- tenzwei, 175 c.c. of oxygen, and, according to Terrell, 200 c.c. The great difference in these statements, which would make this method, otherwise simple and practical, appear inaccurate, is very likely due to the different degrees of concentration of the alkaline solutions used, as, according to Mittenzwei, 1 grm. of tannic acid in 200 c.c. of potash lye of 35 per cent. KOH, absorbed, after continued and rigorous shaking, not more than 22 c.c. of oxygen. This interesting fact deserves closer inves- tigation. We will further mention that Terrell, in modifying Mittenz- wei's method, and using a concentrated 30 per cent, potash lye, in place of dilute solution, found that, by extending the dura- tion of the action to twenty-four hours, a larger quantity of oxygen was absorbed. The calculation of the result is very simple. Suppose 140 grms. of water have been drawn from the beaker glass into the flask, they would correspond to 140 c.c. of oxygen. If a more accurate result is desired, this volume is reduced to 32° F., and 29.922 inches pressure with a simultaneous consideration of the tension of steam. As, according to Mittenzwei, 175 c.c. of oxygen correspond to 1 grm. of tannic acid, the amount of tannic acid found by calculation (175 : 140 : : 1 : x) will be 0.8 grm. In the presence of tannic and gallic acid, Mittenzwei pro- poses the precipitation of the first by depilated skin, to place the filtrate in the absorbing flask, to add 3 to 4 per cent, of potassium or sodium hydrate, and determine the gallic acid in the above manner. If the total quantity by absorption of oxy- gen in the flask has been previously determined, the percentage 150 THE MANUFACTURE OF LEATHER. of tannic acid is found from the difference in tlie two determina- tions. It is recommended to make a preliminary experiment in or- der "to approximately calculate from it the quantity of substance fixed by 175 c.c. of oxygen. It is an open question whether the tannins derived from various substances absorb, under equal conditions, a like quantity of oxygen. As the property of absorbing oxygen in alkaline solution is possessed by tannic acid in common with a series of other Qr- ganic substances, it still remains to be determined, whether such substances as pectine, etc., which generally accompany tan- nic acid, would not also become more highly oxidized, and the found percentage of tannic acid, in consequence of this, be too high. Hallwachs, who compared Mittenzwei's with various other methods, found at least that the result obtained by it was more than 1 per cent, too high. Terrell, who used the same process, found, as previously mentioned, that 0.1 grm. of tannic acid absorbs 22 c.c. of oxy- gen. The absorption is complete only after twenty-four hours. Terrell executes the experiment in a tube divided into cubic centimeters, and provided on one end with a glass faucet and hermetically closed on the other end with a glass stopper 0.1-0.2 grm. of the substance to be examined, and 20 c.c. of a 30 per cent, potash lye are placed in a tube, and allowed to react for twenty-four hours, with frequent shaking. The tube is then opened in a beaker glass filled with water, and the absorption taking place observed, the percentage of tannic acid being cal- culated from the latter. Although this method is rendered inconvenient by the neces- sity of taking into consideration the conditions of temperature and pressure of air, it deserves to be thoroughly tested to make it available in the future. Grassi's Metliod. — Grassi^ proposes the precipitation of the tannic acid with barium hydrate as barium tannate, to separate from the latter the barium by means of sulphuric acid, and to ' Bertclit der deutscli. cliem. Gesellsch. 1875, 254. EXAMINATION OF VEGETABLE TANNING MATERIALS. 151 determine the tannic acid by titration with potassium perman- ganate. This method requires to be further perfected. Wagner^s Method.— Wagner^ first divided, as previously mentioned, the various tannins into pathological and physical. The latter only being of value to the tanner, he endeavored to determine them by a simple method. As in his opinion the pathological tannic acid or tannin obtained from gall-nuts, which was formerly employed for making the titre, could not be used as a basis for the determination of the physiological tannic acid, he endeavored first to determine the atomic weight of the latter. He chose for this purpose tannic acid obtained by boiling the inside layer of oak bark. He precipitated the bark extract with sulphate of cinchonin, converted the resulting pre- cipitate into tannate of lead by boiling with acetate of lead, and decomposed the tannate of lead into tannic acid and lead mono- sulphide b}^ means of sulphuretted hydrogen. The tannic acid contained in the solution was once more precipitated with cincho- nin solution, the precipitate washed and dried, and, after weigh- ing, suspended in water, and compounded with potassium per- manganate, added drop by drop, until the tannic acid was entirely destroyed. To this fluid was then added sulphuric acid, in order to convert the cinchonin contained in it, into sulphate of cinchonin. The latter was dried at 248° F., and weighed as neutral sulphate of cinchonin. By assuming the atomic weight of cinchonin as 308, Wagner found, that of quercitannic acid as 813. For the precipitation of 1 grm. of quercitannic acid, 0.3715 grm. of cinchonin, equal to 0.4523 grm. of sulphate of cinchonin, is required. Besides cinchonin, which is chosen as being considerably cheaper, quinine, morphine, strychnine, etc., may be used for the purpose. Sulphate of cinchonin purified by recrystallization is of a constant composition. An admix- ture of cinchonidine, both bases being isomeric, is not inju- rious. To execute the determination, Wagner dissolves 4.523 grms. of sulphate of cinchonin in 1 litre of water. As an indicator he uses acetate of roseaniline, of which he adds 0.08-0.1 grm. to the ' Dingl. Polyt, Jour., clsxxiii, 227. 152 THE MANUFACTURE OF LEATHER. above fluid. In connection with the cinchonin solution, the aniline red indicates the end of the precipitation of tannic acid by coloring the fluid beneath the precipitate red. 0.061 cubic inch of the mentioned cinchonin solution is equal to 0.1 grm. of tannic acid. It is of advantage to add before the experiment 0.5 grm. of sulphuric acid, as this accelerates the settling, and makes the precipitate less soluble. Wagner used for his deter- minations 10 grms. of the substance containing tannic acid, and after boiling with water for some time and filtering, diluted the obtained solution to 500 c.c. To 50 c.c. of this solution, which were equal to 1 grm. of the substance used, he added cinchonin solution from a burette, until the fluid above the flaky precipitate ceased to be turbid, and assumed a slightly reddish color. Although with some experience a conclusion as to the com- pleteness of the precipitation can be drawn from the condition of the precipitate, and the facility with which it settles, it is always best to make controlling experiments. The precipitates consisting of tannate of cinchonin are collected, and, after a con- siderable supply of them has been obtained, boiled with acetate of lead and water, until the reddish coloring of the precipitate is changed into a brown, and all the cinchonin has passed into solution. The excess of lead is separated from the hot filtered solution by means of sulphuric acid, and neutral sulphate of cinchonin obtained from the fluid freed of lead sulphate by evaporation with an addition of sulphuric acid. Blichner,^ who subjected Wagner's method to a thorough test, remarks that in order to observe* the approach of the final reaction by the quick or slow settling of the precipitate, the manner of shaking the bottle exerts a material influence. He recommends it to be done with a horizontal, circular motion, which will effect the settling of the precipitate in five to eight minutes, so that the supernatant fluid will be perfectly clear, and can be readily judged as regards coloring. Many experi- ments have convinced Biichner of the futility of adding less than 0.2-0.3 c.c. of cinchonin solution, since 0.1 c.c. of it ex- ^ Dingl. Polyt. Jour, clxxxiv. 334. EXAMINATIOX OF VEGETABLE TANNIJSTG MATERIALS, 153 erts no perceptible effect upon the final reaction. In case the precipitate settles with difficulty, which is frequently the case with barks containing a high percentage of tannin, several sam- ples are taken from one and the same decoction. To one of the samples 2 c,c, are added and allowed to settle quietly, to another one 4 c.c, to a third 6 cc, to a fourth 8 c.c, and ob- served after some time to see which sample is precipitated. If the third sample, which contained only 6 c.c, is not ready, while in the fourth, which contained 8 cc, the final reaction has been exceeded, only 7 c.c, are added to a fifth sample. The determination can be quickly and accurately executed in this manner. As regards Biichner's experiments in order to study the behavior of sulphate of cinchonin and other sub- stances, used for the determination of tannic acid towards pec- tine substances, which generally accompany tannic acid, we refer the reader to the original essay, but will remark here, that according to these experiments, sulphate of cinchonin, solutions of glue, and alum produced by themselves no precipitation of pectine substances, while the results obtained according to the Persoz and Fehling-Mliller method, were more or less too high. Neubauer, who in his treatise, " Die Schalung der Eichen- rinden"^ (Wiesbaden, W. Kreidel), criticizes Wagner's method of determining the atomic weight of quercitannic acid, shows the incorrectness of the atomic weight found by Wagner, and comes to the conclusion that Wagner's method is not available in its present form, as the results obtained by it are too low. Clark has modified Wagner's method as follows : To a so- lution of tanning material is added an excess of solution of sulphate of cinchonin (•i.523 grms.) of the salt, 0.5 grm. of sulphuric acid, and 1 litre of water. The solution is filtered, washed out, and the residue determined with mercuric iodide (13.546 grms.) of mercuric chloride, and 49.8 grms. of potassium iodide to 1 litre of water. The amount of tannic acid is calcu- lated from the difference bv subtractins; from the cinchonin solu- tion first used the quantity added in excess which is found by . ' " Stripping of Oak Barks." 154 THE MANUFACTUEE OF LEATHER, retitration with solution of mercuric iodide. 1 c.c. of cinchonin solution precipitates 0.01 grm. of tannic acid, and 1 c.c. of so- lution of mercuric iodide is required to precipitate the cincho- nin from 2.74 c.c. of cinchonin solution. This process cannot be recommended on account of the final reaction, as in all pre- cipitating, analyses being very uncertain. LoewenthaVs Method modified hy Neuhauer} — This is the most important of all the methods for determining tannic acid, as, when correctly executed, it furnishes results which always agre§, and besides the process is easy and sure. It has been known for a long time that tannic acid in aqueous solution is readily oxi- dized by substances yielding up oxygen, as for instance, by solution of calcium chloride, or alkaline solution of potassium ferridcyanide, and especially by potassium permanganate. A dilute solution of the latter was first used for precipitating tannic acid by Monier,^ who added it until the fluid assumed a red color by an excess of it. LoewenthaP showed that the tannic acid in the presence of indigo solution is so completely destroyed, that with the dis- appearance of the blue color, the last trace of the tannic acid present is also decomposed, this being a sure and easy guide for the determination of the final point of reaction. For the execution of the process are required : — 1. An indigo solution prepared by dissolving, with frequent shaking, 30 grms. of pure indigo carmine paste in 1 litre of water. The solution is filtered into bottles having a capacit}^ of about 8| ozs., which, after careful closing, are heated in a water-bath to 158° F. for one hour. By heating to this tem- perature the formation of mycelium in the indigo solution is prevented, making the latter available for a long time. Only pure indigo carmine, especially free from indigo red, should be used for this solution, as otherwise the final point of reaction is difficult to determine on account of the reddish or brown shade appearing towards the close. If, on the other hand, the solu- ' Zeitschr. f. aualyt. Cliemie, 1871, 1. 2 Comptes rendus, xlvi. 44. 3 Jouru. f. prakt. Chemie, Ixxxi. 150. EXAMINATION OF VEGETABLE TANNING MATERIALS. 155 tion of indigo carmine is pure, the greenish color appearing finally passes suddenly over into a pure golden yellow. 2. A tannin solution. Chemically pure tannin is dried at 212° F. for a few hours, and 2 grms. of it dissolved in 1 litre of water. As the tannic acid should be as pure as possible in order to obtain accurate results, it is first tested by Hammer's method. 3 grras. of the tannic acid dried at 212° F. are for this purpose dissolved in 250 ce. of water, and the specific gravity determined with a picnometer. The tannic acid con- tained in 150 c.c. of this solution is precipitated with some green depilated skin, the specific gravity is again determined, and the tannic acid calculated as previously mentioned. To make the tannin solution, which is very much inclined to mould, durable, it is filled into small bottles having a capacity ' of about J oz. which are heated in a water bath to 158° F., and preserved lying on their sides. 3. A solution of potassium manganate. This should be of such concentration that 12-14 c.c. of it will decolorize 20 c.c. of the indigo solution, and 9-10 c.c. effect the destruction of the tannic acid in 10 c.c. of the solution containing 0.2 per cent, of tannic acid. 1 c.c. of potassium manganate solution oxidizes consequently 0.0020-0.0022 grm. of tannic acid. Such solu- tion is obtained by dissolving 10 grms. of pure dry crystallized potassium permanganate in 61 grms. of water. 4. A Y^j- normal solution of oxalic acid. In case sufficiently pure tannic acid cannot be obtained a jIq normal solution of oxalic acid prepared by dissolving 6.3 grms. of pure crystallized oxalic acid in 1000 c.c. of water, can be used for making the titre for the solution of potassium manganate. By comparative experiments, Neubauer found that 6.3 grms. of oxalic acid are equivalent to 4.157 grms. of tannic acid.^ To preserve the 1 About 100 c.c. of tannin solution = 0.02 grm. of tannic acid, were, after adding 20 c.c. of indigo solution, titrated with potassium manganate solution, four determinations requiring, on an average, 7.1 c.c. of potassium manganate solution, 1 c.c. of the latter being therefore equal to 0.002817 grm. of tannic acid. 10 c.c. of the normal solution of oxalic acid required 14.6 c.c. of the same solution of potassium manganate, 0.063 grm. of oxalic acid being, there- fore, equal to 0.04118 grm. of tannic acid. Three experiments gave, on an 156 THE MANUFACTURE OF LEATHER. oxalic acid from decomposition by fungus vegetation, it is heated in well-closed bottles to 158° F. for a few hours. 5. Pure animal charcoal. Finely pulverized animal char- coal is completely extracted with hydrochloric acid and then washed with water by decantation until the reaction of chlorine disappears from the wash water. The animal charcoal thus prepared is preserved in a closed bottle under water. 6. Pure dilute sulphuric acid. Making the litre. — The re- lations between indigo solution and potassium manganate solu-. tion are first determined by compounding 20 c.c. of indigo solution with 700 c.c. of water and 10 c.c. of dilute sulphuric acid, placing the beaker glass containing the fluid upon a white support — a white porcelain plate — and adding, with constant stirring, solution of potassium manganate until the solution, in the commencement deep blue, becomes first dark green, then pale green, next greenish-yellow, and finally golden-yellow. The addition of solution of potassium manganate must be made very carefully towards the end of the reaction, and the fluid thoroughly stirred after adding a few drops, as otherwise the final reaction may be easily exceeded. "With good indigo the transition from the greenish into the pure golden-yellow shade is quite sudden. After determining the consumption of solution of potassium manganate for 20 c.c. of indigo solution, the experiment is repeated with an addition of 10 c.c. of solu- tion of tannic acid, 20 c.c. of indigo solution, 700 c.c. of water, 10 c.c. of sulphuric acid, and 10 c.c. of solution of tannic acid. From the number of cubic centimeters of solution of potas- sium manganate consumed, is deducted the quantity required for 20 c.c. of indigo solution, and then is found the number which was required by the 10 c.c. of solution of tannic acid. The effective value of 1 c.c. of solution of potassium manganate can be readily calculated by simple division. To control and average, 0.063 grm. of oxalic acid = 0.04157 grm. of tannic acid. By taking, according to Streeker, the molecular weight according to the formula Cj-HooOj, as 618, 15 molecules of C2H2O4, are according to the above determinations = 2 molecules of tannic acid. 63 grms. of oxalic acid are equal to 41.20 grms. of tannic acid, while the practical expei'iment mentioned above gave 41.57 grms. of tannic acid. EXAMINATION OF VEGETABLE TANNING MATEEIALS. 157 affirm the result, the experiment is twice repeated. Care must be had that the indigo solution is so concentrated that 20 c.c. of it require at least as much solution of potassium manganate as 10 c.c. of solution of tannic acid, or, what is surer, one-half more than the latter. The titre of the solution of potassium manganate must be frequently controlled. Where gallic acid appears in connection with tannic acid, Loewenthal's method as modified by Neubauer cannot be used. LoewenthaP has, therefore, altered his method in the following manner : — He makes two titrations, the first with the "original" solu- tion of the tanning material and the second with " the fluid freed from tannic acid by precipitation with glue or skin pow- der." The difference gives the quantity of potassium manga- nate consumed for the tannic acid. The glue solution is, according to Loewenthal, prepared by soaking 25 grms. of the finest Cologne glue in water over night, liquefying it the next day in a water-bath, saturating it com- pletely with pure common salt and diluting with saturated solu- tion of common salt to 1 litre. Kathreiner,^ who subjected this method to a thorough test, gives the following description of a suitable manner of execut- ing it: — ' The solution of potassium manganate used for titration is prepared by dissolving 1.333 grm. of crystallized potassium per- manganate in 1 litre of water. The strength of the indigo solu- tion used by Kathreiner and Loewenthal, is considered by them as exerting no influence upon the result. The concentration of the solution used by Kathreiner was such that 20 c.c. of it re- quired for oxidization an amount equal to 9-10 c.c. of potas- sium manganate. The only thing of importance is that the quantity of indigo used in titration requires at least 1.5 times the quantity of potassium manganate of that which is necessary for the oxidation of the oxidizable substances to be determined. The quantity of indigo solution to be added to the extract of 1 Zeitschr. f. analyt. Chemie, 1877, 33, u. 201. 2 Dingl. Polyt. Journ., ccxxviii. 54. 158 THE MANUFACTURE OP LEATHER. tanning material to be tested, is determined by a preliminary experiment. It is advisable not to use too mncli solution of tanning material, as this would require the addition of such a large quantity of indigo as to make the coloring too dark to allow the final reaction to be judged with sufficient accuracy. For acidulating the titrating fluid, Kathreiner uses dilute sul- phuric acid (1 : 5) of 1,18 specific gravity. The original solution is to be filtered and the filtrate must in all cases be diluted to 2.113 pints. The duration of titration is, for the above conditions, about four minutes for the original solu- tion, and about six minutes for the filtrate precipitated with glue.^ The determination of the titre is effected, as in ISTeubauer's method, by a -^-^ normal solution of oxalic acid. Kathreiner executed the titration,^ on account of the final reaction being ' Too high results are obtained by a too quick titration of the filtrate still containing glue. 2 The process of determining the tannic acid in tanning materials, for in- stance in sumach, was as follows : — Experiment a. 1. 10 c.c. of sumach } require for decolorization 13.9 c.c. of solution of potassium 20 c.c. of indigo 5 manganate. 2. 10 c.c. of sumach } require for decolorization 14.0 c.c. of solution of potassium 20 c.c. of indigo ' manganate. 20 c.c. of sumach and 40 c. c. of indigo re- } 27.9 c.c. of solution of potassium quire therefore, J manganate. From this is to be deducted for 40 c.c. of > 20.5 c.c. of solution of potassium indigo, J manganate Remainder, = 7.4 c.c. " " " 20 c. c. of sumach solution require therefore, 7.4 c.c. " " " Experiment b. 100 c.c. of sumach solution are compounded in a beaker glass with 100 c.c. of glue solution and stirred, and to tliis are added 50 c.c. of water, containing 2.5 grms. of sulphuric acid of 1.80 specific gravity. 250 c.c. cubic centimeters. This mixture remains standing covered over night, and is then filtered through a dry filter. 50 c.c. of this filtrate titrated ^ with 1 litre of water and V 12.8 c.c. of solution of potassium manganate. 20 c. c. of indigo, required, ' 50 c.c. of the filtrate, and 20 ^ c.c. of indigo solution, and > 12.9 c.c. 1 litre of water consumed, ) EXAMINATION OF VEGETABLE TANNING MATERIALS. 159 easier recognized, in a white porcelain saucer instead of in a beaker glass. Kathreiner says :^ " It would be desirable in titrating the 'filtrate' with the potassium manganate consumed for indigo, to be able also to deduct that consumed for the oxidizable sub- stances of the glue. This may be approximately attained by comparative experiments with skin powder. But in case the oxidizable substance of the glue is not precipitated in an equal proportion to the precipitated quantity of glue, only average values are, of course, again obtained, since a like quantity of glue is not always precipitated. The case is different, if the oxidizable substance of the glue is either not precipitated at all, or entirely. Until this question is definitely settled, I propose to bring half the ' glue error' into calculation. Besides the glue error becomes less by replacing the glue solution partly by saturated solution of common salt." In conclusion Kathreiner recommends the general introduc- tion of Loewenthal's improved method of determining tannic acid. Examination of Oak Barh. — 1. Preparation of bark extract. A microscopical examination of oak bark shows that the tannic acid is by no means equally distributed in all parts. By placing According to this 100 c.c. of the ^ filtrate, and 40 c.c. of indi- r 25.7 c. c. of solution of potassium manganate. go solution require Deduction for 40 c.c. of indigo solution, Remain for the 40 c.c. of the original sumach decoction, For the oxidizable substance (not tannic acid) a 40 c.c. of sumach decoction require therefore, Deduct for oxidizable substance Remainder, = 9.6 c.c. " " " Of the total quantity of tannic acid found by titration with solution of potas- sium manganate 64.86 c.c. are precipitable with glue, and 35.14 c.c. (oxidizable substance) 7iot precipitable with glue. ' Dingl. Polyt. Jour., ccxxviii. 62. 20.5 c.c. 5.2 c.c. 160 THE MANUFACTUEE OF LEATHER. a few cross cuts of young and old oak bark in glycerine, and adding a very small quantity of ferric chloride, the portions con- taining tannic acid can be distinctly distinguished with the miscroscope by the appearance of a beautiful blue or black coloring. The cells forming in young bark a ring between the middle and inner bark contain, according to Neubauer, no tannic acid whatever. It occurs scattered in the middle bark, in the last layer and rind. To obtain a correct average sample the ground bark should be thoroughly mixed, special attention being paid to the thorough mixing of powder and fibres, since the first, according to Neubauer, is richer in tannin than the latter. To obtain a correct sample, T. Kathreiner^ proposes the following method : Spread the samples taken from the different portions upon a smooth, clean support, so that the first sample occupies a surface of 15 square inches and lying 0.4-0.6 inch deep, and then add the second, third, and succeeding samples until the pile is from 4 to 6 inches high. Now take out in 8 to 10 places samples of 15 square inches, and lay them in the order as taken upon each other ; but spreading them over one square foot of surface. The three or four samples of about 15 square inches each, which are to be tested, may be again laid one above the other before delivering them to the analyst. This method, of which the above is an example, must of course be changed according to circumstances as regards the extent of surface to be covered. Samples of nnground valonia are sometimes taken by breaking pieces from the separate rinds with a pair of pincers. Kathreiner advises the taking also of the part of the cup upon which the acorn sits, as this consists largely of cells containing only traces of tannin. Neubauer pulverizes a sample of 1000 grms. in a steel mill. A portion sufficiently large for analysis is completely dried in a water-bath at 212° F., and, while hot, placed in a carefully dried matrass, and this hermetically closed. When cold, the quantity required for preparing the aqueous extract is weighed off" in portions of 20 grms. each. It is best to extract an equal ^ Gerberzeitung, xxiii. No. 12. EXAMINATION OF VEGETABLE TANNING MATERIALS. 161 quantity of bark by boiling for an equally longtime. 20 grms. are boiled witli 750 c.c. of water for three-quarters of an hour. When cold the decoction is put in a litre flask and the latter filled with water to the mark and thoroughly shaken. The fluid is then allowed to settle, or is filtered. For each experi- ment 10-20 CO., according to the greater or smaller percentage of tannin in the bark, are taken out with a pipette.^ 10-20 c.c. of this aqueous extract, 20 c.c. of indigo solution, 10 c.c. of dilute sulphuric acid, and 750 c.c. of water are placed in a large beaker glass standing upon a white support, and solu- tion of potassium manganate is added from a Gay-Lussac or Geisler burette until the blue color passes over into a beautiful golden yellow. The objection was raised to this method of determination that the bark extract is not a pure tannin solution, but contains, as previously mentioned, a series of other bodies, and that the tannic acid occurring in oak barks, which Wagner designated as physiological is not identical with the pathological, i. e., the tannin of gall-nuts, to which the results are referred. Regarding the last objection, it must be admitted that the results obtained do not give the absolute percentage of tannic acid in the oak bark. The figures obtained are only relative, but perfectly comparable with each other. The tanner and technologist do not, as a general rule, care to know the absolute percentage of tannic acid, but only wish to find out how much more tannic acid one bark contains as compared with another, and for this purpose the method in question furnishes very useful results. But, on the other hand, the first objection, that oak bark con- 1 Neubauer (Zeitsclir. f. analyt. Chemie, 1871, 32), shows that boiling even for three hours has no influence whatever upon the result, and that therefore Neubrand's assertion that tannic acid is decomposed by boiling in water, is incorrect. Neubauer confirms Lippowitz and Mittenzwei's opinion that a part of the tannic acid is more fixed and can only be extracted with difficulty or not at all by water alone. He found that a different result was obtained as regards the percentage of tannic acid in one and the same bark, according to whether it was extracted cold or warm. The percentage of tannic acid soluble with difficulty varies in the difterent barks. Barks extracted cold still contain some tannic acid which can be extracted by repeated boiling. 11 162 THE MANUFACTURE OF LEATHER. tains various organic substances which, by suffering destruction by the solution of potassium manganate, influence the results, cannot be denied. To these substances occurring in aqueous bark extracts belong among others, pecticacid, malic acid, fats, etc. Cech^ has already made experiments in regard to the behavior of dilute solutions of acetic, malic, tartaric, and citric acids, sugar, dextrin, gum, fat, caffeine, urea, etc., towards solution of potassium manganate. He found that these substances in dilute solutions are not oxidized, and only after some time when in a concentrated state. To avoid therefore any effect of the solution of potassium manganate upon the substances, it is only necessary, according to Cecil's proposal, to thoroughly dilute the bark extract. JSTeubauer, by repeated experiments, established the fact, that pectic acid exerts no influence whatever upon solution of po- tassium manganate. He found, in making these experiments, that pare animal charcoal possesses the property of withdrawing all the tannic acid from a fluid containing it in solution. Tak- ing this as a basis, Neubauer proposes the following modifica- tion of Loewenthal's method. The tannic acid contained in 10 to 20 c.c. of bark decoction is determined with solution of potassium manganate in the manner described above. Another portion of 10-20 c.c, is treated with pure animal charcoal until the filtrate, after an ad- dition of sodium acetate and ferric chloride, shows no reaction of tannic acid. The filtrate is compounded with 20 c.c. of indigo solution and 10 c.c. of dilute sulphuric acid, and the whole diluted with water to 700-800 c.c, and then titrated with po- tassium manganate. The number of cubic centimeters of po- tassium manganate is, after subtraction of the quantity required for the indigo, deducted from the cubic centimeters of potassium manganate found in the first titration, the quantity of pure tan- nic acid being calculated from the remainder. In the treatment with animal charcoal pectic acid and other substances suffering decomposition by potassium manganate remain in solution. The quantity of solution of potassium manganate required for ' Zeitrichr. f. analyt. Cliemie, vii. 134. EXAMINATION OF VEGETABLE TANNING- MATERIALS. 163 them is determined by itself and may be brought into the cal- culation. Substances not withdrawn by animal charcoal re- quired 0.20-0.25 c.c. of potassium manganate for 10 c.c. of bark extract. Too high results are obtained by Loewenthal's method from tanning materials containing, besides tannic acid, gallic acid which is also oxidized by solution of potassium man- ganate and withdrawn, like tannic acid, by animal charcoal. For such materials as, for instance sumach, valonia, dividivi, etc., it is best to use either Hammer's or Kisle Bennat's method. LoewenthaP himself has, as already mentioned, modified his method. In determining the tannic acid in barks he pro- ceeds as follows. He titrates first with solution of potassium permanganate in the presence of indigo solution, the quantity of solution of potassium permanganate consumed in this process, indicating the amount of tannic acid and other oxidizable sub- stances present. He precipitates then from a fresh measured portion of the bark extract all the tannic acid with glue, or as mentioned under flammer's method, with prepared skin powder, and filters after the precipitate has settled to the bottom. A measured quantity of the filtrate is then compounded with indigo solution and titrated with solution of potassium permanga- nate. The data for calculating the quantity of tannic acid are obtained by deducting the amount of solution of potassium permanganate consumed in the second titration from that in the first. This method gives, according to Proctor,^ good results and is easily executed. Comprehensive Comparison of the Results obtained hy the above described Methods. — We give here a tabular compilation by Hallwachs,^ who compared the different methods of determina- tion by analyzing the same bark according to various methods. The following figures show how great are the differences: — 1 Zeitschr. f. analyt. Chemie, 1877, 33. 2 Chem. News, 1877, No. 924, xxxvi. 3 DingL Polyt. Journal, clxxx. 164 THE MANUFACTURE OF' LEATHER, Percentage of Tannic Acid determined according to the Method of Bark. Fehlinar, MuUer. Loeweuthal. Hammer. Fleck. Mittenzwei. A. . . . 6.16 6.11 13.80 9.74 9.25 8.90 5.24 5.25 13.00 9.00 8.77 8.00 B . . . I . . . II . . . III . . . IV . . . 13.24 9.35 9.28 8.57 12.10 8.48 8.15 7.48 14.07 10.31 10.22 9.27 According to this table, the results obtained by Mittenzwei's method are 0.5 to 0.8 per cent, too high as compared with those bj Fehling-Muller's and Loewenthal's methods. The results obtained by Fleck's method are the lowest, being 0.5 to 0.7 per cent. less than those by Fehling-Mueller's and Loewenthal's, which nearly agree. Between these two are the results obtained b}^ Hammer's method, which are somewhat lower than those by Fehling-Miiller's and Loewenthal's. By assuming with Neubauer that, in the presence of pectine, the results obtained by Loewenthal's method are too high, it appears that results, wbich nearly agree, are obtained by Hammer's and Loewen- thal's modified methods. Note. — For portions of the matter contained in this chapter the sources which have not been specifically indicated, the author desires to acknowledge his in- debtedness to Bolley's Technologie, 35 (Bd. vi. 4), Heinzerliug, also to Diction- naire de Chimie, Pure et Appliquee, Wurtz, iii. 193 et seq. WATER. . 165 CHAPTEE IX. WATER. Section I. General Eemarks Concerning Water. Water occupies an important position in tanning, it being employed, on the one hand, for washing, cleansing, and pre- paring the raw hides, and on the other, as a solvent for all the tanning materials and as a diluent for all the coloring and dye- ing materials used. Empirics have frequently unfairly overestimated the impor- tance of water in tanning by declaring water containing more or less mineral constituents entirely unfit for the preparation of many varieties of leather. Although it cannot be denied that a higher or lower degree of hardness of the water is a factor deserving close considera- tion in the manufacture of leather, it must not be overestimated to such an extent as to lay the blame for obtaining a poor qual- ity of leather entirely upon the properties of the water. We will here briefly discuss the most important admixtures of water, and their influence in tanning. All naturally occurring water contains smaller or greater quantities of alkaline and earthy alkaline salts, and carbonic acid in solution. There is no entirely pure well or river water, i. e., free from all admixtures. By leaving out of consideration the small quantity of ammonium nitrite, organic substances, etc., held in solution by rain water, the latter might be considered chemically pure water. Water is distinguished as Itard and soft^ according to the quantity of earthy alkaline salts it contains, the amount of mineral substances varying from 1 milligrm. to 1 grra. per litre. The principal admixtures occurring in water are, as mentioned above, the alkalies, such as potassium, sodium, alka- 166 THE MANUFACTURE OF LEATHER. line earths, lime, and magnesia ; the oxides of a few heavy metals in combination with ordinary mineral acids, sulphuric, nitric, phosphoric, carbonic, and hydrochloric acids. The gases held in solution are chiefly carbonic acid and atmospheric air, sulphide of hydrogen occurring but seldom. The admixtures of spring and well water consist principally of the constituents of the layers of earth through which it per- colates. Those, for instance, contained in the waters flowing through the doloraitic stratification may be considered as pure solutions of the dolomitic rock, consisting as they do of calcium carbonate, magnesium carbonate, and silicic acid, the quantity of all other, constituents being so small as to make it almost impossible to determine them by quantitative analysis. The waters percolating through the basalt and the new red sand- stone contain principally calcium carbonate, magnesium car- bonate, silicic acid, considerable quantities of free carbonic acid and small quantities of common salt, calcium sulphate, and sodium carbonate. The total dry residue of waters coming from the lias formation varies between 268 and 516 milligrms., the principal constituents being in this case also calcium car- bonate, 200 to 400 milligrms. per litre, magnesium carbonate (varying from 30 to 90 milligrms. per litre), sodium carbonate, free carbonic acid, etc. Besides these natural constituents, spring and well water, but especially the latter when in large cities or in the neighborhood of dumping places for all kinds of offal, the soluble substances of which percolate through the soil, contain frequently in solu- tion organic products of decomposition of organized bodies such as bacteria, fungi, alkaline nitrates, especially ammonia, and alkaline salts. Though such water, for hygienic reasons, is generally unfit for drinking purposes, it may be put to techni- cal use. In determining the qualities of water for tanning purposes, two points, as mentioned, must be taken into consideration, viz., first, the behavior of the water when used as a solvent for the tanning materials, and second, whether it is adapted for pre- paring the hides for tanning. If the water is to be used for dissolving or extracting tanning materials containing tannic WATER. 167 acid, tlie earthy alkalies, lime and magnesia combinations, exert a decidedly injurious effect, as, by forming insoluble combina- tions with the taimic acid, they render a part of the tanning material useless. If the water is to be used for soaking, cleans- ing, and washing the hides, mineral admixtures may exert a favorable influence. In speaking of the chemical properties of the skin tissue and the coriin, we mentioned that some of the alkaline salts exert a dissolving influence upon the intercellular substance or coriin, the effect of small quantities of alkalies being an increased solution of coriin in acids. From this we may draw the conclusion that hard water promotes the soaking of dried hides, but that a part of the coriin is withdrawn from the skin tissue if the hide is too long subjected to the action of the water.'^ Hides intended for sole leather are siuelled or "plumped" in order to cause them to be better adapted to the absorption of the tanning material. In case the natural swelling is not suffi- cient, it is assisted by the use of inorganic as well as organic acids. This swelling process is, for the reasons previously stated, accelerated, and the falling back of the hides into their previous state prevented by the use of hard water. Soft water is preferred for the manufacture of upper leather, as the hides must not be swelled as much as those for sole leather, as otherwise the smooth cut would be injured. The temperature of the water used for preparing the hides must also be taken into consideration. Generally speaking, the water should be as cold as possible for the manufacture of sole leather to prevent the skin fibre from being softened too much. • Eitner (see Der Gerber, 1877, No. 178, and Diiigl. Polyt. Journ., ccxxiv. 524) has made experiments as regards the effect of different inorganic constitu- ents of water upon the depilated skin, using various solutions of alkaline, cal- cium, and magnesium salts in distilled water. He found that water containing only calcium chloride and magnesium chloride had almost no swelling effect, and distilled water scarcely any, it being further remarked that carbonic acid, and consequently water containing bicarbonates, exerted a swelling effect upon the hide. Alkaline chlorides and alkaline earths, such as magnesium chloride, potassium and sodium chlorides, have no swelling effect whatever, even nullify- ing it partly. Calcium and magnesium sulphates proved the best swelling materials for hides, this explaining the advantageous effect produced in swelling by a careful addition of sulphuric acid to water containing much bicarbonate. 168 THE MANUFACTUEE OF LEATHEE. It is also of importance that the water should not be exposed to too great variations in temperature in summer and winter ; 46 to 50° F. may be designated as the most favorable tempera- ture. Spring water coming from deeper strata of the soil, and possessing consequently a more even temperature, is to be pre- ferred to river water. In the manufacture of waxed-calf, it is important that there should be a uniform temperature of the water in which the skins are soaked, and but few of the best manufacturers of this class of leather in France or Germany soak the skin in the run- ning water of the river, because it is extremely cold in winter and warm in summer. In default of water from a live source, it may be drawn from the cistern ; but you will say, it requires a large quantity of water, and that it will be costly to draw it to the surface. But it is very seldom that a tannery does not possess a horse or a steam engine ; the horse is often idle in the stable ; the engine has always a little power to spare above its requirements ; or by means of the simplest machinery a double action pump may be constructed and made to work by horse or steam power, and in this way there can be obtained from 2000 to 2500 gallons per hour more if desired. There should be in the centre of the tannery or in one of the corners, a large tank raised at least six feet above the ground; the water, pumped into the tank, can be distributed at will over the whole establishment. The total expense may amount to $500 or $600 ; and such a figure is not large in consideration of the importance of the result : to have always at disposal a quantity of pure water and of an equal temperature. It makes a much greater difference in the manufacture of waxed-calf than with any other class of leather, whether the water is hard or soft ; still some prefer it soft, as it contains less calcareous substances than hard water, which is, as we have explained, often saturated with earthy salts. "We do not pretend to give in this work the analyses of all the waters that trickle through our soil ; it is the tanner's business to become acquainted with the quality of the water he has at his disposal, and to utilize it according to the elements it contains. Study the water ; if it is soft the ■soaking will be done promptly, if it is hard it will take longer; WATER. 169 but, any way, there is a certainty of arriving at the same result ; that is the aim. As regards the chemical examination of water, we refer the reader to the following section of this chapter. SectiojSt II. Methods for Determining the Constituents OF Water. We cannot enter upon a description of the different qualita- tive and quantitative methods of determining the constituents of water ; but will only briefly describe a few examinations of importance in tanning, and those who may desire a full descrip- tion of the methods and apparatus employed, are referred to the treatises of Wanklyn and Frankland on Water Analysis. The qualitative examinations of water as to its admixtures of lime, magnesia, 'alkalies, chlorine combinations, sulphuric and carbonic acid, the larger or smaller quantity of which gen- erally determines its character, can be executed in the follow- ing manner : — 1. The chlorine combinations are shown by the formation of a white precipitate when treated with nitrate of silver in nitrate solution. 2. Sulphuric acid and sulphates are recognized by the forma- tion of a white precipitate with barium chloride. 3. Carbonic acid is present when the addition of clear lime- w^ater gives a white precipitate. 4. The presence of silicic acid, lime, and magnesia, by evapo- rating to dryness with an addition of hydrochloric acid in a platinum dish of a capacity of about 1 litre. The residue is taken up with hydrochloric acid and water, the portion remain- ing undissolved being silicic acid. The lime can be separated as calcium oxalate from the filtrate with ammonium oxalate. After removing the calcium oxalate by filtration and evapora- tion of the filtrate, the magnesia is precipitated with ammonium phosphate as ammonium magnesium phosphate. 5. Organic substances are shown by adding a few drops of potassium permanganate and some pure sulphuric acid. If or- ganic substances are present, the potassium permanganate. 170 THE MANUFACTURE OF LEATHER. added drop by drop, is decolorized until all the organic sub- stances are completely oxidized. 6. Determination of the entire residue. 1 litre is carefully evaporated to dryness, requiring from twenty-four to twenty- six hours, in a platinum dish, the weight of which has been previously determined. The residue is dried at 356° F. until a decrease in weight no longer takes place. 7. A determination of hardness with alcoholic soap solution serves in most cases for tanning purposes as a substitute for a quantitative analysis. We give, therefore, a short description of it. The process of determining the hardness of water by a soap solution of a determined percentage, which was introduced by Clark, is a very simple one. By an addition of soap solution to water containing too much lime or magnesia, a white pre- cipitate of lime or magnesia soap insoluble in water is formed as long as calcium or magnesium salts are present. When an excess of soap solution has been added, the end of the reaction is indicated by the formation of lather on shaking the fluid. The effective value of the soap solution is determined by testing it with a lime solution of a determined percentage. Clark's method is, according to Faisst and Knauss, executed in the following manner : — The soap solution required for titration is obtained by dis- solving 30 grras. of dried soda soap in 3 litres of alcohol of 90 per cent. The turbid solution is filtered and preserved for use. 200 grms. of this concentrated solution are first compounded with 150 grms. of water (in order to reduce the alcohol to the strength of 56° Tralles, which has been proven to be the most suitable), and then with 130 grms. of spirit of wine of 56° Tralles. 45 c.c. of the solution thus obtained are required for the precipitation of 12 milligrms. of lime in 100 c.c. of water. The exact titre of this solution must be further determined and corrected by adding concentrated soap solution, or alcohol of 56° Tralles, so that 12 milligrms. of lime require exactly 12 milligrms. of soap solution. For the determination of the con- centration of the soap solution a neutral solution of calcium chloride is used, which is obtained by dissolving 0.214 grm. of WATER. 171 calcium carbonate in hydrochloric acid, evaporating the solu- tion, and dissolving the residue to 1 litre. 100 c.c. of this solution contain 12 milligrms. of calcium oxide, or an equiva- lent quantity of calcium chloride. With this solution the soap solution is tested, and the latter sufficiently diluted, so that exactly 45 c.c are required to produce, when brought together with 100 c.c. of lime solution, and shaken, a white lather re- maining for about five minutes. The process of determining the hardness is as follows : A distinction is made between "total hardness" and "permanent hardness." The hardness of water not heated is called "total hardness," and the hardness produced by the earthy sulphates is termed "permanent hardness," because unaffected by ebulli- tion. The term " temporary" or " changeable hardness," being also frequently used to denote the hardness produced by the earthy carbonates, because removable by ebullition. 1. Determination of Total Hardness. — 100 c.c. of water are measured with a pipette into a glass, having a capacity of 200 c.c, and provided with a ground stopper. Water containing much lime is previously diluted with distilled water, so that to a determined number of cubic centimeters (10, 20, or 30) of the water to be tested, 90, 80, or 70 c.c. of distilled water are added. A mark on the glass indicates the point to which it is filled by 100 c.c. of the fluid. Before adding the soap solution, the free carbonic acid is partly removed by shaking the water. As most well-waters have more than 12° of hardness, only 10 c.c. of the water to be tested are measured off, and diluted to the mark with distilled water. Titrated soap solution is then slowly added from a burette until, after vigorous shaking, a dense delicate lather is formed which will hold for about five minutes. The soap solution is first added in half cubic centi- meters and later on in drops. The shaking must always be done in the same manner, and the volume of the fluid amount to 100 c.c. before the soap solution is added. Should a second experiment be necessary, the same quantity of water is used, or, in case but little soap solution has been consumed for the diluted water (10 : 100), correspondingly more (25-50 c.c), so that the quantity of soap solution, which should previously be 172 THE MANUFACTUEE OF LEATHER. approximately calculated, does not exceed 45 c.c. With the assistance of the following table, the respective degree of hard- ness which, in case the water has been diluted, must be multi- plied with the corresponding figure, is found from the cubic centimeters of soap solution consumed. (The corresponding figure is found bj dividing 100 by the cubic centimeters used for the experiment.) 3.4 c.c. soap solution consumed . 0.5 degree of hardness. 5.4 " " . 1.0 7.4 " " . 1.5 9.4 " " . 2.0 The difference of 1 c.c. of soap solution = 0.25 degree of hardness. 11.3 c.c. soap solution consumed . 2.5 d 3gree of hardness 13.2 " " " " . 3.0 15.1 " " . 3.5 17.0 " " . 4.0 18.9 " " " " . 4.5 20.8 " i< , formed around the lower edge of the upper part or case E of the mill, so that the parts B E may be secured to each other by bolts F^ passing- through the ]ugs or flanges C D. The edges of the bowl B and case E should be rabbeted or halved to each other, so as to form a close joint even when the parts are not drawn closely together. GRINDING TAN-BARK, ETC. 189 The upper end of the case E is supported by the arms G^ the inner ends of which are connected with a collar, iT, through which the shaft A passes. Fig. 21. To the shaft J., just below the collar H^ is keyed the wheel or movable part /of the mill, which is made conical in its general form. To the upper part of the wheel / are attached radial cutters e/, to break or cut the bark into pieces as it is thrown into the mill. Upon the surfaces of the wheel / and case E are formed graduated flanges, cutters, or teeth K^ to still further break up the bark as it passes down to the toothed grinding-segments. Upon the inner side of the lower edge of the wheel / are formed lugs or a flange Z, to receive the bolts Ji", which also pass through the lugs or flange iV, formed upon the inner side of the upper edge of the ring 0, to fasten the said ring against the lower edge of the wheel /. The inner surface of the lower edge of the case E and the outer surface of the upper part of the ring have rabbets with inclined or dovetailed shoulders formed in them, which rab- bets, in connection with the edges of the discharge-bowl B and 190 THE MANUFACTURE OF LEATHER. ring 0, form dovetailed grooves to receive and clamp the toothed grinding-segments P. This construction enables the segments P to be made without any bolt-holes through them, and with their ends fitted against each other, so that there will be no cavities and interstices into which wet bark may stick and form a nucleus of a collection that will finally clog the mill. This construction also enables the grinding-segments to be readily taken out when worn or broken and replaced with others. The invention shown in Figs. 22 to 30 relates to machines having rotary cutters for cutting or reducing bark for tanners' use ; and it has for its object, first, to provide certain improve- ments in the rotary cutter, whereby the machine is enabled to run at a lower rate of speed and with less wear and jar than heretofore ; secondly, to provide improved means for separating coarse fragments of bark from the properly-reduced particles ; thirdly, to enable the cutter to be readily exposed or uncovered when desired. Fiff. 22. Fig. 23 Figure 22 represents a side elevation of a bark-cutting machine embodying the invention. Fig. 23 represents a trans- verse vertical section of the same. Fig. 24 represents a modifi- cation. Fig. 25 represents a section on line x x. Fig. 23. Fig. GRINDING TAN-BARK, ETC., 191 Fig- 24. Fig. 25. Fig. 26. ^ ijiiij 1 1 ■) iiin.,..„,. p hf'' =^1 •ii lilf'^ ^"~3 fe^ ^\i\-m r*- Hi llW riUI ill i (O/ .... 1 ~j ^SL— 1^' 1 III Jill Ei [1!^^ ojlll jlH ill nj ^. W\ "1 Hi Ik ill J ja/ 1 a- i^' 1 III liiii i uiil Ik ill 1 ^ w^ 1 z. 11 *, iiiii Fig. 27. Fi-. 28. 26 represents a plan view of the rotary cutter. Fig. 27 repre- sents a section on line y ?/, Fig. 26. Fig. 28 represents a front view of the machine. Fig. 29 represents a side view with the 192 THE MANUFACTURE OF LEATHER. hojDper turned back to expose the cutter. Fig. 30 represents a side view of the hopper detached. In the drawings, A represents the rotary cutter, constituting a part of the invention. This cutter is composed of a cylindri- cal body and independent teeth a a', projecting therefrom, the cutter being preferably formed by placing a series of saws side Fi^. 29. Fiff. 30. by side on an ai'bor, although any other suitable construction may be adopted. The teeth a a' are shaped like the teeth of an ordinary circular saw, and the teeth a are longer — that is, their points project farther from the axis of the cutter than the points of the teeth a', the difference in length being preferably about one eighth of an inch. The teeth are arranged in rows extending longitudinally of the body of the cutter, each longi- tudinal row being composed of alternating longer and shorter teeth, as shown in Fig. 26. The teeth forming the longitudinal rows are placed side by side, each in contact with the next, so that there are no vacant spaces between them ; hence the longi- tudinal rows are continuous. The teeth are also arranged in rows extending around the periphery of the cutter, the teeth of each saw constituting a peripheral row. It is preferable to make these peripheral rows of alternating longer and shorter teeth, as shown in Figs. 26 and 27. By this arrangement of teeth each tooth is enabled to separate an independent fragment from a sheet or piece of bark, and no part of the end of the bark GRINDING TAN-BARK, ETC, 19S is left untouched by each longitudinal row, as would be the case if the teeth were separated by intervening spaces, as has been usual heretofore. When the teeth are so separated the cutter has to be driven very rapidly, in order that the portions of the bark untouched by one row of teeth may be properly cut by the succeeding rows, and unless the cutter is driven very rapidly its tendency is to break or crush off the tongues left on the end of the bark by the vacant spaces between the preceding teeth, the result being the detachment of fragments too large to be properly leached and the reduction of a portion of the bark to powder, which is always objectionable in the reduced bark, because it accumulates in masses and resists the action of water in leaching. This cutter does not require to be driven so rapidly as those heretofore used, so that less power is required to drive it and less jar and vibration are caused by the operation of the machine. The arbor of the cutter is supported in suitable bearings on the top of a supporting-frame, B^ which incloses a chute, C\ below the cutter. In this chute is located a shaft, D, journaled in a movable frame, E^ which is adapted to slide into and out of the frame B. The shaft D is provided with a series of peripheral collars, F^ and intervening peripheral grooves or pockets, 6^, about half an inch wide, and having partitions H H. The interior of the frame E forms a part of the chute C^ and is about equal in width to the diameter of the collars, so that when pieces of bark too large to enter the pockets G fall from the cutter they will be arrested by the collars, the properly-reduced cuttings falling into the pockets G^ and being carried over by the partitions H^ as the shaft revolves. The pieces arrested by the collars F may be cut or broken up by the joint action of teeth /, formed on these collars, and a shoulder, «/, formed on one of the side blocks of the frame E^ this shoulder having grooves K^ through which the collars pass. The pieces of bark are arrested by the shoulder e/, while the teeth / cut or break them. If desired, however, the shoulder «/, and teeth /, may be dispensed with and the shaft Z> may be 13 194 THE MANUFACTUKE OF LEATHER. located nearer the cutter, so that pieces of bark arrested by the collars i^ will be caught up by the cutter, as they accumulate, and carried over by it to the bed-plate, hereafter described, to be reduced, JV represents what we will term the "hopper-frame," which is located at the top of the frame i?, and is provided with lugs P, extending downwardly and pivoted at to the frame B. This frame incloses and covers the cutter when in operative position, and has the general form of a hopper. One side of the frame is inclined and properly arranged with reference to the cutter to constitute a bed-plate, Q, to support the bark as it is presented to the cutter. This bed plate does not extend in one piece to the cutter, but is supplemented by a movable steel plate, a. Two methods of supporting and moving the plate H are shown, respectively, in Figs. 23 and 24. In the former the plate H is attached to an inclined plate, *S', which forms a part of the frame B. The plate i?, in this case, is at right angles with the bed-plate, and is attached to the plate S^ by a bolt, T^ passing through a slot in the plate B. Screws F, pass- ing through a flange, TF, on the plate S, serve to move the plate i? at right angles to the plane of the bed-plate when the bolt T is lowered. In Fig. 24 the plate li is attached by a bolt, T'^ to an inclined plate, S', forming a part of the frame B. The bolt T' is at- tached to the plate JR, and passes through a slot in the plate S'. In this case the plate M is movable in the same plane as the bed-plate. In either case the plate jR constitutes an adjustable terminus of the bed-plate, which receives the wear caused by the action of the cutter on the bark, and is capable of being ad- justed to compensate for wear. The hopper-frame N is provided with a feed-roll, C/, which is positively rotated by a sprocket-wheel, i\''', connected by a chain, N^, to a wheel, iV^, which is journaled on a shaft, N*, projecting from a plate, iV^ attached to the side of the hopper- frame. The feed-roll U is journaled in weighted arms U' U', which are pivoted at u w, to the sides of the hopper-frame, and are adapted to oscillate and permit the feed-roll to move laterally. By pivoting the hopper-frame to the supporting-frame B^ as GRINDING TAN-BARK, ETC. 195 described, and supporting the feed-roll and its driving mechan- ism on' the hopper-frame, it is possible to readily expose the cutter by swinging back the hopper-frame, as shown in Fig. 29, whenever the cutter is to be removed or repaired, thus avoid- ing the labor and delay usually incident to removing the hop- per and other mechanism to enable access to be had to the cutter. The shaft of the feed-roll projects through slots C^, in the sides of the hopper. The sides of the hopper have vertical openings U^^ extending from the slots ?7^, to permit the upward movement of the shaft of the feed-roll when it is desired to remove the latter. The openings ?7^, are closed when the feed- roll is in place by pieces TT^, attached to the cover T/^, of the hopper, said cover being detachable with the pieces U^. F' represents a friction-roll located in an opening in the bed- plate. This invention is No. 229,205, mentioned on p. 197. List of all Patents for Bark Mills issued hy the Government of the United States of America, from 1790 to 1883 inclusive. 1^0. Date. Inventoi'. Residence. July 19, 1794, J. Markley, Mar. 17, 1802, J. Warrel, May 21, 1805, T. W. Prior, ' Philadelphia, Pa. May 7, 1807, C. Tobey, Hudson, N. Y. Mar. 18, 1808, 0. Pease aud Norwalk, Conn. A. Donalds, Mar. 20, 1811, L. Gale, Berkshire, Co., Mass. Jnly 16, 1813, C. Churchman and Upper Chichester, Pa. G. Martin, Jr. April 18, 1814, J. Olds, Meriden, Conn. May 16, 1815, L. Gale, Lenox, Mass. Oct. 31, 1820, N. Sears, Hudson, N. Y. Nov. 22, 1821, E. and J. Trask, Sangerfield, N. Y. May 24, 1822, J. Elliott, Philadelphia, Pa. April 11, 1825, H. Haiglit, Jr., and Stamford, Conn. H. White, Oct. 25, 1826, C. Foss, Madison, 0. Sept. 13, 1827, W. Tarry, Westbrook, Me. Mar. 27, 1828, A. Bull, Caroline, N. Y. May 29, 1828, J. Montgomery, Sangerfield, N. Y. Feb. 1, 1830, M. Hurd, Augusta, N. Y. May 3, 1831, M. Hurd, Augusta, N. Y. 196 THE MAXUFACTURE OF LEATHER. No. Date. luventor. Residence. Sept. 30 1831, C. H. Green and R. Montgomery, Sangerfield, N. Y. Feb. 27 1832, J. T. Gilford, Veteran, N. Y. Mar. 27 1832, D. Humberd and G. Downs, McConnelsville, Pa. April 17 1833, J. Trask, A. Seabury, and W. Young, Sangerfield, N. Y. 484 Nov. 25, 1837, C. Parker, Meriden, Conn. 532 Dec. 26, 1837, A. McMillen, Bedford, N. H. 1,714 Aug. 12 1840, R, Montgomery and L. W. Harris, Sangerfield, N. Y. 2,716 July 11 1842, V. Birely, Frederick, Md. 2,944 Feb. 4 1843, B. R. Beardsley, Sangerfield, N. Y. 3,767 Sept. 27, 1844, M. Beeclier, Remson, N. Y. 4,090 June 25, 1845, A. P. Norton and M. Owen, Sangerfield, N. Y. 4,237 Oct. 25 1845, J. Scudder, Plattsville, N.Y. 4,335 Dec. 26, 1845, A. Lindsey, Canton, Me. 6,916 Reissue 180 ^Dec. 4, J Oct. 15, 1849. 1850. S. A. Bant and W. Andrew, i Frederick, Md. 12,487 Mar. 6 1855. S. W, Powell Tuscarora Valley, Pa. 20,692 June 29 , 1858. B. R. Beardsley, Waterville, N. Y. 28,518 May 29 1860, W. Tansley, Salisbury Centre, N. Y 28,5.54 June 5 1860. J. Brakely, New York, N. Y. ■ 42,811 May 17, 1864, M. Winger, Ephratah, Pa. 44,756 Oct. 18 1864, W. Tansley, Salisbury Centre, N. Y 49,319 Aug. 8, 1865, N. S. Thomas, Painted Post, N.Y. 85,172 Dec. 22, 1868, B. Irving, New York, N.Y. 86,675 Feb. 9, 1869, B. Irving, New York, N. Y. 97,989 Dec. 14 1869, W. Tansley, Salisbury Centre, N. Y 101,984 April 19 1870, J. G. Curtis, Emporium, Pa. 103,246 May 17 1870, R. H. Shultis, EUenville, N. Y. 103,881 June 7 1870, L. H. Hermance, Kingston, N.Y. 107,923 Oct. 4 1870, C. Korn, Wortsborough, N. Y. 111,239 Jan. 24, 1871, G. E. Palen and F. P. Avery, Tunkhannock, Pa. 111,397 Jan. 31 1871, F. Stamm, East Lampeter, Pa. 111,744 Feb. 14 1871, J. Helenbrook, Clean, N. Y. 120,246 Reissue 7,143 )0ct. 24 )May 30 1871. 1876. > 0. Coogan, Pittsfield, Mass. 153,492 July 28 1874, J. Moulton, Ossipee, N. H. 176,709 April 25 1876, S. R. Thompson, Portsmouth, N. H. 179,401 July 4 1876, 0. Coogan, Pittsfield, Mass. 190,182 May 1 1877, W. H. Barber, AUentown, Pa. GEINDING TAN BARK, ETC. 197 No. Date Inventoi-. Residence. 190,777 May- 15, 1877, W. F. Mosser, Allentown, Pa. 198,614 Dec. 25, 1877. C. P. Hayes, Brooklyn, N. Y. 200,361 Feb. 12, 1878, S. R. Thompson, Brookline, Mass. 201,938 April ^ 2, 1878, W. E. Nickerson, Somerville, Mass. 206,494 July 30, 1878, R. H. Shultis, Kingston, N. Y. 210,095 Nov. 19, 1878, W. Chicken, Chelsea, Mass. 211,666 Jan. 28, 1879, W. E. Nickerson, Somerville, Mass. 211,798 Jan. 28, 1879, Wm. Shaw, Kingman, Me. 220,274 Oct. 9, 1879, Wm. Chicken, Chelsea, Mass. 220,945 Oct. 28, 1879, C. P. Ryther, Carthage, N. Y. 221,870 Nov. 18, 1879, Wm. Shaw, Kingman, Me. 229,205 June 22, 1880, S. R. Thompson, S. W. Johnson, Brookline, Mass. West Medford, Mass, 234,324 Nov. 9, 1880, D. Obrien Oswayo, Pa. 238,923 Mar. 15, 1881, S. Kiillman, San, Francisco, Cal. 249,825 Sept. 13, 1881, W. Chicken, Chelsea, Mass. 264,152 Sept. 12, 1882, J. C. Hagerty, Santa Crnz, Cal. 282,771 Aug. 7, 1883, L. F, Reed, Hornellsville, N. Y. Process for preparing Tan-baric for use.^ which consists in crushing the Dry Barh and reducing it to thin flakes by passing it between rollers under heavy pressure after it has been ground. It is well known to those engaged in tanning that it is diffi- cult to extract all the tannin from bark when used in the ordi- nary way in tanneries ; and as tan-bark is becoming constantly more difficult to obtaiii in the required quantities, and conse- quently more expensive, it is very desirable to have some means by which the tannin may be more effectually, and also more quickly, extracted from the bark, and to accomplish this is the object of the present invention. Ordinarily the bark is simply ground in a bark-mill, and then leached in vats ; but when so used the cellular structure of the bark is not destroyed or broken up, and the consequence is that, even though the bark be leached for a long time, more or less of the tannin is still retained in the cells of the bark, and is thereby lost. In Figs. 31 and 82 there is illustrated a simple form of machine for breaking up the cellular structure of bark, invented by Mr. Byron Holbrook, of Kenosha, Wisconsin. Fig. 31 is a perspective view and Fig. 32 a transverse verti- cal section of a machine designed for treating bark in accord- ance with this method. The machine consists of the rollers, A 198 THE MANUFACTURE OF LEATHER. and B^ mounted in a suitable frame, the roller B being mounted in fixed bearings, while the roller A is mounted in adjustable Fig. 31. Fisr. 32. bearings, having set-screws, z Fig. 56. Fisr. 57. Fig. 58. The extract, as obtained by leaching the bark in ordinary leaches or tubs, is conveyed to an evaporator, and concentrated by artificial evaporation to a density of from 7° to 11° of Baume's hydrometer, 10° being the preferred density. It is then con- veyed while hot to a suitable cooler and rapidly cooled to a temperature of from 60° to 80° F. From the cooler the con- densed extract passes into a series of tubs of varying heights, arranged to overflow into one another, or the tubs may be of uniform height, arranged in steps, to receive the overflow from one to another and into a long shallow tank, and thence into a LEACHING TAN-BAEK. Fi":. 59. Fig. 60. 229 ^-- Fis:. 61. Fio;. 62. 230 THE MANUFACTURE OF LEATHER. reservoir which receives the purified extract. The sediment is deposited in each tub, the grosser particles of foreign matter being deposited in the tub nearest the cooler, the finer particles, in corresponding ratio, being deposited in the succeeding tubs and tanks until the extract, refined from all impurities, flows into a storage-reservoir, to be concentrated for market, or into the tanning-vats, as may be desired ; or the cooled extract may be run off into a series of tubs, as before described, each tub provided with a valved outlet, and the extract allowed to stai^^d therein until the sediment is precipitated below the outlets, which are then opened, whereby the purified extract will flow into lower tubs. If the extract before cooling is of less density than 9° pr 11° Baum^, it will not deposit all the sediment in the tubs, and with increased density the deposit will only be partial, and if of the density as it comes from the leaches very little precipitation of sediment will be effected. The lower the temperature of the extract when it comes from the cooler, until 60° or 70° F. is reached, the more sedi- ment will be deposited in the primary tubs. If the extract is filtered before cooling, or if cooled as it comes from the leaches, scarcely any sedimentary deposit would be obtained. It will thus be observed that the essential elements of this process are, first, the rapid cooling of the extract after it has been concentrated to a density of from 7° to 12° of Baume's hydrometer, to cause the sediment to precipitate ; second, in collecting the sediment set free by the cooler in a series of tubs and shallow pans, the extract flowing from one tub to another, each tub remaining nearly full to let the sediment collect, until it finally passes from the trough in an observable clear state. Description of Bradley'' s Apparatus. The leaches and evaporator need not be further described, as they are in ordinary use and well known to all persons skilled in the art of obtaining and concentrating extract of barks ; but as a suggestion it might be stated that the screw form of evapo- rator used by Mr. H. McKenzie, and which is mentioned in the list of patients as No. 150,596, on p. 236, could, with but slight modifications, be employed in conjunction with this process. LEACHING- TA]Sr-BARK. 231 A B are two concentric cylinders, the outer space forming a water-jacket or cooling chamber, of which a is the inlet, con- nected to a source of water-supply, and b an outlet to carry off the same, thus causing a circulation through the water-space. The cylinder B is preferably of sheet-copper, and into the space between it and the revolving shaft (7, with agitators d on it, concentrated extract, while hot, is admitted through the inlet c. C is a hollow shaft provided with agitators c?, and which shaft is stepped into a bridge e, of the end plate D^ of the cylinder, said plate closing the water-space between the two cylinders and opening into a conical chamber E^ attached to the bottom of plate D^ the outlet provided with a stop- valve/. The chamber E has internally a wing (r, a little smaller than the conical chamber E^ and is journaled therein by connection with the end of the shaft C, to revolve and keep the liquor agi- ' tated, and thus prevent the valve / from becoming choked. The agitators d are set inclinedly on the shaft in inverse order to cause counteraction. The agitator-shaft C is driven by connection with a shaft H, passing through the end plate of the cylinders A B. /are brackets carrying a bearing J, for the shaft H, which has a pulley K^ for driving the same by a belt from any suit- able motive power. The concentrated extract becomes cooled in passing through the cooler and falls into a series of troughs or tubs L, arranged to flow or to overflow into one another consecutively, the last one discharging into a shallow trough L'. The concentrated extract, while in these tubs and pan, deposits sediment, the par- ticles graduating in fineness from the first tub toward the trough L', from whence it passes, by overflow-pipes g^ into a suitable receiver, in a clear state, free from sediment. Extract which has been concentrated to the ordinary density of, say, 30° Baume, without being purified by this process, can be purified by diluting it with water to about 10° Baume, and while hot passing it through the cooler and thence into the troughs to purify the same by precipitation of sedimentary de- posit. 232 the manufacture of leather. ^Section YI. Obtaining Tannic Acid in Acicular Form. The invention shown in Figs. 63 and 64 is that of Holtz, and it relates to improvements in the production or manufacture of tannic acid for use in the various branches of tire arts and man- ufactures, and more particularly in the manufacture of leather. The tannic acid employed for technical purposes has been heretofore prepared for market by drying the viscous products of extraction containing the tannin in a high temperature, aijd then grinding the dried product and placing it on the market in a pulverulent form. This method of preparing tannic acid has material disadvantages and defects, one of which lies in the fact that the powdered tannic acid when brought in contact with atmospheric air is partially converted into gallic acid, and, of course, such a product has not the same value as the pure tannin. The presence of gallic acid or other foreign substance (the result of oxidation when the tannin extract is dried in too high a temperature) becomes at once apparent when the dried tannin is dissolved, it being impossible to obtain a clear solution. Another defect of this method of preparing tannin lies in the fact that the powdered product is exceedingly hygroscopic, cakes readily, and is then difficult to dissolve. It dissolves very slowly, and even the thoroughly-dry powdered tannin is apt to cake or form lumps, which impedes its solution materially. The object of Holtz's invention is to remedy these defects and produce a practically pure and readily soluble tannin, bet- ter adapted for use in the arts and manufactures, and offering to the consumer a certain guarantee of its purity ; and to that end the invention consists in the production of tannin in an acicular form by passing the inspissated tannin extract through a finely-perforated sieve, and reeling the thread into bundles, or by allowing it to drop from a height into a chamber, at the bottom of which it is curled into bundles and then broken up. In practice the inventor has found the apparatus illustrated in Figs. 63 and 64 best suited, though any other description of ap- paratus adopted to effect the same purposes may be employed. Fig. 63 is a vertical section of the apparatus, and Fig. 64 a bottom-plan view of the reservoir. In carrying out this process, take the inspissated viscous LEACHING TAN-BAEK. 233 solution of tannin (be this a watery or alcohol or other solu- tion) obtained in the usual manner, and pour it into a vessel or Fiff. 63. Fi,?. 64. reservoir A, located some distance above the ground, lined with copper, zinc, tin, or other suitable material not affected bj the tannic acid, and provided with a finely-perforated bottom a, so that the mass will pass through said bottom in thread-like form, and then reel the threads or otherwise form them in bundles. The more economical and easier way, however, is to allow the fine streams passing through the bottom of the reservoir A to flow from a height into a chamber and cool themselves on the bottom thereof in a dried state ; and to that end it is best to employ a tower B, about 16 feet and 6 inches in height, with 234 THE MANUFACTURE OF LEATHER. one or more peep-holes /;, and a man-hole ?>', the purposes of which are obvious. The reservoir A is surrounded by a jacket G, into which an}' heat-producing medium (preferably steam) may be introduced to maintain the extract in the fluid condition required. The bottom c of the jacket has a series of perforations, equal in number to the perforations a' in the bottom of the reservoir and conaxial therewith, bat of greater diameter. To prevent the contact of the steam with the out-flowing extract the per- forations are surrounded by small tubes c\ secured to the under surface of the bottom of the reservoir and the upper face of the jacket-bottom. The use of these tubes c', surrounding the out- flow-apertures, produces another and more important result — namely, the form-drying chambers, wherein the thread as it issues from the reservoir is brought in contact with a heat- radiating surface of great area as compared with the surface of the outflowing thread-like extract, and which dries this thread sufficiently to enable it to support its own weight for a distance of five meters before the thread reaches the bottom of the tower, being thoroughly dried by the air within the said tower during its progress to the bottom thereof, where it curls itself like finely- curled wool, and may then be readily broken up into needles. It is preferable to make the tower air-tight and produce a vacuum therein by any suitable means, such as a force-pump connected with a pipe D, located at or near the top of the tower, whereby the pressure of the surrounding atmosphere upon the viscous tannin extract tends to force the extract through the perforations of the bottom of the reservoir, thus not only greatly accelerating the operation, but also enabling a more concentrated solution to be employed than would be the case if the passage of the latter depended solely on its weight. The tannin threads when cold are exceedingly brittle, and break into shining golden-yellow acicular fragments, and in this acicular form the tannin, owing to its brittle or glass-like condition, is not hygroscopic, will not cake, and a perfectly clear solution is obtained therefrom. The tannin being prepared under the influence of a low tem- perature does not contain any products resulting from decom- position, such as above enumerated. LEACHING TAN-BARK, 235 List of all Patents for Processes and Apparatuses for Leaching and making Extracts from Tan-hark, issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. Date 1. Inveutor. Residence. Aug. 10, 1791. J. Biddis and • S. T. Bedwell, Oct. 20, 1812. J. W. Fessenden, Walpole, N. H. April 5, 1823. W. Knapp, Milford, N. Y. April 11, 1825. J. Niles, Guilford, Vt. Mar. 15, 1825. W. Leber, Philadelphia, Pa. Nov. 1, 1828. W. Coburn, Gardiner, Me. Nov. 7, 1835. 0. Batchelder, Bedford, N. H. 836 July 12, 1838. A. A. Hayes, Roxbury, Mass. 1,035 Dec. 15, 1838. G. W. Klein, Boston, Mass. 13,403 Aug. 1. , 1855, G. W. Smith, Nanticoke, N. Y. 14,418 Mar. 11, , 1856. A. Steers, Medina, N. Y, Reissue 2,142 Jan. 2, 1866. A. Steers, Medina, N. Y. 27,859 AprillO, 1860. J. Connell, Port Huron, Mich. 29,143 July 17, 1860, J. Connell, Port Huron, Mich. 34,873 April 8, 1862, J. Brainerd and Cleveland, 0, Reissue W. H. Burridge, 2,523 Mar. 19, 1867. J, Brainerd and W. H, Burridge, Cleveland, 0, 36,048 July 29, 1862. Wm. H. Allen and Freyburgh, Me. Reissue Jau. 3, 1865, 0. Warren, 1844 41,782 Mar. 1, 1864, S. W. Pingree, Lawrence, Mass, 47,393 April 25, 1865. J. Chilcott, Brooklyn, N. Y, 45,421 Dec. 13, 1864, J. McGeary, Salem, Mass, 48,365 June 27, 1865. J. M. Caller, Salem, Mass, 50,636 Oct. 24, 1865. S. W. Pingree, Lawrence, Mass. 54,945 May 22, 1866. F. W. Perry and J. H. Pierce, Woburn, Mass. 57,218 Aug. 14, 1866. N. S. Thomas, Painted Post, N, Y. 64,321 Apr. 30, 1867. B. Irving, New York, N, Y. 64,322 Apr. 30, 1867. B. Irving, New York, N. Y, 64,323 April 30, 1867. B. Irving, New York, N. Y. 64,324 April 30, 1867. B. Irving, New York, N. Y, 64,325 April 30, 1867, B. Irving, New York, N. Y, 68,010 Aug. 20, 1867, A. Steers, New York, N. Y, 68,335 Sept. 3, 1867. A. Appleby, Brownfield, Me. 70,439 Nov. 5, 1867. J. W. Jones, Cumberland, Md. 71,765 Dec. 3, 1867. C, Korn, Wurtsborough, N, 1 75,571 Mar. 17, 1868. S. J. Patterson, Bridgeport, Conn. 75,608 Mar. 17, 1868. G. Warren, Roxbury, Mass. 76,775 Apr. 14, 1868, J. W. Jones, Cumberland, Md. 81,643 Sept. 1, 1868. T. W. Johnson, New York, N. Y. 236 THE MANUFACTUEE OF LEATHER. No. Date. Inventor. Residence. 82,121 Sept. 15, 1868. T. W. Johnson, New York, N. Y. 82,739 Oct. 6, 1868. C. H. Mosely, Winchester, Mass. 83,389 Oct. 27, 1868. T. W. Johnson, New York, N. Y. 85,173 Dec. 22, 1868. B. Irving, New York, N. Y. 85,174 Dec. 22 1868. B. Irving, New York, N. Y. 85,175 Dec. 22, 1868. B. Irving, New York, N. Y. 87,119 Feb. 23, 1869. S. Snyder, Cincinnati, 0. 87,984 Mar. 16, 1869. Gr. A. Starkweather, Waymart, Pa. 88,678 Apr. 6, 1869. N. S. Thomas, Painted Post, N. Y. 88,807 Apr. 13, 1869; J. Pickles, Wigan, England. 90,848 ,Iune 1, 1869. T. W. Johnson, New York, N. Y. 92,455 July 13, 1869. T. W. Johnson, New York, N. Y. 95,009 Sept. 21, 1869. L. C. England, Philadelphia, Pa. 96,212 Oct. 26, 1869. L. C. England, Philadelphia, Pa. 96,345 Nov. 2, 1869. J. Pickles, Wigan, England. 102,832 May 10, 1870. S. W. Kennedy, New York, N. Y. 108,793 Nov. 1, 1870. T. W. Johnson and New York, N. Y. Reissue A. W. Goodell, 4.531 Aug. 29, 1871. T. W. Johnson and A. W. Goodell, New York, N. Y. 111,730 Feb. 14, 1871. H. C. Crovrell, Morgan, 0. 118,956 Sept. 12, 1871. W. Maynai-d, Salem, Mass. 134,675 Jan. 7, 1873. T. W. Johnson and A. W. Goodell, New York, N. Y. 137,004 Mar. 18, 1873. C. Korn, Brooklyn, N. Y. 140,469 July 1, 1873. P. M. (Jhurch, Sault de Ste. Marie, Mich 150,595 May 5, 1874. H. McKenzie, Marquette, Mich. 150,596 May 5, 1874. H. McKenzie, Marquette, Mich. 150,597 May 5, 1874. H. McKenzie, Marquette, Mich. 187,468 Feb- 20, 1877. T. W. Johnson, New York, N. Y. 193,120 July 17, 1877. J. J. Johnson, Columbiana, 0. 218,212 Aug. 5, 1879. R. R. Andrews, Smithport, Pa. 230,.398 July 27, 1880. E. Bradley, Three Rivers, Quebec, 231,035 Aug. 10, 1880. P. Gondolo, Paris, France. [Can 231,489 Aug. 24, 1880. Julius Holtz, Berlin, Prussia. 245,006 Aug. 2, 1881. G. B. Moore, Sr., Cincinnati, 0. 245,142 Aug. 2, 1881. J. Davis, Allegheny, Pa. 253,802- Feb. 19, 1882. M. Wise, New York, N. Y. 258,573 May 30, 1882. P. Gondolo, Paris, France. 258,574 May 30, 1882. P. Gondolo, Paris, France. 259,555 June 13, 1882. 0. Kolrausch, Vienna, Austria-Hung. 263,797 Sept. 5, 18h2. A. Mitscherlich, Munden, Germany. 283,881 Aug. 28, 1883. P. Gondola, Paris, France. Note. — For portions of the matter relating to building round leaches and filling and running the sprinkler leach, contained in this cliapter, the author desires to acknowledge the source of his information, which has been derived from a valuable catalogue published by Messrs. Allen & Warren, now of Con- way, N. H. PART ly. CHAPTER XIII. WASHING AND SOAKING HIDES AND SKINS — PROCESSES FOR SOFT- ENING HIDES, SKINS, AND PELTRIES — LIST OF AMERICAN PATENTS FOR COMPOUNDS FOR SOFTENING HIDES — PROCESS FOR PLUMPING BEFORE DEPILATING. Section I. Washing and Soaking. In the manufacture of leather the hides and skins destined to be tanned or tawed and converted into this product are sub- jected to various preliminary operations, the nature, variety, and duration of which depend upon the condition of the hides or skins when they arrive at the tannery, and also upon the class of leather that it is desired to produce. The "green" hides are those from recentlj^ slaughtered animals, and are soaked for a short time in water so as to remove the blood and adhering dirt, and are to be well raised when taken from the soaking, and if to be soaked for a long period, it is necessary to handle them from time to time. The dry hides are soaked for a longer period than the green hides, and afterwards they are worked in the hide-mill, and so through the whole class of hides, there are different processes to which they must be subjected. In order to achieve satis- factory results in every step of the production of leather, it is imperative that there should be similarity of state which must be such as will be conducive to success. Foremost among these demands, there must be a sameness in the condition of the hides at the beginning. The proper selection of hides, according to variety, size, thick- 238 THE MANUFACTURE OF LEATHER. ness, and condition, is of course a difficult problem, but as these matters are to decide the final value of the finished leather, it is absolutely essential that the most intelligent judgment be exer- cised at this. point, for if there be not proper consideration here there will be loss throughout all the subsequent processes, conse- quently a final diminution of profit. All'tanners are, of course, not so situated as to make it expedient to so assort the hides ; but where it is possible, the classification should be made, and the hides of the greatest substance should be picked out and first worked in, thereby allowing a simultaneous completion at each step of the process, by which arrangement it would be much easier to detect and rectify mistakes. It is well known that during the continued submersion of hides in vats of water the variations in the temperature of the weather and of the water and in the quality and purity of the latter, which is constantly being rendered unfit for its designed purpose by the continued accumulation of decomposed particles of flesh and fibre from the hides, there is more or less damage and injury to the hides, which suffer a loss of gelatine and fibre and appear spotted in what are known as " black rot," black or yellow spots, and damage in the process of sweating or liming, usually called " pricks," " pitted," and " frieze." It follows that if these natural results of the necessary steps of procedure in tanning are overcome the product will not only have a clearer superficial appearance, but its texture and fibre will be more uniformly of natural thickness and of desired firmness than is now the case. In the usual first step in the art of tanning — that is, soaking the hides in clean water — pricks, pitted, frieze, and black spots originate. The hide decomposes before it is properly softened, which decomposition is sufficient to cause the above-named in- juries, and no subsequent use of saltpetre or any other restora- tive can prevent them. The term "prick" indicates an appearance such as would be produced by puncturing the hide with pins, and this injury is produced by soaking for too long a time, especially in hot weather, and it may also be produced in a subsequent step in the art known as "sweating." "Pitted" indicates an appearance WASHING AND LEACHING. 239 much similar to the above, but the holes are much larger. " Frieze" is principally caused in the subsequent step of sweat- ing when the grain of the hide is inclined to be tender and has the appearance of being scraped off. " Black spots" are small blotches of dark color, and when the hide is tanned, rolled hard, and finished, these spots cannot be buffed off', and sometimes cover the whole side of leather. They originate in soaking and sweating. As these injuries originate directly or indirectly in the soaking of the hides at the commencement of the process of tanning, the use of a preventive at that time is of great im- portance. Hence Mr. John W. Hammond, of Osceola, N. Y., who claims to have invented the following process of soaking, uses saltpetre in the first step in the procedure. By subjecting hides, either dry or green, to the action of water containing a proper proportion of saltpetre or nitrate of potassa for a proper length of time and at a proper temperature, he claims that they are the better prepared to withstand the deleterious effects of the usual subsequent liming and sweating; processes and of the process of plumping and coloring in the; handlers. The principle upon which this manner of soaking is based is that before subjecting the hides to the decomposing and destriaic- tive action of the sweating and liming processes, in order toi swell and soften the fibre, to the end that the hair may be re- moved and the pores opened for the entrance of the tanining agents, this swelling and softening should be accomplished through the medium of an agency which will at the same time act to preserve the life and fibre of the hide, instead of hasten- ing its W3,ste and decomposition. The use of saltpetre in tanning is not new, it having been already used as an ingredient in tanning liquor, but experience has shown that desirable results are not secured in so great measure by such use as when its effects are given solely and primarily and under the conditions hereafter stated. In practice the use of this preparatory treatment depends upon circumstances, as to quantity, temperature, and time, that are within the discretion of the skilled tanner, and this from the variableness of the condition and quality of the hides to be 240 . THE MANUFACTURE OF LEATHER. treated, the temperature of the atmosphere, and the state of the weather ; but as a basis or rule of general application the follow- ing-mentioned proportions and particulars it is claimed are practical and beneficial in result, though changes may be made in them by reason of the before- mentioned conditional circum- stances, so that the exact proportions, temperature, and time are not vital essentials. For twenty-five hundred pounds of dry hides and the same proportion of green hides use sufficient water to cover or hold that quantity of hides, and intermix with the water before putting them into it from one to six pounds of saltpetre, the same being dissolved in warm water and then added to the water in the vat, the hides being sub- jected to immersion therein, with more or less frequent handling in order uniformly to expose each hide to the full effects of the liquor for from two to thirty days, and at a medium tempera- ture. It will be seen that the temperature of the liquor should be comparatively higher in cold and lower in warm weather, the proportion of saltpetre increased with the increased propor- tion or quantity of hides, as also the time of treatment, all of which is a matter of judgment iu the province of one skilled in the usual methods of tanning. Hides so treated it is claimed assume a plumpness and firm- ness, the pores are opened, and the hair-cells are softened and distended, rendering the subsequent liming and sweating pro- cesses shorter and more effective and the subsequent tanning by submersion less destructive to substance and fibre, and reducing liability to spot. Hides so treated it is claimed can be worked in the processes of soaking and sweating with much higher temperature of weather and water than by the ordinary well- known processes. All grease should be removed from the hides during the soaking, or they will not sweat properly, and if grease is still present after the usual method of soaking and milling, then the use of soda-ash, potash, sal-soda, or an equivalent alkali is re- commended, and in lieu of these hard wood ashes may be used in the soaks if more convenient, as these agents convert grease into a soap, which will wash from the hide very easily in the mill. WASHING AND SOAKING. 241 Small hides or kips, after being well washed and cleaned, are sometimes soaked bj laying them in foul bloody water. This method, which is in use amongst white tanners, requires much attention, like every other process by means of which the hide is restored almost to its original condition. It imparts a perfect softness to the hide, leads rapidly to the result, and is not costly ; but it requires the greatest precau- tions. Another method is the softening of the hide by " sweating," that is to say, heating it without fire and without steam, and of the sweating process, as generally employed, we shall treat in Chapter XY. " With regard to imported salted hides, a proper softening in water will do, and this water should be changed every now and then, so that the hides do not remain long in briny water, and care should be taken to rinse them thoroughly before plac- ing them in the fresh water. Of the influence of water upon the quality of the leather we have spoken in Chapter IX. Of the period which the hides and skins are allowed to remain in the soaks and their usual treat- ment for different classes of leather we shall enlarge upon in the descriptions of the methods of manufacturing sole leather, upper leather, Morocco leather, etc. It is not of course intended that the processes to which reference has just been made should be considered as dogmatic, for no two tanners treat hides in the soaks, sweating, liming, or other steps in tanning, in exactly the same manner and for the same period ; some tanners advocate light soaking, while according to others the quality of the leather is improved in proportion to the duration of the soaking of the hides; but it is undeniable that when it exceeds a certain time the skin acquires a tendency to decomposition, and the quality of the leather is impaired. The construction and operation of the hide-mill is explained in Chapter XIY., and is usually employed after the soaking of dry imported hides. When the hides are dry the soaking should be continued longer, and that operation is facilitated by handling them often. The hides are to remain in water until they have become supple, 16 242 THE MANUFACTURE OF LEATHER. and it is for the intelligence of the workman to determine when this point is attained. Dried and salted hides require a much longer soaking than those which have only been dried. The working and softening of the dry hides in the hide-mill, or upon the horse or beam, are considered indispensable opera- tions by every experienced tanner, in order to remove the stiff- ness and wrinkles, and are of course unnecessary for green hides. When the hides have all been soaked and washed, and are sufficiently supple, after being worked in the hide-mill, they are returned and left in the water for six hours. In running water they may remain eight hours. Reference is here made exclu- sively to large hides, for cow skins may be left without danger for 24 hours, and calf skins 48 hours, being careful to observe the nature of the water and the temperature of the air. Too long soaking in the same water exposes the skins to the danger of putrefaction, and the rapidity of the decomposition is propor- tional to the amount of filthy matters contained in the water. In some parts of France, hides from South America are placed directly in vats filled with lime-water and left for six to ten days, care being taken to work them in the usual manner at frequent intervals during the soaking. The skins are softened by the action of lime and rendered more easy to be handled. At this stage the defective parts may be detected, and some- times they are so damaged as to be suitable only to manufacture glue. Well-salted hides, but not dried, may be cleansed in 48 hours, but they can be left to soak three or four days without danger. They should be handled once a day. When taken out from the water for the last time they should be given a vigorous and thorough rinsing. It is the usual custom in the manufacture of upper leather, after hides have been properly soaked, to split them into " sides ;" previous to which operation they are drawn into a pack with the hair side uppermost, and then a knife is driven from the butt through the centre of the backs, which divides the hides. SOFTENING HIDES. 243 Soaking Dry Hides in Banning Water. As there is still a large amount of soaking of dry hides done in running water, we give separate directions for conducting it. The water should have a temperature not above 55° F. According to the prevailing arrangement, the dry hides are suspended by chains or ropes, or hung over a pole. After twenty-four hours they will be sufficiently soaked to be rinsed, after which they are bent apart and replaced in the water. They are now rinsed every twelve hours, partly for the purpose of changing the position of the hides so that the soaking will be uniform, and partly to prevent mud and other impurities from settling upon them. After six days they are generally sufficiently soaked to allow them to be subjected to the sweating process ; more than eight days' soaking being required only in rare cases ; but this is of course dependent upon the nature and condition of the hides. After the hides have been soaked and swelled so that they can be readily bent (especially the head), and the escutcheon has assumed a glassy appearance, they are removed from the water, it heing of the utmost imi:)OTta,nce that in doing this, they are cleansed from all dirt and impurities. It is best to use for the latter purpose a worn-down broom, with which they, and especially the hair sides, are scrubbed until all dirt is removed and the rinsing water runs off clear. After folding them in the middle and tucking in both ends, they are piled one upon the other until all are cleansed. They are then thrown over a bench and allowed to drain off for a few hours, or over night. Section II. Processes for Softening Hides, Skins, and Peltries. Softening Dry Hides^ Skins, and Peltries, hy Soaking them in the Waste Water from Gas Works. It is known to tanners that serious inconvenience exists in the processes used for the purpose of softening dry hides. The one commonly employed consists in immersing them in a bath 244 THE MANUFACTURE OF LEATHER. of water, together with various subsidiary aids, such as scraping, beating, working them in the hide-mill, etc. The serious inconvenience experienced in this mode is the well-known liability of the hides to putrefy before they are sufiiciently softened to be ready for the lime process. Another objection to the use of the common method is that in cold weather the length of time required for softening is so great as to be a serious loss to tanners. Then, again, there is a risk of destroying the hides if softened during very warm weather. It is claimed that by the use of waste gas- water the above objections can be obviated. Barron's Process. The agents which this inventor claims to be the most eft'ectual for softening dry hides, skins, and peltries are : The reluse liquid of gas-works in the refining process ; gasoline ; and coal- tar. The refuse liquid is employed either alone or slightly diluted with water. When gasoline is used it is diluted with water in about the proportion of one part gasoline to twenty parts water. But exactly the best proportion cannot be defi- nitely stated, inasmuch as the strength of the soak will vary according to circumstances, such as the character of the hides and the state of the weather, etc. The above proportions, it is stated, will generally answer, but may with safety be somewhat varied by slightly less diluting in winter and more in summer. The coal-tar, however, will not answer when taken alone, nor is it' sufficiently soluble in water to be made available with . water only. To be used effectively it must, by the aid of an alkali, be dissolved in water. Caustic soda will answer as the alkali for the above purpose ; and the following proportions, it is claimed, will give beneficial results — to wit : five gallons coal- tar, three pounds caustic soda, and one hundred gallons of water. Each of the above mixtures, it is claimed, contains substan- tially similar active agents, viz : water, alkaline matter, and antiseptics. The alkalies of the above are mainly ammoniacal SOFTENING HIDES, 245 salts in solution. The antiseptics consist principally of soda carbolate and cresylate. The action is as follows : The water is the principal soften- ing agent ; the alkalies remove the fatty parts of the hide, and have a peculiar softening effect upon the hide, and, when taken in connection with the action of the antiseptics, it is claimed, have no injurious effect upon its tissue. The anti- septics preserve the hides from putrefaction while undergoing the above process, and it is claimed that by being to some ex- tent incorporated into the tissue of the hides preserve them from putrefaction for a greater length of time after they have been softened — in case the hides do not go immediately into the lime — than any process heretofore known. When the liquor has been mixed in the vat, as above described, the hides are immersed therein, and receive substantially the same treatment, as regards stirring, mixing, etc., that they would receive under the old processes, and remain therein until they are sufficiently softened. The time required for softening will vary in the same manner, though not to so great an extent as in the old processes, and will, the year round, require on an average, it is claimed, not more than one-half of the time re- quired by the process now in general use. Berry'' s Process for Softening Hides. This process was patented by Berry, and is for softening dry hides intended for sole or upper leather, the ingredients being: : — Slaked lime . J bu. "Wood ashes . |bu. Potash (dissolved in water) . 12 lbs. Oil of vitriol , . . ... 5 lbs. Spirits of salts . 4 lbs. These substances are placed in a vat of water capable of hold- ing twenty-five dry sole leather hides, and after being well stirred the hides are placed in it and remain three or four days. They are next placed in a preparation for unhairing, composed of — 246 THE MANUFACTURE OF LEATHER. Slaked lime ...•..! bu. Wood ashes ...... 1 bu. Potash (dissolved in water) . . . 4 lbs. From the last liquor they are drawn every other day until "raised," and when the hair begins to start they are split into sides and placed in " lime liquor," and handled every day until they are fit to "unhair," and from this point the treatment is- as usual. List of all Patents for Softeniny^ Hides, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Residence. i Feb. 4, 1833. A. McMillen, Bedford, N. H. Mar. 6, 1833. Wm. Berry, New Sharon, Me. 127,947 June 18, 1872. J. Barron, Chicinnati, 0. 152,908 July 14, 1874. J. D. Marshall, Chicago, 111. 234,248 Nov. 9, 1880. Wm. Coupe, South Attleborough, Mass, Section III. Process for Plumping before Depilating, and THE Treatment of Hides or Skins with an Acid Solution BEFORE Liming, for the Eemoval of Salt or other Mat- ters. Mr. Homer Ely, of Balston Spa, New York, has invented a process for " plumping" hides previous to depilating, and it consists in a method of softening and preparing the hides and skins as a preliminary to the action of the tannin liquor, and, though applicable to skins in either the fresh or salted state, it is claimed to be particiilarly applicable to hides and skins which have been previously salted. In carrying out the process, place the hides or skins in a vat of clear water, allowing them to remain a sufficient time to soften and remove all the dirt or other foreign substances that may adhere to the surface, and also to soften the hitherto dry and hard hides or skins sufficientl}^ to allow them to be divided down the back into halves, technically called " sides," The ' In addition see patents Nos. 59, 627, 136,081, and 226,447, described under the head of Depilating. See, also, list of Patents for Hide-Mills and Boarding Machines. PLUMPING BEFORE DEPILi.TING. 247 hides remain in this first vat for twenty-four hours, when they are sufficiently softened to be taken out and divided. When the dividing is performed, place the sides in a vat, preferably suspending them by hanging them over bars in a vertical posi- tion, twenty sides being a convenient number to operate with in a single vat. For this number of sides the inventor uses in the vat a solution of sulphuric acid in water, in the proportion 'of five pounds of commercial sulphuric acid in about twenty-one hundred gallons of water, which will cover the above-specified number of sides when properly placed in the vat. The action of this solution is to decompose all the salt remaining in the hides or skins. It also softens the gelatine, and opens the pores of the hides or skins, exerting that action upon them which is technically known as "plumping," The pores of the surface of the skin are opened in this way for the easy and rapid escape of any deleterious matter contained therein. During the process of plumping, all earthy impurities pre- viously adherent to the hide are thrown out of the pores of the skin, and deposited at the bottom of the vat in the form of a dark-colored-sediment, which is easily washed out of the vat by the aid of clear water. The hides are in this way, it is claimed, thoroughly soaked, plumped, and cleansed, and, at the same time, such portions of flesh as still remain adhering to the hide are softened, so that they are very easily removed. In order to complete this second step in the process thor- oughly, the hides or skins are subjected to the action of the sulphuric acid solution for from eighteen to twenty hours. The acid solution is then drawn off from the vat, and the hides or skins are rinsed thoroughly with clear water. Then remove the hides or skins, and place them in another vat containing about fifteen hundred gallons of water. Then dissolve in a sufficient quantity of water, to make the solution perfect, two pounds of sal-soda and five quarts of soft soap. After these materials are thoroughly dissolved, add the sal-soda and soap solution to the contents of the last-mentioned vat. The action of the soap upon the hides or skins is to neutralize the remain- ing acid in the pores thereof, a certain quantity of the soap be- ing decomposed, and its alkali uniting with the acid to form a 248 THE MANUFACTURE OF LEATHER. soluble salt, which is soaked oat in the water of the vat. A certain amount of oleine, margarine, or stearine, contained in the soap, remains in the texture of the hides or skins, together with a little glycerine. The action of the sal-soda is to keep the hides plump and pliable. When it is omitted from the solution they become shrunken and flat. It is best always to obiserve the precautions to have a slight excess of the soap and sal-soda over and above the amount necessary to neutralize the remaining acid in the hides or skins, and to allow the hides or skins to remain in the vat containing the soap and sal-soua solution for twenty-four hours, at the end of which time they are ready for liming. In the liming the inventor prefers to adhere to the ordinary course employed by tanners, using nothing but lime. After the hides have passed through the lime, and the hair is removed, work them out of' soft warm water, and then the inventor fol- lows the usual course through the " bating." He allows them to remain in the bate three days, after which they are thor- oughly milled, and then, in as rapid succession as possible, they are three times handled in or passed through a solution com- posed of about twelve hundred gallons of water and three pounds of sulphuric acid, the solution being maintained at a temperature of about 100° F. This treatment neutralizes any lime there may be remaining in the hide, and also removes the roughness that sometimes shows itself on the hair side of the hides or skins when the bate is not in a proper condition. If the hides or skins have not been sufficiently softened in the bating, all the remaining hardness will be removed, it is claimed, by the action of the last-mentioned solution. From this solu- tion the hides or skins are passed into another vat containing about twelve hundred gallons of water to which two pounds of sal -soda and five quarts of soft soap, previously dissolved in soft water, are added. The hides are handled in or passed through this solution twice, and are allowed to re- main two hours in the solution after handling. They are now ready for the final working or beaming previous to their treatment with the tanning liquor. After they have been thoroughly worked or beamed, they are thrown into a vat of PLUMPING BEFOKE DEPILATING. 24:9 water maintained at a temperature of from 90° to 100° F., in wbich has been previously dissolved saltpetre, in tlie propor- tion of one ounce to about thirty gallons of water. In this vat they are allowed to remain for one hour. The action of the saltpetre on the hides or skins, it is claimed, is to " plump" or " raise" them, as it is called, facilitating the swelling of the gelatine in the tissue of the skin, and preparing the way for the free admission of the tannin. The hides or skins are then ready for the action of the bark or tanning solution in which they are then placed. After hav- ing reached this stage in the process of converting skins into leather, the inventor follows in every particular the original process of tanning, by the use of barks containing tannic acid, using nothing but bark in the water of the vat, and discarding everything else of a chemical nature. By this process the in- ventor claims to be enabled to dispense with the operation known to tanners as " fleshing," and also to save at least one- fourth of the time employed in converting skins into leather by the usual method. By this process the inventor claims to also utilize for glue manufacturing or other purposes a large quantity of fleshy substance, which is usually thrown away, and also to decrease the expense of time and labor, and facilitate the process of handling, which is performed in a more satisfac- tory manner. The advantage claimed to be obtained by plumping before liming is, that it opens the pores of the surface of the skin, so that the dirt and other deleterious matter which would other- wise obstruct subsequent processes escape freely, and settle to the bottom of the vat. By this process the inventor claims also to obtain an improved quality in the leather, and that the hide acquires a greater degree of softness, pliability, toughness, strength, and weight than by any other process. These qualities, it is claimed, are obtained by preparing the hides so thoroughly for the reception of the tannin as to obviate the necessity of using other chemicals with the tannin, and yet to admit of the hides or skins being tanned perfectlyin a short space of time. By supplementing the bating by the action of sulphuric acid, 250 THE MANUFACTURE OF LEATHER. the inventor claims to avoid any weakening or other injury of the leather by putrefactive action in the bate, which sometimes occurs when the bating is too long continued. Although we have specified the proportions of acid and water in the above-named solution, and the proportions of sal- soda and soap to be used for a given amount of water, it is claimed that it is not necessary to be strictly confined to these proportions, but that the strength of all the solutions may be varied according to the condition of the hides or skins. CHAPTEE XIV. HIDE- MILLS — LIST OF AMERICAN PATENTS FOR HIDE-MILLS — LIST OF AMERICAN PATENTS FOR BREAKING HIDES. It is usual to soften dry hides and skins in the hide-mill after they come from the soaks and have been divided into "sides," and previous to subjecting them to the liming process, and the time which they are worked in this mill depends upon the hardness or softness of the hides or skins. For the sides that are intended to be worked for upper leather, the usual time is from one-quarter to three-quarters of an hour, while skins that are intended for the production of Morocco leather are usuall}^ worked from ten to twenty minutes. The construction of hide- mills differs greatly for the various branches of leather manufacture. Those employed for softening hides and kips are similar to the fulling mills common in woolen factories ; while the mills used for manipulating skins, such as goat and sheep skins intended for the production of Morocco leathers, are sometimes in the form of a large revolv- ing drum the interior of which has a number of oak pins attached securely to it, and so arranged as to soften the skins as they fall upon them, or in other ways continually come in contact with the pins. The number of skins placed in a mill of this kind at one time is from one hundred and fifty to two HIDE-MILLS. 251 hundred, and the Morocco tanners at Lynn, Mass., and other places in New England where it is used, call it a " pin-mill." The Morocco tanners of Philadelphia, Penna., employ, some- times, a softening mill for the dry skins of a very different con- struction, which consists of a central, vertical, or upright shaft, on the top of which is keyed a beveled-wheel, which meshes with a suitable pinion. About two feet above the socket in which the upright shaft revolves, and passing through and secured firmly to the main shaft, is a second shaft about four- teen feet long, and extending horizontally at right angles with the upright shaft so as to divide itself into two arms of equal length. About one foot from the end of each of these arms there is an iron collar secured to the shaft, and against each of these collars a large granite roller, about four feet in diameter and eight inches face, is rested : the ends of the projecting arms of the horizontal shaft passing through the centre of the stone rollers, which are held in place by large iron washers which play loosely on the shaft against a steel pin. A pit is excavated about three feet deep, following the circle described by the inside vertical face of the two stone rollers. The socket in which the main or upright shaft revolves is placed on a level with the bottom of the stone rollers, and is supported upon a pedestal firmly planted in the centre of this circular pit. A workman stands in this pit and arranges the skins under the rollers as they revolve, sometimes exposing the flesh side and at other times the hair side to the rollers, and all the while keeping them moistened by throwing water upon them, which he obtains from the bottom of the pit in which he is standing. Mills of this kind may have theiradvantagesforsofteningskins, or they would not be employed by some of the largest Morocco tanners in this country; but they are to my mind both clumsy and dangerous, as it is simply a question of time when one or both hands or arms of the workman who attends them will be crushed by the rapidly revolving stone rollers, and the skins are constantly exposed to injury by remaining too long in one position under the rollers. 252 THE MANUFACTURE OF LEATHER. The hide-mills in common use, such as that shown in Figs. 65 and 66, are lined with iron, and when properly constructed and cared for will wear for a long time. The hide mill is not a new idea, but was patented in this country in 1812 by Wm. Edwards, of Northampton, Mass. Mr. Edwards was also the inventor of the rolling contrivance now so commonly employed for rolling sole leather, both of which inventions have of course been greatly improved since his time. The idea of the hide-mill is primarily due to the falling machine, of which it is a reproduction with but slight modifi- cations, and to trace out the origin of the fulling machine would carry us far back near to the early dawn of history. A representation of the fulling process is shown on a tomb at Beni Hassan of about the time of Osirtasen, who is supposed to be the Pharaoh who invited Jacob to Egypt and settled him in Goshen. In this picture the roll of cloth is wetted and manipu- lated between a block and a concave inclined table, which table is very similar to the one-half of the trough of our hide-mills, and the water from the wetted cloth is represented as passing into a trough at the bottom of the table. The hide-mill shown in Figs. 65 and 66 can be employed for softening all kinds of hides and skins ; when used for cleansing Fig. 65. and softening sheep skins in the wool, the screen arrangement underneath can be used to save all the wool that becomes loosened. Fig. 65 is a top view. Fig. 66 is a vertical section of the mill. The hides or skins are treated by placing them in the reser- voir A, of the mill, the beaters of which are represented at B B'. The beaters have arms, E E, extending downward from them, HIDE-MILLS. 253 and being jointed to connecting-rods F F^ applied to bell-cranks, O (r, of a shaft H^ which shaft imparts a reciprocatory vibrat- ing motion to the beaters when it revolves. An improved method for connecting the pitman to the beaters is shown in Fig. 66. Fig. 67. After the reservoir or trough of the mill has been charged with the hides or skins, and the beaters set in motion, water is let into the trough. "Whenever sheep-skins are being operated upon, there is placed, as has been mentioned, under- neath the reservoir or trough, a frame, D^ covered with woven wire, and as the wool is worked from the skins it is washed through the opening C, and lodges upon the screen, and in this way a large quantity of fine wool is saved. The improvement in hide-mills, shown in Fig. 67, is the joint invention of Friend and Annable, and relates to the method of connecting the pitman, which actuates the beater of the mill, with the vibrating arm upon which the beater is hung (below the beater), in such a manner tliat the connection is made more perfectly than heretofore, and the parts may be tightened or adjusted from the top of the beater with less difficulty and 2oi THE MANUFACTUKE OF LEATHER. trouble than is the case with the usual method of adjusting the parts. The invention consists, for this purpose, in making the connec- tion of the pitman and vibrating arm by means of a strap, which passes through or around the vibrating arm, having a bearing for the end of the pitman on one side, and a gib and key on the Fig. 67. other side, the key passing up through the beater, and adjusted by means of a nut on the top of the beater ; and in carrying an oil-tube from the working parts up through the beater, so that the connections may be lubricated. The invention is designed to overcome the difficulties and im- perfections of the common method of adjusting the parts before described in hide mills. As usually constructed and operated, it is very difficult to get at the connections for the purpose of taking up the wear which is the result of the continual jar and vibration. HIDE-MILLS. 255 It has been found from experience that it is essential to make this connection below the beater, and consequently, below the hide-box, and from this cause, whenever the connection wears loose, there are no adequate means for readily adjusting it, and no method of lubricating the wearing parts. The wear is thus much greater, and there is more danger of injury to the mill from this cause. All the filth from the hides which are being milled passes down into the cavity below the hide-box, where these connections are located, making it a very disagreeable process to keep the con- nections in order, or to get at them for lubrication. The present invention for making these connections avoids most of these difficulties by making the parts adjustable and capable of being lubricated from the top of the beater, and the result is that the mill operates more perfectly, with less wear and injury to the moving parts, and with greater economy. Fig. 67 represents a vertical section of the beater, the lower part of the vibrating arm, and the parts employed in the new method of making the connection. A represents the vibrating arm. B is the beater, which is attached to the vibrating arm in any suitable manner. Cisa key, which passes through a slot in the strap D^ up through the beater to the top, where it is adjusted by a nut. The lower part of the key G is wedge-shaped, to correspond with the shape of the gib H. The strap D is made of iron, or other suitable material, and passes through the vibrating arm. It has a bearing, E E^ on the side opposite the key C, for the purpose of holding the end of the pitman F. This bearing is made wider than the strap D, for the purpose of shouldering against the side of the vibra- ting arm. G is an oil-tube, which passes down through the beater B, through the strap D, and into the bearing E. When the pitman i^becoraes loose from wear or other causes, it is only necessary to tighten the nut on the top of the beater, which raises the \.qj G, drawing the strap through the vibra- ting arm, and tightening the bearing E E, which incloses the end of the pitman. 256 THE MANUFACTURE OF LEATHER. The mill shown in Figs. 68 and 69 is for softening hides, and also for fulling cloth, and the invention consists in making the bed and back in two pieces, hinged or otherwise connected, and also in combining steam-chambers with the bed and back pieces, and furthermore in the form or shape of the back-piece, and in making it adjustable. Fig. 68. Fig. 69. Fig. 68 is an elevation in cross-section. Fig, 69 is a perspec- tive, partly in section, of the back and bottom pieces. A is the bed piece ; B, the curved slotted guides of the levers a a of the beaters G C. The slotted guides are provided with rubber packing or cushions to deaden the fall of the levers when there are not enough hides in the mill to receive the full HIDE MILLS, 257 Stroke of the beaters. D is the cam-wheel which operates the beaters, b represents a chamber, which is cast or formed in the bed piece, making part of the same, to which steam is to be introduced through suitable pipes. To the end of this bed piece is hinged or otherwise arranged a curved adjustable back, JE, having also cast or formed in its back or rear a steam-cham- ber c, the object of both being to apply heat through the iron bed or back piece to assist the beaters in softening the hides. Making the bed and back pieces in two parts produces an im- portant effect, viz., to permit of the adjustment of the back, which is accomplished by hinging it to the bed piece (shown at e), and by back bolts c? d, which pass through the side pieces F of the frame, which hold the back at any angle desired. This adjustment allows the operator to turn the hides, by the action of the beaters, faster or slower, as they may require, and to turn hides of different grades as regularly and evenly as though they were all alike. Hard flint hides require, in order to be worked equally well, the back of the mill to be at a different pitch or angle than for soft hides. The shape or peculiar curve of this adjustable back U is also a very important feature of this invention, and it has been a work of great difficulty to arrive at the right form, so that the hides will gradually and regularly, by the action of the beaters, be turned over and over, so that each and every part of the hides will, in turn, receive the strokes. A slight change in the curve or shape of the back would result either in the contents of the mill not turning over at all, or, after turning a time, they would wedge fast in the bottom of the mill, which would necessitate stopping it and re- adjusting its contents. The peculiar form of this back piece F and its adjustment to the bed piece A cause the beaters to turn the contents of the mill completely over with a few or many strokes, at the option of the operator. It is claimed that this mill is self-acting, requiring neither tending nor watching. Its use for softening hides should be found very important, as they can be manipulated and softened, it is claimed, in a better and in a much shorter space of time than with ordinary mills. When used for this purpose, iron pins are inserted in the heads 17 258 THE MANUFACTURE OF LEATHER. of the beaters. This mill can be made entirely of metal, thus adding to its strength and durability. The hide-mill shown in Figs. 70, 71, 72, and 73 is the inven- tion of Middleton, and he claims that his improvements in machinery for stocking, unhairing, and softening hides, skins, and leather have the effect of rendering the machines capable of operating much more quickly upon the leather, hides, or skins, consequently doing a greater amount of work. The number of strokes or blows of the machine per minute upon the leather or hides may be varied, as also the strength or force of the blows. Fig. 70 is a part longitudinal section. Fig. 71 a part trans- verse section. Fig. 72 a plan looking at the top, and Fig. 73 a front elevation of part of machine to be described hereafter. Fig. 70. Fig .71. ht- — Vra?| }|ip)) f?il \l3^ rT^ ^ i The inventor places two steam-cylinders a a, on a founda- tion-plate b, side by side, so as to act direct upon the stock-feet c c, which are coupled to the end of the piston-rods d d! by means of ordinary cotters e, as shown. Motion is imparted to the pistons, which are within the cylinders and of ordinary con- HIDE MILLS. 259 struction, by steam, which is admitted thereto through ordi- nary shde-valves by means of a variable valve-motion, //' being the valve-spindles, each being actuated by means of a sliding cam g^ through oscillating levers h and i. The required Fig. 72. motion is transmitted to the cam from one of the piston-rods Co, through lever j and connecting rod h. The motion of the cam y is varied by a self-acting ratchet arrangement. Every stroke of the pistons carries the lever / with them, from which an intermittent motion is transmitted to the bevel- wheels I and V through the rachet-lever m, pawl n, and rachet- wheel n'^ the bevel-wheel I being fitted with sliding key on to the screw a, on which, also, is provided the nut p. On a rotary movement being given to the screw o a traverse motion is im- parted to the nut ^, which carries with it the rachet-gearing, and lever w. also varies the position of the end ¥ of the con- necting-rod k in the slot/ of the lever/, which has the effect of varying the traverse of the cam c/, and thence the motion of the slide-valves employed for admitting steam into the cylin- ders ; also, by this motion the steam is exhausted at variable points of the piston's stroke. The object of this variable move- ment is to cause the stroke of the feet of the stocks to be more or less effective, consistent with the proper working of the leather, hides, or skins. 260 THE MANUFACTURE OF LEATHER. As well as the above automatic arrangement of varying the stroke, it may also be varied by the hand of the attendant. In order to effect a regularity of stroke of both piston-rods d and cZ', the inventor applies a provisional tappet-motion on the piston-rod d'. The position of the clamp or tappet q may be adjusted and fixed in any required position on the piston-rod d\ and in the event of the stroke of the piston-rod d' differing from that of the piston-rod c?, the clamp or tappet q comes in contact with one of the collars r or / on the rod 5, which is mounted in suitable bearings t^ causing it thereby to move either right or left, which movement is transmitted to the slide-valve spindle /', causing thereby the valve to be moved and the stroke of the pistons to be reversed. This arrangement only comes into operation when any irregularity occurs, and has the effect of preserving the stroke of each piston the same. The inventor also conducts the exhaust-steam into jacketed ends u, of the frame-work, suitable openings being provided for the admission and exit of the same, and the steam supplies an inexpensive artificial heat to the stocks for the purpose of quickening the process. List of all Patents for Hide Mills, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Residence. Dec. 30, 1812. Wm. Edwards, North Hampton, Mass. 66,294 Reissue 2,727 )july 2, j Aug 3, 1867. 1867. > J. M. Brown, Boston, Mass. 100,519 Mar. 8, 1870. J. P. Friend and B. R. Annable, Peabody, Mass. Salem, Mass. 109,393 Nov. 22, 1870. J. G. Curtis, Emporium, Pa. 125,135 April 2, 1872. S. Hussey, Gowanda, N. Y. 221,246 Nov. 4, 1879. R. Middleton, Leeds, England. THE LIMING PROCESS. 261 List of all Patents for Breaking Hides, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Kesidence. Dec. 22, 1826. H. C. Clark, Randolph Co., N. Y. Feb. 13, 1833. B. Aylsworth, Masonville, N. Y. 229 June 10, 1837. E. Kendall, Newton, Mass. 6,710 Sept. 11, 1849. I. S. Heershey, Hagerstown, Md. 7,281 Apr. 16, 1850. C. Bauchman, North Whitehall, Pa, 92,776 July 20, 1869. 0. W. Bean, Farmington, Tex. 107,562 Sept. 20, 1870. E. D. Taylor and Wm. Rude, Hornelsville, N. Y. 199,415 Jan. 22, 1878. ^ 202,414 Apr. 16, 1878. > Wm. Coupe, South Attleborough, ' 241,308 May 10, 1881. ) CHAPTER XY. PROCESSES AND COMPOUNDS FOR DEPILATING HIDES AND SKINS —THE LIMING PROCESS — OTHER DEPILATORY COMPOUNDS AND PROCESSES — DEPILATING BY SWEATING — THE COLD SWEATING PROCESS — THE WARM SWEATING PROCESS — OBSOLETE METHODS OF DEPILATING — LIST OF AMERICAN PATENTS FOR COMPOUNDS FOR DEPILATING HIDES AND SKINS. Section I. The Liming Process. Depilation or " unhairing" is the process of removing hair from hides and skiiivS, and wliile there are many methods for accomplishing this result it is commonly achieved by placing them in a solution of lime until the hair bulb is loosened, thereby allowing the hair to be readily rubbed or scraped off'. The use of lime is often inconvenient and in many ways unsatisfactory, as owing to the energetic action which free lime exerts on animal tissues, a considerable portion of the gelatinous tissue of the hide is disintegrated and decomposed during the liming process, being removed from the hide in the form of soluble gelatine, or else so altered as to be rendered incapable of combining with tannin, thereby incurring a serious loss in 262 THE MANUFACTURE OF LEATHEK, the weight of leather that should be produced, and in its quality, as the skins or hides treated by this process produce leathers less supple and more brittle than is desirable. These objectionable results are more of a physical than of a chemical character; the principal modifications of the chemical constitution of the hide or skin treated by the lime process is the slight increase in the quantity of lime which it originally contained, and a decrease in the quantity of fatty matters due to the saponification caused by the lime; the harshness and brit- tleness imparted to the leather being caused not only by the saponification of the fatty matters, but much more so through the presence of the quantity of lime which penetrates into the tissues. Suppleness being an indispensable requisite for upper, Morocco, and other kinds of leathers, it is restored to them after being treated by the lime process by subjecting them to the action of a bating process, performed by immersing the hides or skins in a solution of hen, pigeon, or dog manure, and various other solutions which will be enumerated in Chapter XVII. the object of such treatment being to neutralize the lime con- tained in the tissues. This "bating" is usually performed in consequence of the employment of lime for depilating, and as both of these processes are expensive and add largely to the cost of producing all classes of pliable leathers, it is much to be desired that some substitute for lime should be found which would be generally acceptable to tanners, and obviate the bating process as well as lessen the expense of unhairing hides and skins. From the large amount of attention that is being given to the subject of depilating, both in this country and in Europe, and from the tendency of the age to cheapen all the manufactured products of general consumption, we are probably safe in saying that the time is now near at hand when the slow, inconvenient process of depilating by lime must be succeeded by more effec- tive, rapid, and economical methods. Some of the inconveniences of the liming process we reca- pitulate as follows : — ■ 1st. The contact of caustic lime alters more or less the tex- THE LIMING PROCESS. 263 ture of the hide, and permitting it to penetrate the pores, it remains in them in the state of caustic lime, carbonate, or lime soap. 2d. The rinsings in water, bating, and the workings remove it only partially, leaving an impediment to thorough tanning. 3d. It also hinders the ready penetration of the tan liquor, and the perfect combination of tannin with the skin, and so obstinately resists removal during all manipulations that a portion is always found in the best leather. These disadvantages have already led to numerous efforts for the substitution of other agents, which we will enumerate later in this chapter. The present process to which hides are subjected is termed " raising," and by it the pores are distended, the fibres swollen, and the hair loosened. These results are effected by means of alkaline or acid solutions, and by sweating or fermentation. Milk of lime, as we have stated, is the alkaline liquor generally employed. Lime-water has been proposed as a substitute, but it is less permanent in its action, and requires frequent renewal in order to insure the perfect cleansing of the hides. The primitive manner of removing the hair was to shave it off, but lime was employed even by the early Egyptians. The depilating process in addition to swelling the hide, thereby loosening the hair and disposing it to yield readily to the depilatory operation, also facilitates, by opening the pores, the absorption of the tannin. If there is a desire to tan quickly, and produce good and heavy leathers, it is highly important that the hides or skins should be properly prepared in the beam-house. As the after results depend largely upon the intelligent care bestowed here, much more attention should in practice be given than most tanners are inclined to grant. All hides that are intended for limed stock should be put in the right condition for the lime — that is, soft enough, but not flaccid — as dried skins may be greatly injured by being softened too much. A hide fresh from the animal is the best criterion as to the condition, for in that state it is best suited for the lime. 264: THE MANUFACTUEE OF LEATHER. When placed in the lime they should be frequently handled or agitated, and should remain in the solution no longer than may be necessary to loosen the hair in order that it may be readily removed. The ancients and those whom progress has failed to reach said, and say still, who limes, tans ! Any tanner who entertains such ideas tans his stock without a thought of the difficulties he is creating for the currier. Lime is a factor, useful and hurtful at the same time, and it therefore becomes necessary that the tanner should occupy himself actively with the conduct and the good management of his lime-pits, and he should in case of necessity entrust this work only to a reliable man, a good workman. Most tanners neglect their work at the lime-pits; and when our American calf-skin tanners fully realize this point and shall take care of their lime-pits, and see to the intelligent beamwork of their stock, they will produce calf-skins of the first quality, for we possess better bark for this work than can be found in Normandy or any portion of France. We shall diverge for a moment and speak of the proper treatment of calf-skins in the limes. When the slaughtered calf-skins peel they should be immediately taken out of the lime. After having allowed them to drip well, put them in a vat with enough water to cover them without floating. They thus undergo a first disgorging; they may, if necessary, re- main in this water for eight or ten days without spoiling. This method is preferable to piling, for while in the water the skins disgorge and the action of the lime is weakened, and in the pile the lime continues its action, and if workmen in piling are not careful to open them evenly,- the skins get what the curriers call " lime folds," which are almost impossible to eradi- cate in currying. But best of all, as soon as the skins peel, take them out of the lime-pits, rinse them and unhair them at once, as promptness in the execution of labor is an economy of capital. From this first stage the work must go on as fast as possible. Salted calfskins after being properly soaked should be put into the dead lime-pit, and afterwards treated the same as slaughtered stock from this point; but the dry skins require a THE LIMING PEOCESS. 265 milder lime-liquor than the salted skins and the fresh slaughtered stock. This work is thus rendered a little slower on account of the lime-liquor in the dead lime-pit having been previously carefully weakened. Lime in depilating has been at times replaced by acid liquors ; but their employment requires the exercise of judgment. The dilute mineral acids make the hair yield easily ; but at the same time they swell and soften the hide too much, so that the use of organic acids is preferable. In some tanneries lime is replaced by a mixture of slacked lime and ashes. Through the mutual action of the lime and the carbonate of potassium a caustic alkali is formed, which operates more energetically. Lime-vats are constructed either of timber or of masonry, and in tanneries where hides are worked they are sunk into the ground so that the tops of the vats are on a level with the floor of the beam-house ; but in goat and sheep-skin tanneries the vats are partly below and partly above the level of the floor, as shown in the view of vats in Figs. 236 and 263. The vats destined to swell the hides to facilitate the depilation and raising are usuall}?" constructed so as to take sides instead of whole hides, the hides being usually split after soaking, which answers for upper leather ; but it is very much better for the stock that is intended for sole, belt, and harness leather to lime the whole hides and then to split them into sides after liming. When split previous to liming the thin portions of the hide, shoulders, etc., contract to a much greater degree than the butts and other thicker portions, and consequently the back line is irregular, which would not be so noticeable if the lime had uniform action on the whole hide, thus economizing the waste in cutting harness leather, but more especially belt- leather, where straight back lines are very desirable. The number of hides determines ordinarily the quantity ot lime necessary for each vat. To make a new vat throw into it unslacked lump lime, cover with water gradually so as not to drown it, and stir well with a " stirrer" until slacked and reduced to the consistence of milk. This operation completed, leave it until it is ready to receive the hides. Sometimes the lime is prepared in a hogshead, and from this poured into the vat, care 266 THE MANUFACTURE OF LEATHER. being observed to retain the sediment in the bottom of the hogshead, which keeps the lime vats cleaner and is beneficial in many respects. The vats are distinguished as dead, weak, and live vats, and sometimes as old and fresh limes. The dead or old vat is that which has been frequently used and which has been nearly exhausted of its strength, the weak is that which has been used long enough to deprive it of a portion of its force, and the live or fresh vat is that which has not yet been worked. It is easy to understand that the live vat becomes successively the weak and the dead vat. When a tanner uses more than three vats he establishes between the dead and live vats as many middling terms vats as convenient and the whole of the vats are called the raising series. The raising should be commenced in the dead vat, and con- tinue in consecutive order through the series to the live vat. In some tanneries in Europe the series consists of twelve or more vats ; and in that case there should be a graduation in the strength of the liquors. The duration of this operation varies in different localities, as in all portions of Europe the hides are limed for a longer period than with us. The practice is still in vogue among some tanners of using old limes which are charged with the decomposing matter ex- tracted from previous packs, which practice, in warm weather, beconies extremely hazardous. The time usually employed for liming different classes of hides and skins will be mentioned in the chapters devoted to the manufacture of sole, upper, calf, Morocco, and other leathers. The reel is now generally employed for handling in the lime- vats and it is the most economical, convenient, and effective method, the sides being strung together, and passed over the reel from vat to vat. Steinmann's apparatus for handling hides in the lime-pits is shown in Figs. 74 to 77. Fig. 7-i represents a pit furnished with this contrivance. Fig. 75 is a vertical section in the plane of one of the spikes. THE LIMING PROCESS. Fig. 74. 267 Fig. 75. Fig. 76. -\v\\v\^ Fig. 77. F , 268 THE MANUFACTUKE OF LEATHER. Fig. 76 is a vertical section of the operating jack or gear-work. Fig. 77 represents, on a larger scale, a form of lever, pawl, and ratchet movement adapted for use with such apparatus, one in- closing-plate being removed. The pit A may be of any suitable form, from the bottom of which there rise two spikes, B B, with the points curved somewhat toward the interior of the pit, which makes it much easier for them to engage and disengage the hides than if they were straight, and besides the hides are in much less danger of injury. In other contrivances of a similar character blocks are sometimes used, having a roller on each side of the spike, and it has been found, in practice, that blocks thus constructed are liable to bind and hitch in the operation of hoisting the hides. It has also been found that portions of hide and hair would lodge in the unprotected rollers, and clog them to such an ex- tent as to render the device nearly inoperative. But Mr. Stein- mann claims to remedy both these defects by constructing the frame of the block in the form of a tube or sleeve (7, half of which, c, is semi-cylindrical, and closely hugs one side of the spike, while the other half is made of proper form and dimen- sions to contain two rollers, I) D'^ journaled, one vertically over the other. Extending from the upper part of each- sleeve or block is an eye, E^ for engagement of the hook on the extremity of a chain F^ attached to a windlass, operated by a lever and ratchet and gear movement. A suitable step or bearing, H^ affords journal-bearing for the windlass- shaft, which shaft carries a spur-wheel, /, that gears with a pinion, J, on the ratchet-shaft K^ to which shaft is per- manently fastened a ratchet-wheel, L. A lever, if, having a pawl, N^ engages in this wheel. A tentative pawl, P, pressed by a spring, 0, prevents any retrograde rotation of the spur- wheel /, and thereby enables the windlass to hold the hides to the degree of elevation desired, or, being released, permits the parts to " run down," and the hides to descend by their weight to the bottom of the pit. The length of the lever and the ex- cess of diameter of the spur-wheel /over the pinion ./impart so high a purchase that one man can do the work of two or DEPILATOEY COMPOUNDS, 269 more under tlie plan of previous contrivances of a similar char- acter. Fig. 77 sliows the preferred form of operating lever, pawl, and ratchet ; L represents the ratchet-wheel, having a central orifice, /;, whereby it is fitted and keyed fast to the shaft of the windlass-cylinder. R is the lever-socket, sleeved, and capable of revolving upon a boss of said wheel. (Shown by dotted line.) iV^is a pawl, held to the position shown, or to the reverse position, or to one just intermediate, by spring-follower S. If it is desired that the lever M should feed in the opposite direc- tion, the pawl is reversed, and the tentative pawl P is applied on the other side. If it is desired that the lever should be in- operative, so as to allow the hides to descend freely into the pit, the pawl N is placed so that its apex n will engage with the notch s of the follower. In some tanneries in the -West an apparatus is employed for liming hides which was invented in 1865, by Mr. Wra. H. Study, of Economy, Ind. ; the contrivance consists of a rotary rack, so applied to a shaft as to adjust the distance and adapt the racks to hides of various sizes. The frame used in conjunction with the rack is so arranged as to be readily raised or lowered, and the bottom of the liming vat in which the racks revolve is concave. - Section II. Other Depilatory Compounds and Processes. Rohinsoii's Process. This process consists in loosening the hair or wool from hides or skins by the direct application of steam thereto while sus- pended in any suitable apartment to which steam can be ad- mitted. Ward's Process. This method consists in the application of a compound solu- tion of carbonate and sulphate of soda. 270 THE MANUFACTURE OF LEATHER. Wikon's Process. In this method the depilatory compound is composed of 3 gallons of lime, 2 ounces of potassium, 2 quarts of strong soft soap, 2 ounces of ammonia, and 3 ounces of sulphur to each 100 gallons of water. This composition it is claimed will start the hair in two days. Carter and KeitKs Process. ' This is a solution composed of one barrel (33 gallons) of water, in which are dissolved sal-soda, carbonate of potash or common lye 11 pounds ; prussiate of potash or nitrate of soda, 11 ounces; common salt, 11 ounces; lime, 22 pounds. De Montoisoii's Process. This process consists in subjecting the skins to the influence of a solution consisting of hydrate of lime, sulphide of barium, sulphide of arsenic, potash and hydrosulphate of soda, or other form of alkali. Head's Process. In this method the hides are placed in a vat about 8 feet long, 4 feet wide, and 4 feet deep, containing water into which has been poured a mixture of about one and one-half bushels of sal- soda, and one bushel of quicklime, which composition it is claimed will shorten the time for liming the hides to about six hours. They are afterwards soaked in a vat of water at a temperature of about 110° F. for two hours and then unhaired and lime shaved. Depilating loith Steam in a tight Room or Vat, The following method of depilating was invented by Banks. After the hides are softened in the usual way they are sus- pended in a tight room or vat, and subjected to the action of steam at a temperature not exceeding blood heat. This process is to be continued in warm weather about four days and in cold DEPILATORY COMPOUNDS. 271 weather about seven days, when it is claimed the hair can be easily and readily removed. The inventor states that this method of unhairing is to be applied only to those hides that are to be manufactured into sole leather. Depilating hy the use of Soda-ash^ Caustic Lime^ Monosulphuret of Potassium, Hard Soap^ and Soft Water. For depilating a pack of fifty sides of cow hides, or one hun- dred and thirty calf skins : — Take fifteen pounds of soda-ash, thirty pounds of caustic lime, stir them in ten gallons of soft water, and boil the mixture in an iron or other suitable vessel for one hour ; let the solution become cold and then add one pound of sulphuret of potassium dissolved in water, and stir the whole thoroughly. The next thing required is a vat of suitable capacity to receive the pack of hides or skins, with a sufficient quantity of soft water to cover them. Into this vat of water a small quantity of the preparation before described should be poured, and the vat well stirred. If the attendant by dipping his finger into the vat and ap- plying it to his tongue does not feel a sensation and taste pecu- liar to the alkali, more of the solution must be added until the strength of the liquor is sufficient to produce these sensations. Two or three pounds of hard soap may now be dissolved in water, added to the liquor and well stirred, which completes the preparation of the vat, and the hides or skins are to be placed in it, and agitated frequently in order to expose every part of them thoroughly to contact with the liquor. Mr. A. K. Eaton, of New York City, who invented and used this process for a long period, states that in order that the hides or skins may not be too much plumped for the first twenty-four hours, the strength of the liquor up to the end of that period should not be increased ; but after that it may be gradually strengthened as the process advances, and until it is completed, which will be in from two to four days according to circum- stances, when the hair will come off very readily. By increas- 272 THE MANUFACTURE OF LEATHER. ing the proportion of the sulphuret of potassium, the time re- quired for the process will be correspondingly shortened. The labor involved in this process is comparativelv slight, the stock, it is claimed, is in a better condition for being treated with the tanning agents, and it is also claimed that it is heavier than when the ordinary depilating process is employed, as less gelatine is dissolved. The leather when finished, it is also claimed, is closer grained, more flexible, as well as more dura- ble, and less pervious to water when the skin is unhaired by this process than when unhaired by a process that dissoHes more of the gelatine, as the texture is less open and the leather not so spongy. The sulphuret of potassium, before mentioned, may be pre- pared as follows : Take equal parts by measure of finely pul- verized charcoal and sulphate of potash, mix them thoroughly and expose them to a dull-red heat for an hour in a covered crucible, the product will be the sulphuret required, ComjDosition for Depilating Green and Dry Hides^ with Nitrate of Potassa^ Chloride of Sodium^ Sulphuric Acid, and Tartaric Acid. Hides may be depilated in an easy and expeditious manner and it is claimed without injury, and so as to produce a greater percentage in the weight of the leather than is possible by the ordinarj^ means, by the use of the following composition: One- quarter of a pound nitrate of potassa, one quart chloride of sodium, four and a half pints sulphuric acid, one ounce tartaric acid, or, in lieu thereof, one pint of vinegar, twelve pounds of wheat-bran, and five hundred gallons of sour or spent tan-liquor. These ingredients are properly commingled and then applied to the depilation of dry or imported hides in the usual manner. In treating green hides the first two ingredients, nitrate of potassa and chloride of sodium, and the wheat-bran, are omitted from the composition, their functions being solely to soften the hard, dry imported hides, and reduce them to a condition simi- lar to the normal condition of the green hides. It is claimed by Mr. Peter G. Schlosser, of Middletown, Frederick Co., Md., who discovered this composition, and who proved it by a long DEPILATOEY COMPOUN"DS. 273 course of experiment and trial to be a very valuable one for the purpose above specified, that the injurious consequences re- sulting from the use of lime for that purpose are avoided, the substance of the hide itself not being eaten away and destroyed, as it oftentimes is when lime is employed. But all the body and strength are preserved, and a greater amount of leather is produced than it is possible to obtain when lime is used. Be- sides this it is also claimed that the time heretofore consumed in "bating" or cleansing the hide from the lime, which was very great, and the labor are entirely saved, and the whole process of preparing the material for tanning is in that degree shortened. Mr. Schlosser also claims that by this process twenty-five pounds of dry hide will produce about forty pounds of leather, and one hundred pounds of green hide will produce about seventy pounds of leather. The employment of Sidphuretted Hydrogen Gas in connection xoitli Lime^ Soda-ash, etc., as a Deiyilatory, and for the purpose of Swelling Hides, The object of this compound is to depilate and raise hides and skins preparatory to tanning, thus dispensing with milling and breaking. In order to accomplish this the inventor, Mr. George W. Adler, of Philadelphia, Pa., uses a compound consisting of gas- lime, that is lime charged with sulphuretted hydrogen gas, which is the refuse lime of gas-works, an alkali, such as soda, potash, pearlash, or soda-ash, pure lime and an oil, and he also claims that this compound acts as a preservative as well as a depilating and raising agent. The proportions are as follows : Of lime, pure unslacked or slacked, two bushels; of soda-ash, or any other alkali, fifty pounds ; of oil, either vegetable, fish, animal or mineral, two and one-half gallons ; .and of gas-lime, or lime charged with sul- phuretted hydrogen gas, two bushels, or enough to make a solution of the required strength as a depilatory. In mixing or forming the compound, take the gas-lime and add sufficient water to make a solution, then take the two bushels of lime and slack, after which add the fifty pounds of 18 274 THE MANUFACTUKE OF LEATHER. soda-ash, or other alkali, and dissolve it in water, or add the soda-ash or other alkali direct to the solution, now add the two and one-half gallons of oil, and mix the whole together, so that they will be thoroughly incorporated. The compound is now ready for use, and is applied according to the judgment of those skilled in the art of treating or tanning hides and skins. When the gas-lime is added to water sufficient to make a solution it makes a most powerful depilatory, but this is of no use, except as a depilatory, until the soda or alkali is added, as a raising agent for the purpose of swelling the hides or skins ; the oil forms a basic or mineral soap in connection with the soda and lime, and it is claimed prevents the destructive action of the alkali upon the gelatine and tissues or fibres of the hides. Those who employ this method need not of course confine them- selves to the exact proportions which have been given, as this is a matter of judgment; but the formula herein given has pro- duced the best results in practice. A Compound of Potash^ Lime^ Salt and Sulphur^ and Charcoal for Depilating. After the hides are prepared for depilation by soaking, mill- ing, or breaking, in a proper manner, Mr. John Henry, of New York City, prepares and uses the following composition :— Into four barrels of water put five pounds of potash, ten pounds of lime, ten pounds of salt, one pound of sulphur, and one-half pound of pulverized charcoal ; having previously dis- solved the other articles in blood-warm water. The whole, which is sufficient for one hundred calf-skins, or an equivalent of hides, is then put into a revolving wheel, together with the skins or hides to be depilated, and the Avheel is made to revolve at the rate of twenty revolutions per minute. Mr. Henry claims that the skins or hides are, by the method above described, brought into direct contact, as to their whole surface, with the composition, and that, being agitated and kneaded, while in the composition, the process can be com- pleted in ten hours. He also claims that this composition is less injurious and DEPILATORY COMPOUNDS. 2iO more speedy in its action, and enables the skin or hide to be tanned more rapidly afterward than if lime alone were used. The Use of " Refuse Gas-Lime^'' as a Depilatorj. The bluish-green mass which is produced in the purification of illuminating gas, and which is considered a very obnoxious refuse by gas-makers, is generally known by the name of " re- fuse gas-lime." This substance, it is stated in the patent for the present process, consists of sulphide and sulphydrate of cal- cium, and small quantities of the lime salts of carbonic and sub- sulphurous acids. The first two named ingredients, sulphide of calcium and sulphydrate of calcium, render this substance applicable for the purposes of depilation. Mr. John E. Siebel, Chicago, 111., the patentee of the applica- tion of this waste product for depilating, states that mixed with water this refuse forms a mixture which, on account of its con- taining sulphydrate of calcium, he used as a cheap and effec- tive agent in tanning for freeing the hides from hair. For this purpose the refuse gas-lime, as soon as possible after it leaves the refining apparatus of the gas-works, is mixed with water to form a thick liquid, in which the hides are immersed until the hair is loosened, and ready for removal by the unhairing knife.^ 1 I fail to see on what grounds a patent could be issued for this process, as Boettger had proposed the use of lime that had served for purifying gas, and the employment of this material for depilating purposes had been mentioned in technical books long previous to the date of this patent. See also Boettger's process for depilating with hydrosulphate of lime, described on p. 288. This material is a mixture of caustic lime, of carbonate, sulphite, hydrosul- phite, sulphate of lime, of sulphuret of calcium, of hydrosulphuret, of sulpliu- ret, and of cyanuret of calcium. The two last soluble salts especially act energetically on the hair bulb to dissolve it or to disunite it ; besides the gas- lime may be replaced by an aqueous extract of such lime. In order to avoid the inconvenience caused by the liberation of prussic acid, it is best not, immediately after the peeling by means of gas-lime, to submit the hides to the action of acid liquids. A mixture of nine parts of lime and of one part of oi'piment, which causes the formation of hydrosulphuret of calcium, may be used to peel the skins of small animals. 276 THE MANUFACTURE OF LEATHER. Depilating with the Double Sulphate of Sodium and Calcium. This compound is the invention of Jules Watteau, of Antwerp, Belgium, and is intended to be used for facilitating the pulling of wool or hair from the skins of sheep or other animals. There are taken — 38.50 parts, by weight, of carbonate of soda, 38.50 parts of hydrated oxide of lime, 13.00 parts of flowers of sulphur, 6.50 parts of pulverized wood-charcoal, ' 3.50 parts soot. These elements are pulverized and then intimately mixed together, and the mixture is boiled for about two hours, in a vessel containing about three times its weight of water, thereby producing a liquid of a dark-green color. This liquid, by means of a brush, is spread upon the fleshy side of the skin from which the wool or hair is to be removed. The skins are then placed in a pile, wool against wool, fleshy side against fleshy side, and after a few hours, it is claimed, that the wool can be pulled with the greatest facility without injury to the skin. The soot and charcoal are not essential parts of this composi- tion, but enter into it as inert matter, and so remain, as does also the carbonate of lime, which is one of the results of the combination above described. The liquid, it is claimed, de- rives its extraordinary depilating power from the resulting sulpho-sel or double sulphate of calcium and sodium. The inventor gives the proportions of the carbonate of soda, hydrated oxide of lime, and flowers of sulphur, which, in practice, he finds to be best ; but these proportions may vary considerably. The patent of Brainard, dated May 20, 1862, No. -35,293; and the English patent of Claus, 1906, granted in 1855 ; and the application of Lynds, filed in the patent office in September, 1854, would appear to conflict with this invention, but the double sulphate of sodium and calcium is not obtained in any of the combinations and processes therein described. In one or more of them sulphide of sodium and sulphide of calcium are produced, but there is no chemical union between these two sulphides. DEPILATOEY COMPOUNDS. 277 By boiling in water, however, as the inventor directs, there takes place, it is claimed, a chemical union not otherwise pro- duced, or not produced to so great a degree in any other man- ner. By the boiling the two sulphides are chemically united at the instant of their formation, giving the double sulphide. Depilating ivith Charcoal. In lieu of lime for removing the hair and cleansing the pores, charcoal may be employed either as a substitute for lime, or the hides or skins may be, as heretofore, first partly treated with lime and finally treated with charcoal. The carbonaceous matter employed may be either animal, vegetable, or mineral charcoal in suspension, and it is claimed by Mr. William Anderson, of Inverkeithing, near Edinburgh, Scotland, that the results of this treatment are that the hairs are loosened, the pores of the skins or hides purified, and the putrescent matter, grease, and other impurities removed. Mr. Anderson states that the most advantageous method of carrying this invention into effect is as follows : The hides or skins are placed in water of 60° F. with powdered wood-char- coal sufl5.cient to give it the consistence of cream, the hides or skins being removed and then placed back in the same liquor each day until the hairs are sufficiently loosened to yield easily; care being observed to stir the charcoal-powder which may have subsided in the intervals of removal, in order as far as possible to keep it in suspension. The hides or skins are afterwards washed, fleshed, and scudded as in the ordinary method, when they are ready for tanning without other treatment, and the charcoal-powder may from time to time be revivified by drying it in thin layers in the sun or in a current of air. In order to render them flat and soft, and to remove lime and other impurities from hides or skins, which may have been treated with lime for the purpose of removing the hairs, the process which has just been described may be applied. 278 THE MANUFACTURE OF LEATHER. Maynard^s Method for Depilating hy the employment of Lime in Water, together ivith Suljohurous Acid. Liming hides, as we have seen, has been done by the use of lime simply, or lime and sulphur, potash, soda, arsenic, etc., alone or in combination, the time employed being of different du- rations. It is claimed by Maynard, the inventor of this process, that hides may be rendered fitfor depilation by its use in a very short period of time, and at but small expense. Maynard claims that the use of lime in water, together with snlphurous acid, causes the lime to seize hold of the oleaginous matter of the hide, producing a saponifying effect or giving a soapy feeling to the hide, and that by introducing sulphurous acid the sulphur and hydrogen attack the hair-bulbs, decompos- ing the sulphur contained in them, loosening and releasing the hair preparatory to depilation.^ The combination of Lye from ^Vood- Ashes, or Potash, and Lime which has been treated by the Gas generated by Sulphuric Acid, Sulphuret of Iron, and Water, for unhairing Hides and Shins and for pulling Wool. The following process is the invention of Mower, and consists in a compound for "liming" and unhairing hides and skins, and for pulling wool ; and consists of quicklime, lye from ashes or potash, sulphuric acid, and sulphuret of iron. A compound is prepared in the following manner : Slack one pound of quicklime by the use of four quarts of water in a pail, to be as thick as good whitewash. Take a bottle that will hold one pint or more, clear white glass being the best. Have a half- inch lead pipe twelve to fifteen inches long, and fit one end air- tight in the mouth of the bottle. Bend this pipe so that the other end will enter the lime in the pail, one or two inches below the surface of the lime. Place four ounces of sulphuret of iron in the bottle, and cover the same well with water. Add sulphuric acid sufficient to cause the contents to boil. Then fasten the lead tube in the bottle, and let the other end into the 1 Maynard's process for bating hides and skins, which can be employed in combination witli tliis process or alone is described in Chapter XVII. DEPILATORY COMPOUNDS. 279 lime, as above stated. The sulphuric acid, when in contact with water and sulphuret of iron, will generate a gas, which is conveyed through the tube to the lime and colors the lime blue. The lime being an absorbent, the gas unites with the flour of lime. This operation should be performed in the open air, as it has a disagreeable odor. "When the action in the bottle ceases and the contents become dry, add water and sulphuric acid, as at first; but should any water remain in the bottle after the action ceases, pour off the water and add water and sulphuric acid, as above, and continue the operation until the sulphuret of iron is all consumed. The lime is stirred occasionally, so as' to mix the gas through the lime. In order to test the strength of the thus prepared lime, if sufficiently charged with the gas, it will, if a small quantity be put on the arm, remove the hair, if any, in five or six minutes, causing no pain or doing no harm to the skin. One gallon of the above-prepared lime will be sufficient to strengthen from five to six gallons of lime prepared after the common mode for liming hides. The above proportions may be followed for preparing any quantity required. To prepare large quantities of the prepared lime, for one barrel slack thirty-two pounds of quicklime by adding one gal- lon of hot water to each pound of lime. As there is a difference in the quality of lime, the operator will have to use his judgment in preparing it to do the work intended. Hides in this process of liming should be handled often ; or the best way is to have two limes prepared in adjoining vats and handle from one vat to the other once an hour for four to six hours, and occasionally after, as this process works rapidly, and by being handled often, will lime more uniformly. For harness, upper, and calf-skins add lye sufficient to give a slippery feeling to the lime as follows : For a pack of one hundred and fifty sides of upper-leather, harness, or equivalent of calf-skins add lye from ashes or potash dissolved in water, from ten to fifteen gallons. Eenew the lime by adding of the prepared lime from three to six gallons for every new pack to 280 THE MANUFACTUEE OF LEATHER. be limed, -which will keep the lime in good working condition. This process, as specified, will lime sole-leather hides in from ten to twenty-four hours, harness and upper-leather hides in from six to fifteen hours, calf-skins in from three to six hours. All depends on the strength of the lime and on being properly handled. Sole-leather hides, when unhaired, are to be rinsed in cold water, when they are ready for the tanning process. Harness and upper leather and ski'ns, when unhaired, are to be immersed in clear water and worked on the flesh side. When worked they are to be put in a vat of clean warm water and allowed to remain therein for a short time, and then the grain side worked, when they will be ready for the tanning process. To pull wool, spread the flesh side up and apply a thin coat- ing of the prepared lime with a brush. In about, one hour the wool will come oft' easily, after which the skin is immersed in water the same as calf-skins and both sides worked, ready for the tanning process. In the old method of liming the hides become so impregnated with lime that much bathing and labor are required to reduce them sufficiently to make good leather ; but in this process it is claimed that the hides raise rapidly and remain soft without this bathing and excessive labor. Lime, though an insoluble ingredient, cannot be dispensed with, as it is an absorbent, uniting with the gas generated by the action of the sulphuric acid, sulphuret of iron, and water. Lye, being a soluble alkali, penetrates, cleanses, and softens, in connection with lime in removing the hair, and will readily wash out with water. Sulphur is very penetrating and soften- ing. Iron is important in connection with sulphur in making sulphuret of iron and making gas. Sulphuric acid in this pro- cess is an important ingredient in preparing hides for tanning and in connection with the sulphuret of iron and making gas. The above ingredients prepared as specified simply dissolve the roots of the hair, and the hide retains its weight and strength. This preparation it is claimed is especially adapted for dry hides, as the ingredients, except lime, have softening qualities, which overpower the lime and raise and plump the hides, so that they will be and remain soft and pliable. DEPILATORY COMPOUNDS, 281 By this preparation it is claimed that the cost ot preparing hides for tanning is materially reduced, and considerable time and labor are saved ; and the tanning process will, if the hides have been previously prepared by this process, take one-third less time, and will produce leather of better weight, color, and quality. Depilating and removing Grease with a compound of Water, Lime, Soda- Ash, Saltp)etre, and Floivers of Sulphur. The ingredients of this compound, and the proportions in which they are to be mixed for the purposes indicated, are as follows : Pure water, five hundred gallons ; unslacked lime, one barrel ; soda-ash, one hundred pounds ; saltpetre twenty pounds ; flowers of sulphur, ten pounds. The above quantity is for treating one hundred ox-hides (or two hundred sides), and the following is the manner in which the compound is to be prepared, used, and applied for the pur- poses indicated : Clean the hides by water of all salt and im- purities, allowing green hides to soak one day and dry hides eight days, or thereabout. Then take of pure water, iive hundred gallons ; of unslacked lime, one barrel ; of soda-ash, one hundred pounds ; of saltpetre twenty pounds, and of flowers of sulphur, ten pounds. Mix all of the ingredients well to- gether until they are thoroughly dissolved. Then place the hides, so cleaned, in the solution and allow them to remain in it forty-eight hours. Then remove the hides and unhair them in the usual way. By the above process it is claimed by Tinnerbolm, the in- ventor, that the hair is speedily and thoroughly loosened, and the hides, while retaining the portion of their substance which can be tanned into leather, are, at the same time, cleaned from grease and other substances which prevent them from tanning quickly. The above procees and solution it is claimed may be used and applied in the process and art of tanning or curing all kinds of hides and skins, care being taken to regulate the time in which they are kept in the solution, according to their thickness and the class of skins to be tanned. 282' THE MANUFACTURE OF LEATHER. The composition can be used and applied by any person of ordinary skill as a tanner. Softening^ Plumping^ and Depilating Hides and Skins through the employment of Sulphide of Bariuyn in solution. Foley invented the following process for treating hides and skins previous to tanning, and it relates to removing the hair and epidermis from hides and skins of every description and however cured, softening dried and cured hides and skins, and separating tlie wool and hair from skins in their natural state. For unhairing he uses, instead of lime, but in a somewliat similar manner, solutions of sulphide of barium of varying strengths, prepared by dissolving in water solid sulphide of barium, produced by heating finely-ground sulphate of baryta mixed with carbonaceous substances to about a white heat in a reverberatory furnace or other suitable appliance. In treating green slaughter hides and skins to remove the hair and epidermis, first wash them to remove the blood and dirt, and then immerse them in a strong solution of sulphide of barium, about 15° Baume, for about three to six hours. They are then withdrawn, again washed, and taken to the beam- house, to be treated in the usual manner. In the treatment of salted or cured hides and skins for the removal of the hair and epidermis, first immerse them about ten to twelve hours in an old or partially-spent solution of sul- phide of barium, for the purpose of cleansing them and destroy- ing the effect of the salt or substance with which they were cured ; and afterward immerse them in a solution of sulphide of barium of about 6° to 8° Baume for about ten hours, when they are ready for the usual treatment in the beam-house. In the treatment of dried or flint hides and skins, it is neces- sary, before the hair and epidermis can be removed, to soften them, and this do by soaking them about twenty-four hours in a solution of sulphide of barium that has already been used for unhairing, or in a weak fresh solution of about 3° Baume. After the dried hides and skins are thoroughly softened in all their parts, in the manner above set forth, immerse them, DEPILATORY COMPOUNDS. 283 for the purpose of removing tlie hair and epidermis, in a solu- tion of sulphide of barium of about 5° Baume for about six hours, and then pass them on to the beam-house. In the treatment of skins for the removal of wool and hair, apply on the flesh side of the skins, by any suitable means, a concentrated solution of sulphide of barium mixed with any inert substance to the consistency of a thin paste. The solution applied in this manner penetrates the skin, loosens the roots of the wool or hair, and allows it to be removed uninjured and in its natural condition. Tliis invention has advantages over the liming process now in use for removing hair from hides and skins and softening them, and among others the following are claimed by the inven- tor : No part of the gelatinous tissue, grain, or substance of the hide is removed or disturbed ; hides and skins are left in their natural state and suppleness; at least twenty-five per cent, greater weight of leather can be obtained from hides treated by this invention than by the old process of liming. The hair, it is claimed, is removed in one-twentieth part of the time usually employed, thus effecting a great saving in time, labor, and expense. Hides aud skins treated by this invention and intended for upper-leather do not require to go through the operation of "bating," which effects another saving in time and expense.^ ' A number of patents have been obtained for sulpliide or snlphuret of cal- cinm for the purpose of depilating hides and skins. Sulphide of calcium has been tried by tanners, both in Europe and America, and sometimes abandoned, owing to its cost, the increased expenditure for labor attending its application, and its supposed injurious action upon tlie hides. It is claimed against it that it dissolves and removes a portion of the fibrous tissue, a very formida- ble objection to its use, if true. In my observations, I have found that sulphur combined with lime simply renders the lime more soluble, allowing it (the lime) to act more quickly ; but in this state the lime also penetrates the hide, and, notwithstanding repeated washings, remains in the hide and forms with the tannin an almost insoluble tannate, which deprives the hides of their suppleness and renders them dry and brittle. 284 THE MANUFACTUEE OF LEATHER. Depilating luith a comjwund of Watej-^ Burnt Oolite, and Muriatic Acid. In describing this compound and its use, tlie inventor, Tinner- holm, has based it on an estimate of one hundred pounds of skins or hides to be treated. One-eighth of a bushel of lime is dissolved in water and the lime solution poured into a vat containing sufficient water to cover the hides. Next a suitable quantity of burnt oolite (or other limestone of a like nature — i. e., pure calcareous spar) is treated with two ounces of muriatic acid, after which a proper quantity of water is added to form a strong lye, when this solu- tion is also poured into the vat and the whole is thoroughly stirred. The skins or hides are now deposited in the liquor and allowed to remain therein three days. They are then taken out and the hair scraped off, after which they are placed in a vat containing fresh water and left to remain one day. They are then removed, the flesh and lime still adhering is scraped off, and they are in condition for the bating process, which fol- lows the liming in the manufacture of certain classes of leather. Depilating with a Mixture of Water, Lime, and Blood. The preferred manner of carrying out this plan as stated by the inventor Bollman, is as follows : The hides or skins are first soaked in water to remove the blood and like adhering matter, after which they are drained oft'. They are then placed in a vat containing water, lime, and blood in about the proportions of one bushel of lime and one and a half gallons of blood to fifteen barrels of water for the first supply or charging of the vat. As the water, lime, and blood are absorbed, to a greater or less extent, it becomes necessary or desirable to replenish them after each stock of hides is removed, or, in other words, to maintain about the relative proportions stated. It will be understood that the proportions of the ingredients may be considerably varied ; but the formula given is preferred, being found, it is claimed, in practice to give excellent results. In some cases the first washing may be dispensed with and the skins placed at once in the lime-vat, in which case, the DEPILATOEY COMPOUNDS. 285 skins already containing a considerable quantity of blood, the amount separately added to the water of the lime-vat may be materially lessened. While as far as it goes the inventor con- siders this plan the equivalent of the first, and as included within the limits of his invention, he does not deem it the full equiv- alent of the first-described method, because he finds by actual experience that it does not produce as fine a quality of leather. He also claims to have found in practice that hides or skins treated in this way require a much less prolonged soaking in the tan -bark solution than hides treated in the old way, the difference in time being as one and three, and from that to one and ten. Leather prepared in accordance with this method is soft and pliable, yet tough and firm, and, it is claimed, will not become rough with use or wear, and will shed or exclude water far more perfectly than leather prepared by other plans. Again, he claims that he is enabled to accomplish the tanning operation with a far less quantity of bark than is required by other plans, from one-half to one-quarter the usual quantity being sufficient. It is claimed that the presence of the blood causes the hide to come from the lime-vat soft and flexible, without being worked, handled, or treated in any other way than mentioned. Besides decreasing the expense by reducing the required quantity of bark and shortening the necessary period of immersion in the bark solution, thus permitting other hides to be immersed therein, and also saving a great amount of labor formerly required in handling the hides in the lime and bark-liquor vats. A bating mixture has been proposed, in which blood and ammonia were to be used (with or without sawdust and urine) with water ; and it has been proposed to apply blood " at its stage of separation from the serum''^ to skins or hides, and there- fore Bollman does not claim broadly the use of blood. The invention differs from the first of these plans in that, instead of being a bating solution, it is a depilating mixture designed to render a bating solution unnecessary, by leaving the hides in a soft, pliable, and desirable condition, and, it is claimed, ready to be placed in the tan- vat. It differs from the second plan in 286 THE MANUFACTURE OF LEATHER. that, it is claimed, that by the use of lime the depilating action is materially hastened, while the presence of blood prevents the injurious effects which would otherwise be occasioned by the employment of lime. Depilating luith Water^ in an open Vessel. This invention relates to the employment of a process for un- hairing skins of all kinds such as those of sheep, lambs, goats, rabbits, hares, calves, oxen, cows, etc., by means of a water- stove, in which the skins are vertically suspended. The means employed are the following : Make a water-stove instead of a fermenting-stove, but with this difference, that in- stead of having a hermetically-closed chamber simply establish a large or small basin or pan capable of being left uncovered. Arrange hooks exactly the same as in a fermenting-stove, and hang the skins thereon by the shanks, side by side, taking care to keep them perpendicular. The skins being hung up and de- scending nearly to the bottom of the basin or pan, fill up the latter until all the skins are entirely submerged. The water naturally causes the peeling, and when this peeling takes place the skin has not suffered at all in the water. On the contrary, it has gained in value and the wool is completely preserved. When the moment for peeling has arrived, it is only necessary to empty the basin or vat, the skins drain separately, and they can be peeled easily. By this water system it is claimed by Mr. Aime Laure, of Mazamet (Tarn), France, the inventor, that he is also enabled, while preserving the leather and the wool, to accelerate more or less the operation of peeling. If it is pre- ferred to let the skins follow their natural coarse, cold water may be used both in winter and summer. It will be under- stood that the skins take longer to peel in winter than in sum- mer ; but no harm is occasioned by that. If, on the contrary, it is desired to accelerate the operation of peeling, use tepid or hot water, and add to the bath any material capable of hasten- ing this operation — such as soap, soda crystals, strained bran- water, etc., — provided, always, that the materials employed are not such as would injure either the leather or the wool. It may be observed that, if care has been taken to put the DEPILATORY COMPOUNDS. 287 skins into the water-stove perfectly scoured and washed (by means of what is known as the " Paech Process," for example), wool can be obtained of a value hitherto unknown. By this process of peeling, it is claimed by the inventor that the leather obtained is not only worth more, but it can be man- ipulated immediately, or the skin may be salted, and, more especially, it may be dried without losing any of its quality. As will have been seen in the foregoing description, the in- ventor has tried to replace violent and dangerous means by a most natural, practical, and economical method. He does not claim laying hides or skins one upon another in a bath. This has been done before, and is objectionable, because the skins lying one on top of the other prevent free action of the bath on their surfaces. In fact, the uppermost skin will be finished on its upper surface before any appreciable effect has been made on any of the other surfaces, and will mislead the attendant into the belief that the lower skins are in the same condition as the upper. Again, the pressure of the pile of skins is liable to injure the lower skins. Finally, the skins, when placed one upon another in a bath, cannot be drained without being first rehandled, while by this process, when the water is let out, they drain without being disturbed. Depilation hy Sulphuret of Calcmvi and Soda. Boudet, in trying the old method of depilating by means of a paste of orpiment and caustic lime, observed that the arsenic had no decided influence upon the hair, and that the depilatory action was due to sulphuret of calcium in the nascent state, formed by the reaction of lime upon the orpiment (sulphuret of arsenic). He replaced the orpiment by sulphuret of calcium, which, when made into a paste with lime, acted so promptly that, after twenty-four or thirty-six hours' contact, the skins were completely depilated. The lime alone has no depilating effect, and the sulphuret of sodium only a partial action. • Tanners are opposed to this method, which, it is said, sur- charges the leather with an amount of water that escapes by evaporation during storing, to the great loss of the dealer, but we do not think that this objection is tenable. 288 THE MANUFACTURE OF LEATHEE. Potash, Lime, and Orpiment as a Depilatory. Macerate the hides for three days, put them in the vat, raise three times, and then for each skin put — Potash 2| drms. Lime . . . . . . . 5 oz. Orpiment , J oz. This quantity is sufficient for three small goat or sheep-skins. For twenty-five hides take — Potash 1 lb. Lime . . . . . . .2 lbs. Orpiment . . . . . . 2 oz. The whole is dissolved in fifty gallons of water. This vat is much less commended than the preceding, and is liable to numerous objections, and the principal is the danger to health accompanying its manipulation. Depilation hy the Hydrosulphate of Lime. Boettger has proposed to depilate all kinds of hides with the hydrosulphate of lime, in paste, which is prepared as we shall see hereafter. To use it, the skin is put, with the hair up, on a table, when the hair is slightly impregnated with the paste, so as to penetrate as far as the roots. In the same way is treated a second hide, which is placed on the other. These two hides are covered with a board loaded with stones. Two hours after the hair is transformed into a kind of soap, which is easily removed. Preparation of the Hydrosulphate of Lime. The hydrosulphuret of calcium, or hydrosulphate of lime, when it is not convenient to obtain it from gas-works, is pre- pared by saturating a very thick milk of lime with sulphuretted hydrogen gas. The necessary apparatus is shown on page 289. Fig. 78 represents a leaden generator, of cylindrical form, thirty-six inches high by twenty-four inches in diameter, sup- ported by a wooden jacket. This vessel has a movable cover of cast iron, with a projecting ledge, through which pass the DEPILATING COMPOUNDS. Fig. 78. bolts c, c, for fastening it down. In this cover there are three openings, as shown in Fig. 79. The larger one, ^y, is the man- hole for the admission of the sulphuret of iron and for cleaning out. Of the two smaller, the one, d. receives the stationary funnel tube, d, through which the dilute sulphuric acid is to be introduced. The side hole, k, contains a short tube, J, with a screw at its upper end for coupling the flexible exit tube, m (made of vulcanized rubber), which is to convey the gene- rated gas into the lime paste contained in the closely covered receiver, x. A pipe running down the side of the generator, interiorly, is for the coupling of the steam pipe when the admission of steam is necessary. The protosulphuret of iron rests upon the bottom of the generator. When'the sulphuric acid and water (one vol. of the former to three or four of the latter) are poured in through the funnel tube, c?, to the height indicated in the figure, chemical action immediately ensues. The water, which is composed of oxygen and hydrogen, is decomposed, and the former gas goes at once to the iron, which is deserted simultaneously by its sulphur, and thus becoming an oxybase indulges its affinity for 19 290 -■ THE MANUFACTURE OF LEATHER. the sulphuric acid and unites with it to form sulphate of iron. The hydrogen unites with the sulphur to form sulphurretted hydrogen, which escapes through the tube, 7n, leading into the milk lime with which it combines as hydrosulphuret of calcium. The current of gas is continued until the lime is saturated. When the current of gas slackens, hasten it by the addition of a little acid and water. The occasional admission of steam facilitates the reaction. When the paste is saturated, stop the connection of the tubes 7n and k, and the generator is emptied by the man-hole, g, so as to be ready for another operation. The receiving vat should be of wood, strongly bound with iron hoops, and fitted with a cover and appliances for keeping it close enough to confine the gas, but not so tight as to cause an explosion. The paste should be made in quantities as required, for it must be used immediately, as the action of the air soon converts it into sulphate of lime. Depilation hy Caustic Soda. M. F. Boudet, as a substitute for lime, for raising and depi- lating hides, proposed caustic soda. For this purpose the liquid is prepared by decarbonating a very dilute solution of soda ash with a sufficient quantit}^ of lime, allowing repose, and decanting the clear supernatant liquor of caustic lye. Hides immersed in this liquor swell out rapidly and considerably, and are ready to scrape in two or three days. Moreover the alkali forming soluble salts with the fatty portions, facilitates the cleansing, and produces a smoother grained side than is common. Hides thus prepared imbibe the tan liquor more rapidly than those which have been treated with lime. They undergo the entire process of tanning in much less time, and suffer less loss than those prepared by the usual method. Forty- four pounds of sal- soda dissolved in one hundred and thirty-two gallons of Avater, and mixed with thirty-three pounds of slacked lime, suffice for steeping two thousand two hundred pounds of fresh hides. depilating by sweating, 291 Section IIL Depilating by Sweating. In the preliminary preparation of sole leather we use the "cold-sweat" process, while in Great Britain and other portions of Europe, the warm-sweat method is employed ; but for the production of upper leather, the hides are limed about as we do. Dry flint hides are the ones that are usually prepared in this country by the employment of the sweating process for depi- lating, and it is highly essential that the hides should be properly soaked, and all their parts be thoroughly softened before they are subjected to the sweating process, for if not intelligently prepared, they harden in spots, forming " old grain." " Frieze" is principally caused during the process of sweating when the grain of the hide is inclined to be tender and has the appearance of being scraped off". " Black spots" or " old grain" are blotches of dark color, and when the hide is tanned, rolled hard, and finished these spots cannot be buffed off", and some- times they extend over the whole side of leather, as has been stated in the chapter treating of the washing and soaking of hides. Gold Stv eating Process. This process, much used in New York, New Hampshire, and the northern part of Pennsylvania, has all the advantages of the older processes. It gives a gain in the leather over the warm sweating process and the liming. The process is as follows : A vault, pit, or building is pre- pared for the reception of the hides. The walls may be built of brick, stone, or of a planked frame. There should be one alley for entrance six feet long, having a door at each end, the outer one made double, and filled in with spent tan, to prevent the communication of warm air from without. A ventiduct, made of planks ten or twelve inches square, should extend from the centre of the bottom three or four rods therefrom, and placed not less than four feet below the surface of the ground. This serves both as a drain for discharging the water of the vault and to admit damp, cold air, to supply the place of that which 292 THE MANUFACTURE OF LEATHER, has become rarefied, and thus keep up a current through the ventilator at the top. The ridge of the roof if a vault is used maj be level with the ground ; and on the ridge, extending its whole length, set up two planks edgewise, two inches apart. The space between these is to be left open, but the remainder of the roof must be covered with earth, to the depth of at least a yard. The earth covering upon the vault and drain is to pre- serve a low temperature for the hides so that they may unhair without tainting. Spring water should be conducted either in pipes or logs, around the angles formed by the ceiling with the walls of the vault, from which water should be allowed to flow in small quantities, either forming a spray, or falling so as to raise a mist or vapor, and saturate the atmosphere of the vault. The temperature of spring water is generally about 50°. Water evaporating at all temperatures, it is plain that if a constant supply be afforded, this evaporation, by requiring a large por- tion of heat, would keep the temperature of the vault nearly uniform. To suspend the hides in the pit, place three bars lengthwise, at equal distances, near the ceiling with iron hooks, two or three inches apart, inserted therein. Soak the hides as usual for breaking, then hang them singly upon the hooks by the butt, so that they may be fully spread open. In the course of a few days, when the hair begins to loosen upon the upper parts, take them down, raise the middle bar, and hang them by the other end until they easily unhair. The hides should not be broken until they are taken from the vault and are ready to unhair. In a good vault where the thermometer ranges from 40 to 56° F., which it should never exceed, and where there is a free circulation of damp air, hides require from 6 to 12 days for unhairing. "When the temperature falls below 4-1° F., the ventilator should be partially closed, and when it rises above 56° cold damp air must be forced in, or an increased quantity of cold spring water may be thrown from a hose. Hides thus treated are free from all extraneous matters, and contain all their gelatin, albumen, and fibrin, in an unimpaired state. The action is confined to the surface or grain of the skin, expanding the outer portion, softening the roots of the DEPILATING BY SWEATING. 293 hair, and thus rendering its removal easy. The effect is due to the softening action of the vapor, and it is a simple case of absorption and swelling of the tissues of the skin and roots of the hair. This process has been proved by experience to obviate many of the evils arising from hot sweating or from unhairing the hides by the lime process. A Building f 07^ Siueating Hides or Skins, The arrangement shown in Figs. 80, 81, and 82 for sweating hides and skins, is the invention of Mr. William M. Mason, of Fis:. Buffalo, N. Y., and the valuable points which it contains will be readily appreciated by tanners who employ the process of sweating. Fig. 80 is a sectional elevation of a building embodying the 294 THE MANUFACTURE OF LEATHER. improvements. Fig. 81 is a horizontal section in line x x. Fig. 82 is a vertical section at right angles to Fig. 81. Fig. 81. Fig. 82. * W\\\\\\\\\\\\\\\\\\\\\\\\\\\^ This invention consists of a vault or apartment having a ven- tilator provided with a regulating- valve, and a water-floor con- sisting of a series of communicating-troughs, arranged and operating as hereafter described, for the purpose of softening dry hides and sweating the same. In the drawings, A represents a building of any kind, and B is a ventihitor at the top. If the whole building is used as the vault, the ventilator simply extends from the top, as in black lines. Fig, 80, but, if only one story is used, the ventilator is extended below and passed through the flooring, as shown by the dotted lines, thereby leaving the upper story or stories free for other uses. A valve, a. is preferably hung in the ventilator at any point, and provided with cords h 7?, by which it is ope- rated. The use of the valve is to graduate the escape of the cur- DEPILATING BY SWEATING. 295 rent from tlie interior, by closing more or less of the ventilator space. Any desired number of the ventilators may be used, and they may be extended to -any desired height, the latter being preferable as it produces an active ventilation. A water-floor, (7, is employed, to which is applied water to pro- duce the evaporation. The inventor prefers the form shown, which consists of a series of troughs or water-ways, c c c^ open at alternate ends, as shown at d c?, so as to form a zigzag water communication around, as indicated by the arrows in Fig. 81. The water enters by an induction-pipe, /, at one end, and escapes by the eduction-pipe,/', at the other end. This current or flow of the water is essential to discharge such gases as are absorbed by the water and keep the water pure. Either fresh or salt water may be employed ; but the latter is preferable, espe- cially in hot weather, as it produces a colder atmosphere, and the salt acts as a preservative to the hides in sweating. A diffe- rent arrangement of the water-floor and its troughs may be used, and the throwing or spraying of the water on the floor might be used with a similar effect, g g g are the slats or poles for hanging the hides, h h h are slats laid as a flooring over the water-troughs, with interstices left between to allow of the evaporation. By the means above described, there is produced cold sweat- ing in contradistinction to the warm sweating heretofore prac- tised. By so doing, it is claimed that the requisite dampness is always obtained without any danger of heating and spoiling the hides. The ammonia and gases are all carried off" as fast as they are generated, thus removing at once the great cause of putrefaction. There is, consequently, no loss of the hides from this source, and but little care or time is necessary in conduct- ing the operation, as compared with the usual method. Any arrangement of doors, windows, or other apertures or entrances may be used, and the vault may be so arranged that an opening may be made in the same at the bottom at any time, for the purpose of admitting air to assist the ventilating action wdien the atmosphere is heavy, as is sometimes the ca.se. 296 THE MANUFACTUKE OF LEATHER. Care to he Observed in Sioeating Hides. Some tanners prefer to maintain the temperature for the sweating pits at from 60° to 70° F. ; but the risk increases largely in proportion to the increase of temperature. Faithful attention should be paid to the hides during the advanced stage of sweating, and when any give indications of advancing too rapidly they should be removed to the bottom of the pit, and properly cared for. • When the sweating process is used for small hides or kips, they should be thoroughly washed in very clean water, spread out after four days' soaking, well rinsed and drained, then laid together in packs in such a manner that the hair is outward, and the pairs of skins back to back. Hang them over the poles of the sweating pit, with the tail end upon one side, and the head on the other. Then close the door and stop it up well so that the air may be excluded as much as possible, and leave matters thus until the odor of the sweating process becomes quite strong, which is an indication that the process of depi- lation is about to begin, and from this time out the greatest attention should be paid to the stock. The working of the sweating process is shown by a sharp lye- which forms under the hair, and which drops oft" the instant fermentation sets in. Light hides should not be placed in too strong lime ; these hides should rather be operated upon by degrees and always with weak lime, after coming from the sweating vault. The sweating process regulates and hastens the expansion of the hide, opens the pores, and places the hide in a state similar to that in which it was at the time the animal was slaughtered. To prepare it for the leather dressing process, it will be found enough to work the hide lightly on the flesh side with the iron, when it is taken out of the sweating vat, so as to stretch out the wrinkles that may appear before the hide is placed in the lime-pit, which, as has been said, should always first contain a weakened lime bath. With regard to the large hides, such as those imported from South America and elsewhere, we urgently recommend that DEPILATING BY SWEATING. 297 tliey should be subjected to the sweating process for, we repeat it, the sweating system has not only the effect of facilitating the process of depilation, but of giving to dry wild hides that development of which they stand in need, Buenos Ay res hides are a species of hide which softens easily and in a regular manner. It is admitted that hides which are allowed to remain continuously in water soften less readily than those which are alternately soaked and piled. And now let us consider how piling compares with sweating. Piling is nothing more nor less than a slow inward sweating, and while it is slow you run the risk of having the edges damaged, by giving the time necessary to effect a good result. So in order to save the back and extremities you are obliged to dispense with a com- plete softening of the hide, and moreover lose time, which is always the result of irregular soaking. We seek to attain in soaking the hide the raising up of the fibres, in order to save those parts of the hide which were wet, and became dried dur- ing transportation ; and the best mode of doing this consists in accelerating the operation, so as to obtain a thorough soaking by the sacrifice of from seven to eight days. Stagnant water does" not give the dry hide time to become completely softened again, at least it injures the grain, which becomes lost before the water has had ^me to penetrate the fibres of the hide. Under these circumstances, sweating is alone of use, and if necessary, a softening during twenty-four hours in open water will be sufficient to secure a satisfactory result, as experiment has proven. Soak the hides in water for twenty-four hours, mark the flesh side well, and rinse the hair side thoroughly, so as to rid it of all foreign substances, so that no faulty spots may ensue ; let them drain in a heap during four or five hours, and bring them to the sweating process as above described. Sprinkle them with fresh water from a gardener's watering-pot, provided with a sieve-like spout, and after the hides have been again allowed to drain off, put them back in the sweating vat. Three sprinklings with the watering-pot will be found ample, in combination with the sweating process, to soften the driest .298 THE MANUFACTUKE OF LEATHEE. and oldest hides to such a degree, that, even if they are of the heaviest, they can at once be divested of the hair. Then separate them after rinsing them, lay them again in water, clean and scrape them, and do not interrupt the gradual course which the hide has to undergo. What we have last above stated should only be resorted to when suitable water is wanting for proper soaking, for we recommend above all things that the hide be carefully soaked in water, as this raises it well, but in all cases, whichever mode of soaking be followed, the hides should never, as a general rule, be allowed to stay in the water longer than four days, or from five to six days in severely cold weather. Of course the sprinkler with a watering-pot is then superfluous, and there will then only remain the placing of the hides in the sweating vat to be attended to. They should be left in it from four to six days, according to the season of the year. The Warm Siveating Process. The process of warm sweating largely employed in Germany and many other portions of Europe is usually conducted in a buried box of suitable size, from which the air is rigidly excluded. The box has racks firmly attached to the sides, opposite each other, and into which stout notched poles are fitted to receive the hides after they are properly rolled. The cover of the box is usually composed of loose boards, which are convenient for handling in filling or emptying the sweat-box. After removal from the water and draining off' for a few hours, the hides are placed, hairside out, alongside the sweat- box, and the sides folded in towards the back, or the hides are rolled together from the side towards the back. If the sweat-box is of a sufficient depth, folding in of the head is not necessary, but otherwise it has to be done to prevent the hide from touching the bottom of the box. To keep the head from sliding out, which might easily happen, both ends of the rolled hide are securely tied with twine. After covering the bottom of the box with a layer of spent tan three or four inches thick, the. hides are hung close together over the above-men- tioned poles. The box is then tightly covered with boards DEPILATING BY SWEATING. 299 upon which, to prevent all access of air, tan is piled to the depth of about ten or twelve inches, and well trodden down. Warm steam is frequently used in order to accelerate the sweat- ing process. Though this method offers some advantages, great risk is connected with it and the utmost care must be exercised to guard against overheating. Spontaneous heat, which is generally developed in five to six days, is always preferable, as it acts more uniformly than heat produced by steam. After remaining in the sweat-box for a few days, the con- dition of the hides is examined by removing the tan from one corner and pushing a board far enough back to allow the introduction of the hand. If after examining several hides, it is found that no heat has been developed and the hair not loosened, the box is immediately closed. With some experi- ence and skill it is an easy matter to determine how long the hides will still have to remain in the box ; fourteen days being frequently required before the hair becomes loose. The great- est care and precaution are necessary during the entire sweating process, as putrefaction promoted by heat makes rapid progress and may cause great loss. Sweating fresh Hides. After cutting out the horns, fresh ox hides intended for sole leather ai'e spread out and thoroughly salted upon the flesh side. After folding each hide in the middle from head to tail and tucking in the hoofs, sides, and head, it is formed into a pack. Several of these packs are then piled upon one another and covered with Avoolen covers or straw. It is best to perform these operations in a cellar. It is advisable to use three pounds of salt for a large hide, as this quantity is required to protect the flesh side against putre- faction, and besides makes the hide more solid. After twelve to sixteen hours the hides are turned. The packs are taken apart, the hides refolded and again piled up and covered, after which they require turning only every three or four days. By this method the hair becomes loose in two to three weeks. Fresh salted hides are generally not subjected to the sweat- ing process, it being preferred to place them, after thorough 300 THE MANUFACTUEE OF LEATHER. soaking in water, in weak lime, when the hair becomes suffi- ciently loose in from six to eight days to allow of the hides be- ing unhaired. Section IV. Other Methods of Depilating now NEARLY OBSOLETE. The other methods of depilating formerly practised by the tanners of Europe at times, were raising by barley and other grain dressings, and sour tan-liquor. The first is accomplished by placing the hides in a series of vats having a regular gradua- tion in the strength, for instance, five hides are placed in the first vat where they remain twenty-four or twenty-eight hours, and are then transferred to the second, which is slightly more sour, and so successively through all the vats. After the skins have been treated properly they are washed in clear water for the removal of the dirt, and when they come to the last dress- ing they are rinsed and scraped over with the fleshing knife; at last they are again put in water and brushed over on the hair side. Some, after this manipulation, lay the hides in the vats, but many persons subject them at first to a red dressing. This dressing is given by spreading the hides in a vat, one above the other, and placing between each pair two or three handfuls of ground bark. They add water until the hides are submerged. This process requires two days, and the hides require only one withdrawal to allow them to drain. In giving the finishing wetting, care must be observed to supply bark where it is wanted. This method of cleaning and unhairing presents as many ob- jections as the lime process, and besides has other disadvantages. The efficiency of the bath is destroyed when exposed to a low temperature, and it is not resorted to when the bath thaws. The leather is in danger of being injured by the putrid fermen- tation of the materials. In England, for coarse hides, they sometimes used the barley dressing, and completed the operation in six days. • The hides passed through four or five dressings, and from the weak pro- OBSOLETE METHODS OF DEPILATING. 301 gressively to the strong. The hides remained 24 hours in the last vat, which was new, and had been soured for 15 days. It was made by mixing 60 lbs. of barley meal in hot water. As a long time was allowed for the development of acid, and con- sequently the dressing was more active than ordinary ones, it was necessary to watch carefully when the required point was reached, otherwise the hides would be injured. Another method was to deprive the hides of hair by stacking them in heaps and promoting warmth by covering them with straw or manure, until the hair was ready to be removed. If it came off" with difficulty upon the beam, its separation was facili- tated by the use of sand spread upon the hair side. This method is disadvantageous and injurious to the skins. liaising hy Sour Tan Liquor. This process is still employed to a very moderate extent in France and Germany for depilating, and is conducted about as follows : — The skins are soaked for 24 hours in fresh water, and carefully fleshed and deprived of all superfluous parts. ■ When perfectly clean and well rinsed, they are deposited in the liquors by which they are to be swelled for depilation. These liquors are con- tained in a series of eight or ten vats made of oak, hooped with iron ; they are 3 feet 8 inches in depth, and 5 feet 5 inches in diameter. In each vat deposit seven or eight skins, and cover them completely with the liquor. Let them soak 24 hours in the first vat, which contains the weakest liquor, and during that time take them out twice to drain for one hour, the skins being placed on boards which are inclined so that the fluid dripping from them runs back into the vat. After two days take them out, let them drain one hour, and place them in the second vat, which contains a stronger infusion. The same operations are repeated daily until the skins have passed through all the vats. If at the end of this time the hair appears ready to fall ofi', it is removed from the skins b}^ work- ing them in the ordinary manner upon the beam with the un- hairing knife. In cold weather it is sometimes the case that the process has not been sufficiently completed at the end of the time 302 THE MANUFACTURE OF LEATHER, mentioned, and that the skins require exposure to the strong liquors for five or ten days longer, in order that the hair may be removed with facility. Tlie skins are then " plumped" and treated for the reception of the tanning liquor. Raising hy Yeast. Yeast has the property of raising hides and skins, and has heen used for this purpose. It is mixed in a vat with warm water, the vat is covered, and fermentation takes place. When this is fully established, a quantity of salt is thrown in, and the skins are deposited in the vat, the contents of which are then treated precisely as in the case of barley dressing. The opera- tion can be conducted in the cold, but is much more rapid and successful if the temperature of the liquor be kept elevated. We have given the above now nearly obsolete processes to satisfy manufacturers, rather than to induce them to use them ; for the dressings with barley, and generally with grains, are not followed now, on account of the influence of the temperature upon them, and the great liability of the hides so treated to become putrefied, or injured by the undue fermentation of the materials employed. List of all Patents for Compounds for Depilati/ng^ Hides and Skins, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Eesideuce. June 30, 1836. J. Banks, Dixmont, Me. 336 July 31, 1837. B. F. Emery, Bath, Me. 2,096 May 15, 1841, F. and H. Robinson, Wilmington, Del. 2,842 Nov. 4, 1842. J. W. Cocliran, New York, N, Y. 12,151 Jan. 2, 1851. A, . H. Ward, Jr. Boston, Mass, 12,369 Feb. 6, 1851. Z. W. Fiske, Louisville, Ky. 17,562 June 2, 1857. A, , K. Eaton, New York, N. Y. 29,392 July 31, 1860. D. Luflvin, Cleveland, 0. 35,293 May 20, 1862. J. Brainard, Cleveland, 0. ' Such patents as No. 144,150 for depilating or removing hair from scalded hogs by machinery, and Nos. 121,565 and 141,972 for depilating by pulling wool from pelts by machinery, will be found under the list of patents for unhairing machines. PATENTS FOR DEPILATING. 303 No. Date. Inventor. Residence. 52,464 Fel). 6, 1866. B. F. Taber, Buffalo, N. Y. 59,627 Nov. 13, 1866. J. M. MuUer, North Becket, Mass. 78,543 June 2, 1868. P. Ct. Sclilosser, Middletown, Md. 86,506 Feb. 2, 1869. L. Clozel, • Grenoble, France. 92,179 July 6, 1869. A. Fan and E. Fan, Castres, France. 99,387 Feb. 1, 1870. a. W. Adler, Philadelphia, Pa. 104,734 June 28, 1870. J. Henrj, New York, N. Y. 116,638 ] Reissues 4,449 1 July 4, 1 Sept. 12, 1871.) 1871. ) J. E. Siebel, Chicago, 111. 4,550 J 120,606 Nov. 7, 1871. R. P. Wilson, New York, N. Y. 123,598 Feb. 13, 1872. J. Watteau, Antwerp, Belgium, 123,748 Feb. 13, 1872. C. J. Tinnerliolm, Quiucy, 111. 125,020 Mar. 26, 1872. A. C. Keith, .lersey City, N. J. 131,927 Oct. 8, 1872. Wm. Anderson, Inverkeithing, G. B. 136,081 Feb. 18, 1873. Wm. Maynard, Salem, Mass. 136,082 Feb. 18, 1873. Wm. Maynard, Salem, Mass. 136,488 Mar. 4, 1873. J. Carter and A. C. Keith, Jersey City, N. J. 145,436 Jan. 10, 1871. Wm. M. Mason, Buffalo, N. Y. 153,636 July 28, 1874. C. J. Tinnerliolm, Chicago, 111. 158,608 Jan. 12, 1875. C. J. Tinnerliolm, Keokuk, la. 158,648 Jan. 12, 1875. H. Mower, Camden, N. J. 165,348 July 6, 1875. E. Manasse, Napa, Cal. 176,606 Apr. 25, 1876. J. L. De Montoison, Manchester, Eng. 181,061 Aug. 15, 1876. Wm. Farris, Yarniouth, Me. 196,672 Oct. 30, , 1877. J. Kent, Gloversville, N. Y. 211,532 Jan. 21, 1879. C. J. Tinnerliolm, Brooklyn, N. Y. 223,200 Dec. 30, 1879. J. Wells, Wilmington, N. C. 226,447 Apr. 13, 1880. J. Foley, Montreal, Canada. 236,860 Jan. 18, 1881. C. J. Tinnerliolm, Brooklyn, N. Y. 257,442 May 2, 1882. J. Head, Hornellsville, N. Y. 262,924 Aug. 22, 1882. J. B. Bollman, Dayton, 0. 281,287 July 17, 1883. J. L. Moret, Pari-s, France. 285,044 Sept.18, 1883. A. Laure, Mazamet, France. 287,255 Oct. 23, 1883. A. H. Stone, New York, N. Y. 304 THE MANUFACTURE OF LEATHER. CHAPTEE XVI. UXHAIRING AND FLESHING- — UNHAIRING BY THE HAND PROCESS — FLESHING BY THE HAND PROCESS — SOAKING HIDES AFTER FLESHING — UNHAIRING AND FLESHING BY MACHINERY — tiST OF AMERICAN PATENTS FOR UNHAIRING AND FLESHING MACHINES. Section I. Unhairing by the Hand Process. In this country the unhairing and fleshing of hides is accom- plished both bj hand and machinery. The hand process is still the general manner, and we shall consider it first and the machine process afterwards. The operations are conducted in the "beam-house," an inte- rior view of which showing the forms of beams employed and other details is given in Fig, 83 ; the German form of beam and stand, used in tawing establishments for skins is shown in Fig. 84, and the unhairing knife in Fig. 85. After loosening the hair, the hides, if they have been sub- jected to the sweating process, are removed from the sweating- vaults, drawn through fresh water, and allowed to drain. This operation prevents drying, promotes cooling off, and interrupts putrefaction, and as hides thus treated will usually keep for two days without suffering damage, unhairing need not be hurried. Limed stock is taken from the "limes" directly to the unhair- ing beams and not passed through water as in the case of hides that have been subjected to the sweating process. The "unhairing" of hides and skins is usually effected by placing them upon a beam and scraping the hair off with a con- cave blade called the " unhairing knife," which agrees with the curvature of the beam, and the operation is performed by men of great physical strength, endurance, and skill, acquired only by long and continued application ; but this manner is too slow to or? UNHAIRING AND FLESHING. 505 meet the large and constantly increasing demand for leather, and consequently aids in rendering this material too dear for a commodity of such varied and indispensable employments, and in order to facilitate unhairingalarge number of machines have been invented both in this country and in Europe. Fis. 84. Fig. 85. To offer increased resistance to the tool in the hand process, very fine sand, or road dust, mixed with a small quantity of ashes, is sometimes rubbed, into the places where the hair is difficult to remove; but this practice is injurious to the grain and should not be employed. As depilation is more easily accomplished by pushing the knife against the hair, the sides from the hind hoof towards the head are first operated upon and then towards the back. Fresh hides are operated upon as soon as the hair can be pulled out around the hoofs, and from the upper part of the head. After depilation the hides are again placed in water, and rinsed and left to remain over night, after which they are usually ready for fleshing. In the process of unhairing hides and skins sometimes- some 20 SOQ THE MANUFACTURE OF LEATHER. of them are cut or so injured that thej are reduced from the first quality to a lower grade, and thus loss is occasioned. It is well known also that after the hair has been removed by the usual process of liming and scraping or rubbing it off, there remains a short fine hair or fur, and also hair on the edges and extremities of the hide, which has to be removed generally during the scouring by a sharp knife or other instrument called the "short-hair knife." The chief mischief is done to the hides in removing the fine hair by cutting or clipping the grain of the hide, and when this is too frequently done a guard should be attached to the knife in order to prevent the possibility of damaging the skin, especially when it is intended for delicate work. This knife is m.ade of steel, like ordinary knives, with the usual handle, but for convenience the blade may be made with a double edge, the under side of which is somewhat convex, being thickest in the middle and gradually decreasing in thick- ness to the edge. The upper side of the blade may have a dovetail rib in the middle or thick part of the blade, and from this rib to the edge on either side the blade should be somewhat concave. The guard is made with a dovetail groove, so as to slip closely on to the rib. It is made of German-silver, brass, copper, or any suitable metal or material, and should project beyond the edge of the blade about the sixteenth part of an inch. Its edges should be thick enough, or slightly corrugated on the inner side, so as to give it requisite stiffness. When the knife needs sharpening the guard may be easily slipped off and also ground down if necessary. The concave side of the blade and the openings of the guard allow the hair to pass off without inconvenience. The knife is used in the same way as the ordinary knife, and is of great value in cleaning kid-skins and other varieties of skins used for glove leather, where so much care has to be exercised to prevent clipping the grain. In France particular attention is paid to the beam work on calfskins, and we will describe the process of unhairing and fleshing as practised in that country. U:^rHAIEIXG AND FLESHIXG-. 307 The beam-house is so arranged as to avoid loss of time for tlie workmen in taking out of the vats and putting back the skins they are working. They have at least three vats for five or six beam-hands ; these vats have a capacity of 375 or 400 gallons each ; the water runs into and out of them with rapidity so as to fill and empty them promptly. The unhairing beams are five feet long, and are covered with strong sheet zinc, and thus have a smooth surface convenient for the work of the operator, and which avoids breaks and knife cuts on the grain side. The sheet of zinc is 3 ft. 4 in. long and 2 ft. 1 in. wide; the beam presents a convex line of 7|- inches rise. The zinc is fastened with round-headed tacks well nailed down, and must be put about 1^ inches below the head for the following reasons : It often happens that it is necessary to put for dripping 25 or 30 skins on the same beam and to leave them on it for several hours, in which case the undermost hide which rests on the edge of the head of the beam will have a deep curved mark pressed on the neck, and this mark cannot be taken out in tanning or even in currying. The grain at that spot looks like parchment and refuses to take the tannin. A prominent French tanner tried to discover the origin of these spots, and found that they had been caused by the sharp edge of the beam-head, and he put the zinc about 1^ inches further down, and from that time he did not find any more of these creases which had previousl}'' spoiled the skins and diminished their value. The beam for fleshing the skins and for thinning the neck is broader, and less arched than the other ; it is lens shaped. This facilitates the work of the knife, for by having a broader surface, the edge is less liable to slip and make flaws, and the work progresses more rapidly, as the operator is not forced to change the position of his calf-skin so often, and when he reduces a throat or a head, he does so in a more uniform manner. To unhair slaughtered calf-skins fresh from the Paris market, the workman lays two large skins at a time on the beam, and when of medium size places three ; but when the calf-skins are 308 THE MANUFACTURE OF LEATHER, small, places four. In order to avoid scratches and to make the action of the knife easier, the workman gives great care to the edge, and leaves no trace of hair upon them. He then places them in water, and rinses them. Next a skilful workman cuts the navels and nipples, trims the rumps, fashions the breeches and the tails, going entirely around the skins and reaches the neck, which requires special treatment. Should there be any flesh left by the butcher on the flanks and necks it is lightly removed with the fleshing knifq. Section II. Eleshing by the Hand Process. This operation, which consists in removing all fleshy and fatty matter by means of a sharp blade, requires great skill. In some tanneries the work is performed with a fleshing knife hav- ing a curved blade, which measures about seventeen and a half Fi?. 86, inches be^een the handles for the kind used for hides, and about si:j^^h and a half inches for skins ; this form of flesher is shown in Fig. 86. A workman once accustomed to handling this tool can turn out very clean work, but it is far better to use for this purpose Fig. S7. the so-called German fleshino- knife, which has a blade measur- ing from tAventy to twenty-three inches between the handles, and about an inch and three quarters wide, and which is shown in Fig. 87. The German, or spring fleshers, are especially recommended UNHAIRIN'G AND FLESHING. 309 for extra clean work, they make a more satisfactory cut than the other styles of fleshers, as the workman is able to readily adjust it to the curved shape of the beam, which is a great ad- vantage over the stiff straight-edged fiesher cutting on an oval or convex surface. The spring pating fleshers measure about seventeen inches between the handles. In the commencement of fleshing a hide is laid escutcheon part down over the beam, and shaved the entire width of the beam and as far down as the workman can reach, this hide forming a support which is later on replaced by one entirely shaved. The hide to be fleshed next is laid, head down, over the beam, and after shaving it, first the entire width of the beam and next the sides, it is turned over and finished by shaving the escutcheon. In fleshing the left hand precedes the right, and, to prevent injury to the hide by cutting into it, the workman should accustom himself to drive the knife without stopping, as far as he can reach from the top to the bottom of the beam. The projecting filaments or shreds, and those parts of the borders of the skin which are thicker than the rest, are cut off" with a sharp knife and the portions thus removed are sold to the glue manufacturer. For the removal of butcher cuts not accomplished by fleshing the smoothing stone often proves a great advantage. The saw-toothed flesher sometimes employed for dry hides is shown in Fig. 88. Fig. 88. The turning steels employed are round and three square, sometimes the latter style is file cut on one side. The three square plain turning steel is shown in Fig. 89. In the portion of this chapter devoted to the unhairing of calf-skins, page 308, the manner of cutting the navels and 310 THE MANUFACTURE OF LEATHER. nipples, and trimming the rumps, etc., of calf-skins was described. Following this operation the flesh sides are gone over with the " worker," the skins being pushed crosswise or diagonally, start- Fig. 89. ing from the humps of the shoulder. Large calf skins are put on the beam one at a time ; but two skins are put at once on the beam if they are of medium size or thin. In order to have this work done successfully the workman must, by means of short and brisk blows, applied in a kind of moving fashion, get off by main strength all the fleshy and parchment-like tissues, from the body of the hide and from the sinews of the fore and hind legs. The action must be brisk and vigorous on the crupper where the nerve of the hide must be entirel}^ broken ; go over lightly on the fore and hind flanks without even trying to take oft' the tissues with which they are covered ; the collar must also be managed carefully; the action must be brisk on the necks and heads if there are any tissues. In acting in this way the nerves of the hides are completely broken on their sinewy parts, and due consideration is given to the weak or hollow spots. This work is very important, and must be overlooked with great care, as the skins that are not worked in the way just explained, but which are merely and indiscriminately scraped for flesh, never develop themselves well in tanning, refusing to absorb the tannin and give poor results in the currying. When all the skins have undergone this process they are put to soak for six hours in a vat of clear water. Then they are next counter-fleshed, putting two hides at once on the beam ; they are again soaked in water for an hour or two ; they are taken up and gone over with the " worker," put- ting two large skins on the beam, or more if they are small ; the flesh side to be upwards. It is very important to have this operation well done with the " worker," slight blows at first, UNHAIRING AND FLESHING. 31T then "heavier, in order to empty and purify them of lime ; then the grain is cleaned with a knife of which the bevel must be very smooth in order to avoid scratches. After these two operations the hides are put to soak in clean water for three or four hours. They are then taken in hand again and given a last working of the grain on the body of the hides only ; are rinsed for the last time, and piled awaiting stor- age in the vats. It requires a sure hand to do the fleshing of a calf-skin. The work must be done in mowing fashion only, as straight heavy blows are apt to enter the skin and leave marks of cuts. The butchers do generally enough mischief to the hides with- out the tanners adding any more. It requires then some know- ledge and experience to avoid all mishaps; and furthermore the tanners' is a rough trade and it requires a pair of stout, hard and vigorous arms to make a good beam.-hand. Section III. Soaking Hides after Fleshing. This operation exerts a great influence upon the quality of the leather, and is much more highly esteemed in Germany and France than in this country. After fleshing, the hides are placed in water as clean and clear as possible, and if running water is used a location where there is but little current, or none whatever, is chosen. If a river or creek has to be used for the purpose, a pole is driven perpendicularly in the bottom of the river upon which the hides are successively strung through the ear hole and pushed towards the bottom, care being observed to keep them spread out horizontally. If the water is deep enough as many as twenty hides may be suspended one above the other. To give a better support to the pole the end projecting above the water is pushed through a strap secured to the bank of the river. The hides are drawn up twice daily by means of a hook, rinsed off, moved and replaced in the manner described. 312 THE MANUFACTUEE OF LEATHER. Soaking Hides in a Steering Cistern after Fleshing. In tanneries located on a river or connected with a water conduit, provision is generally made in Germany and France for steeping cisterns, which are of great advantage for the prepara- tion of sole and upper leathers. They are constructed either of stone or wood and so arranged that the water can be admitted and drawn off very rapidly at will. After fleshing the hides are placed in the steeping cistern previously filled with fresh water. After 12 hours they are moved, the water is drawn off, and the hides, after the admit- tance of fresh water, are replaced in the steeping cistern. This operation should be scrupulously repeated twice daily to pre- vent putrid soaking from making its appearance to the injury of the hides. By putrid soaking, which is recognized by a foul odor of the water, we understand the assumption of a flabby condition by the hides, while, on the other hand, with a fresh and sound soaking, they feel firm to the touch and smooth upon the grain side, and the water has no odor whatever. Hoiv long should the Hides soak after fleshing^ and what indicates their readiness for Scouring? In this country the hides, after fleshing, are soaked for a much shorter period than in Germany and France. Hides intended for sole leather, with us, are generally allowed to soak over night, while in the countries which have been named, the time for soaking is from three to five days, the period depending much on the temperature of the water, the hides meanwhile being frequently examined as regards their readiness for scour- ing. They are ready, 1st, when the fine film still adhering on places after fleshing can be readily detached by scraping with the finger nail, and 2d, when by pressing with the fingers upon the grain side the indented places remain visible. As these in- dications can be most readily perceived after rinsing, it is well to make the tests after each rinsing operation. Hides intended for the production of upper leather after being " green shaved" are placed directly in a bate of hen manure and worked for 8 or 9 hours with a drench wheel, after UNHAIRING AND FLESHING. 313 which for about 10 minutes they are worked in a wash-wheel, and are then worked over with a hide-working machine and are next placed in spring water to soak over night. It is con- ceded that the bate neutralizes the lime in the hide and leaves this class of leather more pliable than when it is subjected to long soaking in water, which while it will extract the lime imparts an undesirable harshness to upper leather. Section IV. Unhairing and Fleshing by Machinery. The processes of unhairing and fleshing hides as usually per- formed are the most laborious operations in the business of tan- ning and require the workman to be constantly in contact with cold, wet hides, which is very injurious to the constitution, subjecting most operators to disease and forcing many to leave the business. Attempts have been made to perform this opera- tion by machinery. The unhairing of hides and skins by machinery is now an accomplished fact, true there is still room for improvement in these machines, but in those that are generally accepted by the trade these improvements are of only minor importance. But such is not the case with fleshing machines and they are not generally employed, for in an extended visit to many of the largest tanneries in this country I saw but few fleshing machines at work. At one tannery located about four miles out of Boston, Mass., I saw two fleshing machines in constant operation in the beam-house ; but in many other tanneries fleshing machines have been tried and abandoned, while in still other tanneries experiments were being made to convert them into " slating" or other forms of machines. The tendency to either " scab" or " slight" the hide is a principal objection to fleshing machines as a class, and the necessity of going over the edges and other portions of the hide by hand after it leaves the machine is another drawback, which deters tanners from em- ploying them at present; and still another objection is that they work the hides too much in some portions and render them soft and flabbv. 314 THE MANUFACTURE OF LEATHER, Larrahee's Unhairing Machine. Larrabee's machine for unhairing and scouring hides and skins is shown in Figs. 90 to 95. The operation of Larrabee's machine is as follows: The machine being set in motion, the operator places a hide or skin upon the apron, with the hair side up, spreading it out as smooth as he can thereon, the apron in the mean time carrying UNHAIEmG AND FLESHING. 315 the skin toward the drum D until its end comes in contact therewith, when the upward movement of the drum prevents the skin from being carried around the inner apron roll, and compels the skin to follow the movement of the drum, and Fig. 92. Fiff. 93. pass between it and the feed-roll P, where it is pressed hard upon the drum, and, being in a wet state, adheres firmly thereto, and is carried around thereby till it is slipped off by coming in contact with the shield T. 316 THE MANUFACTURE OF LEATHER. When the skin has advanced around the drum till its end is between the drum D and the knife-cylinder J/, the operator places his foot upon the treadle, and, depressing it, causes the drum D to be moved toward the knife-cylinder till the edges of its knives come in contact with the surface of the skin with sufficient pressure to remove the hair, the knife-cjlinder re- Fig. 94. volving at a high rate of speed, while the hide or skin is fed forward quite slowly. The skin, continuing to adhere to the drum, is carried between it and the brush i?, also revolving at a high rate of speed, for the purpose of cleaning the skin. The skin then comes in contact with the shield T, and is stripped off from the drum, and, sliding down the shield, is discharged from its end at any desired point. Fig. 90 is a plan of Larrabee's machine. Fig. 91 an end ele- vation. Fig. 92 an elevation of the rear side. Fig. 98 is an elevation of the end opposite to that shown in Fig. 91. Fig. 94 is a vertical section on line x x on Figs. 90 and 92. Fig. 95 is a section on line z z on Fig. 90, illustrating the method of mov- ing the supporting-drum toward the knife cylinder. The side frames A A are connected by the tie-rods B B and girt G. The work-supporting drum D is covered with rub- ber, in order that its outer surface may be elastic and accommo- UNHAIEING AND FLESHING. 317 date itself to any inequalities in the thick- Fig. 95. ness of the hide or skin, the boxes a a in which this roll is mounted are detached and movable in the oblique slots b 5, formed in the frames A J., and motion is imparted to the drum D by means of the driving- shaft ^, and gears F, (7, H and I. J and K are two rolls, around which passes the endless apron L^ having motion imparted thereto by the pulley c on the end of the drum-shaft, and the belt c?, leading therefrom to and around the pulley e on the end of the shaft of the apron-roll K. The upper surface of the apron L\^ placed some two or three inches below the level of the top of the drum D^ so that the hide or skin will be presented to the drum by the movement of the apron at a point where the periphery is moving upward and backward, say at an angle of about forty-five degrees, the roll t/" being so placed that the apron, passing around it, shall move in close proximity to the periphery of the drum i), but not in actual contact. M is the cleaning cylinder provided with the right and left hand spiral projections or blades//, and mounted in the boxes g g^ so arranged that the cylinder M may yield and accommo- date itself to different thicknesses of hides and skins. Eotary motion in the direction of the arrow is imparted to the cylinder M by means of the pulley iVon the end of the cylinder-shaft, the pulley o on the end of the driving-shaft E^ and the endless belt F^^ as shown in Fig. 91. P is a feed-roll adapted to be adjusted by means of the set- screws m m, rotary motion being imparted to the feed-roll by means of the gears / and Q. i? is a cylindrical brush, mounted in suitable bearings in the frames A A^ in such a position that its periphery shall be in contact with the surface of the drum i), or the hide or skin passing over and partially around said drum, for the purpose of cleaning the hide or skin after it has been acted upon by the knife-cylinder M. Rotary motion is imparted to the brush i?, in the direction 818 THE MANUFACTURE OF LEATHER. indicated by the arrows, by the belt S, leading from the pulley n on the shaft of the cylinder if to the pulley o on the end of the brush -shaft, as shown in Fig. 91. ^ is a curved shield or guard extending across the machine below the drum D and the brush jR, with its upper edge in close proximity to the under side of the drum, so as to serve the purpose of a " doctor-plate" to strip the hide or skin off from the drum, and also to direct the hide or skin to the de- sired position for discharge. ?7is a rocker-shaft, having its bearings in the frames J. J., and having firmly secured thereon two radial arms, p p, one near either end of said shaft, the outer or movable ends of which bear against the under sides of the boxes a a, in such a manner that a movement of said arms, in the direction indicated by the arrow, will cause said boxes a a and the drum i), having its bearings therein, to be moved obliquely in an upward direc- tion. It will be observed that the radius-arms p p and the rocker- shaft U are so arranged relative to the boxes a a that the radius-arms ppact upon the boxes more in the nature of a wedge moving in an arc of a circle than as a direct lifter, and that by moving one of said radius-arms around the axis of the rocker-shaft slightly, while the other arm j) remains fixed, one end of the drum D may be raised or lowered, while the other remains stationary, for the purpose of adjusting the drum to the proper level. T^is another radial arm, also secured firmly upon the rocker- shaft Z7, and connected at its outer or movable end by means of the connecting-rod V to the treadle W, so that the operator, by placing his foot upon the the treadle W, can move the drum toward the knife-cylinder. Talpey^s Unhairing Machine. Talpey's machine for unhairing and scouring hides is shown in Figs. 96 to 99. The operation of Talpey's machine is as follows : The table G is first moved into the position indicated by dotted lines in Fig. 96, when the hide or skin to be worked is spread evenly UNHAIEING- AND FLESHING. 319 thereon with the middle of its length over the slot 5, when the table G is moved endAvise in the direction indicated by the arrow 7n, by the operator or otherwise, till the stop I strikes the bar E and arrests the motion, when the carrier-plate P is made to move upward through the slot I) of the table 0^ lifting the hide from the table by its middle, and carrying it upward be- tween the cylinders H H^, which are made to revolve toward each other, as indicated by the arrows n o, and at the same time are pressed against the hide by the weights K K, each of which acts independently of the others, so that if the hide should be thicker at one edge than at the other the cylinders will adjust themselves to the general surface of the skin, any small, short, or sudden variations in the thickness of the skin being compen- sated for by the independent yielding of the several sections or any one of them. When the hide has passed up between the cylinders it may be removed from the plate P, and the cylinders H H^ may be thrown apart by the operator pressing downward upon the end of the lever iV while the carrier-plate F is returned to the starting-point. Fiff. 96. Fig. 96 is a plan of Talpey's machine. Fig. 97 is a side elevation. Fig. 98 is a vertical longitudinal section on line x x on Fig. 96, and Fig. 99 is a central longitudinal section through one of the knife cylinders and its barings. A A are the side frames of the machine, connected by the 820 THE MANUFACTURE OF LEATHER. Fig. 97. Fiff. 98. Fig. 99. base-board B and the tie rods (7, Z^, ^, and F^ and each having formed in its inner face a horizontal groove, a, into which is UNHAIRING AND FLESHING-. 321 fitted the table G^ having in the centre of its length the slot S, extending transversely of the table, and of a length equal to the width between the frames A A. H and H^ are two knife- cylinders, mounted respectively in boxes c c and c' c', supported on the screw-pivots d d and d' d' set in the slides / / and I' /', which slides are fitted to and adapted to be moved horizontally in suitable ways formed in the upper portions of the frames A A. J J and J' J' are levers, pivoted respectively to the front and rear ends of the upper portions of the frames A A Sit points marked e e, the short arms of these levers bearing against the outer ends of the slides / and /', while the long arms extend horizontally and carry thereon the counter-weights K K^ as shown in Figs. 96, 97, and 98, which are of sufficient weight, and so adjusted that the cylinders H H^ will be forced toward each other with enough pressure to produce the desired action upon the hide or skin as it is moved up between the cylinders. L L are two levers, each 'pivoted, as at/, to one of the frames J., with its lower end between the slides /and I\ and so shaped and arranged relative thereto that a movement of its top end toward the front of the machine will cause the slides /and P, and consequently the cylinders H and /?\ to be moved away from each other at about an equal rate of speed. The upper ends of the levers / / are each connected by a link, J/, to an arm or lever, N or N\ formed upon or secured to the rock-shaft 0, mounted in bearings formed in the frames J., as shown in Fig. 96. The arm N is extended beyond the attachment of the link i/, to form a lever or handle for operating the levers / to move the cylinders outward. P is the carrier-plate, arranged in a vertical position, with its upper end just below the level of the under side of the table G and between the ties or guide-bars E and F^ and set at its lower end in the bar Q^ which has a bearing at each end upon the vertical guide-rod i?, upon which it is free to be moved up and down by any suitable means for imparting a reciprocating motion thereto and to the carrier-plate P. To each end of the bar Q is attached one end of a cord or 21 322 THE MANUFACTURE OF LEATHER. chain, >S', which, after passing over the guide-pulley T^ has its other end secured to the drum or pulley U^ mounted upon the shaft T, adapted to be revolved by means of the crank TT, or in any other well-known manner, to wind the cords or chains upon the drums, and thus move the carrier-plate upward between the cylinders H i?\ to present the surface of the hide or skin doubled over the upper edge of the carrier-plate P to the action of the knives or scrapers g y' upon the cylinders. The cylinders -ff j&^ are made up of several short sections, placed end to end upon a shaft, each section being made up'of an inner cylinder or sleeve, A, made of metal, and secured firmly upon the shaft W in such a manner that it can neither move endwise nor revolve thereon, an outer cylinder or sleeve, A', made of metal, and provided with the blades ^arranged obliquely upon its periphery, and an intermediate cylinder or sleeve, ^, of rubber interposed between the two metal sleeves, the rubber being so compressed, in uniting the several parts, that the outer sleeve of each section is held from rotating about the inner sleeve by the friction of the rubber, while at the same time the rubber retains sufficient elasticity to allow of the outer sleeve yielding radially to accommodate itself to the irregularities in the surface of the hide or skin being worked. In the under side of the table G is set the staple or pin Z, in such a position relative to the slot h that when the table is moved under the cylinders H H^ from the front toward the rear of the machine the staple or pin I comes in contact with the T or guide-bar -fi" just when the slot h in the table is directly over the carrier- plate P, as shown in Fig. 98. McDonalcV s Uvhairing Machine. McDonald's machine for unhairing and scouring hides and skins is shown in Figs. 100 to 102. ■ McDonald's invention has for its object the following de- scribed improvement in unhairing and scouring machines, con- sisting, first, in the peculiar scouring-roll employed ; second, in the arrangement for effecting the release of the skin or hide from the feeding-rolls, and from between the scouring and sup- porting rolls, when the same may be necessary owing to the UNHAIRING AND FLESHING. 323 skin or hide becoming folded in its presentation to the feed- rolls or to the scouring-rolls ; third, in the organized machine, consisting in the combination of the supporting-table, feed-roll, bed, scouring and supporting rolls, arranged in relation to each other to operate substantially in the manner hereafter described in the drawings. The operation of the machine is as follows : A hide or skin is arranged upon the table by the operator, and presented to the feed- rolls D D^^ and by them fed over the bed to the sup- porting roll 6^, which is positively actuated and revolved in the same direction as the lower feed roll, and the scouring-roll, which, preferably, is arranged immediately above the same. The relation of the supporting-roll to the scouring-roll is regulated by means of the springs supporting its boxes and by means of the treadle F. It will be observed by thus providing a yielding support or bed for the hide to be scoured, or for the skin to be unhaired, and by also providing a scouring-roll which shall possess a sur- face so shaped as to conform to any irregularity in the surface of the hide or skin caused by variations in its thickness, that a great improvement has been effected over the stiff arbitrary mechanism formerly employed. Fig. 100. Fig. 101. ( ^ ^ \ A'<^ Fig. 100 is a side elevation of McDonald's machine. Fig. 101 is a central vertical section. Fig. 102- is a plan. The scouring-roll A is provided with the system of spiral 824 THE MANUFACTURE OF LEATHEK. projections or blades a, projecting from the circumference of the roll and conversely arranged thereon from the longitudinal cen- tre of said circumference. These spiral projections do not ex- tend to the edge of the roll, as in the roll in the two previous patents by the same inventor, on this machine, but are broken, as it were, at certain points, as shown at a'. It will be observed that in shaping these projections, and in providing the roll with the system of recesses a' on the line of the spiral blades or knives, the blades are so arranged that not more than two recesses ever come in line ; and it is desirable that the recesses and the projections should alternate regularly. This scouring-roll is supported upon the frame .5, and is pro- vided with the driven cog B\ which is driven by the driving- cog G. The driving-cog (7 is fastened to the shaft C\ which carries outside the driving-cog G the pulley C^, and upon its other end the small driving-cog G^. The feed-rolls D D^ are located in front of the table E. The upper feed-roll, Z>, is provided with a vertical movement in its bearings c/, in which it is floated between the springs. The operator may lift the roll by means of the treadle F^ which is pivoted at/, and is provided with the arms/\ which are pivoted at/^ to the frame of the machine, and which lay hold of the con- necting bars /^, which operate the levers /^, pivoted to the side of the frame, as shown, and operating, through the links/^, the UNHAIRING AND FLESHING-. 325 boxes carrying the feed-roll i), and, through the link /^, upon the other end of the lever, the boxes carrying the supporting- roll Q. The machine is further provided with the bed H. The boxes ^, carrying the supporting-roll (?, are supported upon the springs (/^, and the degree of tension upon these springs may be ad- justed by means of the set-screws (f^ which compress or relieve the springs supporting the boxes, as occasion requires, it being found in practice that in some instances it is desirable to have the boxes yield unequally, so that a hide or skin which is thicker at one end than at the other will be firmly held against the scouring-roU, while at the same time, by the increased ten- sion of the spring, the thin portion of the head or skin is closely held against the said roll. The feeding-rolls, together with the supporting-roll, are posi- tively actuated by means of the gearing //' G' D^ D^. (Not shown.) The set screws c?^ serve to lift the boxes d^, supporting the lower feed-roll, Z^\ when the same may be necessary to secure a proper adjustment of that roll in relation to the inner edge of the table and to the upper feed-roll. McDonald's Ira'prove'ment in Feed- Rolls for Unhairing Machines. In feeding skins and hides to unhairing and scouring machines it is necessary to spread the hide or skin upon the feed-table or belt as flatly as possible, in order that all folds and wrinkles may be removed before the same is seized by the feed-rolls. It is not always possible, however, to so spread the skin or hide, and even if it is properly prepared it is of such irregular shape and varying thickness that, unless the feed-rolls act to spread as well as feed, it may become wrinkled or folded in its passage. As a consequence, the portion wrinkled or folded is not only not properly unhaired or scoured, but it is liable to interfere with the operation of the unhairing or scouring roll upon the remainder, or to be torn or a hole burned therein in its passage through the machine. To obviate this defect the inventor employs a lower feed-roll, which is so shaped that, in connection Avith the upper feed-roll, 326 THE MANUFACTURE OF LEATHER. it automatically spreads the skin or hide, and at the same time requires less care in preparing the skin or hide upon the table or belt for feeding. Fig. 103 is a perspective of McDonald's improved feed-roll, and Fis. 104 is an elevation of the same. A cross section of his machine with the feed-roll in place (like the one in Fig. 103) is shown in Fig. lOL Fis. 103. Fig. 104. The feed-roll is provided with right and left spiral grooves. The right spirals on the one side of the centre act in opposi- tion to the left spirals on the other side, and their combined ac- tion automatically removes wrinkles and folds, and spreads and keeps spread the material presented to them by the opposed spreading action of the conversely-arranged grooves. They are arranged upon the circumference of the roll, and extend from its longitudinal centre to the edge. The feed-roll may be used in place of the lower feed-roll of the machine patented by McDonald, December 10, 1878, or in lieu of the lower feed-roll in the machine patented by him February 5, 1878, or instead of the feed-roll i), shown in the machine patented by Larrabee, and shown in Figs. 90 to 95, or in connection with any other machine, in which it is necessary to automatically spread and keep spread the material which is being passed between a pair of feed-rolls. Of course, this roll may be provided with all the adjustments which the rolls above mentioned have in relation to the other feed-roll, and in relation to the scouring-roll. In operation the hide or skin is seized by the two rolls, and UNHAIRING AND FLESHING. 327 the upper roll pressing it upon the lower roll enables the grooves to spread the hide, the portion at the centre first laying hold of the hide, and by the continued revolution of the roll cause a separating action upon the stock from its centre toward each edge as it is being advanced, the folds or wrinkles being wiped out by the stretching action of the spiral depressions act- ing in opposition to each other from the centre. Taylor' s Machine for Unhairing^ Fleshing^ and Working Hides and Skins. This machine which is for unh airing, fleshing, and working hides, calf-skins, pelts, and other skins in the raw or green state is shown in Figs. 105 and 106. The invention consists in a rotary tool-stock for carrying and operating the slickers, stones, blades, or other tools necessary to effect the desired treatment of the skin, combined with a travelling carriage for holding the skin and presenting every portion of its surface to the action of the tools, the skin during its treatment overlying a bed, which is preferably supported upon springs, so as to yield to any obstructions encountered by the tools in working the hides, etc. The operation of the machine is as follows : The tools neces- sary for the operation to be performed — viz., unhairing, flesh- ing, or working the hides, etc. — having been placed in their holders, the wheel is rotated by power or otherwise, and the hide, skin, or pelt having been placed upon the carriage, its near edge is moved over the bed m and there subjected to the action of the tools, the skin being progressively moved over the bed as each portion is treated until the work is com- pleted. The rubber face of the bed and its springs, it is claimed, ren- der the bed sufficiently resilient to admit of the tools passing over any obstruction or extraordinary thickness in the skin without damage. The tools are set at an angle or tangentially to the wheel's rim, in their holders, in order to better perform their necessary work. 328 THE MANUFACTUEE OF LEATHER. Fig. 105. Ficr. 106. Fig. 105 is a top-plan view, and Fig. 106 a side elevation of Taylor's machine, partly in section. UNHAIEING AND FLESHING. 329 In a suitable frame-work, a, there is mounted a shaft, 5, having suitable power appliances. Upon this shaft is secured a wheel or tool-stock, c, having a number of tool clamps, c?, arranged about its rim. These clamps consist, in the present instance, of screw-spindles e, with squared heads e', seated against rotation in squared holes or sockets in bosses / in the rim of the wheel or stock, and secured by their tails in lugs (j on the wheel spokes or arms li by nuts ^. Bach spindle has its head flattened and extended laterally to receive the tool v — viz., slicker, stone, blade, or other implement — the tool being held and secured therein by suitable clamping devices, as a plate, j/', and bolts or screws, h. The tool stock or wheel is provided with any desired or conve- nient number of these tool clamps or holders. A portion of the frame a' is projected upwardly on the circle of the wheel, and the concavity of this projection of the frame is covered with a table, I. Within a slot in this table is ar- ranged a bed, m, the surface of which is covered with a soft material, n — such as rubber cloth, felt, or other fabric- — to break the force of the blow of the tools upon the skin being treated, and to prevent the breaking of the skin. In order to make this bed still more yielding, it is arranged upon springs o, which are confined in sockets j? on the frame a', said springs projecting out of the open ends of the sockets next adjacent the under side of the bed, and bearing thereupon with a tendency to press the bed toward the wheel. The bed is held adjustably in place by means of screw-bolts r, secured thereto, and passing through the sockets and retained by jam-nuts 5, whereby also the posi- tion and resilience of the bed may be regulated. Upon the top of the projecting frame a', and above the table /, are arranged tracks or ways t^ which receive a travelling car- riage, w, upon which the skin or pelt to be treated is supported, and by which such skin or pelt is moved progressively over the bed m, under the operation of the tools on the revolving wheel, to treat every part of the said skin or pelt. This car- riage may have any suitable fastening devices for retaining a skin, and may be further provided with suitable handles or other conveniences for moving it upon its ways. 380 THE MANUFACTUEE OF LEATHER. Janson's Machine for simultaneously Unhairiny and Fleshing Hides or Skins. This invention relates to improvements in machinery for unhairing, fleshing, pairing, shaving, and setting hides, sicins, or pelts, by means of which both sides of a hide, skin, or pelt may be worked upon simultaneously ; and it consists essentially in the use of two knife-cylinders, with their respective elastic rollers, instead of a single knife-cylinder as hitherto. The inventor claims to attain this object by the mechanism illcis- trated in the drawings, in which — Figure 107 is a front elevation of the machine; Fig. 108 a left-end view of the same ; Fig. 109 a transverse section on the Fis.107. line 1 2, Fig, 107, showing position of lower roll when inaction; and Fig. 110 a plan of the whole as seen from above. A A are the end standards. B is the feeding-table ; (7, the upper knife-cylinder ; Z>, elastic roll ; E, second or under knife- cylinder ; F, lower elastic roll ; 6^, clips or draw-bar ; H^ guide- bars for same; /, treadle for raising roll ; K^ connecting-rod; L, lever ; i/, cross-shaft ; N^ counter-lever ; 0, bearing for roll Z> ; P, counter- weight ; ^, bearing for lower roll, 7^; R, rod for actuating same ; S, cross-shaft ; T^ cranks ; f/, hand-lever ; F, quadrant ; IF, bell-crank lever ; X, belt for driving shaft ; Y^ cross-shaft; Z^ rope-wheels. UNHAIRING AND FLESHING. 331 It will be seen that, whereas the roll D is capable of a verti- cal motion, the lower or second elastic roll, F^ is free to move Fig. 108. 2,225 ^ 49,496 49,811 49,839 56,687 60,636^ Reissue > 3,839* Patents for Unhairing Machines^ issued hy the Government United States of America, from 1790 to 1883 inclusive. Date. July 12, 1812. Nov. 4, 1830. Oct. 31, 1831. May 13, 1834. June 13, 1846. July 13, 1858 Sept.lO, 1861. Aug. 22, 1865. Sept. 5, 1865. Sept. 5, 1865, July 31, 1866. Inventor. N. Kirk and S.C.Clark, T. Williams, T. Williams, J. Dunaway, G. Welty, J. R. Bumgarner and L. White, H. L. Arnold, M. Bray, S. S. Weed, S. S. Weed, A, Adler, Dec. 18, 1866. H. Lampert, Residence. St. Clairsville, 0. Rochester, N. Y. Rochester, N. Y. Woodville, Va. West Newton, Pa. Davenport, la. Elk Horn, Wis. Boston, Mass. Stoneham, Mass. Stoneham, Mass. Paris, France. Nunda, N. Y. 334 THE MANUFACTUEE OF LEATHER. No. Date. Inventor. Eesideuce. 66,124 June 25 1867. E. Brock, Ellenville, N. Y. 66,176 June 25 1867. J. Schultz, EUenville, N. Y. 66,640 July 9 1867. J. SchiflFer, New York, N. Y. 81,247 Aug. 18 1868. E. Brock and J. Schultz Ellenville, N. Y. 89,864 May 11 1869. A. Hasbrouch, Ithica, N. Y. 100,907 Mar. 15 1870. H. Lampert, Rochester, N. Y. 121,565 Dec. 5 1871. J. Watteau, Antwerp, Belgium. 141,972 Aug. 19 1873. J. Watteau, Antwerp, Belgium. 144,150 1 Reissue >■ 9,714 i Oct. 28 May 17 1873. ) 1881. ^ D. H. Sherman, Jersey City, N. J. 184,175 Nov. 7 1876. T. Roberts, Lynn, Mass. 193,412 July 24 1877. B. F. Larabee, Lynn, Mass. 199,597 Jan. 22 1878. J. A. Tapley, Somerville, Mass. 200,078 Feb. 5, 1878. J. W. McDonald, Woburn, Mass. 207,081 Aug. 13 1878. J. A. Tapley, Somerville, Mass. 209,298 Oct. 22 1878. G. T. Sheldon, Chelmsford, Mass. 210,797 Dec. 10 1878. J. W. McDonald, Woburn', Mass. 220,930 Oct. 28 1879. J. W. McDonald, . Woburn, Mass. 221,545 Nov. 11 1879. Wm. Gerber, Fremont Centre, Mich. 224,286 Feb. 10 1880. A. Gerard, Soigneies, Belgium. 227,974 May 25 1880. Wm. Gerber, Fremont Centre, Mich. 234,542 Nov. 16 1880. J. Curson, Lyons, France. 239,841 Apr. 5 1881. A. W. Reid, Schenectady, N. Y. 241,073 May 3 1881. C. Schultz, Milwaukee, Wis. 241,171 May 10 1881. E. D. Warren, Woburn, Mass. 249,114 Nov. 11 1881. C. H. Taylor, Woburn, Mass. 256,326 Apr. 11 1882. J. M. Jones, Wexham, North Wales 257,495 May 9 1882. J. W. Janson, London, England. 262,520 Aug. 8 1882. E. D. Warren, Woburn, Mass. 280,698 July 3 1883. A. E. Whiting, Winchester, Mass. List of all Patents for Fleshing^ Machines, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Residence 239 June 17, 1837. R. Shailer, Haddam, Conn. 4,712 Aug. 26, 1864. A. Smith, Cumberland Valley, Pa. 59,692 Nov. 13, 1866. J. S. Wheat, South Wheeling, W. Va. 109,379 Nov. 22, 1870. J, M. Brown, Boston, Mass. 170,855 Dec. 7, 1875. Wm. H. Holmes, Philadelphia, Pa, 192,479 June 26, 1877. T. W. Appleyard and W. L. Appleyard, Hunslet Carr, England. ' See also in the list of Unhairing Machine patents, Nos. 4,570, 20,861, 33,229, 56,687, 66,640, 89,864, 221,545, 224,286, 239,841, 241,073, 249,114, 256,326, 257,495. BATING. No. Date Inventor. Residence. 198,941 Jan. 8, 1878. E. B. Holcob, and D. A. Clay, Port Leyden, N. Y. 212,555 Feb. 25, 1879. H. A. House, Bridgeport, Conn. 239,522 Mar. 29, 1881. J. W. McDonald, Woburn, Mass. 247,648 Sept.27. ,1881. H. A. House and S. D. Castle. Bridgeport, Conn. 265,293 Oct. 3, 1882. } A. Whiting, Rochester, N. Y. 275,305 Apr. 3, 1883. 335 Note.— The illustrations of fleshing knives in this chapter are from the cata- logue of Messrs. Wm. H. Horn & Bro., Philadelphia, Pa., who are the leading manufacturers in America of tanners' and curriers' tools ; their goods being not only largely consumed in this country, but also exported to Russia and other portions of Europe as well as to South America. CflAPTEE XVII. Bating. bating and final preparation for the ooze — bating com- pounds — list of american patents for bating com- POUNDS. Section I. Bating and Final Preparation for the Ooze. The operation of immersing hides and skins intended for the manufacture of upper, Morocco, and other pliable leathers, in an alkaline solution consisting of the dung of chickens, pigeons, dogs, or in bran water, or in any of the compounds intended to supersede the dung solutions, or to be used, in combination with them, is termed either "bating," "abating," " grainering," " drenching," or " puring." The bate is used in the manufacture of soft and pliable leathers after the hides are taken from the "limes" and have been " unhaired" and "fleshed," and before they enter the " handlers," which is the first stage of the actual tanning process. The period which the hides or skins remain in the bating solution is dependent upon the temperature of tbe bate and the 336 THE MANUFACTUEE OF LEATHEE. thickness of the material subjected to its action. The object of bating is to allow the solution to penetrate the hide and neutral- ize the lime in the pores. The dung of chickens is the material usually employed for bating upper leather, while dogs' dung is used for Morocco leather, and the bate for sheep-skins is usually prepared from bran-water. The theory of dung bating, while obscure, is that a chemical combination is formed with the lime under the influence of the agents of which the droppings are composed, the ammoniacal chloride parting with its chlorine to form the chloride of lime, which is readily dissolved in water. Hydrochloric acid possesses the property of dissolving lime in the manner accomplished by the bate, as was shown by Mac- Bride in 1774. Carbonate of ammonia was employed by Warrington in 1841, for accomplishing the purposes of the bate. Sugar was used by Trumbull in 1847. in the proportion of four or five pounds of cane-sugar or molasses to seventy gallons of water, and this solution, it was claimed by him, formed a soluble saccharate of lime. In addition to the substances narned, carbolic acid, sulphuric acid, dilute phosphoric acid, organic acid, muriate of ammonia, alum, etc., are now also employed. Some of the objections to the present method of bating in addition to its expensiveness are : — 1. The disagreeable odor and uncleanliness attendant upon the use of the excrement of animals. 2. The difficulty in obtaining properly skilled labor to super- intend the operation, which is necessary because of the tendency to decomposition produced by the use of animal excrements. This decomposition is designated by tanners generally as " run- ning away," and means literally that the skins are frequently decomposed into a state of liquid putridity, and only skilled tanners by watching the vats can detect the approach of such a condition. 3. Then there is such great difference in the strength of the same kind of animal excrements, as that of dogs for instance (due BATING. 337 to the different varieties of food upon which thej^ have been fed, vegetables, bones, etc.), that practically no definite period can be positively set within which it is safe to let the excrement operate. 4. The influence 'which the electrical condition of the atmos- phere has upon stock in the bate, which is frequently damaged or spoiled during thunder-storms. The bating is usually accomplished by placing the hides or skins in a vat having a circular and tight bottom, over which vat is arranged a revolving paddle wheel, marked 1 in Fig. 112, which dips into the solution contained in the vat, thereby agitat- ing it and maintaining the sides or skins in constant motion, thus hastening the work of bating and greatly lessening the time and the danger of spoiling the material in the bate. After the sides or skins have been properly treated they are placed in the interior of the Avheel or drum, marked 2 in Fig. 112, and washed with clear water for a few minutes. The English wheels used for agitating the bate liquor, and the wheel used for washing the sides or skins are shown in per- spective view in Fig. 112. When the sides show the right condition scouring is proceeded with, this operation being effected either by hand or by a hide- working machine such as is shown in Figs. 114 and 115, or the scouring may be performed hy the McDonald, the Larrabee, and other machines shown in Section lY., Chapter XYI., at the time of unhairing, if such latter operation be performed by machinery. The object of this scouring, which should not be confounded with the scouring which is to be hereafter described for remov- ing the bloom from the hides after tanning, is to free the hides from lime and dirt and fit them for the reception of the tannin ooze to which they are to be first subjected in the handlers. In the preparation of sole leather the hides are scraped on the grain side with a curved knife, in order to cleanse them from lime remaining in the pores after the last soaking, and this operation is termed " graining." The hand process of scouring upper leather is effected with a tool called a scouring slicker, consisting of a steel blade fixed in a stock or handle, the blade being sharpened by grinding it per- 22 338 THE MANUFACTUEE OF LEATHER. pendicularlj and then on either side, thus producing two edges or rather right angles. Tliis tool is shown in Fig. 113. Six to ten hides having been spread over a broad beam 'the slicker is applied stroke after stroke, but not too vigorously, and any fleece hairs which may be found are removed with a sharp knife. If during this operation the ground becomes read- ily detached so that it runs down perceptibly, the hides have acquired a sufficient degree of softness. Final Soahing hef ore 'placing the Hides in the Ooze. After treating the hides in the above manner, and being as- sured by the previously described tests that they have been sufficiently soaked, it is only necessary to replace them in water for 12 hours longer. The safest indication of the hides being ready for the ooze is that, when passing the fingers over them, strokes remain as indentations. For the final soaking of sides intended for upper leather spring water is usually employed. Lampert'' s Appnrattis for Working Hides. The machine shown in Figs. 114 and 115 is the invention of Lampert, and, in addition to unhairing and fleshing hides, it is also much used in working out the lime and dirt after bating. Fig. 11"! is a side elevation of Lampert's invention. Fig, 115 is a transverse section at the dotted line x, Fig, 114, The cross-head F and worker g are operated by the pitman G and driving- crank H. The slides m are arranged in a vertical line upon the side of the frame D. and the cross-head moves between them, as shown. Lugs cZ, upon the cross-head, embrace the slides and retain the former in place, ■ ' BATING. 339 The worker (/, provided with a knife or scraper, e, is suitably secured to the spring bar A, which passes through a slot in the Fiff. 114. Fig. 115. block/, pivoted to the lower end of the suspenders h^ Figs. 11 J: and 115, These suspenders slide in grooves formed in the lugs c?, upon each side of the cross-head, and extend a short distance above the latter, where thej are con- nected together by the stud o. Fig 115. The spring, h\ rests at one end upon the stud 0, or upon the end of the suspenders, and at the other upon a horn, /, projecting from the cross- head. This spring is retained at a certain degree of tension by a staple, a, secured to the cross-head and embracing the spring at or near its centre, thus causing the worker to bear upon the beam (shown in dotted lines in Fig. Hi) or upon the hide placed thereon. By this arrangement a pressure is obtained not only upon the worker independently of the bar h and its adjustments, but 340 THE MANUFACTURE OF LEATHER. also, since tlie elasticity of the former is divided between the bar h and spring h\ the worker is retained more squarely upon its work. The inner end of the bar h is jointed to the link ^, and con- nected by it to the pitman G at a, suitable point between the cross-head and crank. The link i is made adjustable in its length by means of set- screws sliding in slots, or by other equivalent device, whereby the worker g is adjusted vertically, and consequently the ten- sion of the spring bar h varied. It will be observed that by the action of the pitman O the worker g is lifted from the hide during the forward stroke, and depressed upon it during the backward stroke, by means of the pivoted spring-bar h and link i, as indicated by dotted lines in Fig. 114. A stop upon the stud o, Fig. 115, prevents the sus- penders and worker from descending too far. A still further vertical adjustment of the worker may be had, if necessary, in case of the wearing away of the knife or scraper, by inserting the bar h in either of two or more slots formed in the block y, Fig. 115. In working the flesh side of the hide it is often necessary to use a knife or stone, set at such an angle as to cut or separate the fibre of the fleshy material. For this purpose the upper face of the worker g is somewhat inclined where it is attached to the bar A, whereby the tool e acts as a scraper, as shown in dotted lines in Fig. 114. When, however, the worker is reversed horizontally, as in- dicated by dotted lines, the tool assumes a sharper angle with the work, and acts as a knife. The worker is secured to the bar h in a convenient manner for removal. Provision is made for longitudinally adjusting the pivoting point of the link ^ upon the pitman, by which the amount of lift of the worker and the exact point of its ascent and descent is determined. The pivoting-point of the bar h to the suspenders h is made horizontally adjustable by means of the set-screw t in the block y, thus varying the amount of lift of the worker in proportion BATING. 341 to the throw of the crank H^ and also the tension of the springs h and h'. Hides are easily handled upon this machine, the drum, shown in dotted lines, revolves, allowing the hide to move sideways with but slight effort, and as the parts are finished the hide is drawn towards the operator. Section II. Bating Compounds. Sating with Muriate of Ammonia either alone or in combination with Hen''s^ Pigeon'' s^ or Dogh Diing. This bate was patented by Zollickoff'er in 1838, and was used very successfully by him for a long period. He used the muriate of ammonia as a bate for all kinds of hides and skins, either alone or in combination with either hen's, pigeon's, or dog's dung, and he states that he bated hides and skins in a much shorter time than is required by using either of the last- men- tioned substances alone. When he used muriate .of ammonia alone, he took seven pounds, which he reduced to a coarse powder, and upon which he poured ten gallons of hot water, in order to facilitate its solution. This solution he would throw into a vat containing a sufficient quantity of clean water to cover five hundred pounds of hides or skins, dry weight, in a state of preparation for the bate. Into the bate thus prepared the last- named quantity of hides or skins was thrown. All kinds of skins were bated in one hour, horse hides in two hours, and ox hides and other thick hides in three hours. The ox and other hides he handled once during their continuance in the bate, in one hour after they were placed in it, and when the muriate of ammonia was used in combination with either hen's, pigeon's, or dog's dung he took two and one-half pounds of muriate of ammonia, dissolved in four gallons of hot water, after having previously reduced the ammonia to a coarse powder. This solution he would throw into a vat containing the qaantity of either hen's, pigeon's, or dog's dung bate necessary for bating five hundred pounds of hides or skins, dry weight. Into this bate was thrown the quantity of hides or skins in 342 THE MANUFACTURE OF LEATHER. the usual state of preparation for undergoing tlie process, taking the precaution, however, previously to place them in a pool of clear water for five minutes to wash oft* the adhering dirt and lime. By this last process all kinds of skins were bated in three hours, horse-hides in six hours, and ox-hides and other thick hides in nine hours. The last-mentioned hides Mr. Zollickoffer would handle three times, the end of the second, fourth, and sixth hour after they were submitted to the bate. Horse-hides were handled twice, the end of the second and fourth hours ; and all skins were handled once, the end of the first hour. The hides and skins which were bated by this process were reduced and softened analogous to those bated with either hen's, pigeon's, or dog's dung alone, and the hairs, dirt, and lime worked out with equal ease. After they are bated by this process they are to be treated like all other hides and skins bated in the usual way. In 1842 Zollickoffer patented another composition for bating hides by using in combination the muriate of soda, super-tartrate of potassa, and tartaric acid. The manner of preparing it is as follows: Take two pounds of the muriate of soda, one pound of super-tartrate of potassa, and one-half pound of tartaric acid, all of which throw together into a suitable vessel and upon which pour five gallons of boiling water, and as soon as they are dis- solved throw the solution while hot into a clean vat containing a sufficient quantity of clear water to cover five hundred pounds of hides or skins already unhaired, fleshed, and washed in clean water, then agitate the fluid so as to mix the water and the dissolved composition thoroughly together, and into this throw the prepared hides or skins. Skins smaller than calf-skins are removed in less than one- half hour and stoned and beamed, calf-skins in one-half hour, horse-hides in one hour, and ox-hides in one and one-half hours, and placed upon a heap, and after they are stoned returned to the bate again, where thev are to remain the same length of BATING. 843 time as before. Upon the completion of the last period the hides are to be worked over the beam. With this bate hides and skins need not be handled if they are put into it in a workmanlike manner ; but before thej go into the bark they are to be washed off in clean water, and will then be prepared for the action, of the tannin. If the hides and skins cannot be conveniently worked out of this bate in forty-eight hours they will not sustain the least injury, as this process is a preventive of the putrefactive con- dition by which hides and skins often become destroyed by the bate in common use. With this bate it is claimed that hides and skins are reduced and softened in a superior manner, and the operator is enabled to work out the hair, dirt, and lime with great ease. The grain side, gelatine, and general texture not being impaired, and the leather prepared after its operation is equally flexible, more compact and ponderous than that prepared after the bates in common use, which act upon the principle of putrefaction. Bating loith a compound of Carbolic Acid, Muriate of Ammonia, and Alum. Parkins, the inventor of this compound, explains its action on hides and skins, which have been depilated by lime, as follows: — The lime remaining in the hide or skin after all mechanical means have been employed (such as repeated washing, rinsing, scraping, soaking, etc., for its removal), does not amount to a large percentage, still there is sufficient lime left to form with the tannin an insoluble compound, which retards the progress of tanning by closing the pores and preventing the tan-liquid from penetrating the interior of the hides or skins, aside from which leather containing this tannate of lime is often harsh and brittle. The bating solution which Parkins employs is composed of, say three-fourths of a pound of carbolic acid,^ six pounds of muriate of ammonia (sal ammoniac), and six pounds of alum dissolved in one hundred and fifty gallons of water ; but these proportions may be varied to conform to. the experience of those who use this compound. S44 THE MANUFACTURE OF LEATHER. When liides or skins are immersed in this liquid (after being freed from the lime by mechanical means) for twenty-four hours or longer, it is claimed that all the remaining lime is entirely removed, and the pores of the hides or skins opened so as to make them absorb the tannin more rapidly and thoroughly, and therefore making a plumper and softer leather. Hides and skins having been treated with lime should be worked in this improved bate precisely as in any other; and as regards the length of time they are to remain in the bate, this will depend on the thickness and other conditions of the pa'ck ; but practical tanners will know when the hides are bated sufficiently ; and in order to make the bate penetrate uniformly, they are worked on the beam once or twice during the bating. Bating ivith a Mixture of Sulphuric Acid with the Lime Liquor in which the Shins have been already treated for removing the Hair. This composition is the invention of Vickers and Holmes, and the object is an economical and effective solution for bating skins, consisting of a mixture of sulphuric acid with the lime- liquor in which the skins have been already treated for remov- ing the hair. After the skins have been depilated in the usual manner by treating the same with lime, the patentees take the resulting lime- liquor and dilute it with warm water, and then add sulphuric acid until the liquor accords in strength with the character of the skins to be acted on. This solution is used for bating the skins in place of the usual solution of dog and pigeon manure, which, aside from its unclean- liness, has a tendency to rot the skins, whereas it is claimed that this solution, in which the skins are permitted to remain from one to ten hours, breaks up the gristle, opens the pores, and loosens the animal matter from the skins, so that it can readily be worked out, and at the same time toughens the skins and renders them easier to tan and firmer after beino; tanned. BATING. 345 Bating iviih Bran^ Oil of Vitriol^ and Salt. Stack lias invented a new and improved process for bating and cleansing hides, of which the following is a description. In a vat six feet by four feet, and six feet deep, containing about three feet of water, put three bushels of bran, three pints of oil vitriol, and one peck of salt, and the same proportions for vats of different sizes. In this vat put a batch or pack of sixty sides or two hundred skins. This bates the hides, it is claimed, in from eight to forty-eight hours, according to age — say twenty-four hours for calf, goat, and sheep, and forty-eight hours for harness and upper leather. When the bate is old, eight or nine hours, it is claimed, will do for skins, and twenty- four hours for sides, upper, and harness leather; but the time will be regulated mainly by the judgment of the tanner. For a second pack, one bushel of bran, one pint of vitriol, and two quarts of salt will do ; and for a third pack, half a bushel of bran, one pint of vitriol, and two quarts of salt will be required. To prepare the bate, put three bushels of bran in a barrel, cover it about three inches with water, and let it stand seven or eight days before putting it in the vat. For a new bate, always keep a little bran and water in a barrel ready for use ; and after the third pailful or two of bran and water for every pack, add one pint of vitriol and one pint or quart of salt, according as the bate is strong or weak. In a new bait, "handle up" the hides three times the first day and twice the second. In another vat, commonly the one called the pool, with suf- ficient water to cover the hides, put in a half- barrel of tar-water and soda, in the proportion of two-thirds of a barrel of water, one pailful of coal-tar and one pound of bicarbonate of soda, and wash and cleanse the hides in it after they have remained a sufficient length of time in the bate, which completes the pro- cess, and makes the hides ready for the tan-liquors. "When the bate gets old, put into it half a barrel of tar-water. It acts as a check on it, and keeps the smell down. 346 THE MANUFACTURE OF LEATHER. To make a very fine quality of calf or kip, work the skins lightly on a beam out of this mixture in the pool. This process it is claimed makes the leather from five to ten per cent, heavier than the common process. Bating ivith Glucose and dried Sour Cheese. The object which McMurtrie had in view in the invention of this bate was to form a compound which, when complete, would be in condition convenient for packing, storage, and transportation, and be always ready for use in any quantity. Tliis he claims to have accomplished by thoroughly incorpo- rating with dry pulverized glucose, or its equivalent, a suit- able proportion, about ten per cent., of dried sour cheese or its equivalent, forming a compound which may be packed, transported, and stored, without danger of deterioration, and which when added to the vats containing the skins impregnated with lime, will, it is claimed, undergo molecular transformation with production of lactic acid. The acid thus formed, combining with the lime, makes a sol- uble compound, which may be removed by washing with water, or the ordinary treatment of the skins. Instead of glucose, starch, dextrine, cane-sugar or other amy- laceous or saccharine substances suitable for making a portable compound maybe substituted; and for cheese gluten in any form, or albumen, from whatever source it may be obtained in a dry condition, it is claimed may be used. These have, however, the disadvantages of being either more costly, and of being more tardy in their action, and glucose and cheese are, it is claimed, therefore preferable. In case of either of these substances being used, the compound formed should be well dried before packing. Bating with a Liguor composed of Water impregnated with Sul- phur Dioxide that has previously been employed in soaking and softening Hides. The object of this invention is to cleanse and purify hides and skins from lime and humus, and also to remove the epider- mis when desirable, and any hairs remaining from the depila- BATING. 347 tion after liming. In practice the inventor, Maynard, discov- ered that he could utilize the "soak," which is a liquor composed of water impregnated with sulphar dioxide that has previously been employed in soaking and softening the skins in preparing them for the liming operation. This results, it is claimed, in a great saving of expense, and besides avoids the disagreeable odor attendant upon the use of excrement of animals, which is at present generally emploj^ed. The soak, after the softened hides have been removed, contains sulphur, phosphorus, and carbon, with traces of nitrogen, in combination with hydrogen, because in the soaking operation the skins have absorbed oxy- gen while the elements above described have been eliminated from the skins and rejnain in the bath. All these in combina- tion are efficient, and especially the phosphorus and hydrogen, in the cleansing and puring process. It has been found that this solution sometimes lacks sufficient ammonia for the purpose of cleansing rapidly, and also that the lime requires something with which it can enter more rapidly into combination, and which will also render it soluble. The inventor, therefore, occasionally employs chloride of ammonium, and sometimes sugar in small quantities, while he has found argols to assist the effect produced by the soak, and to be a very useful, and in some cases necessary, adjunct. The inventor claims to have found that the use of argols and chloride of ammonium, singly or in combination, is non-effective without the soak, inasmuch as while the lime has been eliminated the skin itself has not been left in that absolutely necessary state of reduction and softness technically known to tanners and readily distinguished by them as " pured."' This imperfect state or condition of the skin Maynard claims to have obviated by the use of the soak, either alone or in combination with small quantities of chloride of ammonium or argols, or both. The inventor claims to have found that in puring he could more or less successfully use the following as substitutes for the chloride of ammonium and argols, viz: sugar, hydrochloric acid, chloride of potassium, and caseine ; but recommends the chloride of ammonium and argols as preferable. Instead of using the soak, as above set forth, it is, of course, 348 THE MANUFACTURE OF LEATHER. possible to manufacture sulphuretted hydrogen, or even the hydrogen compounds of carbon and phosphorus ; but this ex- pensive course need not be resorted to, because the soak is al- ways at hand and available without cost, after it has served its ordinary purpose in the soaking operation. By the use of this invention, it is claimed to be practicable to calculate, by knowing the strength of the " bate," which is easily obtained, the period of time in which the bating or pur- ing can be safely and thoroughly performed. This period will, in practice, vary somewhat, according to the nature of the skins and the electrical condition of the atmosphere ; but ordinarily it is claimed that in about one-fifth the usual time necessary where animal excrement is employed the paring will be satis- factorily completed. Different hides being of varying age and toughness are more or less sensitive to the action of lime; there- fore a greater or less quantity of lime has to be used, and it necessarily follows that the bate also should be of variable degrees of strength. Maynard states that he has found in prac- tice that the strength of the liquid, when chloride of ammonium is used, should vary from one-half pound to one pound per hundred gallons of the soak, according to the thickness, age, and toughness of the hides and skins to be treated. Although this rule is a guide, it is not arbitrary, because much depends upon the number of skins to be treated in a given quantity of liquid, but these facts or elements being all such as can be known by a competent superintendent in advance, it is quite easy for him to calculate the short period of time that will be required for the bating operation. It is to be understood that the liquid should be agitated from time to time and the skins moved in the same during this bating process. By this invention it is claimed that all the requirements are fulfilled at less expense and without the disgusting odor, the danger of decomposition by the formation of too much ammo- nium, or the action of phosphuretted gases upon the skin, attendant upon the use of excrement, while the removal of the lime is also claimed to be certain and the action upon the epi- dermis perfect, without the possibility of damage.. Further- more, the chief agent by which these desirable results are BATING. 349 brought about is a product of the tannery itself, which has hitherto been deemed worthless. Mullen'' s Process. This process consists in drenching in a liquor composed of soft soap and sal-soda dissolved in water, in about the following proportions: For one hundred sides, about 3 quarts of soft soap and one pound of sal-soda, dissolved in a sufficient quantity of water to cover the sides. After being properly softened the sides are left in the solution four or five days, then unhaired and afterwards placed in a fresh solution for twelve hours, after which it is claimed they are ready for the tan -liquor. Adamson's Process. This method consists in bating hides and skins in dilute phos- phoric acid, precisely as the ordinary mixtures are used for the same purpose. Note. — Vast quantities of dilute phosphoric acid are formed in glue factories, by treating with muriatic or sulphuric acid and water bones and horn- piths, for the conversion of the same into glue-stock. The residuum after this treat- ment is dilate phosphoric acid, which is largely permitted to run to waste as an article of no commercial value. Soderherg^s Process. In this process the bate consists of water, chloride of soda, and dissolved sulphur, mixed in the following proportions : about 400 gallons of water, to which are added about 10 pounds of chloride of soda, and 10 pounds of dissolved sulphur, in which the hides are treated for about two days. The dissolved sulphur is obtained by boiling 10 pounds of sulphur, with about 12 gallons of water and about 5 pounds of common soda. The object of the chloride of soda is to open the pores of the hides or skins, so that the sulphur can act upon them more quickly for the purpose of removing the lime. 350 THE MANUFACTURE OF LEATHER. Wilso7i^s Process. This process consists in treating hides and skins to a solution, for the purpose of bating them after thej have been subjected to the action of lime for removing the hair. Note. — This bate is composed as follows : Wheat or groand barley, 2 bushels ; chloride of sodium or common salt, 50 pounds ; sulphate of magnesia or Epsom salts, 3 pounds; sulphuric acid, 3 pounds; the ingredients being thoroughly mixed with 5 or 6 barrels of water, or sufficient water to cover when in the tank about 150 hides. < If the liquor be not agitated the hides or skins remain in the solution about 36 hours ; but if agitated by a revolving wheel, such as is shown in Fig. 112, then it is claimed that about 5 hours will be sufficient for the action of the solution. JVells^s Process. This process consists in bating with a strong solution of salt and water. Tucker''s Process. This bate is compounded as follows : — "Water Wheat-bran Starcli Hen manure Muriatic acid Buttermilk 20 gallons. 1 bushel. 4 pounds. 1 peck. 1 pound. 1 gallon. Stir the mixture well before the hides are immersed in it, and handle several times daily until freed from lime. Swan''s Process. This process consists in subjecting limed hides to the action of an aqueous solution of alum, whereby it is claimed that the lime is removed, by combining with the alum in solution and leaving the hide forming an insoluble precipitate that falls to the bottom of the vat in which the hides are bated. Note. — The alum bath consists of 2 ounces, avoirdupois, of alum to 1 gallon of water. BATING. 351 Turleifs Process. This process of bating and tanning hides, consists in first subjecting the same to the combined action of carbonic and sulplmrous acid gases, and then partially tanning and afterwards subjecting the partially tanned hides to the action of said com- bined gases, and finally tanning in the usual manner. List of all Patents for Compounds for Bating^ hy the Government of the United States of 1883 inclusive. Hides and Skins, issued America, from 1*190 to No. Date. Inventor. Residence. 592 Feb. 3, 1838. Wm. ZoUickoflfer, Middleburg, Md. 2,332 Nov. 10, 1841. S. Guilford, Lebanon, Pa. 2,756 Aug. 18, 1842. Wm. ZoUickoflfer, Middleburg, Md. 5,261 Aug. , 28, 1847. Dr. A. Turnbull, London, England. 8,500 Nov. 4, 1851. W. B. Milligan, Edinburgh, Va. 35,293 May 20, 1862. J. Brain ard. Cleveland, 0. 38,267 Apri 1 21, 1863. R. Wagner, Lancaster, Pa. 59,627 Nov. 16, 1866. J. M. Mullen, North Becket, Mass. 79,177 June 1 23, 1868. Wm. Adamson, Philadelphia. Pa. 86,506 Feb. 2, 1869. L. Clozel, Grenoble, France. 87,202 Feb. 23, 1869. L. F. Robertson, Morrisania, N. Y. 99,387 Feb. 1, 1870. G. W. Adler, Philadelphia, Pa. 109,656 Nov. 29, 1870. C. F. Paukin, Charleston, S. C. 110,161 Dec. 13, 1870. L. F. Robertson, New York, N. Y. 144,328 Nov. 4, 1873. M. W. Fry, Guyandotte, W. Va. 146,789 Jan. 27, 1874. J. Vickers and H. Holmes. Philadelphia, Pa. 152,187 June 16, 1874. Wm. Slack, Sussex, Canada. 153,636 July 28, 1874. C. J. Tinnerholm, Quincy, 111. 158,608 Jan. 12, 1875. C. J. Tinnerholm, Keokuk, la. 181,621 Aug. 29, 1876. A. W. Barnes and W. F. Yocum. Weston, Mo. 184,114 Nov. 7, 1876. M. J. Siiderberg, Malmo, Sweden. 189,536 Jan. 2, 1877. N. Wilson, Becket, Mass. 194,090 Aug. 14, 1877. R. Hein, St. Mary's, Pa. 197,739 Dec. 4, 1877. Wm. McMurtrie, Oxford Township, Warren Co., N. Y. 223,200 Dec. 30, 1879. I. Wells, Wilmington, N. C. 229,928 July 30, 1880. T. P. Tucker, Independence Co., Ark. 237,630 Feb. 8, 1881. J. S. Swan, Mongaup Valley, N. Y. 249,540 Nov. 15, 3 881. Wm. Maynard, New York, N. Y. 262,516 Aug. 8, 1882. M. Turley, Council Bluffs, la. ' See also patents, Nos. 76,824, 104,719, 135,214, 196,672, 221,187,. 254,962, and 262,924 in Tanning Processes, etc. PART V. CHAPTEE XYIII. HANDLING- AND PLUMPING. Section I. Handling. The occasional removal of hides or sides from the vat, and then replacing them, also the agitation of the stock at stated times while remaining in the liqaor in the vat, is termed "hand- ling," the object of which is to equalize the action of the lime in the unhairing process, the bate in the bating process, and of the weak liquor or ooze in the first stage of tanning. The old manner of handling hides like most of the primitive methods of the tanner's art was exceedingly slow as well as laborious ; but of late years numerous appliances have been per- fected for mechanically performing this work by means of which the stock is handled with great facility and at the expenditure of but little labor. One .old method was to haul up the sides by hand from the vat and pile them, and in this condition, allow them to press and drain, and then after a sufficient time throw them again into the vat. Another and later method was to " shift" or change the sides from one vat, over into another by means of hooks. Handling and transferring the sides by the medium of a revolving device, such as the hand reel, is an old-fashioned method which has not yet become obsolete ; but which continues to be employed in the majority of both small and large tanneries in this country. This manner of handling seems to be both convenient and economical, and as there are but few objections that can be urged against it, there are at present but slight chances of it being generally abandoned for later processes, of which we have a great variety. HANDLING AND PLUMPING. 353 There are two modes in vogue of connecting the sides, which are to be handled, with the reel. One is to tie them together with strings and the other is to connect them with a tie-loop ; but the first method is most commonly employed, and is the least expensive. The hand-reel is about three feet high and is made as light as possible, consistent with requisite strength, in order that it may be readily moved by two men from one vat to another. When in use the reel is placed intermediately on the alleys between the two vats in which the hides are to be handled and the sidesor hides are drawn over thedrumby the workman who turns the crank attached to the shaft on which the drum is fastened. Two men are required to operate this reel, one to adjust the sides or hides in the head vat, and the other to work the crank. Another form of handler in use is known as the rocker handler, and it consists of a frame constructed of wood, and hung by pivots in the centre of the top of the vat so as to give a dipping movement of 7 or 8 in. to each end of the frame, and the sides are hung over sticks placed across the frame from the two sides, motion being usually imparted to the handler from shafting placed overhead. The apparatus shown in Figs. 116 and 117 was invented by L. 0. England, in 1871, and consists in a good method of keep- ing the stock suspended in the liquor so that all parts may be brought into constant contact with the ooze, and its employment in liming, bating, and handling should produce a smooth grain and good quality of leather. Fig. 116 is a perspective view of the apparatus, showing it removed from the vat. Fig. 117 is a vertical section of the same showing it applied to a tan-vat. The frame i^is made to conform to the interior of the vat, and consists of the upper and lower rails, jS^ /S'\ S^, and S^, and the cross rails -£/, HJ^, E,^ and ^^, which are joined together by means of the uprights U, Z7^, U^, C^, and U*, and which uprights serve as guides to retain the frame in a horizontal position. The frame i^is also provided near the lower part with two diagonal braces, J5, B^, at the point of intersection of which is 23 354 THE MANUFACTURE OF LEATHER. an upright shaft, i?, to which power is applied to operate the frame, the braces serving to agitate the liquors. The series of bars d d d, are held bj the binders 1\ T^ which prevent them from shifting as the frame moves downward. Fi-. 116. Fig. 117. The stock is hung on the movable bars d d d with head and butt down, and the proper liquors supplied. HANDLING- AND PLUMPING. 355 The frame is placed in the vat so that the top of the stock resting on the bars may be about eight or ten inches, more or less, below the surface of the liquors. The whole frame is then caused to move upward in a vertical line of a few inches, four to six being sufficient, but should not be allowed to raise the stock above the surface of the liquor. The stock being loose on the bars will, when the frame moves downward, be left suspended in the liquor, entirely free from contact with the bars, thus allowing the liquor free access to the parts of the stock, which, when the frame is at rest, adheres to the bars on which it is placed. I'lie upward and downward vertical motion given to the frame will keep the stock at nearly the highest point at which it is raised by the first stroke of the frame upward, the frame being moved faster than the stock would sink in the liquor if unobstructed. Every returning upward stroke of the frame will carry the stock back to the highest point again. The frame is caused to move only so fast as will -have the desired effect, and at intervals, as occasions may suggest. The specific gravity of the frame and stock being very small, the power required to give the necessary motion while they are submerged in the liquor is correspondingly small. The paddle-wheels for handling shown in Chapter XVIL, Fig. 112, which were also invented by L. C. England, in 1847, are largely employed in handling heavy, medium, and light leathers. These wheels work within three-quarters of an inch of the sides and are usually five and a half feet in diameter, and have eleven paddles about seven-eighths of an inch thick, and spaced equidistant apart, which is about eighteen inches between centres at the outer edge. The vats in which the wheels revolve have the bottom con- cave to conform to the convexity of the wheels which are placed over the centre of the vats, so that the wheels dip about eight inches in the liquor, and thereby cause a gentle but thorough agitation of the ooze and stock, which moves in an opposite direction from that of the wheels. The motion of the wheels causes the stock to move up in front, pass under the wheels, and down on the concave bottom to the 356 THE MANUFACTURE OF LEATHER. back of the vat, and thus by means of the paddles, and the con- stant changing position of the stock a thorough and gentle agitation is maintained. But if the bottom of the vat should be made square, the agitation would be too great to answer the purpose. No fixed length of time can be set for running these wheels, as the period depends upon the stock being handled ; light sides, as those used for upper leather, being handled for a shorter period and not so often as the heavy whole hides employed for making enamelled and patent leathers. The wheel for no class of leather should be run at a greater speed than eighteen revolutions to the minute, and the motion should be steady and regular. Cog-gearing is best, and pos- sesses a great advantage over belting, as the latter, from the slow motion required, often becomes troublesome. Wheels of this kind'are generally arranged in a line, as shown in F.g. 112, and sometimes so constructed that any one of them can be thrown out of gear, by means of a clutch connected with the loose pinion on the shaft. It has at times been tried to apply these wheels to quicken the after-process of tanning ; but while they answer for light leathers, it is the opinion of some who have experimented with them upon heavy leathers that they will not answer ; but not- withstanding this opinion, I have seen them successfully em- ployed at Newark, N. J., and other places, for tanning heavy whole hides to be used in the manufacture of enamelled leather. This wheel furnishes a most simple and effectual mode of moving the incipient leather in the liquor, and does away en- tirely with the necessity of handling by hand, facilitates the after-process of tanning, economizes in labor, forms a handsome grain, and in all respects improves the quality and texture of the leather. Methods of handling, such as lacing it together and drawing the stock through rollers, or placing the hides, sides, or skins upon a web, unlaced and feeding the stock to the rollers, are not now employed in this country. However, they continue to be profitably used for some classes of leathers by a few European tanners, the theory being that by pressing the liquor out of the HANDLING AMD PLUMPING. 357 pores in handling that, upon re- immersion, the liquor into which the stock is placed acts more quickly and in the end produces a heavier weight than is ordinarily obtained. In the manufacture of pebble and grain leathers the sides are tacked upon sticks and handled into stronger liquor about every three days, and it might here be stated that any method of handling which allows both the grain and flesh sides to be uni- forml}^ exposed to the action of the liquor will fill all the re- quirements, provided there is a gentle agitation of the fibre at occasional periods. In some portions of the country the handling is performed by placing the stock in the interior of a large revolving drum about 10 feet in diameter, one half of which turns in the liquor of the vat, the centre shaft upon which the drum is supported turning in bearings resting upon the top of the vat. The interiors of these drums are best divided into three or four compartments, as it is easier upon the green stock than allowing it to be treated in an unpartitioned wheel, and besides the operation of the contrivance is facilitated by retaining a portion of the contents near the centre. In Gorsline's apparatus for handling, the sides or skins are placed in the vat resting upon five straps, having cross slats at- tached to them, and one end of each of the straps is attached to the top of the vat, and when it is desired to raise the pack, the centre strap is wound around a drum which gradually raises it, and as it approaches the top the operator standing upon the alley can easily seize the hides and throw them out. The slats slide over the centre strap which winds upon the drum, thus preventing them from striking the frame and stop- ping the machine. In raising the pack the inclined position it assumes has a tendency to wash off the sediment or bloom, presenting the same advantage in this respect as in handling by hook in the ordinary way. This contrivance is better adapted for handling kips and skins than for heavy sides or hides. Steinmann's apparatus for handling hides in the lime-pits is shown in Figs. 74 to 77. Study's contrivance for liming hides has been described on page 269. 358 THE MANUFACTURE OF LEATHER. List of all Patents for Tanners^ Vats, Agitators, and Handling Appli- ances, issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Residence. Jan. 9, 1834. S. Stem and D. Wireman. Mechanicstown, Md 795 June 20, 1838. W. L. J. C. Rouse and S. Tabor. Wade's Post Office, 1,906 Dec. 17, 1840. W. Buchannan, Milford, Pa. 2,552 April 11, 1842. J. Southvvick, Boston, Mass. 2,729 July 20, 1842. W. Wallace and J. Fleming. Lehman, Pa. 2,868 Dec. 5, 1842. D. H. Mason, Dahlonega, Ga. 4,851 Nov. 14, 1846. A. H. Brescliermann, New York, N. Y. 6,340 April 17, 1849. T. W. Brown, Howardsville, Va. 7,854 Dec. 24, 1850. L. C. England, Williamsburgh, N. 8,500 Nov. 4, 1851. W. B. Milligan, Edinburgh, Va. 12,369 Feb. 6, 1855. L. W. Fiske, Louisville, Ky. 14,135 Jan. 22, 1856. D. H. Kennedy, Reading, Pa. 15,844 Oct. 7, 1856. E. A. Eliason, Georgetown, D. C. 20,093 April 27, 1858. D. Philbrick, Manchester, N. H. 23,053 Feb. 22, 1859. C. Weston, Salem, Mass. 33,203 Sept. 3, 1861. W. P. Martin, Salem, Mass. 33,448 Oct. 8, 1861. S. J. Patterson, Bridgeport, Conn. 33,645 Nov. 5, 1861, D. A. Havaland and S. A. Phillips, Fort Dodge, lud. 39,824 Sept. 8, 1863. B. B. Mereness, Georgetown, N. Y. 41,336 Jan. 19, 1864. J. S. Wheat, / W. H. Study, S. J. ■ Berkley Springs, Va 48,758 July 4, 1865. } Miller and A. B. ( Barnett. '. - Economy, Ind. 59,469 Nov. 6, 1866. J. Snell, Jr., Pottsville, Pa. 68,861 Sept. 17, 1867. L. C. England, Philadelphia, Pa. 70,306 Oct. 29, 1867. J. C. Williams, Philadelphia, Pa. 80,947 Aug. 11, 1868. J. Hammond, Lattsburgh, Ohio. 91,402 June 15, 1869. H. W. Adams, ^ T. K. Parsons, Chas. • Philadelphia, Pa. 1 116,626 July 4, 1871. \ E. Getchel, and S. i W. Fairfield. - Salem, Mass. 116,766 July 4, 1871. N. Smith, McAllisterville, Pa. 122,157 Dec. 26, 1871. J. W. Coburn, East Walpole, Mass 123,192 Jan. 30, 1872. D. F. Noyes, Lewiston, Me. 135,231 •Jan. 28, 1873. " Reissue C. H. Manning, Washington, D. C. 8,639 Mar. 15, 1879. 138,906 May 13, 1873.. ^ HANDLING AND PLUMPING. 359 No. Date. Inventor. Residence. 150,657 May 5, 1874. S. H. Hall, Belle Plaine, Iowa. 163,021 May 11, 1875. C. H. Manning, Washington, D. C. 165,212 July 6, 1875. W. Coupe, South Attleborough, Mass. 170,330 Nov. 23, 1875. "i Reissue [ 0. W. Bean, Tecumseli, Mich. 7,311 Sept. 19, 1876.^ 182,198 Sept. 12, 1876. J. J. Johnston, Columbiana, 0. 182,614 Sept. 26, 1876. J. R. Teass, St. Albans, W. Va. 3 97,426 Nov. 20, 1877. C. Steinmann and J. Mitzger. Cincinnati, 0. 199,534 Jan. 22, 1878. J. T. Gorsline, Parma, N. Y. 205,596 July. 2, 1878. A. Whiting and J. A. Smith. Rochester, N. Y. 211,063 Dec. 17, 1878. C. Steinmann, Cincinnati, 0. 214,220 April 8, 1879. A. Whiting, Rochester, N. Y. 214,439 April 15, 1879. A. Palmer, Rochester, N. Y. 219,537 Sept. 9, 1879. J. A. Smith, Rochester, N. Y. 240,988 May 3, 1881. C. Flohr, Canisteo, N. Y. 276,634 May 1, 1883. G. Ruemelin, Milwaukee, Wis. 278,331 May 29, 1883. D. Halsey, Jr. Newark, N. J. 281,061 July 10, , 1883. J. Head, Richmond, Va. Section II. Swelling or Plumping. The swelling or "plumping" follows the unhairing and fleshing, and after the bating of the hides, which has been described, and it consists of a more or less prolonged immersion in an acid liquor which is gradually increased in strength. Its essential action consists in completing the swelling of the cells, distending the pores, and thus favoring the absorption of the tannin. A sec- ondary action takes place ; it is a commencement of tanning due to the presence of a certain quantity of tannin in the liquor ; the swelling being due to the action of the acetic acid and of the lactic acid of the hide. Both acids are products of decom- position and oxidation of the tannin. Some wood vinegar may be added to the sour tan liquor in order to accelerate the swelliag. This process does not cause any damage to the quality of the leather ; but some tanners replace the acetic acid by sulphuric acid, which, at an equal degree of acidity, costs considerably less. This practice is prejudicial to the quality of the leather. It is true that the 860 THE MANUFACTURE OF LEATHER. swelling is satisfactorily produced, and the leather looks well , bat, prepared in this manner, it retains traces of sulphuric acid which corrode it internally after a time, and make it very brittle and more subject to alteration by moisture, and there are other defects which will be mentioned shortly. The " plumping" process is applied to the heavier classes of hides only, such as those employed for the manufacture of sole- leather, upper-leather, etc. Pluinping hy Means of Sour Liquor. There are at present two methods in common use by which this plumping is accomplished, as has been stated. In one of these the tanning-liquor which has been in use for some time is made use of under the name of " tailings," or sour liquor, and in which the hide having been properly prepared is first placed. The fresh tan-liquors after a short time become changed in their character and nature, and the resultant is a liquid in which we find tannic, gallic, and acetic acids in varjnng proportions, combined with decaying vegetable and putrescent animal matter, but the presence of the latter substances seriously interferes with the exhibition of those active principles which the tanner seeks to utilize from his sour liquors, and it is the presence of this decomposed matter that forms the only objection to this method of plumping hides, and which gives it the principal danger, which, while not great, still requires watchfulness. The second method of plumping, and which will be enlarged upon in the next section of this chapter, is to steep the hides in a cold, dilute, sulphuric-acid liquor. But while the latter method expedites the work, it has the effect of rendering the leather harsh, liable to be brittle, and gives a dark grain to the same, it being conceded by all practi- cal tanners that the process in which the plumping is wrought by the presence of the acetic or aceto-gallic acid principle in the tailings is far preferable, could the same be divested of the trouble arising from the decaying animal and vegetable sub- stances present in all tanning-liquors which have been used for any length of time. H. J. Botchford, of Leyden, N. Y., proposes to remedy this by HANDLING AND PLUMPING. 361 subjectiug the soar liquors to a distillation in a still suitably constructed, by whicli the acetic and gallic acids are recovered in a pure form, freed from the other substances of the liquors. The distillate thus resulting is now taken, and, in a properly dilute form, is again used as a liquid in which the plumping of the hides may be very expeditiously and satisfactorily accom- plished. In the practical working of this process the distillation is best accomplished by the use of a still in which the liquors from which the acid products are to be recovered are heated by means of a steam-worm coiled within the bodj'" of the retort containing the said liquors, the vapors of the acids thus liberated being con- ducted from the head of the retort through a tubular condenser, the temperature of which is maintained at a sufficiently low point for the proper condensation of the acid vapors by surrounding the same with water at a low degree of heat; but any apparatus ordinarily termed a "still" will answer, as long as its materials are arranged to be proof against the attack of the acids to be recovered, and the heat of which can be maintained equally. Plumping hy means of Sulphuric Acid. In 1773, David MacBride, a physician of Dublin, introduced the employment of sulphuric acid for swelling or plumping hides, and though it may appear strange that such an improvement should have been made by a member of the medical profession, still this, like many other advances, was the result of accident, which arose from a series of experiments carried on for purely medical purposes, for confirming a theory that an infusion of malt would cure the sea scurvy. MacBride for four years kept the matter a partial secret, imparting the knowledge to only one firm of tanners in the city of Dublin ; but on May 31, 1777, after being at liberty to dis- close it he did so in a communication to the Eoyal Society, and it is recorded among the Philosophical Transactions. Vitriol or sulphuric acid, as it is also termed, is used for plumping both lime and sweat stock. The coloring and plump- ing of the latter are usually accomplished simultaneously in the 862 THE MANUFACTUEE OF LEATHEE. handlers, the liquor being strengthened after the removal of each pack. But while vitriol can be employed without danger on limed stock, it is desirable to observe caution in employing it upon sweat stock in order that it may not be too much swelled, as its action is more energetic upon hides which have been subjected to the sweating process. Some tanners find that it is an improvement to treat sweated hides to a weak lime bath, especially when they are to be plumped by sulphuric acid. The acid is diluted with cold water, and sometimes more or less of the old sour tan liquors are employed in conjunction with the sulphuric acid in order to hasten the process of pre- paring the hides for the tanning proper. It is, of course, impossible to give the exact proportion of vitriol to be employed in every case ; but the quantity now used is about the same as that prescribed by MacBride, more than a century ago, viz., to use his own language, "a wine pint of the strong spirit of vitriol is sufficient for fifty gallons of water to prepare the souring at first; therefore, all you have to do in raising sole leather, is only to prepare it beforehand in the usual way, and when it is fitted for the souring, mix up a quantity of vitriol and water, according to the number of hides that you require to have raised, still observing the pro- portion of a pint to fifty gallons, which will be enough if the vitriol be of the due degree of strength. The hides may lie in the souring till you find them sufficiently raised, for they will be in no danger of rotting, as they would be in the common sourings, which in time might turn putrid and rot the leather, whereas the vitriolic liquid keeps off putrefaction." In the early use of sulphuric acid by our tanners, an almost general lack of knowledge of the nature and effect of the sub- stance under certain conditions was largely prevalent, and much harm resulted from its injudicious employment in the handlers, but while practical experience has done much to aid the tanner in obviating disastrous results, there is still much desirable knowledge regarding its use in tanning that can result only from chemical experiments. LAYING- A WAY. 363 The most concentrated sulphuric acid is a definite combina- tion of forty parts sulphuric oxide and nine parts of water, the formulas representing it being HjO, S03, or H^So^, and is a color- less oily liquid having a specific gravity of about 1,85, of in- tensely acid taste and reaction. Oil of vitriol has a most energetic attraction for water, it withdraws aqueous vapor from the air, and when it is diluted with water great heat is evolved, so that the mixture requires to be made with a little caution. The specific gravity of sulphuric acid being so much greater than tan-liquor, it has at all times a strong tendency to settle and mark with spots of different colors the grain of the pack, and it is only by strict watchfulness that this can be avoided, and when vitriol is added to the pack, it should be done before the sides are thrown in, and the plunging should be faithfully per- formed in order to prevent the discoloring of the grain by the settling of the acid. The swelling or " plumping" process is, for the reasons previously stated on page 167, accelerated, and the falling back of the hides into their previous state prevented by the use of hard water. CHAPTER XIX. LAYING-AWAY. The hides having been raised, the texture dilated, and therefore weakened, and being deprived of that natural gum which ab- sorbs moisture, are in a condition to be tanned, that is, to have their fibres strengthened and re-united. Tannin is, therefore, an astringent and impregnating sub- stance, by the agency of which the fibres maintain their inde- pendence and the faculty, as it were, of sliding one upon another in their moist state, and by the means of which, also, the dried leather is rendered manageable and elastic. Without tannia the skin becomes horny as it dries, and loses all elasticity and malleability, which is due to the fact that the 364 THE MANUFACTUEE OF LEATHEE. bandies of interwoven and compact fibrous cellular tissue, of which it is composed, stick together, and constitute then a con- tinuous, semi-transparent mass. Leather is probably not, as has been heretofore considered, a chemical combination of the animal substance with the tanning substance ; for the reason that the latter is never absorbed in equal proportions, but in variable quantities, according to the concen- tration of the liquid and the nature of the dissolvent. " One may even obtain leather by the sole use of fatty substances, for which there can be no question of a chemical combination with the animal tissue. Mr. Knapp has even succeeded in tanning or making leather without tanning elements. Starting from this principle that the filaments adhere or stick together only Avhen they are swollen by water, he has put the hide in contact with such a liquid as alcohol or ether, which, expelling the water by endosmosis, deprives the fibres of their faculty of stick- ing. He has obtained in this way a tawed skin, of a nice white, and having all the physical qualities of tawed hides. The same result is obtained by suspending a cleansed skin in anhydrous ether placed above a layer of chloride of calcium. The water with which it is impregnated diffuses itself in the ether and is gradually absorbed by the chloride of calcium. Any leather thus prepared — the only difference in which from the moist hide, dried and horny, consists in the physical state of the fibres which have kept their independence — becomes an ordinary skin, with all its qualities, as soon as it is moistened. " It results from these interesting experiments that tanning is based rather on a physical action than on a chemical reaction. The tanning substances, penetrating the hide by endosmosis, envelop the fibres, adhere on their surface through an attrac- tion similar to that which causes the precipitation of coloring matters on the surface of textile fibres. The fibres thus sur- rounded by a layer of foreign matter do not adhere any more in drying. " The faculty which the tanning substances possess besides, of rendering the leather imputrescible, is independent of their physical action.' It may disclose itself more or less energeti- cally, according to the more or less antiseptic nature of the com- pound used. LAYING-AWAY 365 " A very interesting experiment of Knapp shows besides tliat one maj^ compare the leathers, as regards the solidity of the tanning with dyed tissues, some of which are of good tint and others of false tint. "Thus the hides tanned with tan-bark resist the action of. water, while those prepared with the tannin of the gall-nut come back to the state of untanned hide, after a prolonged wash with carbonate of soda, which proves that the active sub- stance of tan is not entirely identical with gallotannic acid."^ Following this theoretic discussion we shall now proceed with the final step in the process of tanning heavy hides and skins, such as are employed for sole and upper leathers, etc., which is the laying-away of the stock. The usual size of the lay-away vats for sole leather hides is nine feet long, seven feet wide and six feet deep, and in these the stock is usually placed with the grain side up in order to avoid " hook marks" in removing them. Fis. 118. Fig. 118 shows the manner in which the stock is laid away, it being spread out smoothly and upon the bottom of the tan- vat, and between each layer there is sprinkled a slight thickness 1 Wurtz. Dictionnaire de Chimie, Pure et Ap^jliquee, iii., 193 et.seg. 366 THE MANUFACTURE OF LEATHER. of ground bark until the vat is filled by the stock and bark thus laid in stratum super stratum. Tan-liqnor is then run into the vat, and when the interstices are filled the whole is crowned with a layer of bark which tan- ■ ners call a " heading." Formerly the inter-laying layers of bark were depended upon to do the tanning ; but at the present time in this country the bark-liquor is relied upon and not the interlaying bark. In European countries the layers of ground bark are still gener^ally depended upon to do the tanning, and the time is consequently longer than with us. In the early stages the green stock requires more attention than when it is nearly tanned, as at first it absorbs the tannin very rapidly and then gradually its capacity for absorption grows less until at the finish it refuses further to imbibe the tannic acid, and, as has been stated on page 129, the skins do not absorb an unlimited quantity of tannin, and are probably not improved by remaining a long time in the vat. The number of layers and the period of each differ for the various leathers, and depend upon the substance and weight of the stock, the strength of the liquors to which it is subjected, the season of the year and various other appendant matters ; but it is not uncommon in this country to tan the heaviest sole- leather in four layers of the following periods, the liquors at the end of each stage being of the indicated degrees of strength, which gradually increase from say 6° at the start, to about 30° at the finish : — 1st layer, 12 days 16° 2d " 18 " ..... 20° 3d " 24 " 25° 4th " 36 " ..... 30° Making the whole period ninety days, and in some cases it has been accomplished in much less time. In order to obtain full weight and brighter color the time of the final layer is prolonged, for when insufficient time is allowed to this layer there will be lack of solidity and the grains will be inferior. In the manufacture of finer grades, such as oak-tanned LAYING-AWAY. 367 sole leather of tlie kind wliich is used for the soles of ladies' and children's shoes, the packs are generally laid-away five times. 'New liquors, or mixtures of new and old, are preferable for dry hides, old liquors for slaughtered. "When laid-away in bark the packs are changed, as has been stated, until tanned. Much care and judgment are necessary in proportioning the continu- ally increasing strength of the liquors to the reqairements of the leather in the different stages of the process. The liquors should also be kept as cool as possible, within certain limits, and ought never to exceed a temperature of 80° F. Too high a heat, with a liquor strongly charged with the tanning princi- ple, is injurious to the life and color of the leather, and the use of a too weak one must also be avoided. Hides treated with liquors below the proper strength become relaxed in their tex- ture and lose a portion of their gelatine. The leather loses in weight, and is much more porous. The greatest strength of liquor used for handling should not exceed 16° by the barko- meter ; and that employed in laying-away should mark at its greatest strength from 80 to 35°. It is the custom, when the liquors in the lay-away vats are gradually increased in strength, to remove the packs after the stock has laid-away long enough, and run the ooze through wooden pipes into a receiver, and from thence to pump the liquor back to the leaches where it passes through the bark and is restrengthened, and then run as new liquor into the vats. Another method is to allow the fresh and strongest liquor direct from the leaches to pass first upon the head packs of the last layer, and from thence to the next, and so on through all the layfers, and of course decreasing in strength and becoming more acid until finally it passes upon the first lay-aways, or into the handlers where it is exhausted. When this method is employed the liquors when they come from the leaches should be at least 30° and ought not to exceed 35° in strength ; but the liquor should never in the end be allowed to remain upon the stock after its strength is spent. When heat is used on the head leaches the liquor sometimes enters the lay-away yard in a hot condition, and the intent is of course to turn it into the head lay-away ; but sometimes the attendant by mistake allows it to run on the green stock, thereby 368 THE MANUFACTURE OF LEATHEE. causing damage to the leather, as the " black rot" will be certain to set in to a greater or less extent, especially in the heated sea- son of the year. In tanning heavy upper leather the practice among some of our best tanners is to first handle the sides on sticks for ten or twelve days, and then lay them away twice in bark both lay- aways generally extending over a period of about sixty days, the first lay-away being for about twelve days and the second for about forty-eight days. After this the sides are split and then, after being levelled off, the sides, twentj^-five at one time, are placed in a large revolving wheel and worked for about ten minutes with moderately strong gambler liquor. From thence the sides go again into the handlers, but this time without sticks, and are drawn each day for about fifteen days. This completes the tanning of the upper leather, and it is then ready for the scouring and finishing. CHAPTER XX. SPLITTING LEATHER. After the sides have been removed from the lay-away vats they are — in the manufacture of upper leather and some other varieties of leather — hung on poles in the yard of the tannery to harden, and then carried to the cellar and dampened prep'aratory to being split. For other, and more minute details in relation to splitting leather the reader is referred to the chapters treating of the manufacture of upper and buffed leather. Fig. 119 shows an interior perspective view of the cellar of an upper-leather tannery. Piles of sides that have been dampened, and in condition to be split are shown at 1 and 4. The three split- ting; machines in a line, marked 2, are known as the Union- Splitting Machines; the one in the background marked 3, is the Belt-Knife Machine. The manner in which power is supplied SPLITTING LEATHER. 369 to the machines by means of a line-shaft is shown, the line-shaft being marked 5. For those who are building or equipping tanneries, views of this kind contain many valuable suggestions, as those in this work were taken under the author's personal supervision from the most modern and concededly the best arranged tanneries in the United States. The view shown in Fig. 119 is from the tannery of Mr. Thomas E. Proctor, Peabody, Mass. Splitting Machines. Early in 1831 Alpha Richardson, of Boston, Mass., patented his first splitting machine for leather. Seth Boyden, of Newark, N. J., had nearly a quarter of a cen- tury previous to this invented a machine for this purpose ; but while a large number of machines of this character had come into use there were numerous objections to them which it re- mained for Richardson to overcome. He gave great attention to the perfection of his contrivance, and continued to improve it until 1856, when he combined all his patents in the "Union Splitting Machine," which is now in such general use. Since the successful introduction of splitting machines hides have been split to meet all required conditions, and they may be split either in a green or tanned condition. In the manufacture of heavy upper leather, as is fully ex- plained in the chapter on that subject, the sides are split after being only partially tanned. When it is desired to split whole hides, as in the manufacture of enamelled leather for carriage tops, etc., a machine constructed on a different principle is employed. The one in most common use for this purpose is known as the "Belt-Knife Splitting Machiiie," which was invented in 1854 by Joseph F. Flanders and Jere A. Mardenof Newburyport, Mass., and which machine is now manufactured by The American Tool and Machine Co., Boston, Mass. The facilities afforded by machines of the character that have been mentioned, allow good " grain splits" to be obtained, which are used very largely for shoes, and also for harness,, trunks, 24 370 THE MANUFACTUEE OF LEATHER. etc., and the large production of buffed and grain leathers, which are now so much used in this country, and form an important item in our export list, has been greatly aided by them. Fig. 120. Fie. 121. Fig. 120 shows a perspective view of the A. Richardson or Union Splitting Machine, geared so as to be run by steam power, and Fig. 121 is a perspective view of the hand power machine, and the operation of splitting the side of leather is the same in both cases. The leather to be split, after having been properly dampened, is drawn between the knife and roller. In Fig. 121 A is the SPLITTING- LEATHER. 371 cast-iron piece connected with the gauge-roller jB, which revolves on the centres e e, and is turned up by the lever o, to allow the placing of the leather npon the top of the knife and back-spring A A. The skin being in right position, the gauge is then turned back, and forms the gauge for the thickness of the skins which may be regulated at will, by means of the screws h h. Bis the roller with the sectional tubes g g g, which are arranged to turn on its end, and to serve as friction-rollers when the shanks and loose parts of the skin are being drawn through. The knife D is bolted firmly to the bed by the screws i i % i. The leather is placed upon the cylinder (7, and drawn through against the knife D by the aid of the crank at the end of the machine. A modification of this machine is shown in Fig. 122, and is used largely for splitting and skinning heads, etc., in the manu- facture of sole leather, and upper leather, and for welt leather, and stiffenings for boots and shoes. Fig. 122. The machines shown in Figs. 120 to 122 operate by means of rollers, which force the leather against the edge of the knife. A is the gauge-roller, which is regulated by screws according to the thickness it is desired to split the skin. B is the lower roller, which forces the leather, or hide, against the knife, and the two are put in motion by the crank or pulley as the case may be at the end. Fig. 123 shows a perspective view of an attachment patented in 1883 by John A. Enos, to prevent injury to the arms of those who operate the ordinary splitting machines of the character which have been described above. As generally practised in the factories of New England, where leather-splitting is carried on largely, the leather is held 372 THE MANUFACTUEE OF LEATHER. pressed against and wrapped around the drawing-roller bj the hands of the operator, who is in great danger of being caught and having his arms broken, such accidents being of very fre- quent occurrence. Fia:. 123. Machines have also been made in which the leather has been drawn or fed against the edge of the knife or cutter by a pair of cylindrical rolls which act upon the opposite surfaces of the leather, pinching it between them ; but when a stationary knife or cutter is employed, it is claimed that it has been found im- practicable to use such a pair of feeding-rollers, as their holding power is not sufficient to draw the leather uniformly against the edge of the cutter. Enos discovered that by fluting or corrugating the surfaces of the drawing or feeding rollers, and preferably also gearing them together, so that the projections or convex portions of one roller will fall within the recesses or concave portions of the other roller, it is possible to obtain suffi- cient holding power upon the leather to draw it properly against the edge of the knife and split the leather. Enos's invention is shown in detail in Figs. 124 to 126, and consists, essentially, in the combination, with the usual splitting knife and parts co-operating therewith to present the leather properly to its edge, of a fluted or corrugated drawing roller and a corrugated or fluted auxiliary or gripping roller, and mechan- SPLITTING LEATHER. 373 ism hy which the operator can force the rollers against the leather between them. In the present embodiment of this invention the gripping roller is mounted in bearings upon pivoted arms which are acted upon bj an actuating-treadle to draw the gripping roller Fis. 124. Fig. 125. Fig. 12(1. toward the drawing-roller, and the gripping roller is drawn back or retracted bj its own weight or other suitable retractor, so that the operator hy merely raising his foot can at once re- lieve the pressure on the leather, which will then cease to be drawn. ST-i THE MANUFACTURE OF LEATHER. Fig. 124 is a front elevation of a leather-splitting machine embodying Enos's invention ; Fig. 125 an end elevation thereof; and Fig. 126 a vertical section on line x .t, Fig. 124. The framework a, knife 5, and mechanism for presenting the leather to be split to the knife-edge may all be of any usual construction, these parts not constituting the present invention. The leather presented to the knife at a short distance from the end of the piece or side has its end carried over the corrugated or fluted drawing-roller e, mounted on a shaft /, shown as actu- ated by a gear, g^ meshing with a pinion, A, on a shaft, ?", hav- ing the usual fast and loose pulleys for the driving-belt. Thus by wrapping the leather around the roller e, or pressing it against the surface thereof, the leather will be drawn against the edge of the knife and split by the power by which the roller is rotated, although it is necessary, in addition to the power, to provide means for holding the leather upon the sur- face of the drawing-roller. This is accomplished in accord- ance with the present invention by the auxiliary or gripping roller rn^ having its bearings in carrying-arms n^ pivoted on the shaft 0, so that the roller can be swung or oscillated upon, the arms toward and from the roller e. The arms n have exten- sions n\ forming therewith a bent actuating-lever for moving the roller m toward the roller e, the extensions or arms n' being provided with counterbalance-weight:^ w^ for partly balancing the weight of the roller m. The arms n' are connected by links or rods p with the actuating-treadle ?', so that the operator, by depressing the treadle, forces the roller m toward the roller e to grip the leather between them. The roller m is corrugated or fluted to correspond with the roller e, as shown in Fig. 126, and the roller e is provided at one end with a gear, s, meshing with an intermediate, ^, that meshes with a pinion, t\ fixed upon the shaft 0, which has at its other end a pinion, w, meshing with a gear u' ^ connected with the roller m. The gears s and u' are of the same size, and the pinions t t" u are of uniform size, so that the rollers 7>i and e rotate in unison in opposite directions and the projections of the one roller fall into the recesses of the other. The two rollers thus co-operate to grip and draw the leather, which passes down between the rollers instead of being SPLITTIN"G- LEATHER. 375 wrapped around one roller, as in the machines heretofore em- ployed. By the employment, in connection with a fluted draw- ing-roller actuated by power in the usual manner, of a corres- ponding fluted auxiliary roller — or, in other words, a co-operating pair of fluting, gripping, and drawing rollers — the danger to the operator, it is claimed, is removed, and the operation and capa- city of the machine for splitting the leather are improved and increased. In the old machines employing but a single roller, the leather, when wrapped around it, frequently forms bunches, causing in- equality in the tension of the leather, and consequent inequality in the thickness of the split material. McDonald and Beygs'' Leather Splitting Machine. The leather-splitting machine shown in Figs. 127 to 131 is the invention of John D. McDonald and William Beggs, of Woburn, Mass., and the invention relates to a leather-splitting machine of that class in which the leather to be split is drawn by a suitable drawing-roller against the edge of a stationary knife, the thickness of the split being regulated by a pressing or gaging roller, the periphery of which is just above the edge of the knife, against which it holds the leather being drawn, so that the thickness of one portion of the leather is equal to the distance between the edge of the knife and the periphery of the roller. In leather-splitting machines as heretofore constructed the gaging-roller has usually been mounted to turn loosely upon its arbor or bearings, so as not to resist the movement of the leather beneath it. The present invention consists in the combination, with the pressing or gaging roller, of means to rotate it positively for as- sisting in feeding the leather against the edge of the knife, and thereby reducing the work of the usual drawing roller. The gaging-roller is mounted in the usual beam, which is pivoted to enable the roller to be lifted up away from the knife to facilitate the introduction of the piece of leather to be split, and in this embodiment of the invention the roller is provided with a pin- ion meshing with a pinion upon a shaft coincident with the axis 376 THE MANUFACTURE OF LEATHER. Fig. 127. F]V. 128. Fis. 129. Fig. 130. Fio". 131. SPLITTING LEATHER. 377 of rotation of the beam, and provided with a pulley and clutch- ing device whereby the movement of the gaging and feeding- roller may be controlled as desired. A locking device for the beams prevents it from being turned on its pivots by the reac- tion of the roller in feeding the leather. Figure 127 is a front elevation of a leather-splitting machine embodying this invention ; Fig. 128, an end elevation thereof; and Figs. 129, 130, and 131, sectional details on lines a?, ?/, and z, Fig. 127, the beam being shown in Fig. 130 as turned to the position to raise the gaging-roller for the introduction of the leather. The frame-work a, leather-supporting bed or table Z>, knife c, drawing-roller c/, and its actuating-gears e e', the latter mounted on the main actuating shaft/, provided with a pulley /', are all of usual construction. The machine is also provided with the usual beam, A, pivoted to turn on bearings at A', it being oper- ated by a handle, t, and carrying the gaging-roller /<:;, by which the leather is held against the edge of the knife c and the thick- ness of the split regulated, the bearings of the beam h being adjustable by screws li^ to determine the thickness. When the beam is turned down to bring the roller ^' into operative position, its movement is limited by the toe A^, engaging the adjustable stop li'^. (See Fig. 129.) In order to cause the roller h to operate also as a feeding- roller to assist in forcing the leather against the edge of the knife in accordance with this invention, the roller is provided near one end with a pinion, m, meshing with a pinion, n, upon the roller-actuating shaft o, concentric with the bearing of the beam A, so that the rotation of the latter to raise and lower the roller ^, as shown in Figs. 130 and 181, does not disengage the pinions. The shaft o has loose upon it a pulley, p, actuated by a suitable belt, and having its hub made as one portion of a clutch, the co-operating portion r of which is splined upon the shaft, and is moved longitudinally there on to engage and dis- engage the clutch by a shipping-lever, s, connected by a link, ^, with a treadle, w, at the front of the machine. Thus when the treadle is depressed the clutch is engaged and the pulley |) made to connect with the shaft to rotate it, and, through the pinions 378 THE MANUFACTURE OF LEATHER. in w, to rotate the roller h in the direction to force the leather against the edge of the knife. By positively rotating the roller h so as to feed the leather, the roller is itself forced backward, tending to turn the beam h from the position shown in Fig. 129 toward that shown in Fig. 130, and such movement is prevented by a locking device, shown as a pin, Iv' (see Figs. 127 and 129), made laterally adjustable by set-screws A", and adapted to be engaged by the end of the shipper-lever s when moved to throw the clutch into engagement, and thus apply the power to the roller. If desired, such a locking device may be applied at the other end of the beam U. The Belt- Knife Splitting-Machine. Fig. 132 represents a perspective view of the belt-knife split- ting-machine, which has already been mentioned, and the one shown is the common size employed for splitting sides of leather, the knife presenting a cutting edge of fifty-seven inches. The manufacturers make another size, the knife of which presents a cutting edge of seventy-two inches for splitting whole hides, as for the manufacture of enamelled leather. These machines are successfully employed on all varieties of leather. If proper attention is given to the knives of these machines there is not much liability of annoyance from the other parts, and it is necessary to see that the operatives use proper care in the adjustment of the knife on the machine, and that they es- pecially avoid pinching it too tightly within the jaws. It should also be observed that the knife wheels are kept true, and that they are about 2-V ^^ ^'^ inch larger in diameter near the flange than they are at the opposite edge. The wheels, when new, are in this form, but, after a time they get worn and require to be newly turned. It is also extremely important that the axle of each wheel presents the same angle to the knife, so that two lines drawn across the edges of the wheels will meet in the centre between the wheels. By observing these direc- tions there will be but little occasion for mending knives. We here take the opportunity to say that a broken knife less than SPLITTING LEATHER. 379 two inches in width, is not worth mending, as a knife that is broken at one place, is frequently at the point of breaking in many places. 380 THE MANUFACTURE OF LEATHER. Eustace Gummincjs' s Iimq^rovement in Belt-Knife Splitting -Machines. Heretofore in leather-splitting machinery having a belt-knife the sides of leather have been fed to the knife by means of the feed and gage rolls arranged in front of the cutting-edge of the knife, and the operator simply guides the same as it leaves the knife and examines it from time to time to see that it is being split to the proper thickness. Cummings claims to have dis- covered that by the addition of drawing mechanism placed upon the opposite side of the belt-knife from the feed-rolls, which shall produce a constant and uniform tension upon- the leather as it is being drawn from the knife, that it can be much more uniformly split than would otherwise be the case. In fact the inventor strongly claims that a substantially perfect result is reached in that the leather is split uniformly or of the same thickness throughout, this result being obtained because it is drawn and held firmly to the gage-roll. Figure 133 is a back or rear elevation of a belt-knife machine such as made by Barton & Co., of Boston, Mass., containing Cummings's invention. Fig. 134 is a side elevation, and Fig. 135 is a vertical cross-section. A represents the belt-knife. It is revolved by means of driving wheels or pulleys in the ordinary way. h b' W represent the ordinary feed-rolls of the Barton machine. The roll 5 is a rubber-covered roll, which revolves the smaller sectional roll l'^ and the leather is fed between this smaller sec- tional roll and the gage-roll JJ^ to the knife. It is of course apparent that there is a space between the cutting edge of the knife and the portions of the rolls which almost impinge, and which is sufficient to cause the leather to be pressed from a straight path and down from the gage- roller as it is being fed to the belt-knife, and it is this movement from a straight line that causes the leather to be split unevenly. It is equally ap- parent that if the leather be drawn taut upon the knife this fulness between the cutting-edge and the feed and gage-rolls is prevented. This is claimed to be accomplished in the present invention by means of the drawing mechanism, consisting, pre- SPLITTING LEATHER. 381 Fig. 133. Fig. 134, Fis. 135. ferably, of two rollers C C, positively driven from any suitable shaft by means of a belt, c, and pulley c', or in any other desir- able way. These rollers are run at a speed greater than the speed of the feed and gage-rollers. The lower of the two rollers 382 THE MANUFACTURE OF LEATHER. preferably is covered with rubber, felt, or other like material ; but while this is an improvement upon a metal-surfaced roller yet the inventor does not wish to be understood as limiting himself thereto. The rollers are arranged above the plane of the knife, so that the split portion of the leather takes a diagonal course upward thereto after leaving the knife. The upper roller is provided with a vertical movement in relation to the lower roller so that it may be moved to receive the forward end of the leather as it passes the knife, and also to permit of the adjustment of the leather while it is being split, or, on ac- count of its shape (when a side), it does not feed uniformly in a straight line. This is accomplished by means of the sliding boxes D B\ the rods d^ the lever d\ connecting-bar d^^ and the treadle #, and it is preferable that the construction be such that the upper roller shall automatically lift from the lower roller, and this may be accomplished either by counterbalanc- ing weights rf*, attached to the bar d^^ or b}^ means of springs adapted to lift the treadle and the upper roller. In this case the front portion of the side of leather passes the knife, enters between the two rollers, and the operator then with his foot presses the upper roller down upon the leather and lower roller sufficiently to give as much tension or friction thereon as may be desired, and as the rollers revolve faster than the feed-rollers the leather is drawn taut between the feed and drawing rollers and upon a straight line parallel with the rollers, but somewhat inclined between the drawing-rollers and the feed-roller. The teeth of the gear-wheels upon these rollers are made long, so that a separation of the rollers can take place without interfer- ing with the positive rotation of either roller, so that when the upper roller is brought down upon the sides it will be rotating at the same speed as the lower-roller. By this device Cummings claims to be enabled to split the leather to a uniform degree of thickness, and thereby dispense with the subsequent shaving now necessary, and consequently save the cost of much labor, as well as prevent the waste of the stock ; that which before made shavings forming a portion of the split leather, and of course making it stronger, heavier, and of better quality. SPLITTING LEATHER. 383 It is not necessary in all kinds of work to use both drawing- rollers, as the lower one, especially when covered with a fric- tional material, like rubber, will answer to draw the hide, especially when held down thereon by hand. List of all Patents for Leather Splitting Machi ment of the United States of America, from 1 nes, issed by the Govern- 790 to 1883 inclusive} No. Date. luventor. Residence. July 9, 1808. S. Parker, Jan. 7, 1809. S. Boyden, Newark, N. J. April 26, 1809. S. Parker, July 12, 1810. P. Dow, Boston, Mass. April 5, 1813. S. Parker, May 3, 1820. E. Howard, and J. Butters, Boston, Mass. May 31, 1822. J. Butters, New York, N. Y. April 23, 1831. A. Richardson, Boston, Mass. Dec. 31, 1833. J. P. Shaw and J. C. Briggs, Boston, Mass. 1,010 Nov. 20, 1838. E. Putnam, Danvers, Mass. 1,272 Aug. 2, 1839. H. White, Binghamton, N. Y. 1,967 Feb. 9, 1841. A. Richardson, Boston, Mass. 3,541 April 17, 1844. A. Richardson, Boston, Mass. 5,456 Feb. 22, 1848. J. P. Fairlamb, Wilmington, Del. 8,227 July 15, 1851. W. Panton, Milton, Mass. 8,369 Sept. 16, 1851. A. Richardson, North Enfield, N. H. 9,980 Aug. 30, 1853. C. Weston, Salem, Mass. 11,604 Aug. 29, 1854. J. F. Flanders and J. A. Mar den. Newburyport, Mass. 12,114 Dec. 9, 1854. E. Pratt, Salem, Mass. 12,392 Feb. 13, 1855. M. H. Merriam and J. B. Crosby, Chelsea, Mass. Stoneham, Mass. 13,407 Aug. 7, 1855. J. B. Tay, North Woburn, Mass, 13,756 Nov. 6, 1855. J. A. Marden and H. A. Butters, Newburyport, Mass. Haverhill, Mass. 14,430 Mar. 11, 1856. E. Pratt, Salem, Mass. 22,108 Nov. 23, 1858. H. E. Chapman, Albany, N. Y. 23,900 May 10, 1859. D. H. Chamberlain, West Roxbury, Mass. 28,559 June 5, 1860. D. H. Chamberlain, West Roxbury, Mass, 29,649 Aug. 14, 1860. J. F. Flanders, Boston, Mass. 30,553 Oct. 30, 1860. S. S. Turner, Westborough, Mass. 1 This list does not include skinning and leather splitting machines used in the manufacture of boots and shoes, only those used in tanneries and currying shops. 384 THE MANUFACTURE OF LEATHER. jVo. Date. Inventor. Residence. 31.746 Mar. 19, 1861. J. A. Safford, Boston, Mass. 35,850 July 8, 1862. A. H. Van Gieson, Newark, N. J.. 38.763 Juue 2, 1863. B. Rowe, Albany, N. ¥. 39,695 Aug. 25, 1863. H. Wing, Buffalo, N. Y. 41,448 Feb. 2, 1864. J. A. Safford, Boston, Mass. 43,]59 Juue 14, 1864. C. S. Stearns, Marlborough, Mass. 53,741 April 3, 1866. J. A. Marden, Newburyport, Mass 53,771 April 10, 1866. C. W. Baldwin and L. D. Hawkins, Charlestown, Mass. Stoneham, Mass. 54,043 April 17, 1866. A. H. Van Gieson, Newark, N. J. 54,571 May 8, 1866. J. A. Marden, Newburyport, Mass 70,175 Oct. 29, 1867. A. Dawes, Hudson, Mass. 74,734 Feb. 18, 1868. F. J. Vittum, Newburyport, Mass 75,823 Mar. 24, 1868. J. H. Abbott and J. A. Marden, Maiden, Mass. Boston, Mass. 78,697 June 9, 1868. C. S. Stearns, Marlborough, Mass. 83,888 Nov. 10, 1868. J. Taggart, Boston, Mass. 95,780 Oct. 12, 1879. H. Cunningham, Albany, N. Y. 98,068 Dec. 21, 1869. C. Keniston, Somerville, Mass. 98,888 Jau. 18, 1870. J. A. Safford, Winchester, Mass. 100,082 Feb. 22, 1870. C. S. Stearns, Marlborough, Mass. 123,589 Feb. 13, 1872. , C. S. Stearns, Marlborough, Mass. 139,744 June 10, 1873. A. F. Stowe, Worcester, Mass. 144,899 Nov. 25, 1873. J. Goebel and J. Preis , Caledonia, Wis. 147,172 Feb. 3, 1874. G. Reynolds, Woburn, Mass. 149,542 April 7, 1874. C. S. Stearns, Marlborough, Mass. 156,652 Nov. 10, 1874. J. A. Safford, Winchester, Mass. 179,948 July 18, 1876. H. F. Osborn, Newark, N. J. 191,855 June 12, 1877. J. Hodskinson, Salem, Mass. 209,001 Oct. 15, 1878. A. E. Whitney, Winchester, Mass. 211,187 Jan. 7, 1879. J. A. Safford, Boston, Mass. 230,895 Aug. 10, 1880. J. A. Safford, Boston, Mass. 244,196 July — , 1881. C. Daneel, New York, N. Y. 278,562 May 8, 1883. J. E. Enos, Peabody, Mass. 279,659 June 19, 1883. J. D. McDonald and W. Beggs, Woburn, Mass. 288,551 Nov. 13, 1883. E. Cummings, Woburn, Mass. PART yi. CHAPTEE XXI. scouumG. After the leather has been split it is commonly handled in liquor for about two weeks, which completes the tanning pro- cess, and the next operations to Avhich it is to be subjected are the drying and finishing for market. Of course different varieties of leather pass through different modes of treatment, and while there is but little to be done in the finishing of sole leather, except the drying and rolling, there is much to be done in finishing upper leathers, Morocco leathers etc. We shall therefore devote one chapter to each of the subjects of scouring, stuffing, blackening, and polishing leather, and then for other details of special branches of manufacture and for coloring and dyeing leather, refer the reader to the various chap- ters treating of those subjects. The tools used in the hand method of scouring leather are the brush, stone, and slicker ; the brush is shown in Fig. 136, Fi^. 136. . . llhlPI'i iHI I,'jiIlMiIVIMi#' ^IMt^, and the perspective view. Fig. 137, shows the form of tables and other mechanical details connected with the hand method of scouring leather. 25 386 THE MANUFACTURE OF LEATHER. This manner is laborious and expensive, which has caused it to be superseded almost entirely by machinery. Fiff. 137. A review of all the leather-finishing machines that have been perfected since 1867 will, I think, show none of so much import- ance to the tanner and currier as the leather scouring and set- ting machines which have, during that time, become so common in our tanneries and currying shops. Some of these machines are so arranged as to do simply the scouring, while others will perform either the scouring or setting. Lockivood's Machine. The Lockwood Automatic Leather Scourer and Setting- Machine, shown in Figs. 138 to 140, is valuable for performing the work of scouring all kinds of leather that are thus treated, or for setting calf-skins, kip, buff, and wax. SCOURING. 387 388 THE MANUFACTURE OF LEATHER. It is a costly machine, but its work is so satisfactory that I have not heard a complaint against it in the various large tan- neries and currying shops, where I have seen it in operation, in the neighborhood of Woburn, Salem, Peabody, and other points in Massachusetts. In one tannery, that of Messrs. Bryant & King, located near Woburn, Mass., the author saw seven of these machines setting calf-skins, and was much surprised at the ease with which they were operated and the excellence of the finished work. Fig. 138 shows a perspective view of the Lockwood machine. Fig. 139 is a vertical and longitudinal section of the same. Fig. 140 is a vertical transverse section of the same. SCOURING. 389' The table A is supported upon a stage, B, wliicli is erected upon the floor C of the apartment or the foundation of the machine, whatever the latter may be ; and the inventor has made provision for levelling the table A, or adjusting it to slop*- Fiff. 140. ing or irregular floors or foundations. In the drawings, the floor is represented as sloping and depressed at the rear, which is desirable in order that refuse water and liquids may pass off. To compensate for the inclination or irregularities of the floor G, the inventor prefers to dispose the front ends of the lower beams, D, of the stage B, upon metallic blocks, and screw through S90 THE MANUFACTUEE OF LEATHER. the ends of the beam screws to bear upon the blocks, by which means the irregularities or inclination of the floor are overcome. In the rear of the table A is disposed an upright truck, K, the movements of which are guided by a horizontal rail, L, secured to the rear ends of the beams D and parallel to the edge of the table. Wheels J/ are interposed between the triick ^ and rail L to reduce friction, while a second series of rollers, iV, are pivoted to the feet of the truck and roll upon or against the front edge of the rail, and serve as rolling bearings to retain the wheels Min place upon the rail L and overcome the great fric- tion incident to leverage of the truck over the upper rail, P (see Fig. 140), as a fulcrum. The inventor pivots to the adja- cent parts of truck antifriction rollers Q, which travel against the rear edge of the ledge or upper rail, P. The trundle-frame i? of the carriage m (shown in Figs. 139 and 140) is placed between the side pieces, B^ E^, of the hori- zontal beam i?' of the truck, and has V-shaped bearings to fit correspondingly-shaped grooves a in these side pieces. The carriage, composed of the trundle-frame B and vertically-ad- justable head m', is moved longitudinally with relation to the beam R' and transversely of the table by means of a screw- threaded shaft, jS (see Fig. 140), held in suitable bearing, h c, the screw fitting a threaded nut, cf, fixed to the rear part of the trundle-frame of the carriage. The screw-shaft jS is rotated by a bevelled gear, d, fixed to its rear end, which bevelled gear is engaged and driven by a second bevelled gear, e, secured to the upper end of a vertical shaft,/, which is supported in bearings h i, erected on bars j Jc, which unite the side plates or housing, T T', of the truck K. When the strokes of the tools are to be repeated several times in the same direction the handle of the catch is raised and that of the latch elevated by the spring 2, interposed between the two, the nose of the latch being thereby forced into one of the notches y*, and the yoke, with the hand- wheel, is thus locked to the annular plate J' of the head of the carriage. Mr. Lock- wood's object in thus locking the yoke and hand- wheel is to re- lieve the attendant from the manual labor of holding, the guide- SCOUEING. 391 bar y* in a fixed position, which is essential to impart rectilinear motion to the tools. The tool-holders o* |/, pivoted to the tool-carrier /*, will be lifted from the skin during their backward stroke. When it is desired that the tool-carrier, with the dressing- tools, be moved diagonally across the table, it is necessary to simultaneously move both the carriage on the beam B' and the truck K on its rails. This is accomplished by moving the handle of the guide-lever F' in the direction it is desired the tool-carrier to take, the movement of the guide-lever simul- taneously turning the rock-shafts (?' W'^ causing the bands to rotate two of the pulleys JL', e^, F, or/^, which is necessary in order to insure the proper direction of the movement of the parts. This hand-operated guide-lever i^', the position of which determines the direction of movement of the tool-carrier and tools, and the position of the dressing-tools with relation to the skin, greatly simplifies the labor of the attendant, places the machine more perfectly under his control, and consequently enables more and better work to be done. The present invention is an improvement on the machine which Avas patented by the same inventor in 1876. In devising this later machine, Lockwood had in view, first, to drive the operative parts of the machine by direct positive mechanical devices in lieu of a belt, thereby insuring uniform and certain actions of the various agencies and reducing the power required to run the machine ; and, second, to relieve the attendant to a great extent of the constant care and watchful- ness heretofore devolving upon him, and enable the main func- tions of the machine to be controlled by a single hand or guide- lever. In order to obviate the lifting of the beam when the dressing- tools are lifted, and to give increased rigidity at the junction of the beam-arms and truck, Lockwood has made the beam-arms as a fixed part of the truck, and divided the so-called " cross- head" or carriage into two parts, one of which we will denomi- nate as the "trundle-frame" and the other as the "head." This head is made vertically adjustable with relation to the horizon- tally-movable trundle-frame, and there is mounted in this head the axially-movable yoke having upon it the guide-rod which 392 THE MANUFACTURE OF LEATHER. receives the reciprocating tool-carrier. The head in the present invention is made vertically adjustable by means of a hand- operated shaft located at the front of the machine, and such ad- justment may be made during the operation of the machine. The truck is made movable longitudinally with relation to the skin-supporting table by means of a rotating nut placed on a screw-threaded rod held in a fixed part of the frame-work of the machine. This nut may be rotated in one or the other direction on the rod, the ends of the nut acting against the truck to move the same longitudinally. This nut and screw enable the truck to move positively in both directions and hold the truck firmly in place, thus dispensing with pawls and their actuating mechanism. There are also other improvements in this machine over the one patented by the same inventor in 1876, such as driving the operating parts of the machine, positively by means of shafting and gearing instead of belting, and also in substituting a single lever in lieu of the double-hand levers for controlling the truck on the ways and the so-called " cross-head" and carriage. The new Lockwood machine, as will be seen by Fig. 138, has a large table on which to place the stock, so that one work- man can be preparing a side at one end Avhile the other will be directing the machine in the automatic setting out of a side pre- viously arranged on the other end. The working thus keeps two men constantly busy, but the physical labor required is light, for the machine takes all this. The strokes made are either strong or light, as desired, being directly under the con- trol of the operator, who, with his hand on the wheel, guides and almost, as it were, feels them. So, in going over the bellies and flanks, working out folds and thoroughly setting out thick portions of a side, the work is not only done quickly and well, but the leather is made to measure enough more, on all stock sold by the foot, to quickly pay for the machine in the gain thus made. Holmes's Machine. The Holmes Scouring, Setting, and Hide-Working Machine is shown in Figs. 141 to 145, and is an improved form of the old Fitzhenry and Ball, and Pray and Fitzhenry machines. SCOUEIISTG-. 393 394 THE MANUFACTURE OF LEATHER. Fig. 141 shows a perspective view of the machine in opera- tion ; Fig. 142 is a front elevation of the portion of the machine Fig. 142. embodying Holmes's improvement of March 8, 1881 ; Fig. 143 is a plan thereof; Fig. 144 is a vertical section on the line x x of Fig. 143 ; Fig. 145 is a vertical section, to which reference will be made hereafter. Fig. 143. In operating this machine the hide is laid upon the table, which is mounted upon rollers, and provided with universal SCOUEING. 395 movement on a horizontal plane beneath the head A, and the cranks set in motion. This causes the tools to be applied alter- nately, according to the direction of movement of the tool head, to the skin or leather with a slicking motion. 144. Fig. 145. n jS 55 ^^^=^ The head or framework A is arranged to be reciprocated upon the horizontal and parallel ways a a' by a crank and con- necting-rod or pitman, B. This connecting-rod or pitman, or an extension thereof, is pivoted at to the head J., and a portion extends beyond the pivot, and consequently as the head is re- ciprocated, the end V and the point W" are alternately lifted and lowered in relation to the line Q of the table upon which the hide is scoured, finished, or otherwise treated, and this oscillating 396 THE MANUFACTURE OF LEATHER. Fig. 146. Holmes's Improved Scourixg Machine Parts. S. Wrench, f in. and 1|- In. Hexagon. 2' " f " I in. " S. " I " 4 in. Square. T. " iin. T. " 5-16 in. fin. Hexagon Nut. 7-16 in. " I in " " 7-16 in. X 1 in hardened Set Screw. 7-16 in. xliin. " " 7-16 in. x2Hn. " " f in. Tap Bolt for Brake Strings. I in. s U in. hardened Set Screw. 4 X 1 in. Spring Pins. .'i-16ia. X 2 in. Steel Pins, f in. X 4 in. IS. Brass Lever Nuts. 19. Levers. 20. L. H. Slide Brake. 21. R. H. " 22. Brake Spring. 23. .5-16 Brush Pin and Tools. 21. R. H. Brush Cam. 25. L. H. " 26. Brusli Spiral Spring. 27. Brush Handle. 28. Brush Top Bar. 29. Brush Pre.ssure Bar. 30. Brush Roll Holder. 31. Brass Back Brush. 32 Brush Top Screw. 33. Brush Rod | iu. 31. Spiral Tool Spring. SCOURING. 397 movement of this portion of the connecting-rod or pitman in relation to the centre b is utilized for the purpose of alternately lifting the tools from the work and allowing them to bear upon the work. The tool-carriers D D' are pivoted or hinged at the points d to the head J., and the tool-carrier lifting-rods c?' d} lay hold of the tool-carriers and are provided with buft'ers d^ d^. The in- ventor connects the nuts or blocks E E' by the long arm or lever e, which is pivoted at e' e^ to the blocks. He prefers that the lifting-rods d' d^ be provided with a screw-thread, and that their position in relation to the blocks E E' be adjusted by the nuts e^. The tools are held down to their work by means of the con- tractile power of the coiled springs F E\ which, at their lower ends, are connected with the tool-carriers, as represented, and at their upper ends hook upon the rods//', which are adjustably secured to the arm or lever e by the nuts/^. This construction and combination of springs, tool-carriers, lifting-rods, oscillating lifting rod or plate, and connecting lever 35. Spiral Spring Tool Rod 78. Long Right Hand. 36. Stirrup. Long Lpft Hand for Latch Screw. 'V 37. Tool Rod 1 in. 79. Shoit Right Hand Arm. T3 38. Flanged Nut Short Left Hand for Latch Screw. a 39. Rubber Cushion SO. Bracket Clamp, Left Hand with 40. Handle Rod. Stud. 40i . Handle End. Bracket Clamp, Right Hand with § 41. Wood Handle. Stud -■2 42. Table Handle P in 81. Latch Spring Holder. 43. Table Handle E ar 82. Tap Bolt for SI. 44. Table Handle. SX Latch Catch Screw. a 45. Caster Holder. ■ 84. Latch Right Hand. _o 46. Caster Roll. " Left Hand. to 47. CastferPin. " Caster Complete. 85. Latch Spring. OS 48. Caster Shell. 1 86 Latch Press Pin. 49. Caster Screw N It. J 87. Brush Handle Arm. " x 50. Elliptic Spring. 88. " " Clamp, Right 51. Stirrup Guard. Hand. r^ 52. Spring Holder. Brush Handle Clamp, Left yo p: a 53. Pressure Box. Hand. JSffl 54. Tool Holder. 89. Brush Handle Slide. as .55. Stone Guard. 90. Pressure Screw Ear and Screws. .56. Water Guard. 91. Spiral Spring Top Lever. .57 f in. Tool and sci Uato r Pin. 92. Pressure Screw. 58 Side of Carriage 93. Spiral Spring Nut End. 59. i Top of Carriag e. 94. " " Loop End. 60. Oscillator. 95. Slide Brake, U. Slide. 61. Connecting Rod E nd. 96. " " Connecting Rod. 62. " " St rap. 97. Spiral Spring Hook. 63. I* I. B 5X. 6t. a u G b. Parts not Illustrated. 65. " '• K ey. 71. Wood or Brass Gibs f thick. 66. " " lev. 72. Walpole Machine Stones. 67. i( a T russ Screw. ■ 73. Brass or Steel Slickers. 68. " " T ■usa Post. 74. Crank Shaft. 69. Brackett. 75. Pulleys. 70. Slide. 76. 77. Balance Wheel. Post Boxes. 398 THE MAKUFACTUEE OF LEATHER. or arm, give and permit a uniform and equable pressure upon the tool-carriers, and consequently upon the tools, at all points of their reciprocation or stroke, and this was not the case with the mechanism of the old form of these machines. For lifting one or both tool-carriers during the reciprocation of the head from their work Holmes employs the two pairs of rods, G G' and (7^ (r^, arranged so that each pair is supported at both ends by independent swinging arms g y\ which are piv- oted at y^ to any suitable stationary portion of the device for holding the frame a'. One of the two pairs of arms y g' is longer than the other pair, in order that each pair of rods may be on a different level. Upon each of the inner rods, G' G'^, there is arranged a slide, y*, and one of these slides, by means of a connecting-rod, c/^, connects with the latch or slide-bar H, and the other slide, ^*, by means of a like connecting-rod, ^^, connects with the latch or slide-bar H' . Both these slide-bars are adapted to be pushed under the lever e, for the purpose of holding the tool-carrier from the work when desired. Mr. Charles Holmes died shortly after improving this machine ; but since the fall of 1883 his estate has continued the manufacture of these machines at the old stand in Boston, Mass. For the convenience of those owning and operating these machines who may desire to order duplicate parts, we show them in Fig. 146, Fitzhenrif s Machine. Figs. 147 to 151 show the latest improvement on the Fitz- henry Leather-Dressing Machine, and it consists in the construc- tion and arrangement of the devices for raising and lowering the tools, and for starting and stopping the same to and from the work. Fig. 147 is a perspective view. Fig. 148 is a side elevation of the steam cylinder and carriage embodying Fitzhenry's in- vention. Fig. 149 is a partial longitudinal section of the same. Fig. 150 is a transverse vertical section thereof; and Fig. 151 is a view of detached parts of the machine. A represents the steam-cylinder provided on its sides with the grooved ways a, in which the frame or carriage B is moved SCOURING. Fig. 147. 899 Fig. 148. A / FiR. 149. f^ S 400 THE MANUFACTURE OF LEATHER. back and forth by the piston-rod h passing through both ends of the cylinder. In the lower portion of the frame or carriage B at each end is a rocking shaft, d, with arms e e projecting out- ward therefrom, and to the outer ends of these arms the tool- Fig. 150. Fig. 151. holder G is secured. D is the tool, and E the covering-plate, which are fastened to the tool-holder by screws / / passing through them. From the back of each rocking shaft d extends an arm, A, which is curved upward, as shown, and the upper portion slotted or forked and pivoted to a slide, G. This slide or sleeve is placed loosely on a bar, H^ to each end of which are pivoted two links, i i. The links at one end of the bar H are placed loosely on a shaft, m, while the links at the other end are secured to a similar shaft m. The two bars JT^with their links are so arranged that each shaft m has two links fast thereon and two loose links. At one end of the frame or carriage B are pivoted two pit- men, / /, which connect with and operate two fly wheels, J e/, placed on the ends of a shaft, ?z, above the cylinder A in the centre. On this shaft are secured two cams, p p, each of which operates a lever, Z, pivoted in a slotted bar, P, placed in the framework connected to the cylinder. The lower ends of the levers L L are, by bars or rods R i?, connected with cranks 5 s SCOUKIISTG. 401 on the shafts m m — that is, one lever connects with one shaft, and the other lever with the other shaft. When the machine is in operation the shafts m m are rocked by means of the cams 2^, levers Z, connecting-bars /?, and cranks 5, whereby the bars H are moved lengthwise, and alternately raised and lowered, thereby alternately raising and lowering the tools. S is the hand-wheel for swinging the entire mechanism in any direction. On the under side of this wheel are two rods, t t^ each of which connects with hinged levers V V carrying a wedge, W. These wedges are pushed down in grooves at the ends of the fulcrum-bars P P to hold them stationary while the machine is in operation. To stop the tools it is only necessary to push the rods t inward, when the wedges will be drawn and the bars or boxes P become movable, thereby removing the fulcrums of the levers L so that they will not operate. The Avedges W are guided in their up and down movement by means of pins x x. Burdori's Machine. The Burdon Machine is shown in Figs. 152 to 154, and it is for dressing, setting out and scouring hides, skins, and leathers; and has for its object to facilitate the operation by providing for a perfect adjustment of all parts to hides varying in thickness and quality. The invention consists, chiefly, in the use of a rotating, scour- ing, and rubbing cylinder, which is hung in a pendulum-frame, so that it can be swung any suitable distance from the bed that supports the hide to be dressed. Fig. 152 shows a perspective view of the machine, and Fig. 153 shows a side view, partly in section, of the cylinder and elastic bed. The scouring cylinder A revolves upon an adjustable and elastic bed B^ as shown in Figs. 152 and 153. The scouring surface of the cylinder consists of a succession of stones and brushes, arranged in alternate rows, and secured to its surface. The pressure of the cylinder upon its work is regulated by mov- ing the pendulum frame C, in which the scouring cylinder 26 402 THE MANUFACTURE OF LEATHER. Fiff. 152. SCOUEING. 403 revolves towards and from the bed. This is done by means of the arms D and E^ which being connected with the treadle F^ are at the control of the operator. This latter feature of the machine renders it equally applicable to the heaviest sole and belt leather, and to the thinnest splits and calf-skins. Ym. 153. The pendulum frame (7 is suspended from the upper driving- shaft, and carries at its lower end a horizontal shaft. A belt connects the pulleys for the purpose of transmitting motion to the shaft /. Upon the shaft /is mounted the scouring cylinder or disk A^ which carries the rubbing or scouring implements, in the form of stones G and brushes H. Each stone is made of triangular or other suitable form, and is dovetailed into a dovetail groove of the cylinder J., being- locked therein by a wedge or key, c. The bed B is arranged above a fixed table Z, and is by springs d d underneath, held against and in contact with the scouring cylinder. The under portion J/ of the bed B is concave, and over it is stretched, by being fastened to the ends, a sheet of rubber, leather, or other flexible or semi-elastic material. This sheet constitutes an elastic cushion, for the material to be treated. This is a valuable labor-saving machine ; it removes the bloom 404 THE MANUFACTURE OF LEATHER. and softens the grain in a thoroughly satisfactory manner, is economical in space, requiring only about 6xQ feet square and 9 feet height. It scours flanks and shanks with as much facility as the body of the side, and it does its work equally well on all grades and qualities of leather, from the heaviest baud or har- ness leather to the finest and lightest calf or goat-skins. It is well adapted for the tanyard, cleansing the hide effectually from lime and from the bate, and preparing it for the handlers. It is also well adapted for removing bloom from sole leather after it is tanned, and preparing it for the roller. Fig. 154 is a side elevation of the Burdon scouring machine, and shows the arrangement and another manner of hinging the Fisr. 154. table differing from that shown in Fig. 153. In Fig. 154 the table is made adjustable by means of levers, and Fig. 154 also shows a manner of hinging the spring-bed and combining it with the table. The scouring-bed if is at one end hinged to a table, N, which is by a hinge, a, secured to a fixed platform or floor, 0. A set of toggle levers, P, or other suitable mechanism, applied against the under side of the table, and connected with a treadle or handle, F, can be used to force the table and bed with suitable power against the cylinder. SCOURING. 405 A spring or springs, e, interposed between the free end of the bed J/ and the table, serves to hold the bed against the cylinder. The upper or contact face of the bed may be made slightly concave, as shown, to receive a sheet, B^ of leather, rubber, or other material, which is stretched over its ends to constitute a cushion surface, upon which the leather to be treated is placed. Daheney^s Table for Leather -Scouring Machines. Daheney's table for leather-scouring machines is shown in Figs. 155 to 159, and the invention has for its object to produce a more durable and convenient table than those heretofore used for this purpose. The tables usually employed at the present time are either of wood or of slate, both of which materials are expensive and are rapidly worn out, the table thus having to be renewed frequently. Fig. 155. This table is composed of two metal plates and an intermedi- ate strengthening framework connected with the said plates, to support them at various points between their surfaces, substan- tially as described. Fig. 155 is a plan view of a table embodying this invention, a portion of the surface-plate being removed to show the sup- 406 THE MANUFACTURE OF LEATHER. porting framework ; Fig. 156, a side elevation thereof, showing the table mounted on rollers or casters in the usual manner ; Fig. 157, a partial plan view of a modified form ; and Figs. 158 and 159, sectional details on lines x and y of Figs. 155 and 157, respectively, on a larger scale. Fis. 156. m 5 M^^--^^ (mm=^m -Its (F CP <^ ^ i? __ It /? \ \ 3 ' Fig. 157. Fig. 158. ®S o Fig. 159. The table consists, mainly, of a surface plate, of thin metal, preferably of sheet-steel, and a strong rectangular frame, 6, pass- ing wholly around the table and connected with the edges of the surface-plate a. As shown in Figs. 155 and 158, the frame h has connected with it a series of thin webs or ribs, c, the points of intersection of which are enlarged to afford sockets d for rivets e, or other fastenings, by which the surface-plate a is connected with the framework, the webs with their intersect- ing points forming rests to support the thin surface-plate at intermediate points or between its edges. When the table is intended to be movable upon rollers, as shown in Fig. 156, there will be similar surface-plates a at both sides of the framework b c d^ the plates being preferably united by rivets passing wholly through the table, and being finished even with the surface. In some cases it will be sufficient if the webs are omitted and tubular posts d' used at suitable intervals, as shown in Figs. 157 and 159, they forming the rests to support the surface-plates a, scouRmo-. •±07 and keep them parallel with one another, the posts having pas- sages for the shanks of the rivets e, as shown. In some instances one surface-plate a only might be used, and the plate, together with the strengthening ribs or frame- work, might be made from a single piece of metal, although it is usually preferable to make the surface- plates independently and fasten them upon the stiffening framework. List of all Patents for Scouring^ and Setting Machines, issued hy the Government of the United States of America, from 1790 to 1883 in- clusive. No. Date. Inventor. Eesidence. Nov. 21, 1831. R. Ernes, Boston, Mass. 17,576 June 16, 1857. p. E. Hummel, Pulaski, N. Y. 49,606 Aug. 29, 1865. W. M. Clarke, Butternuts, N. Y. 60,149 Dec. 4, 1866. F. Davis, Lawrence, Kan. 61,182 Jan. 15. , 1867. E. Fitzhenry and I. Ball, Portland, Oregon. 61,250 Jan. 15, 1867. J. A. Pray and E. Fitzhenry, Portland, Oregon. 63,307 Mar. 26, 1867. A. W. Roberts, Hartford, Conn. 65,224 May 28, 1867. A. Howard and G. F. Howard, Wellsville, Md. Chicago, 111. 76,619 Aprilll, 1868. E. Fitzhenry, Boston, Mass. 79,832 July 14, 1868. A. Howard, and G. F. Howard, Wellsville, Md. Chicago, 111. 84,001 Nov. 10, 1868. F. W. Rust, Umatilla, Oregonc 90,664 June 11, 1869. C. Holmes, Boston, Mass. 98,121 Dec. 21, 1869. J. T. Melrose, Boston, Mass. 100,387 Mar. 1, 1870. E. Fitzhenry, Boston, Mass. 101,508 April 5, 1870. A. W. Reed, Schenectady, N. Y. 102,270 April 26, 1870. S. Hutchinson, 105,419 July 19, 1870. D. P. Burdon, New York, N. Y. 106,439 Aug. 16, 1870. J. R. Williams, Salem, Mass. 108,782 ) Nov. 1, 1870. ( H. C. Havemeyer New York, N. Y. 108,783 i t and D. P. Burdon, 114,809 May 16, 1871. D. Harrington, Boston, Mass. 117,921 Aug. 8, 1871. J. C. Parmerlee, Bean Blossom, Ind, 118,002 Aug. 15, 1871. E. Fitzhenry, Boston, Mass. 118,003 Aug. 15, 1871. E. Fitzhenry, Boston, Mass. 119,513 Oct. 3, 1871. E. Fitzhenry, Boston, Mass. ' For other forms of scouring machines, see those combined with unhairing machines in list on page 333. 408 THE MANUFACTURE OF LEATHER. No. D ate. Inveutoi'. Residence. 125,276 129,251 131,831 April July Oct. 2, 16, 1, 1872. 1872. 1872. E. Fitzlienry, A. W. Reid, N. F. Snow, Somerville, Mass. Schenectady, N. Y Salem, Mass. 143,829 Oct. 21, 1873. F. A. Lockwood, Boston, Mass. 151,144 154,249 May Aug. 19, 18, 1874. 1874. J. Maxwell, J. Head, Woburn, Mass. Andover, N. Y. 156,991 Nov. 17, 1874. E. Fitzlienry, Somerville, Mass. 157,691 Dec. 15, 1874. F. A. Lockwood, Boston, Mass. 173,627 Feb. 15, 1876. J. Head, Andover, N. Y. 176,216 April 18, 1876. H. D. Chemberlin Berlin, Wis. and J. P. Luther, 179,928 July 19, 1876. F. A. Lockwood, Boston, Mass. 180,018 193,615 194,806 196,793 July July Sept. Nov. 18, 31, 4, 6, 1876. 1877. 1877. 1877. E. Fitzhenry, W. Panton. T. L. Daheney, C. T. Ford, and Somerville, Mass. Quincy, 111. Stoneham, Mass. Salem, Mass. 235,131 ^ Reissue > 9,824* 238,589 Dec. Aug. Mar. 20, 2, 8, 1880. } 1881. ^ 1881. S. A. Ford, J. W. Cubbage, C. Holmes, Gallipolis, 0. Boston, Mass. 240,997 252,369 May Jan. 3, 17, 1881. 1882. W. Goodman, W. Goodman, Boston, Mass. Boston, Mass. 258,659 May 30, 1882. F. A. Lockwood, Boston, Mass. 260,492 July 4, 1882. J. C. Mayer, Somerville, Mass. CHAPTER XXII. STUFFING LEATHER — HAND STUFFING AND STUFFING WHEELS — STUFFING AND CURRYING COMPOUNDS — MACHINE FOR REMOV- ING GREASE FROM LEATHER — LIST OF AMERICAN PATENTS FOR STUFFING APPARATUSES AND FOR STUFFING AND CURRYING . COMPOUNDS. Section I. Hand Stuffing and Stuffing Wheels. In the manufacture of upper leather, after the sides have been scoured as described in the preceding chapter, thev are exposed to the air to harden and are next carried to the cellar of the shop to be dampened and tempered, so as to facilitate the absorp- STUFFING LEATHER. 409 tion of the grease ; the tempering process generally extending through two days. The period of tempering depends upon whether the leather is to be stuffed by hand or machinery. When stuffed by hand the leather requires to be damper than when stuffed by means of the wheel. Ordinarily the hand process of stuffing leather is accomplished after rolling the sides into bundles with the grain side in and softening them by treating or beating, and then applying to the flesh side by means of a brush, a mixture of oil and tallow in a heated state. In addition to the trouble and expense of the hand method of stuffing another objection arises from the fact that the leather has to be dampened to such an extent that it necessitates a long period for drj^ing, and then again, after the partial absorption of the oleaginous and fatty materials the sur- face of the leather has to be separately cleaned of the unabsorbed matter. Another great objection to the hand method of stuffing leather is that the stuffing materials, unless great care is observed, pene- trate only slightly beyond the surface, thereby leaving the leather, as regards the main body, dry and unchanged, and con- sequently hard. But when the modern stuffing wheel is used for this purpose the leather is usually thoroughly permeated and thereby rendered soft and pliable. Stuffing Wheels. The first stuffing wheel patented in this country was invented by L. W. Fiske, of Louisville, Ky., early in 1855, although pre- vious to this time they had been used in France and Grermany in the crude form of a revolving hogshead. But those which are now in use in the United States are of permanent construction, and show the usual evidence of mechan- ical ingenuity for which American inventors are pre-eminent. Reed and Winchester'' s Stuffing Wheel. The stuf&ng wheel shown in Figs. 160 and 161 is the inven- tion of Reed and Winchester. This invention in stuffing leather has for its object a method. 410 THE MANUFACTUEE OF LEATHER, wlierebj the grease may be put into the leather more regularly than heretofore. The leather must be warm, and be kept warm uniformly during the time the grease is being applied to it. The leather to receive grease or stuffing is usually placed in "a rotating drum or wheel previously heated by steam or hot air blown into it while the wheel is empty, for it has been found that steam injected into the drum in the presence of the leather is apt to burn it. A drum heated only before placing the leather in it commences to cool immediately thereafter, and the stuffing or greasing operation is retarded. Another serious objection to the direct introduction of steam into the drum with the leather and grease is that arising from water of condensation, as even a small amount of water added at that time, the leather having been evenly and sufficiently moistened before it was placed in the drum, will be taken up by the leather, thus lessening the amount of grease entering the leather at that spot where the water of condensation in the grease meets the leather, and, further, the heat derived from free steam varies materially, according to the pressure of steam in the boiler. To obviate the objection of free steam the drum has been placed in a second drum heated by steam. In this invention the interior of the drum and leather therein are kept at the desired temperature by means of heated air forced therein while the drum containing its charge of leather is being rotated. The hot air is supplied to the drum by a blower or pump through pipes, in connection with a receiving- chamber of a suitable heat-generating apparatus. Figure 160 represents, in vertical section, an apparatus embodying Reed and "Winchester's invention, the wall of the heat-generating apparatus being also in section. Fig. 161 is an elevation of the left-hand end of the drum, the latter being partially broken out. The drum a, about seven feet in diameter, has a door, h, for the introduction of the leather therein, and a series of pegs, c, at suitable intervals apart to lift and tumble the leather as the drum is rotated, all as usual. This drum has at one journal a pipe, d^ for the introduction at suitable times of hot grease, and at its other journal it has a pipe, e, for the continuous admission STUFFING LEATHER. 411 of hot air while the drum is being rotated with the leather and grease therein. The pipe e is preferably placed, in coil or other form, in the combustion-chamber/, heated in any usual way, so that air forced through the pipe by an air-forcing apparatus. Fig. 161. g (shown as a blower, but which might be a pump), will be heated before reaching the drum. The side of the drum will be provided with openings of suitable size for the escape of the heated air, so as to maintain proper circulation. The air so escaping might be delivered into an annular chamber, /i, placed 412 THE MANUFACTURE OF LEATHEE. next to the openings of the wheel (see Fig. 160), having a pipe, «', to lead the air out of the building, if desired. The air-pipe, at a point between the chamber / and drum, may have a branch, Jc, by which, if desired, to divert the heated air into a water- box and over a pan of water, to thus add a little moisture to the hot air, if too dry ; or we may inject a small amount of steam into the pipe e containing the hot air, to slightly moisten it, care being taken to so regulate the steam that no water of condensation is permitted to form or enter the drum. In this process it is possible to keep the interior of the drum and the leather therein at a uniform temperature, which may be indicated by a thermometer properly connected with the drum which enables the leather to be greased or stuffed uniformly and rapidly, and thatwitliout fear of injuring the leather in any way by over-heating, as when steam is depended upon, or by too rapid cooling, as when the drum is heated only before ap- plying the leather. The grease, in proper quantities, can be introduced from time to time, as needed. This valuable invention appears to have been suggested by that of Dr. Friederich Knapp of Brunswick, Germany, who in- vented an improvement in tramping-drums in 1878, which pos- sessed the combination of the drum and hollow trunnions and the blower or fan and other arrangements very similar to the stuffing wheel which has just been described; but while our Government granted Knapp a patent for the fan attachment to the stuffing wheel the German Government had previously refused it as not being a new idea. Frederick CarVs Improved Stuffing Wheel. The stuffing wheel shown in Figs, 162 and 163 is the inven- tion of Frederick Carl, and is an improvement upon the machine patented by him in 1867. Figure 162 is an isometrical perspective view, and Fig. 163 a vertical longitudinal section of Carl's improved stuffing Avheel- A represents the body or cylinder of the machine, which is journaled at B in the supporting- frame C, and provided with an opening, D, for inserting the leather. A steam-supply pipe, STUFFING LEATHER. •il3 E, passes through one of the journals B, with which it revolves, and thence at right angles upwardly along the outer side of one end of the body A, as seen at F^ terminating in the branches d d\ for conveying steam to the twin or corresponding heater dis- posed within the cylinder, of which the heater is shown at G in Fig. 163. Fig. 162. The heater consists of a continuous pipe, or pipe without joints, bent to form parallel sections a a, and curved laterally to conform to the interior curvature of the cylinder, a drain-pipe or stopcock, H, being provided to draw off the water of con- densation. A series of slats or bars, J tl, provided with pins 7n m for catching and holding the leather, are secured longitiidinally 414 THE MANUFACTURE OF LEATHER. within the cylinder, the heaters being disposed between said bars and the outer casing of the body A. There is also a screen or wire-netting, K (shown as partially removed in Fig. 163), attached to the bars J" J, the pins mm projecting inwardly through the netting when the same is in position. The netting forms the interior side walls of the cylinder, its object being to eftectually prevent the leather from coming into actual contact with the pipes without preventing the heater from properly acting on the stuffing or leather contained in the cylinder. . In the use of this stuffing wheel, steam having first been let into the apparatus through the pipe E^ the leather and compo- sition for stuffing the same are inserted in the body A through the opening i), which is then secui'ely closed, and the cylinder caused to rotate by any suitable means, thus rapidly and effec- tually performing the operation of stuffing in a manner which will be readily understood by all conversant with such matters without a more explicit description. The wheel may be made to revolve either by suitable gear- wheels or a belt may be passed from a pulley on a revolving- shaft around the cylinder A. List of Patents for all Apparatuses for Stvjffiyig and Greasing Leather^ issued by the Government of the United States of America, from 1790 to 1883 inclusive. Inventor. Residence. L. W. Fiske, Louisville, Ky. G. Huttelmaier, Allegheny, Pa. F. Carl, Charlestown, Mass. H. Muller, North Cambridge, Mass. J. W. Schayer, Boston, Mass. H. Smith, Jr., Milwaukee. Wis. W. A. Perkins, and Salem, Mass. J. A. Enos, Peabody, Mass. J. A. Enos, Peabody, Mass. Gr. H. Williams, Milwaukee, Wis. J. A. J. Shultz, St. Louis, Mo. J. W. Hildreth, Boston, Mass. N. H. Dodge, Brooklyn, N. Y. ,J. A. J. Shultz, St. Louis, Mo. H. P. Reed, and P. Peabody, Mass. L. Winchester, Jr. F. Carl, Somerville, Mass. No. Date. 1855. 40,079 Sept. 22, 1863. 63,856 April 16, 1867. 78, \ J. T. r.arnstead, Peabody, Mass. 4,258) Feb. 14, 1871.) . 105,506 July 19, 1870. J. Starratt, Salem, Mass. 122,130 Dec. 26, 1871. J. Perkins and Gr. L. Newcomb, Peabody, Mass. 123,643 Feb. 13, 1872. W. A. Perkins, Salem, Mass. 252,559 Jan. 17, 1882. E. V. Wliitaker and J. Hull, Gloversville, N. Y. WHITENING LEATHER. 423 CHAPTER XXIII Whitening- Leather. next " set out" (which for calf-skins or the Fig. 165. The side having been stuffed and latter operation can be performed heavier grades of upper leather by the Lockwood machine shown in Figs. 138 to 140, or the Fitzhenry machine shown in Figs. 147 to 151), the next step in the process of manu- facturing upper leather is that of whitening. This is usually accom- plished by one of three ways: The leather may be placed on a table and whitened with a slicker, or cut over with a currier's knife or a beam, or the whitening can be performed by machinery. Fig, 165 shows the French pattern of whitening slicker, which is the kind usually employed in this country. The blades, which are of cast steel, are usually of two degrees of hardness ; the bright blade compares in temper with a medium hard blade, the half polished are softer, being of a lower temper. Fig. 166 shows the form of beam now generally employed in currying shops. The beam-bed and face are adjustable by means of screws, and the beam may be elevated or lowered at any necessary height to suit the convenience and comfort of the workman. The faces may be either of lignum vitge or of glass. There is a great variety in the construction of currier's knives; but the form shown in Fig. 167 is the most common. The blades are screwed in the brass jaws by three screws from each side, thus securing equal strength. The blades for the currier's knives are made from hammered steel, and are either 424 THE MANUFACTURE OF LEATHER. bright or unpolished, and vary from seven-eighths to two inches in width, and those kept in stock bj the manufacturers are Tis. 166. Fig. 167. made in nineteen and twenty gauge ; but other gauges are manufactured to order. Clements' s Leather- Whitening Machine. The leather-whitening machine shown in Figs. 168 to 172 is the invention of John E. Clements, and it is an improvement on the leather whitener patented by Enos and Clements in 1881. Fig. 168 is a plan view of the machine. Fig, 169 is an end WHITENIKG LEATHER. 425 view. Fig. 170 is a cross-section on line x x of Figs. 168 and 171. Fig. 171 is a longitudinal section on line y y ol Fig. 168, and Fig. 172 is a detail section of the thrust-box. Fiff. 16 Fig. 169. A is the bed-plate, i? is a stand supporting the rocking hub G by its spindle a. Z) is a stand carrying feed-bed E. h h are stands supporting a horizontal shaft, ^, which carries fast and 426 THE MANUFACTURE OF LEATHER. loose pulleys h ¥ for the belt from the main driving-shaft and a pulley, Z, for a belt to drive an overhead counter-shaft. Fig. 170. -,^:,rr„,-r^^^\.:,jj\>.J.,\^^J'^jjAf^J'fJ'ffI^J!ZSZ± FicT. 171 Fig. 172. h V are arms projecting from hub G. e is the cutter-shaft sus- tained in suitable bearings on the arm &', and carrying the cutter- head/ above bed E, and also provided with a pulley,, g. i^ is a stand supporting a horizontal slide-way, m, at the end WHITENING LEATHER. 427 of arm 7;, and n is a slide-block fitted for movement on the slide v\^ay. is a wrist-pin on the slide-block, to which is connected a rod, p^ from a crank-wheel, §, on shaft i. T is a gudgeon attached to slide w by a pin, r', and fitting a slot, s, in the end of the arm h of the hub (7, so that by move- ment of the slide the hub is rocked, the movement of the gud- geon in slot /S', allowing for change of position. The grinder a' is an emery-wheel, bearing on the cutters at one side of the head, the intention being to have continuous contact which is regulated, as the grinder wears, \>y turning the screws u to force shaft %o downward. A worm-shaft, c' , carried by brackets t and engaging worm-wheels u' on the screws, is used for simultaneous movement of the screws. On the grinder shaft lo is a pulley, c?', connected thereto by a pin and key-slot, that allows endwise movement of the shaft. e' is a rod sustained in guides e^ on boxes v , and connected by a rod,/', to the crank-arm of a short cross-shaft, (j\ that is sus- tained on the rocking-arm h. The shaft g' is connected by a worm and pinion at h' with a shaft, ^', that extends to hub (7, where it has a pulley, /c', turned by contact with the driving- belt V of the cutter shaft, so that the rod eJ is given an endwise reciprocation. On the grinder-shaft is a thrust-box, m' (shown most clearly in Pig. 172), which has internal flanges taking into grooves on the shaft, and has also an apertured flange, n\ clamped on rod e' by a set-screw, whereby the grinder-shaft is reciprocated with the rod. By these devices the grinder is moved back and over the cutters from one side of the cutter- head to the other. The same movement may be obtained by connecting the outer end of reciprocating rod direct to grinder- flanges by means of a fork. In this case the grinder-shaft does not reciprocate, but same motion is communicated to grinder and flanges which reciprocate upon the end of shaft having spline, key, or feather set into it, giving the grinder a rotary movement. The cutter and grinder are driven by the belt V from the overhead counter-shaft, which, as before mentioned, is driven from the shaft ^. The belt V passes first beneath a tightening- pulley, o', that is hung on a bracket, p', then upward and over 428 THE MANUFACTURE OF LEATHER. the pulley d' of the grinder- shaft, and then beneath pulley g of the cutter-shaft, as shown most clearly in Fig. 170. The driv- ing-belt thus extends at right angles, or nearly so, to the plane in which the hub G rocks, and is slightly twisted by the rocking movement. That arrangement is more reliable, because the belt remains centred on the pulleys, and is not shifted from side to side, as is the case with a belt extending in the plane of vibration. The bracket ^' of the tightener-pulley o' is attached to hub G by screws passing through slots in the bracket, so that adjustment can be readily made. In place of the cutter-head, a smooth or fluted roller, hollow and heated by steam, may be substituted, and the machine then used for ironing and glossing leather. Smith'' s Leather- Whitening and Buffing Machine. The machine for whitening and buffing leather invented by Oliver C. Smith is shown in Figs. 173 to 176. Fig. 173. Fig. 174. WHITENING LEATHEK. 429 Fig. 175. Figure 173 represents, in top view, a machine embodying Smith's invention ; Fig. 174, a longitudi- nal vertical section thereof on the dotted line X X, the table or bed being shown in elevation. Fig. 175 is an enlarged detail, partially in section, showing the boxes of the sliding frame ; and Fig. 176, a section of Fig. 175 on the dotted line y y. In this invention the pulley A is fixed directly upon the crank-pin A, joining the two cranks i k, projected from shaft B. The weight of the pulley A is counterbalanced by the weights C, one on each crank. The belt u on this large fixed pulley A is extended over the pulley t on the shaft a^ at the upper end of the usual swinging frame, and rotates the said shaft, together with its pulleys 5, which by small belts r revolve the rotary cylinder or tool p in the usual manner as the link g, herein made double, reciprocates the carriage D on the guide-rods c. This carriage is composed of yokes 20, 21, connected by a bar, 22, the yokes having depending from them bearings a^ to receive the shaft a^, which turns in the said bearings. The boxes which run on the guide-rods c have Babbitt or other linings, E F. Upon the lin- ing F^ the inventor has placed an adjusting- wedge, G^ provided with one or more inclined teeth or wedging-surfaces, 9, and above the adjusting-wedge he has placed a cap, /, having at its under side one or more opposed teeth or inclines, 8. 430 THE MANUFACTUEE OF LEATHER. List of all Patents for Currier'' s Slickers, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Eesidence. 20,098 April 27, 1858. H. H. Sultzbach, Marietta, Pa. 52,491 Feb. 6, 1866. J. Hankey, North Cambridge, Mass, 62,064 Feb. 12, 1867. D. Peters and J. W. Pauly, Keokuk, la. 42,397 April 19, 1864. D. Peters and W. D. Wilson, Keokuk, la. L15,709 June 6, 1871. Gr. T. Collins, North Eastham, Mass. 127,756 June 11, 1872. G. B. Fowle, Boston, Mass. List of all Patents for the United States Currier's Knives, issued hy the Government of of America, from 1790 to 1883 inclusive. No. 20,911 28,594 37,285 51,942 94,197 111,901 137,671 149,563 193,806 208,593 Date. July 13, 1858. June 5, 1860. Jan. 6, 1863. Jan. 9, 1866. Aug. 31, 1869. Feb. 21, 1871. April 8, 1873. April 14, 1874. Aug. 7, 1877. Oct. 1, 1878. 227,597 May 11, 1880. Inventor. J. B. Wentworth, W. P. Moses, G. Featherston, J. P. Hawks, L. A. Gignac, J. T. Barnstead, C. A. Gardner and J. A. Enos, A. H. Beschormann, R. E. Cherington, T. Hansen and G. H. Weifenbach, J. Tuggle, Residence. Lynn, Mass. Exeter, N. H. Ausable Forks, N. Y. Troy, N. Y. Troy, N. Y. Peabody, Mass. Peabody, Mass. San Francisco, Cal. Holyoke, Mass. Racine, Wis. New Middleton, Tenn. Machines for Sharpening Currier's Knives. No. Date. Inventor. Eesidence. 1,064 Jan. 8, 1839. W. Eagleston, Troy, N. Y. List of all Patents for Machines for Whitening, Buffing, and Shaving Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. 732 26,641 Date, May 10, June 5, 1838. 1860. S. J. Inventor. Graham, Turner, Residence. Roxbury, Mass. Cambridgeport, Mass, 63,191 Mar. 26, 1867. T. F. Weston, Salem, Mass. 65,919 June 18, 1867. C. Korn, Wurtsborough, N. Y. 77,025 85,030 April 21, Dec. 15, 1868. 1868. L. C. B. Fox, Schmitz, Williamsport, Pa. Philadelphia, Pa. 89,789^ Reissue > 4,534 5 May 4, Aug. 29, 1869. 1871. A, , W. Pratt, Salem, Mass. BOAEDING AND GRAINING BY MACHINERY. 431 No. Date. Inventor. Residence. 138,874 May 13, 1873. J. A. Enos, Peabody, Mass, 150,285 April 28, 1874. J. M'. Caller, Salem, Mass. 157,442 Dec. 8, 1874. J. E. Fisk, Salem, Mass. 157,939 Dec. 22, 1874. 0. C. Smith, Ipswich, Mass. 191,173 May 22, 1877. W. A. Perkins, Salem, Mass. 191,400 May 29, 1877. J. G. Buzzell, Lynn, Mass. 202,226 April 9, 1878. J. G. Buzzell, Lynn, Mass. 247,014 Sept. 13, 1881. J. E. Clement and J. A. Enos, Peabody, Mass, 248,290 Oct. 18, 1881. P. De Chamberet, Paris, France. 248,518 Oct. 18, 1881. 0. C. Smith, Ipswich, Mass. 252,928 Jan. 31, 1882. J. G. Buzzell, Lynn, Mass. 259,497 June 13, 1882. J. E. Clement, Peabody, Mass 261,309 July 18, 1882. J. E. Clement, Peabody, Mass CHAPTEE XXIV. BOARDING AND GRAINING BY MACHINERY. Following the whitening the next step in the production of upper leather is that of " stoning out," and while this is some- times done by hand, it is almost generally accomplished by machinery, which is usually a "jack," very similar in many points of construction to the machines used for polishing and pebbling leather. If after " stoning out" the leather should require softening it is "boarded," and when this is done by hand it is a tedious and laborious operation ; but in this as in other branches of leather manufacture machinery has come to the aid of the workman, and now the softening and graining can be accomplished most satisfactorily, and at the expenditure of but little power, and with but little effort on the part of the operator compared to the old way. Before the introduction of boarding and graining machines, this portion of the finishing suffered its full share from the neglect or incompetence of the workman, and manufacturers were compelled to sell their leather at considerably less' per foot 432 THE MANUFACTUEE OF LEATHER. than thej might have done with this department well looked after. But now the upper leather when boarded and grained on the best of these machines has that peculiarly soft and velvety feeling which formerly distinguished imported stock, and which is now common in the leather made by us both for home con- sumption and for our export trade. The armboard in common use is shown in Fig. 243, and it continues to be emploj^ed principally for Morocco and other light leathers. Coogari's Boarding and Ora.ininy Machine. Fig. 177 shows a perspective view of Coogan's Machine for boarding and graining leather. The two rollers A and _S, Fig. 177, may be of cork or a com- position covering, which with proper usage will last for one year or more, and when worn they can be renewed at but a trifling expense when compared with cork rollers. The rollers are each about eight inches in diameter, and placed one above another, and run on iron shafts, set in a frame at either end, but so that the upper roller can be raised or lowered at pleasure and adjusted at any desired distance from the lower one and held permanently in position by means of. the screws F. The upper roller is about four and one-half feet long, but the lower one is somewhat longer, forming a table, and the frame in which the shafts of these cylinders revolve is about seven feet long. Opposite the top of the lower roller B^ extending its full length, and arranged so that by a slight pressure on the treadle D underneath, or b}'' pushing with the hand, it can be brought to bear directly in the centre between the two rollers, is a thin steel feed-plate G. The rollers revolve in the same direction, so that by placing the leather on the feed-board C, with one end or side just over the edge, and moving it against the revolving rollers, the upper roller carries it in, and the lower roller carries it out, turning it sharply under the edge of the plate, and almost instantaneously boarding a side or whole hide, the time required for the opera- BOARDING AND GRAINING BY MACHINERY. 433 28 434: THE MANUFACTUEE OF LEATHER. tion being about one-tenth of that which would be required to perform the same work by hand. Soveyh Boarding and Graining Machine. Hovey's machine for boarding and graining is shown in Figs. 178 to 182, and the invention consists essentially of a stationary concave bed having an elastic or yielding surface on its inside and a reciprocating worker movable on an axis, and provided with a yielding convex surface adapted to work within the concave bed, also of a revolving brush-roller located in bearings attached to the worker, a little in advance of the holding device which will be mentioned, for the purpose of properly laying and keeping the leather smooth and to prevent it from wrin- kling during the process of boarding or graining it. There is an automatic device for locking and holding the leather attached to the forward end of the worker until the boarding or graining is accomplished. The inventor also uses a self-acting reversing device for automatically reversing the motion of the reciprocating worker during the operation of the machine. The reciprocating worker is provided with an adjust- able pressure-regulating device, by means of which the surface of the worker may be adjusted more or less in or out, as may be required, for regulating the pressure on the leather between the worker and the concave bed, according to the thickness of the leather that is operated upon. The concave bed and its re- ciprocating worker are of a sufficient size to take in a whole side of leather at one time, so that the soft and thin parts of the side may receive the same relative pressure as the thick parts and thus grain the side equally all over. Figure 178 represents a front elevation of Hovey's machine. Fig. 179 represents an end elevation of the same, showing the worker in the act of drawing the leather into and laying it inside of the concave yielding bed. Fig. 180 represents an end view of the machine, showing the motion of the worker, as reversed, in the act of boarding or graining the leather. Fig. 181 represents an end view, seen from X in Fig. 178 ; and Fig. 182 represents a front elevation of the automatic reversing device for the reciprocating worker. BOARDING AND GRAINING BY MACHINERY. 435 In using the machine one end of the leather to be grained or boarded is inserted between the bars d and d', which are made Fig. 178. automatically to close upon each other and to hold the leather firmly between them, and the reciprocating worker then pro- Fig. 179. ceeds in the direction shown by the arrow in Fig. 181. The reciprocating worker continues in the same direction to draw 436 THE MANUFACTURE OF LEATHER. and lay the leather D within the concave bed in a manner as shown in Fig. 179, and continues in the direction shown bj Fis. 180. d ''^' BOAEDING AND GEAINING BY MACHINERY. 437 arrows in Fig. 179 until its projection 71 hits the projection on the belt-shipper, when the motion of the worker is reversed, as shown by arrow in Fig. 180, and causing the leather D to be grained or boarded by being doubled upon itself, and, as it were, rolled between the elastic concave bed b" and the elastic cover- Fig. 182. ing c* in a manner closely resembling the manner of graining or boarding by hand tools. The worker continues to move in the direction shown by arrow in Fig. 180 until the reciprocating worker has completed nearly a revolution around its axis, and until the projection w again comes in contact with the reversing- projection 0, when its motion is reversed to that shown by the arrow in Figs. 179 and 181, and during this motion of the worker the hinged foot c?® on the end of the arm or lever d" is brought in contact with the inward projection /', causing the holding device d d' to open to enable the finished leather to be taken away and a new side inserted, which is automatically 438 THE MANUFACTUEE OF LEATHER. clamped and beld firmly between the parts dd' as soon as the dog or tooth e comes in contact with the sliding rod /^. The hinged foot d^ will pass freely by the lever-projection/' when the worker is moved in the direction of the arrow shown in Fig. 180, and when the worker is in such motion the dog or tooth e will also pass freely by the inner end of the sliding rod / ^. In the drawings, a and a' represent the ends or frames of the machine, between which is secured the concave bed, com- posed of an outer concave metallic frame, ft, wood lining Z;', and yielding elastic surface Z/", made of cork. India-rubber, or similar elastic material ; 7:) represents the counterweight to the reciprocating worker. Machine for Boarding and Graining Morocco. The machine showii in Fig. 183 is for boarding and graining Morocco, and is an improvement made by G, "W. Baker, of Fig. 183. Wilmington, Del., on the machine invented by Owen Coogan, which is shown in Fig. 177. This machine will soften light leathers in a highly satisfactory BOARDING AND GRAINING BY MACHINERY. 439 manner, the " bone" all being taken out, and the machine will also " spring up" the pebble grain of Morocco equally as well as hand work. The machine is simple in its construction and operation. Two rollers, twelve inches in diameter, covered with composi- tion, revolve in the same direction, and adhere firmly to the skin. The table is connected with the treadle-motion on which the skin is placed with the grain side down for softening, and put in with the shanks parallel with the steel blade fastened to the edge of the movable table. The operator, by a slight pressure of the foot, pushes the blade between the running rollers, the skin being carried around the edge of the plate by the rollers, the top one carrying it in, while the lower one carries it out. This operation bites the skins over the edge of the plate, giving the same breaking action as the cork-hand boarding, only that it takes one-half of the skin in, which runs rapidly through the machine ; it is then reversed and the other part run through. The softness depends entirely on the number of times it passes through the machine, but ordinarily, twice is sufficient. In graining, the skin is reversed ; instead of putting the grain side down, put it up. The machine runs slowly, about forty-five revolutions per minute, and requires a little less than one-half horse-power, does its work cheaply and well, and is worthy of the attention of the Morocco trade. List of all Patents for Machines for Boarding and Graining Leather^ issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date, Inventor. Eesidence. Mar. 25, 1835. C. Bassett, Boston, Mass. 14,211 Feb. 5, 1856. J. B. Wentworth, 15,807 Sept. 30, 1856. J. Greeuleaf, 48,971 July 25, 1865. W. H. Moore, Salem, Mass. 54,360 May- 1, 1866. G. R. Joliiison, Wilmington, Del, 54,821 May 15, 1866. J. Parker, Woburn, Mass. 62,514 Feb. 26, 1867. J. E. Wiggin, Stoneliam, Mass. 94,196 Aug. 31, 1869. L. A. Gignac, Troy, N. Y. 108,319 Oct. 13, 1870. M. B. Bishop, Whitingham, Vt. 440 THE MANUFACTURE OF LEATHER. No. Date. Inventor. Eesideuce. 110,944 Jan. 10, 1871. U. R. Williams and Wni. P. Martin, Salem, Mass. 119,743 Oct. 10, 1871. 0. Coogan, Pittsfield, Mass. 126,105 ^ April 23, 1872. Reissue > L. Townsend, Terra Haute, Ind. 8,088) Feb. 19, 1878. 135,350 Jan. 28, 1873. N. 0. Lownsberry, Wilmington, Del. 138,133 April 22, 1873. 0. Coogan, Pittsfield, Mass. 140,633 July 8, 1873. N. 0. Lownsberry, Wilmington, Del. 157,632 Dec. 8, 1874. P. O'Brien, Boston, Mass. 161,269 Mar. 23, 1875. A. W. Perrin, New York, N. Y. 168,497 Oct. 5, 1875. H. Howson, Philadelphia, Pa. 176,535 April 25, 1876. L. R. Jenkins, Philadelphia, Pa. 202,414 April 16, 1878. W. Coupe, South Attleborough, Mass, 218,908 Aug. 26, 1879. L. P. Mason, Salem, Mass. 241,303 May 10, 1881. W. Coupe, South Attleborough, Mass, 248,220 Oct. 11, 1881. A. Schray and A. Barentigam, New Albany, Ind. 253,533 Feb. 14, 1882. J. H. Hovey, Woburn, Mass. CHAPTER XXY BLACKING LEATHER. Section I. Blacking and "Smutting" Appliances. The side of leather having passed through the previously described operations and been last boarded, is now in the state for blacking, and this is performed both by hand and machinery. It is thought by manufacturers that the hand process is pre- ferable for the heavy grades of upper leather ; but upon what ground it is not plain, as some of the machines constructed for this purpose are models of mechanism, and perform the work much more economically and thoroughly than is usually done by the hand process. Figs. 184 and 185 show the two forms of blacking brushes in common use, and they are made both soft and stiff" the best quality are extra copper-wired, and have all bristles. The BLACKING LEATHER. 441 oval form is always made with a strap ; but the round form have either handles or straps. Both brushes are made in first Fig. 184. Fig. 185. and second qualities ; but it is economy to purchase the best grade, as the extra wear more than compensates for the small difference in price. Batchdder's Leather Blacking^ Coloring^ and Dressing Machine. Figs. 186 to 195 show the leather blacking, coloring, and dressing machine patented by Batchelder. Fiff. 186. Figure 186 is a left-hand-side elevation of a machine embody- ing Batchelder's invention ; Fig. 187, a front view thereof, with the table n omitted ; Fig. 188, a longitudinal vertical section of 44:2 THE MANUFACTURE OF LEATHER. Fig. 187 ; Fig. 189, an enlarged detail to be referred to ; Fig. 190, a detail in top view of Fig. 189, with the brush c omitted ; and Fig. 191 is a modification to which reference will be made. Fig. 187. The blacking or liquid dressing, or material to be applied to the upper surface of the hide or skin B, is placed in the recep- tacle e, which is shown as an open box, the sides of which, at its lower end, are concaved, to fit the periphery of the receptacle- BLACKING LEATHER. 443 roller e', which may be made to travel near the straight lower edge, 2, of the bottom of receptacle by means of the adjusting screws e^, the amount of space between the edge of the bottom Fig. 190. 191. of the receptacle e and the roller e' determining the amount of blacking or dressing to be delivered to the brush c. The roller e' may be driven more or less rapidly to carry or de- liver more or less blacking or dressing to the brush c. This may be done by changing the size of the gear e^ on the journal of the roller e', the toothed speed-wheel /, which engages the gear e^ and drives the roller e', being mounted on a stud of an adjustable carrier,/', provided with a locking device, /2, to engage an arch,/^, and hold the carrier in proper position. It is preferable to slightly groove, flute, or pit the roller e\ to enable it to take up a greater quantity of blacking or dressing. The hide or skin as it leaves the supporting-surface a* is deliv- ered upon an endless belt or moving bed, (/, shown as composed of cords or tapes extended about rollers g' ^^, the one g' being driven positively from the toothed wheel h by the intermediate worm, A, which engages the pinion /?/ at the end of the shafts/'. The tanned h:de or skin to be dressed is introduced between the supporting-surface a^ and roller or brush c under a roller, ?, which, as clearly shown in Figs. 188 and 189, has its journals mounted on levers or arms l\ pivoted at V- and acted upon by springs Z^, to keep the roller depressed upon the hide or skin to properly hold it. The front ends of the levers or arms /' are joined to a holding-bar, w, which is of a shape to fit the space between the brush c, the support a^, and roller I. The under 444: THE MANUFACTUEE OF LEATHEE, side of this holding-bar (see Fig. 189) is so shaped, curved, and located with relation to the surfaces of the roller I and the sup- porting-surface a* as not to bear upon the hide or skin until after the passage of the edges of the same beyond the nip of the roller ?, the holding-bar being devised to act upon and hold the end of the hide or skin, after passing beyond the nip of roller I (the latter then dropping), and prevent the hide or skin being drawn in too rapidly. In front of the apparatus there is placed a table, n. In some instances and for some classes of work the inventor modifies the machine so far described, as represented in Fig. 191, and where there is shown the roller / as elevated consider- ably above the position shown for it in Figs. 188 and 189, and in such position there will be left sufficient space to permit the operator to retain hold of and control the position and move- ment of the hide or skin being acted upon by the brush or rol- ler c, and in such case also the holding-bar m is omitted. To prevent the blacking or dressing being thrown from the brush or roller c toward the front of the machine there is pro- vided the auxiliary spatter-guard o. The roller ?and the holder m, when used, also serve to prevent the blacking or liquid dressing from being thrown out at the front of the machine. The supporting-surface a^ and brush e are as long as the maxi- mum width of the hide or skin to be blacked or dressed ; but as the hides or skins being finished or dressed are always different, both as to width and outline at their edges, it results that the brush c always applies blacking or dressing to more or less of the surface a^. The blacking or dressing applied to the surface a* must all be removed and the surface be left clean so as not to apply blacking or dressing to the under side of the hide or skin as it comes in contact with it. To do this the inventor has provided a wiper or cleaner, p (shown clearly in Figs. 187 and 188), as a strip of flexible material held by a suitable adjustable bar, j9^, so that the edge of the wiper or cleaner may be pressed with more or less force against the surface a'*, the degree of its pres- sure being preferably regulated by adjusting-screws p^. The material wiped or scraped from the surface a* drops into the BLACKING LEATHER. 445 trough q and passes therefrom iato a suitable pail or bucket to be rinsed, if desired. Bj driving the brush-roller c and the supporting-surface a* independently, the inventor is enabled to rotate either at any desired speed, and thus rub the blacking, coloring, or dressing matter more or less into the surface of the hide or skin. The bearings for the brush c and roller e' will preferably be made adjustable vertically to accommodate for the thickness of the leather and compensate for wear. Batchelder in 1883 patented an improvement on the machine just described, Avhich improvement is shown in Figs. 192 to 195. In the machine described in Figs. 186 to 191, the brush- roller which applied the blacking or the liquid dressing to the leather on a rotating supporting surface or roll had its bristles set radial ; but with such a brush the distribution of the black- ing is not so uniform and thorough as is desirable, so, to cause the brush to apply the blacking to every minute part of the face of the leather being blacked or treated, Batchelder has inclined the bristles of the alternate rows of bristles of the brush in different directions, those of one row inclining toward one end of the cylinder and those of the next alternate row toward the opposite end of the cylinder, so that the ends of the bristles, besides travelling over the leather in the direction of rotation of the brush-roller, also, when in contact with the leather, spring or yield in opposite directions, the free ends of the bristles of alternate rows moving in opposite directions longitudinally as compared with the axis of the brush-roll, thus working the blacking backward and forward across the leather, as well as in the direction of its movement over the supporting-surface. In this way every particle of the upper side of the leather is effec- tually blacked and streaks are effectually prevented. Fig. 192 represents in section a sufficient portion of a leather blacking or dressing machine to illustrate the present improve- ment ; Fig. 193, an end view of the brush-roller on a larger scale ; and Figs. 194 and 195 two partial sections thereof in the dotted lines x and y. The supporting bed a*, color-roller e', deflector c?, spatter-roller Z/', and roller i are as in the machine shown in Figs. 186 to 191. 446 THE MANUFACTURE OF LEATHER. The roller c, which applies blacking to the leather B^ has its alternate longitudinal rows of bristles a h inclined in opposite directions, those of one row being as in Fig. 194, and those of the next row as in Fig. 195, so that as the bristles yield on coni- Fig. 192. Fig. 194. ^i Fig. 195. 6 wim ^^^^^%\ \yy^y//. y^>y 1 - \ — -— -i W/Z/i^^/^A ^/^ '^/A ^tmmmmmm^m ing in contact with the leather B those of one row, as in Fig. 194, will yield and move toward the left end of the brush-cylin- der, while those of the adjacent row (see Fig. 195), oppositely inclined, will move toward the right of the cylinder, the bristles of the two rows thus moving over the leather one after the other in opposite directions, in the direction of the length of the supporting roller a^, at the same time that all the bristles sweep over the leather as it is carried under it by the roller a*. In this way the blacking is brushed on the leather both longitudi- nally and transversely. The brush-cylinder has a metal jour- nal at each end, the journal preferably forming part of a metal shaft extended through the cylinder c of wood. The cylinder c is provided with a series of diagonal holes at opposite inclina- tions (see Figs. 194 and 195), into which the bristles a h are in- serted and held by glue and wooden plugs or galvanized nails, or in QXij usual manner. BLACKING LEATHER. 447 Macliine for '■'• Sviutting'''' Leather. The macliine shown in Figs. 196 and 197 is the invention of Mr. Charles B. Bryant, of the firm of Messrs. Bryant & King, the well-known calf-skin tanners and curriers near Woburn, Massachusetts. In the manufacture of upper leather, after the skin has been tanned, it is removed from the tanning-liquor and shaved, and subsequently, while wet. is scoured or washed to remove from it the dirt. Scouring brings the leather into condition to be oiled or stuffed, after which, the leather having been dried, it is' whitened, and then grained and " boarded," as it is called, and thereafter blacked, and after blacking, the leather, to be fully finished, is " smutted." This invention has for its object the production of a machine for "smutting" leather, smutting being one of the processes or steps for the fine or better finishing of leather. That class of leather, calf-skin, etc., wherein the black face produced by or due to the application of lamp-black and an oleaginous material, is most commonly used in the manufacture of boots and shoes and other articles of leather without smutting, and the face of the leather shows a dull black the material of which easily cracks off"; but in some instances this black face is rubbed by a cloth and then by hand to rub the black into the leather and remove all surplus material therefrom, so that the black color will not rub off or smut when handling the leather. The process of smutting by hand — the only way it has been done up to the present time — is slow and expensive. In accordance with this invention, Bryant takes a hide or side of leather, blackened by machine or by hand, and subjects it to the action of rubbers or smutters and of brushes. The rubbers or smutters, by their friction against the leather, roll or rub up the black film or "skin," as it may be called, on the surface of the leather into small minute crumb-like particles, which are subsequently swept off or detached from the leather by the brushes. Fig. 196 represents in side elevation an apparatus embodying Bryant's invention, and Fig. 197 a view of the same from the left of Fig. 196. 448 THE MANUFACTURE OF LEATHER. A. represents a wheel or drum ori a shaft, B, having its bear- ings in standards G, the shaft being driven by a belt on the fast pullej D. Fiff. 196. The drum or cylinder A has attached to it a series of brushes, a a, the latter being shown as made adjustable with relation to the cylinder and the leather-supporting surface E by nuts /; c on bolts d, as will be understood from the drawings, so that the brushes may be made to act properly on the face of the leather, according to its thickness. Between the series of brushes, and preferably adjustably mounted on the said cylinder A, is a BLACKING LEATHER. 449 series of rubbers or smutters, /, preferably composed of some sort of strong fabric. The inventor has used with good results pieces of Brussels carpet, and there might be employed for the rubbers or smutters either a fabric or a finer and softer brush than the brush a. This machine operates, to perform the work required of it, at a very rapid rate as compared with handwork, and does its work even better than can be done by hand, improves the qual- ity of the leather, and enables it to be sold for considerably more than the ordinary blacked leather which is not subsequently rubbed and finished as stated. List of all Patents for Apparatuses for Blacking Leather, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. 107,625 r Sept. >ate. 20, 1870. Inveutor. H. P. Reed and Thos. E. Wilson, Residence. Peabody, Mass. 128,658 July 2, 1872. H. P. Reed and Thos. E. Wilson, Peabody, Mass. 227,204 ^ Reissue / 9,794 ) May July 4, 12, 1880. 1881. F. B. Batchelder, East Boston, Mass. 227,836 251,401 Feb. Dec. 15, 27, 1881. 1881. F. A. Dupuy, F. B. Batchelder, Ironton, Ohio. East Boston, Mass. 271,971 Feb. 6, 1883. F. B. Batchelder, East Boston, Mass. Section II. Blacking Compounds. The composition of the soap and oil blackings in common use by our American curriers has been described in the chapter treating the manufacture of upper leather, and the blackings Avhich are now to be described are some of the patented com- pounds which are sometimes employed. Flesh Blacking. The following compound was patented by Hayward in 1846. To make one gallon of this blacking, dissolve one pound of pure potash in two quarts of soft water, then add to it one pound of tallow, and boil them together one hour ; then dissolve one- quarter of a pound of potash in a quart of soft water, and stir 29 450 THE MANUFACTURE OF LEATHER, into it two-fifths of a pound of pure lampblack until it is well mixed, and add this decoction to the first one, and boil them together fifteen minutes. After which add one quart of "straits oil" and stir it well into the mixture and let it cool, and it is then ready for use. Compound for Finishing Upper Leolher. ■ In 1877 Shaw obtained a reissue of his patent for a composi- tion for dressing leather, which is prepared as follows: First, one gallon of soft water, to which have been added six ounces of best extract of logwood, is heated nearly to the boiling point, but preferably not brought to boil, and is well stirred until the dye stuff' is dissolved, after which it is allowed to cool. Second, one gallon of soft water, to which have been added six ounces of borax, is likewise heated nearly to the boiling-point, until the borax is dissolved. To this are added one and one-half pounds of gum-shellac, the same being gradually introduced in small quantities, and stirred briskly until thoroughly dissolved. Third, three-eighths of an ounce of bichromate of potash are dissolved in half a pint of hot water, in a separate vessel. This consti- tutes a proper mordant for converting the logwood extract into a black dye or soluble coloring matter, possessing a blue-black shade or tint. Fourth, the first and second preparations are now added together by pouring the logwood solution into the solution of shellac, and stirring well until the two are intermixed. Then, while yet warm, the solution of bichromate of potash is added, and the whole briskly stirred for some time. This mixture is allowed to stand until entirely cool, and then, after skimming ofi' whatever may have risen to the top of it, the liquor is drawn off for use. To make a dressing which may be applied to leather in very thin coats, and at the same time produce a finer and brighter finish than could otherwise be obtained, mix with the liquor last described three or four ounces of concentrated water of ammonia or spirits of ammonia, and then put it up in cans tightly corked, ready to be applied to the leather. The dressing may be made thicker or thinner, as required. BLACKING LEATHER. 451 Finislimg Split Leather. The following composition is the invention of Joel Putnam, and is for finishing the inner side of split leather and giving it an appearance closely resembling the grain side of " kip leather." In carrying out this invention, first make a composition of one pound of glue, one-half pint of boiled linseed-oil, and about one- half ounce of vermilion, or other suitable pigment. The glue should be dissolved in hot or boiling Avater, so as to make a solution of the consistency of such as is commonly used for cementing wood ; afterwards the oil and the pigment should be thoroughly incorporated or mixed with the solution of glue. The composition thus made is next to be applied to the sur- face of the piece of leather by means of a brush, two or anv other suitable number of coatings being so laid on, and each being allowed to become dry before application of the next one. After the application of each coating, it should be " glassed." Finally, the leather so coated should be boarded. List of all Patents for Blacking^ Compounds for Leather, issued by the Government of the United States of America, from 1790 to 1883 in- chisive. So. ] Date. Inventor. Residence. 2,431 Jan. 24, . 1842. N. A. Rowland and H. Miller, Rowan Co., N. C. 2,660 May 30, , 1842. S. Adams, Cleveland, 0. 2,844 Nov. 4, 1842. T. P. Merriam, New Bedford, Mass. 3,144 June 24, 1843. P. Hairll and D. Curran, Roscoe, 0. 3,401 Jan. 6, 1844. W. J. Roome, New York, N. Y. 4,498 May 9, 1846. J. Hay ward, Cleveland, 0. 23,065 Feb. .22, 1859. L. R. Rockwood, Worcester, Mass. 34,530 ^ Feb. 25, 1862. ■i Reissue > \ M. Shaw, Abington, Mass. 7,509) Feb. 13, 1877. } 39,986 Sept. 15, 1863. A. Bond, Philadelphia, Pa. 47,082 April ■ 4, 1865. R. Bartholow, Cincinnati, 0. 47,957 May 30, 1865. P. W. Keating, Norwich, Conn. 50,383 Oct. 10, 1865. D. L. Pickard, Rochester, N. Y. 50,780 Oct. 31, 1865. A. Tomlinson, Cincinnati, 0. ^ See also list of patents for coloring compounds. 452 THE MAXUFACTUEE OF LEATHER. No. ] Date, Inventor. Kesidence 52,391 Feb. 6, 1866. G. W. Corey, Port Jervis, N. Y. 52,920 Feb. 27, 1866. 0. P. Whitman, Lynn, Mass. 54,303 May 1, , 1866. J. A. Dean, Easton, Mass. 54,616 May 8, , 1866. S. Sherwood, New York, N. Y. 55,203 May 29, 1866. T. James, Medford, Mass. 56,526 July 24, 1866. J. M. Butcher, North Lewisburg, 57,567 Aug. 28, 1866. N. F. Quimby, . Wilmington, Del. 58,532 Oct. 2, 1866. W. K. WykoflF, Ripon, Wis. 59,851 Nov. 20, 1866. J. McCrellish, Philadelphia, Pa. 65,535 June 11, 1867. A. Boudron, Philadelphia, Pa. 66,982 July 23, 1867. C. McCleary, (executrix,) Hollidaysburg, Pa. 70,737 Not. 12, 1867. W. B. Moor, Winchester, Mo. 71,485 Nov. 26, 1867. S. A. Hickel, Spencer, W. Va. 73,730 Jan. 28, 1868. H. Lake, San Francisco, Cal. 76,897 April .21, 1868. J. Engelhardt, Carboudale, Pa. 78,372 May 26, 1868. J. Herold and M. Brown, Frederick, Md. 83,817 Nov. 10, 1868. S. S. Allen, Richmond, Md. 93,002 July 27, 1869. J. Putnam, Dan vers, Mass. 94,897 Sept. 14, 1869. J. Knapp, Syracuse, N. Y. 97,857 Dec. 14, 1869. L. Baumer, Columbus, 0. 98,916 Jan. 18, 1870. W. B. Bruthingham, La Fayette, Ind. 103,402 May 24, 1870. G. F. Whitney, Boston, Mass. 111,133 Jan. 24, 1871. E. Milner, Marquette, Mich. 114,354 May 2, 1871. H. A. Sawyer and R. G. Sawyer, Milwaukee, Wis. 118,842 Sept. 12, 1871. C. Brumly, Rochester, N. Y. 119,239 Sept. ,26, 1871. J. H. Patterson, Glen's Falls, N. Y. 120,348 Oct. 24, 1871. 0. K. Tripp, Rochester, N. Y. 124,760 Mar. 19, 1872. H. A. Reams, Durham, N. C. 128,873 July 9, 1872. 0. A. Goold, Portland, Me. 131,245 Sept. ,10, 1872. J. Breinig, Allentown, Pa. 133,400 Nov. 26, 1872. J. N. Baratta, Ayer, Mass. 135,310 July 28, 1873. F. G. Bell, New York, N. Y. 141,829 Aug. 12, 1873. A. D. Strong, Ashtabula, 0. 144,801 Nov. 18, 1873. J. L. Sneed, Frankfort, Ky. 148,582 Mar. 17, 1874. J. Townsend, Darby, Pa. 155,206 Sept. 22, 1874. C. E. Selss, Brooklyn, N. Y. 155,860 Oct. 13, 1874. J. Clausen, New York, N. Y. 157,835 Dec. 15, 1874. H. D. Jewett and J. D. Jewett, St. Omer, Ind. 157,936 Dec. 22, 1874. J. A. Sefton, Cleveland, 0. 158,907 Jan. 19, 1875. E. Clark, New York, N. Y. 160,741 Mar. 16, 1875. C. Alvord, Binghamton, N. Y. 161,203 Mar. 23, 1875. J. Carmody, New York, N. Y. 162,394 April 20, 1875. A. K. Lee, Galveston, Texas. MACHINES FOE GLAZING OR POLISHING, ETC. 453 No. Date Inveutor. Besidence. 1(33,855 June 1, 1875. J. I. Eastman, Philadelphia, Pa. 168,220 Sept. 28, 1875. J. H. Brown and J. G. Whiteside St. Louis, Mo. 176,105 April 11, 1876. P. J. Weber, BuflFalo, N. Y. 178,319 June 6, 1876. H. F. H. Miller, Boston, Mass. 190,495 May. 8, 1877. C. L. Jones, Stoughton, Mass. 203,138 . April 30, 1878. J. H. Gordon, Brooks, Me. 203,498 May 7, 1878. N. Quinland and J. H. Quinland, Glen's Falls, N. Y Jr., 204,528 June 4, 1878. C. H. Broad, Rochester, N. Y. 209,570 Nov. 5, 1878. J. H. Hyatt, Newark, N. .J. 241,876 May 24, 1881. G. E. Millar, Austin, Nev. 258,404 May 23. 1882. J. H. Garrett, Terre Haute, Ind. 259,009 June 6, 1882. M. Hackett, New York, N. Y. 259,188 June 6, 1882. E. N. McKimm, Lathrop, Mo. 260,416 July 4, 1882. C. Richter, St. Paul, Minn. 272,606 Feb. 20, 1883. J. A. Van-Keuren, Bridgeport, Conn. 277,017 May 8, 1883. W. H. Durkee, Cincinnati, 0. CHAPTER XXYI. MACHINES FOE, GLASSING OE POLISHING, PEBBLING, FINISHING, EOLLING LEATHEE, ETC. The leather after being properly blacked is next glassed, and while this operation is sometimes performed by hand with a glass slicker, such as is shown in Fig. 198, still by far the Fig. 198. greater part of the leather curried in this country is glassed by machinery, and a large number of contrivances have been in- vented for this purpose as well as for pebbling, finishing, and 45i THE MANUFACTURE OF LEATHER. similar operations. The scarcity of labor in all the Northern States from the commencement of the late war of the rebellion, and the enormous demand for leather which immediately arose, stimulated inventors in all lines of leather production, and machinery for this purpose which came into use from 1860 to 1873 is still the kind that is now commonly employed in all sections of the country. Martin'' s Machine. Martin's machine, which is largely used by leather, Morocco, and lining finishers, was invented in 1860, and it is shown in perspective view in Fig. 199. Fiff. 199. The machine is simple in design and very compact, the action is easy and silent, and the adjustment can be accomplished with facility. It can be operated at a high rate of speed, and its general employment by our leading finishers is an evidence of the quantity and quality of the work which it will perform. In currying it will " set out," pebble, " stone out," " glass in black and paste," using either oil or soap blacking, entirely without hand labor. In Morocco and lining finishing the machine will glaze, roll, pebble, and glass out, and perform the work in a satisfactorj'- manner. Martin's invention, shown in detail in Figs. 200 to 203, con- MACHINES FOR GLAZING OR POLISHING, ETC. 455 sists in the employment, in combination with a yielding bed for sustaining the leather to be operated upon, of a reciprocatory carriage arranged about parallel with the bed, and a combina- tion of pivoted levers, whereby the tool-stock is carried along in contact with the bed and back over it. Fi?. 200. Figure 200 is a side elevation ; Fig. 20 L is a similar view, showing the parts in a different position; Fig. 202 is a detail section at the line x x of Fig. 200 ; and Fig. 203 is a detail sectional elevation of the work-table, which is omitted in Figs. Fig. 201. 200 and 201 in order that the working parts of the machine may be more clearly delineated. C represents the base or floor, on which are secured the work- ing parts and the table and frame of the machine. 456 THE MANUFACTUEE OF LEATHER. The frame B^ the peculiar shape of which is clearlj seen, may be made of any suitable material of proper strength, and to the side of the projecting arm portion of this frame is secured the square working bar or way i), upon which travels the Fis. 202. Fi^. 203. reciprocatory carriage h. This carriage l is driven through an intermediate combination of pivoted levers by a pitman, c, con- nected at V to the main crank-pin on the driving-wheel A^ which latter may be rotated on its axis by any motive power. On the sill u is arranged the base-plate r of a metallic stand, j k k. At each end of this metallic stand is a screw-rod, on the lower end of which is a nut, s, and on which are arranged also two other nuts, o o', and a spiral spring, j:/. The lower one, o', of the two nuts o and o' is used to vary and control the action of the spring p on each bolt, while the upper nut, o, supports the adjusting-bar h. This bar has two inclined planes or oblique surfaces near its two ends, on which inclifleld surfaces rest the supporting blocks or lugs d d of the metallic bed c', on which the skin «/ to be operated on is placed. This bed c' may be covered on top with a stratum of leather, as seen at //, Figs. 200 and 201. On one side of the adjusting-bar h is pivoted, at x, one end of a rod, ^, the other end of which has a nut in it, within which works the screw-rod v, which is provided with a knurled head, by means of which it is readily turned, for purposes to be ex- plained. /is the "hand" or tool-stock, in which is hung the tool e. To the carriage h is secured a plate, I to which, at y y, are pivot- ed one end of pitman c, where it is bent up, as at g, and one end of a link, m, the other end of the link m being pivoted in MACHINES FOE GLAZING OR POLISHING, ETC. 457 tarn to one end of bar 7^, which latter is pivoted at its other end to the angle of pitman c y, and also to the hand / by means of the pivot or stud y^. The operation of the machine thus far described may be thus explained : The leather to be rolled, pebbled, or otherwise operated upon being properly placed on the yielding bed at a', and the bed adjusted by means of the nuts o o and sliding bar 7i, the motive power is applied to the main wheel J., causing it to rotate in the direction indicated by the arrow, and through the pitman c impart a reciprocatory motion to the carriage h. At Fig. 200 the parts are shown as they are when the carriage h has just started on its downward stroke in the direction indi- cated by the arrow. It continues during this stroke to travel with the hand or tool-stock/ in such position that the roll e travels in contact with and pressing against the upper surface of the leather or other stock being worked upon. At about the completion of this stroke, and while the crank-pin v is passing a dead-centre, the relative position of the hand/ and carriage h is changed and the parts assume the position seen at Fig. 201, in which position the return or upward stroke of the carriage and pitman is made, the hand/, it will be understood, moving- back above and at same distance from the leather. As the crank-pin v passes over the next dead-centre the hand /is again thrown down on to the leather, as seen at Fig. 200, and another stroke is made, and so on the rubbing over the surface of the leather of the hand is continued. As the operation of the machine continues the yielding bed is manipulated by the ad- justment of the bar A, and supporting- nuts o o, and springs jj 7;, and is familiar to those skilled in the use of the machine. It will be seen that while the machine is running the adjustment of the yielding bed up and down may be effected by turning the screw-shaft v. It will be seen that the various operations of rolling, pebbling, glazing, finishing, etc., may be performed on various kinds of stock by placing different tools in the tool- stock as is shown in the drav/ings; audit will be understood that by means of the jam nuts 0' 0', in connection with the rods and springs p, the amount or degree of elasticity at each end of the yielding bed may be regulated and varied to suit the 458 THE MANUFACTURE OF LEATHER. peculiar nature of the different portions of the stock being operated upon. Most of the features embraced in the yielding bed and its mechanism are so well known that we need not dwell upon that part of the description. The feature that is not generally understood is in the method of applying and working the hand or tool stock/, by attaching it to a system of levers involving a sort of parallel motion in conjunction with a reciprocatory carriage driven from a crank-motion. It is obvious that other peculiar combinations of pivoted levers and mechanical devices may be employed in connection with the carriage b, or its equivalent, to effect the same peculiar motion ascribed to the hand /, or to any tool which may be substituted for it. Friend's Machine. The glassing machine shown in Figs. 204 and 205 was in- vented in 1871 and further improved in 1875 by John P. Friend, and is adapted for work on all kinds of upper leather, sheep, goat, and Morocco. The bed of this machine is level, and arranged upon the principle of the platform scales, in order that it 'can be so ad- justed as to bring any point to bear either side wise or length- wise, and yet the turning of but one screw is required to increase or diminish the pressure uniformly. The pressure is equal at all points of the stroke, and may be increased suffi- ciently for pebbling without strain or injury to the machine. This machine is all within itself, and simply requires placing in position and securing, when it is ready for the belting, and when it is in motion there is but little "jar" or " shock". Fig. 204 shows a perspective view of Friend's machine. The pendulous arm A is pivoted to the frame B by the links or connecting-bars N and 0, which suspend and guide the vi- brating arm, and by which its vertical and vibratory movement is limited. The lower end of the arm A is connected with the foot C, and carries, with the foot (7, the tool-bar D^ which is connected at the upper end with the pendulous arm by the link MACHINES FOE GLAZING OE POLISHING, ETC. 459 E. A connecting-rod, F^ is attached to the foot C and to a crank or crank-wheel, by which a vibratory movement is given to the machine. Fig. 204. Fiff. 205. Fig. 205 shows a vertical section through the table of Friend's machine. A represents the frame of the machine. B the bed-plate, upon which the leather to be finished is laid. The top of the frame A incloses and holds the bed- plate in position. G is the first lever below the bed-plate ; it is jointed to it by the stud D. Below the lever Cis another lever, E^ and the fulcrum F \'& placed between the levers (7 and E. The bed-plate B and lever E are connected at the front of the machine by the bolt or connecting- rod G^, and the distance between the lever E and bed-plate B is adjusted by the nut and screw H. The front end of the lever ^ is supported by the spring /, which works on the standard J", and the tension of the spring is con- ^^^^m 460 THE MANUFACTURE OF LEATHEK. trolled by the nut K. It will be seen that, by this arrangement of levers, the adjustment of the bed is had entirely from the front of the machine. In all the machines used for glassing leather it had been the practice prior to this invention to employ one or more springs under each end of the bed, so that the tool when in the middle of the bed was resisted by the combined force of the two springs, while, when it was at either end of the stroke, it had the force of only one. This inequality of pres- sure is avoided by the use of the devices shown in Fig. 205, and the pressure is equalized through the w4iole of the stroke ; and the vertical movement of the bed is parallel, and it does not rock at each reciprocation of the tool, as it does in the use of two or more springs. Hildretli's Machine. The machine for glassing, and which is also largely used for pebbling leather, invented in 1868 by Joseph W. Hildreth, is shown in Figs. 206 to 208. Fig. 206. Fig. 207. Fig. 206 shows a vertical, central, and longitudinal section of a common form of a " leather glassing" or polishing machine, and Fig. 207 a vertical and transverse section of such a machine with Hildreth's improvement applied thereto. MACHINES FOR GLAZING OR POLISHING, ETC. 461 Fig. 208 is an enlarged side elevation of a portion of the machine, showing the elastic bearing to be hereafter described. A denotes a metallic bed, concave upon its npper surface, resting upon and supported at each end by an elastic cushion or spring, the bed thus supported being upheld by a suitable framework applied to the floor of ^"' an apartment or building in which the machine is located. A large number of the machines for glassing leather, prior to Hildreth's invention, were con- structed so that as the polishing tool approached the centre of the bed A, the pressure upon the leather increased, and the leather became distended and bagary, and reduced in thickness in its central portion. The object which Hildreth had in view in the invention of his machine was to obviate this defect by equalizing the distri- bution of the pressure upon the finishing-bed and leather. Hildreth makes the point of suspension of the vibrating arm c an elastic one, in order to accomplish this. The mode of applying the elastic bearing is as follows : The lever c is upheld by a horizontal cross-bar extending into guides or slots, m, w?, made through the side bars a' a' of the arm c/, the lever c swinging between the two. A spring, w, composed of India-rubber or other suitable material, is placed on top of each end of the cross-bar ?, and within the slots m, m, as shown in Fig. 207. A set-screw, o, is screwed through a cap-plate, p, applied to each bar a', and over and closing the slots m, m, such set-screws pressing down upon a metallic plate placed over the top of each spring n, 7i, and serving to regulate pressure of such springs upon the cross-bar l. If considered necessary or desirable, metallic blocks, recessed for reception of the end of the springs n, n^ may be interposed between the cross-bar /, and such springs to retain them in place, the blocks being formed with splicers or projections upon each, to slide in grooves made in the inner faces of the slots m, m. 462 THE MANUFACTURE OF LEATHER. Baker^s Improved No. 4 Olazing Machine. Baker's former machines for glazing leather have been in use bj a number of the leading houses in the Morocco trade, both in this country and Europe, and have given universal satisfaction. But the great advancement towards perfection in the Morocco business, requires an equal perfection in machinery for develop- ing the art. Mr. Baker, having this in view, has added to his already successful machine some important improvements, which will at once command the attention of the progressive manufacturer. This new glazing machine, which is shown in Fig. 209, has been reduced in size to economize in space, yet Fig. 209. without lessening its capacity for doing the widest range of work. Another important point is, that the balance cranks have been substituted by a balance wheel and crank combined, thereby giving the advantage of the balance wheel, both of which, when placed inside the main frame, give it the required stability of the balance cranks with the advantage of the balance wheel having the power stored in it to overcome the dead cen- MACHINES FOE GLAZING OE POLISHING, ETC. 463 tres and return the beam witli ease over the glazed surface of the leather. Another improvement claimed, is the new style clamp or holder, for holding the glass or agate; this clamp can be removed to put on any of the different rolling and pebbling attachments as readily as before. The horse or buck has been improved by the application of an arrangement for tilting the bed, in case the bed-strap should not be entirely parallel with the glass, which is performed by means of thumb-screws on the side, thereby saving time, and overcoming that imperfection in the stroke known to the trade as " cornering." Baker's Pony Glazing Machine. Baker's Pony Glazing Machine is shown in Fig. 210. For a long time Morocco manufacturers have desired a machine that would perform all the work that the old-fashioned " buck" would do, and without its many disadvantages, and at Fio;. 210. the same time at a cost that would not exceed that machine. To accomplish this end, Mr. G. W. Baker invented the pony glazing machine, as illustrated above. It requires but a small space, and is so constructed as to do 464 THE MANUFACTURE OF LEATHER. anjr kind of glazing in a superior manner. The framework is made of wood ; all tlie working parts are of iron, such as the crank shaft, pulley, and bearings, rock-arms, wrist-clamp, for holding the glass or agate, and are thoroughly substantial. The horse or " buck" is entirely of iron, provided with springs and screws that move independently of each other, and in such a manner that the pressure on the skin can be regulated to a nicety. It uses the improved glazing strap, which stands highly with the trade for durability and the performance of good wopk. Overhead Glazing Machines. There is a class of the Morocco trade that uses an overhead glazing machine made of wood in several parts. One part, including the beam, is fastened to the joists above, with the iron horse immediately below it resting on the floor, and a short dis- tance from the horse two upright posts are bolted to the joists with space between them for the iron balance-wheel. A wood connecting-rod connects the wheel with the beam, and all the working parts have metal bushings. It can be used very well in a good strong building, but where there are more than two, it makes too much strain on the floors, as they receive all the pressure, the force of the roller on the strap having a tendency to push the beam upwards, as it is fastened to the joists, and to push the horse downwards, thus causing the floors to be con- stantly vibrating. There are quite a number of these machines in use, but parties will have more satisfaction from a portable machine; it requir- ing time and expense to change them, and when once removed being useless. Those who have suitable buildings and wish this machine, however, will find it to do good work. Knox's Machine. The Morocco finishing and pebbling machine made by David Knox, is shown in Fig. 211. A medal and diploma were awarded to this machine at the Philadelphia Exposition of 1876 ; but since that time it has been improved and simplified. The machine is easily adjusted, and requires but little power MACHINES FOR GLAZING- OR POLISHING, ETC. 465 to operate it, and Morocco and lining finishers hold it in high esteem. In a tour through the Morocco tanneries of the city of Fi-. 211. Philadelphia, Pa., during the autumn of 1883, the author counted more than one hundred of these machines in operation in that city, which is asufficientguaranteeof the excellence of their work. List of all Patents for Machines for Stoning., Polishing., Finishing., Glassing, Glazing, Flinting, Creasing, and Dicing Leather,^ issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. Date lEventor. Residence. 3,957 Mar. 15, 1845. R. Bracket, Boston, Mass. 4,534 Aug. 29, 1871. A. W. Pratt, Salem, Mass. 7,433 June 18, 1850. E. Brookout and H. Cochen, Jr., Williamsburgh, N. Y 9,292 Sept. 28, 1852. J. M. Poole, Wilmington, Del. 10,379 Jan. 3, 1854. P. T. Tapley, Lynn, Mass. 12,806 May 1, 1855. N. Ames, Sangus, Mass. 1 For other machines for glassing leather see list of patents for scouring machines on page 407, some of which are also used for glassing leather. 30 466 THE MANUFACTURE OF LEATHER. No. Date. Inventor. Eesidence. 13,605 ^ Sept. 25, 1855. C. Weston, 1 Reissue } T. F. Weston, J- Salem, Mass. 839 ^ Oct. 18, 1859. J. W. Weston, I 14,606 April 8, 1856. W. P. Gamble, Philadelphia, Pa. 14,821 May 6, 1856. E. L. Norton, Charlestown, Mass. 16,114 Nov. 25, 1856. W. Crane, Brooklyn, N. Y. 20,861 July 13, 1858. J. R. Bumgarner, and L. W. White, Davenport, la. 24,139 May 24, 1859. T. Newhall, Lynn, Mass. - 24,344 June 7, 1859. T. F. Weston, Salem, Mass. 26,792 Jan. 10, 1860. R. L. Smith and C. Smith, Stockport, N. Y. 26,932 Jan. 24, 1860. R. A. Stratton, Philadelphia, Pa. 27,028 Feb. 7, 1860. G. S. Adler, Philadelphia, Pa. 27,300 Feb. 28, I860. W. P. Martin, Salem, Mass. 27,885 April 17, 1860. R. P. Boyce, Erata, Miss. 28,108 May 1, 1860. W. P. Martin, Salem, Mass. 28,562 June 5, 1860. S. P. Cobb, South Danvers, Mass. 31,879 April 2, 1861. W. Ellard, Woburn, Mass. 40,735 Dec. 1, 1863. S. P. Cobb, South Danvers, Mass. 41,363 .Jan. 25, 1864. J. G. Bushfield, Feltonville, Mass. 48,186 June 13, 1865. R. Lee, Newark, N. J. 52,728 Feb. 20, 1866. W. P. Martin, Salem, Mass. 66,125 June 25, 1867. F. J. Burcliam, Racine, Wis. 76,914 April 21, 1868. J. W. Hildreth, Bostoi;if, Mass. 79,070 June 23, 1868. J. F. Harris, Swampscott, Mass. 80,829 Aug. 11, 1868. P. Lenox, Lynn, Mass. 85,030 Dec. 15, 1868. C. Schmitz, Philadelphia, Pa. 91,219 Jan. 15, 1869. P. Farrell, Albany, N. Y. 109,205 Nov. 15, 1870. H. C. Havemyer and D. P. Burden, New York, N. Y. 114,809 May 16, 1871. D. Harrington, Boston, Mass. 115,312 May 30, 1871. B. R. Hamilton and S. Swan, Deerfield, Mass. Conway, Mass. 117,877 Aug. 8, 1871. J. P. Friend, Peabody, Mass. 118,146 Aug. 15, 1871. G. H. Parker, Detroit, Mich. 121,727 Dec. 12, 1871. N. D. Morey, Saratoga Springs, N. Y. 122,136 Dec. 26, 1871. A. Shedlock, Brooklyn, N. Y. 122,395 Jan. 2, 1872. C. A. McDonald, Woburn, Mass. 123,681 Feb. 13, , 1872. G. Crossley, Philadelphia, Pa. 132,901 Nov. 12^ , 1872. H. Cunningham, Albany, N. Y. 139,442 May 27, , 1873. W. A. Watson, Beverly, Mass. 150,849 May 12, , 1874. W. Ellard, Woburn, Mass. 152,711 June 30, 1874. W. Walter, Yonkers, N. Y. 158,761 Jan. 12, , 1875. J. T. Tullis, Glasgow, North Britain, 163,063 May 11, , 1875. J. P. Friend, Peabody, Mass. 170,983 Dec. 14, , 1875. B. M. J. Blank, Jersey City, N. J. MACHINES FOR GLAZIN"a OR POLISHING, ETC. 467 No. Date. Inventor. Residence. 173,178 Feb. 8, 1876. W. A. Perkins, Salem, Mass. 207,930 Sept. 10, 1878. A. J. Alexander, Gallipolis, 0. 208,918 Oct. 15, 1878. C. Molinier, Buzet, France. 229,895 July 13, 1880. J. Liedtkie, Brooklyn, N. Y. List of all Patents for Machines used for Pebbling Leather^ issued hy the Government of the United States of America^ from 1790 to 1883 inclusive. No. Date. Inventor. Residence. 14,821 May 6, 1856. E. L. Norton, 27,300 28,108 Feb. May 28, 1, 1860. 1860. I W. P. Martin, Salem, Mass. 42,136 Mar. 29, 1864. C. T. Woodman, Boston, Mass. 48,876 July 18, 1863. G. W. Pratt, Salem, Mass. 60,115 Dec. 4, 1866. J. C. Armes, Northamj)ton, Mass. 76,914 April 21, 1868. J. W. Hildreth, Boston, Mass. 117,877 Aug. 8, 1871. J. P. Friend, Peabody, Mass. 119,743 Oct. 10, 1871. 0. Coogan, Pittsfield, Mass. 132,901 Nov. 12, 1872. H. Cunningham, Albany, N. Y. 135,350 Jan. 28, 1873. N. 0. Lounsberry, Wilmington, Del. 140,633 July 8, 1873. N. 0. Lounsberry, Wilmington, Del. 155,931 Oct. 13, 1874. M. Dolan, Boston, Mass. 157,632 Dec. 8, 1874. P. O'Brien, Boston, Mass. 159,092 Jan. 26, 1875. A. M. L. Groflf and J. A. Marvel, Wilmington, Del. 161,046 Mar. 23, 1875. N. 0. Lounsberry, Wilmington, Del. 161,269 Mar. 23, 1875. A. W. Perrin, New York, N. Y. 163,063 May 11, 1875. J. P. Friend, Peabody, Mass. 168,497 Oct. 5, 1875. H. Howson, Philadelphia, Pa. 176,535 April 25, 1876. L. R. Jenkins, Philadelphia, Pa. 205,974 July 16, , 1878. E. B. Parkhurst, Woburn, Mass. 246,278 Aug. 30, , 1881. E. C. Allison, Melrose, Mass. List of all Patents for Machines for Rolling^ Leather, issued hy the Government of the United States of America, from 1790 to 1883 in- clusive. Residence. No. 37,991 40,069 50,079 71,929 Date. Inventor. Oct. 19, 1812. W. Edwards, April 28, 1836. McLaughlin and Hill, Sunderland, Vt. Mar. 24, 1863. J. Whitney, Winchester, Mass. Sept. 22, 1863. J. Whitney, Winchester, Mass. Sept. 19, 1865. D. H. Priest, Boston, Mass. Dec. 10, 1867. J. H. Walker, Worcester, Mass. ^ This list also includes machines for rolling sole leather. 468 THE MANUFACTURE OF LEATHER. Ko. Date, Inventor. ■Residence. 93,465 Aug. 10, , 1869. C. W. Monson, Upton, la. 98,889 Jan, 18, 1870. J. F. Safford, Winchester, Mass 101,197 Mar. 22, 1870. H. J. Weston, Buffalo, N. Y. 101,234 Mar. 29, 1870. G. Curtis, Emporium, Vt. 115,443 May 30, 1871. G. Curtis, Emporium, Vt. 124,709 Mar. 19, 1872. J. Whitney, Winchester, Mass, 149,906 April 21, 1871. J. Whitney and A. E. Whitney, Winchester, Mass, 151,989 June 16, 1874. S. R. Krom, / N. Lindsey, New York, N. Y. ) 171,574 Dec. 28, 1875. ■| J. McCuUough, and ' (w. Clement, I > Lena, HI. 171,867 Jan, 4, 1876. Win. H. Rosensteel, Johnstown, Pa. 176,763 May 2, 1876. J. C. Wells, Warren, Pa. 194,352 Aug. 21, 1877. H. Hudson, Saltillo, Pa. 194,906 Sept. 4, 1877. A. Hanver, Union, N. Y. CHAPTER XXYII. Machines for Measuring Leather. The heavy leathers are sold by weight ; but light leathers, such as upper, Morocco, sheep-skin, and enamel leather, are sold by area. The yardstick, and the common measuring frame, having wires or cords running the length and across it, thus dividing the frame into square feet, do not require special description ; but since 1877 there have been invented in the United States seven different leather-measuring machines, and taking Lynn, Mass., as the centre, all of them have been in- vented by persons living within a radius of about twenty-five miles of that place. The leather- measuring machine invented by David T. Winter, of Peabody, is a convenient contrivance for measuring. The fault found with it by finishers of leather was that after purchasing the machine they were compelled to pay a royalty for its use to other parties who had gained a suit against Winter for an in- fringement of their patent rights. But Mr. Winter has lately MACHINES FOR MEASURING LEATHER. 469 secured the control of a leather-measuring machine which is thought to be free from the objections to the one just men- tioned. Williams, Moore, and Hulhuris Leather-Measuring Machine. The leather-measuring machine shown in Figs. 212 to 216 was invented bj Williams, Moore, and Hulburt, in 1879. The operation of the machine is as follows : The table D be- ing raised, as shown in Fig. 212, the skin or article to be meas- ured is spread upon the table B, and the table D, carrying the pins r r, is brought down upon it, assuming a horizontal position before reaching it, and the pins are deposited in a perpendicular position upon the weighing-platform C, except such as are inter- cepted by the skin. (See x, Fig. 213.) Fig. 212. The dial/ being so marked that when all the pins rest upon the weighing platform the pointer will indicate 0, and the pins upon each square foot of surface that are removed from the weighing platform allowing the pointer to recede a space 470 THE MANUFACTURE OF LEATHER. marked one foot, the area in square feet is indicated correctly, except as far as the brake S may prevent it. A slight pressure then applied to the end of the rod v, forcing it back, removes the pressure of the brake S and allows the pointer on the dial/ to indicate exactly the correct measurement. Fig. 213, Fig. 212 is a perspective view; Fig. 213, a vertical cross- section at line w, Fig. 212 ; Fig. 214, a diagram showing the position of the table carrying the pins and its supporting-levers at different elevations ; Fig. 215, an interior end elevation ; and Fig. 216, a modified form of pin. 1 ,*>. i^.- Fig. ""'ft--'""" 214. 1 ' .■•<» ; 7/^ •••■■V} l^ i:,//;^ D ^ 7fl" '•^J ^^ i ' ^l m %y ) ■^"'m Jt ^^A f \ The following is a description of the manner in which this machine may be constructed : The table D is four and one-half feet Avide, the shaft E may be nineteen and one-half inches MACHINES FOR MEASURING LEATHER. 471 below the same, and fifteen inches from tlie rear side of tlie frame A. The arms i and k and the bars h and g sliould be of tlie following lengths, measuring from the centres of their Fig. 215, pivotal points in each case : arm i, nine inches ; arm k, twelve inches; bar A, twenty-two and one-half inches; bar ^, thirty- eight inches. The upper end of bar h should be pivoted to the table D thirteen and one-half inches from its rear side, and bar g twenty-five inches from bar h, and fifteen and one-half inches from the front side of table. The arms i and k are at such an angle to each other that the distance from the extreme pivotal point of one to the same point in the other is thirteen and one- half inches. These dimensions may be varied to suit the condi- tions required. Upon the shaft ^ is a hub with a radial arm carrying a weight, TF", so that as the shaft is turned in either direction the weight is moved in the arc of a circle of which the shaft E is the centre. If the arm carrying the weight TF be adjusted (by a set-screw in its hub) in a perpendicular position over the shaft JE when the table D is at its lowest point, it will be readily seen that in this position the weight W exerts no upward pressure 472 THE MANUFACTURE OF LEATHER. on the table D. If, now, the table be raised from its lowest to its higbest point, the weight if will, by the turning of the shaft E^ be moved from its position over it to one at its rear, and thus exert a gradually increasing pressure against the table D. It is preferable to set the arm carrying the weight at a slight angle backward from a perpendicular position over the shaft E when the table D is at its lowest point ; but any adjustment may be'made that will suit the convenience of the operator, it being understood that as the table D^ carrying the pins or weights, approaches and the pins are supported by the weighing plat- form, it is necessary, for ease of operation, that the table D should be at least partially relieved from the upward pressure of the weight W. The pins, which are represented in Fig. 212 as suspended in the table D^ and are shown in section in Fig. 213, are formed with a slender shank or body and a base of sufficient size and weight to enable them to stand upright without side support when de- posited in a perpendicular position upon a level surfice. The heads by which they are suspended are the frustums of cones having their larger diameters uppermost, and are of sufficient length to hold the pins firmly in a perpendicular position when placed in holes in which they fit closely. The holes in the table B are so arranged that when the table D is brought down upon it they coincide with those in D^ and are of such a size that the bases of the pins will readily pass through them. These pins are of such a length that when their bases rest upon the weighing-platform C, and the table ]) has been brought close down upon i?, their head^ will project for at least their entire length above the table D, and thus be free from contact therewith. This construction allows the pins to stand on the weighing-platform entirely free from support by the table D, and admits of an accurate weighing of the pins, which is impossible in machines as heretofore made. Fig. 216 represents another form of pin, which accomplishes the same purpose in a slightly different way. The head of this pin is cylindrical, and is prevented from slipping through the table in which it is supported by a slight contraction of the hole just at its lower surface, as shown at A", and it has no enlarged MACHINES FOR MEASURING- LEATHER. 173 base, but is slightly rounded or pointed, so it may readily enter a hole or socket in the weighing-platform, by which it is sap- ported in an upright position. In practice the tapered heads, as shown in the main drawings, are often preferable ; but the pointed pin may be used with ad- vantage in certain cases. It has been found that the oscillation of the pointer of the dial/, connected with the weighing mechanism, is an obstacle to rapid work. This is overcome by means of a brake or lever, aS', pivoted to the frame A at t, and held lightly against the end of lever c by a spring, m, one end of which is attached to the front part of the frame A and the other to the brake s or the rod V, which is attached to it at s, and which extends across to the front of the machine, as shown. The spring may, for con- venience, encircle the rod, as shown. By pressing the projecting end of the rod v backward the brake may be removed from contact with the lever c. This may be arranged so as to operate automatically by the descent of the table D ; but it is preferable to operate it with the knee of the operator. Saioyer''s Leather- Measuring Machine. The Sawyer self-adjusting leather-measuring machine is shown in Figs. 217 to 224, and it is constructed on a different principle from other machines for measuring the areas of sur- faces, and it can be operated either by hand or power. A minimum of power will run this machine, and it can be operated at a fast or slow rate of speed ; 40 revolutions per minute is a good average, which gives five sides in that time. Wax, grain, enamel, goat and sheep-skins are perfectly meas- ured by this machine, which is made in different sizes to suit the various leathers. The machine is made of metal, and any of the series of wheels may be removed or replaced without inter- fering with the others. In machines of this class as first constructed the cords from all the winding devices were connected to one and the same cord, which actuated the index-finger of the scale. This ar- rangement was found objectionable on account of the friction 474 THE MANUFACTUEE OF LEATHER. caused by the great number of pulleys required and the diffi- culty with which the long cord rendered through them. One object of this invention is to obviate these objectionable features; and Sawyer's invention consists in an arrangement of levers by which the travel of each measuring-wheel is caused to properly aft'ect the index of the registering device. The article to be measured is fed into the machine between the wheels and roller, and the leather is smoothed out as it passes between them and so records every inch in the surface. Fig. 217 illustrates a perspective view of the front of the Sawyer Machine. Fig. 218 a partial rear elevation of the Fiff. 217. .1 !'' '- 1 ,.-■■' < I 1 «■ machine with the latest improvements embodied. Fig. 219 is a view, on a larger scale, of one set of five cords and their por- MACHINES FOR MEASURING LEATHER. 475 tions of the main cord, showing the connection with the system of levers. Fig. 220 is a partial cross-section, showing a novel Fiff. 218. way of supporting the toothed segments, so as to allow the removal of any one of the wheels without disturbing the others. Fig. 219. Figs. 221 and 222 are details of the toothed-segments support. Figs. 223 and 224 are modifications of the system of levers. The width of the machine depends upon the number of wheels, 476 THE MANUFACTURE OF LEATHER. and varies for different varieties of leather, as has been stated. In Fig. 218 is illustrated one of the largest size for measuring enamel leather, made from whole hides, and is provided with Fig. 220. forty wheels. In all, however, each wheel is a separate measuring-machine, so that each machine will measure widths ^ varying from that of one wheel up to the total number of wheels. All the wheels A rest on a roller, £, which is revolved MACHINES FOR MEASURING LEATHER. 477 by any of the well-known means. Bach wheel has a hub pro- jecting slightly beyond its rim and side. Each projecting part of the hubs is toothed, and is placed immediately below a toothed-segment (marked C in Fig. 220). To each of the hubs Fig. 221 Fiff. 222. pa H of these segments is attached a cord, D. When an article — such as a side of leather — is inserted between the wheels A and the roller B^ a greater or less number of the wheels, according to the width of the article, will be raised, and their toothed hubs be caused to engage with the teeth of the segments C. As the article is drawn in by the revolution of the roller B^ the wheels in contact therewith will rotate and cause the segments with which their hubs mesh to rotate and wind up the cord attached to their hubs, and the total length of cord so wound up will indicate the total area of the article that passed under the wheels. To aggregate the measurements of the cords by means of a series of levers, the cords may be divided into sets, as indicated by the letters d, d! ^ d^^ #, d'^, cZ^, cZ^, and d^ in Fig. 218. Bach cord is secured at each end, c^^, to a small lever, cZ^, but renders freely through rings or pulleys. Two of these small levers d^ are 478 THE MANUFACTUEE OF LEATHER. pivoted at their centre to the opposite ends of a lever, d^°, which may be pivoted at its centre direct to a weighted arm, F, pivoted to the frame at/, and carrying a racked segment,/', which, meshing with the pinion g, causes it to revolve when the arm i^is moved. The index-finger G is fast to the shaft of the pinion f/, and consequently moves with it. This arrangement would constitute a complete machine of ten wheels. For a com- plete machine of twenty wheels, two levers, c?^*', each having two small levers, d^, with their two sets of five cords, would-be pivoted to the arms of a lever, d^^, which would be pivoted at its centre to the weighted arm F. For the machine of forty wheels (illustrated in Fig 218), two of the twenty-wheel con- nections above described are pivoted to the ends of a lever, d^'^, which is pivoted at its centre to the weighted arm F. By thus shortening the cords the inventor is enabled to substitute for them small chains, which not only render freely and work per- fectly, but are also much preferable on account of not being affected by moisture and of their greater durability. The toothed segments, cords, and levers being arranged as has been described, the same amount of displacement of any one or other member of the segments will cause the index-finger to move the same distance over the graduated scale. The movement of the index-finger is always exactly proportional to the number of segments displaced and the aggregate amount of their displace- ments — that is to say, in measuring a surface of one hundred and forty-four square inches area, it would make no difference whether it were a strip, one and a half inches wide and ninety-six inches long, and rotated only one wheel during 'its passage, or whether it were a piece nine inches wide and sixteen inches long and rotated six wheels during its passage, or whether it were of varying widths in its length and rotated 'a different number of wheels according to its varying widths. The index- finger would in each case indicate the correct area. It will be obvious that the arrangement of levers may be varied, the requirement being that the arrangement shall be such as to correctly aggregate the motion of every measuring-wheel. Thus in Figs. 228 and 224 the wheels are shown in pairs, one cord from each pair extending round a pulley, and two of these MACHINES FOR MEASURING LEATHER. 479 pulleys on each small lever d^. These small levers are connected in pairs by the levers c?^^, and each pair of levers d}^ is connected by a lever, c?'*, each lever (/^, in this case, being connected with four wheels — two at each end — each lever c?^^ with eight wheels, and each lever d^* with sixteen wheels, as shown in Fig. 223. Now, were there but thirty-two wheels in the machine, two levers d^^ would be connected — one at each end — with lever d^"^] but if forty wheels be nsed, then each lever d^* should be connected to a lever, c?'^, and these two levers d^^ should be each connected with a lever d^^ connected with eight wheels to make up the forty, and as the levers fP** have sixteen wheels at their outer ends and but eight wheels at their inner ends, or four for each lever d^^^ the levers d^^ should each have an arm four times as long as the other arm. Figs. 220, 221, and 222 illustrate the new way of supporting the toothed segments C, so as to allow any one of them to be removed when required to take out or replace any one of the wheels without disturbing the others. The support H is pro- vided with two half boxes, h li\ one of which, A, serves to receive the cross-rod J", on which all of the supports II rest. The half box h' receives the journals of the toothed segment C, which is carried by the support H. It will be evident that with the parts so arranged any one of the segments and its support can be lifted out at pleasure and afford access to the wheel below. This arrangement is of much practical value, since in the machines as heretofore constructed the rod e7 passed through the supports H^ and the toothed segments were mounted on pins passing through them and secured in jaws formed on the ends of the supports, so that the whole had to be taken apart to replace a wheel. The supports are adjusted by means of set screws A^, so as to regulate the space between the toothed hubs of the wheels and the segments. 480 THE MANUFACTURE OF LEATHER. List of all Patents for Machines for Measuring the Areas of Hides, Skins, and Leather, issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Residence. 194, S62 Aug. 28, 1877. M. V. B. Ethridge, Lynn, Mass. 194,743^ Reissue V 9,204 J Aug. 28, May 18, 1877. 1880. F. F. Tapley, C. H. Porter, Lynn, Mass. East Stougliton, Mass, 208,942 Oct. 15, 1878. D. T. Winter, Peabody, Mass. 215,853 May 27, 1879. D. T. Winter, r J. H. Williams, Peabody, Mass. Newton, Mass. 218,802 Aug. 19, 1879. < S. Moore, I R. H. Hulburt, Newton, Mass. Sudbury, Mass. 228,791 June 15, 1880. J. S. Wentworth, Lynn, Mass. 231,741 Aug. 31, 1880. D. T. Winter, Peabody, Mass. 256,058 April 4, 1882. W. A, Sawyer, Danversport, Mass. 258,969) 258,970) Jmie 6, 1882. D. T. Winter, Peabody, Mass. 269,962 Jan. 2, 1883. W. A. Sawyer, Danversport, Mass. 281,745 July 24, 1883. C. G. Winter, Boston, Mass. 286,078 Oct. 2, 1883. W. A. Sawyer, Danversport, Mass. PART VII. CHAPTEE XXYIII. SOLE LEATHER. Section I. General Eemarks. By sole leather in the broadest sense we understand a thick leather prepared by tanning heavy hides of oxen, heifers, and cows with any substance, either vegetable or mineral, that will change the nature of the hide so as to render it suitable for boots and shoes. In this country the materials generally employed for convert- ing hides into leather, are oak and hemlock barks ; when the two are used together, the leather is called " union tannage." In the manufacture of sole leather it is sought to combine the greatest possible amount of tannic acid with the hide, and this branch of the tanner's art requires the highest knowledge of the business. While in the production of upper leather as much depends upon the currying and finishing as upon the tanning, and in that variety of leather it is not sought to place the greatest possible amount of tannin in the hide. Oak-tanned sole leather commands the highest price in the market, which arises from a variety of causes. The coloring matter and resin imparted to the hemlock-tanned leather have a tendency to make it harder and more brittle, which militates against it in the market. On account of the better price obtained for oak-tanned leather, the producers of this variety are enabled to pay a better price for the choice of hides, thereby securing usually the best, and the extra price also allows greater care to. be exercised in the tanning and finishing of the stock. As far as the astringent principle of hemlock and oak bark i& 31 482 THE MANUFACTUEE OF LEATHER. concerned there is no difference between them in their action on the hide, which cannot be truthfully said of the japonica and other highly concentrated tanning agents so enormously used in Great Britain. In commerce the hemlock-tanned leather is again graded into two classes, the better being styled as "hem- lock non-acid," and the lower grade as "hemlock acid;" but this is not, accurately speaking, a truthful descriptive division of the two processes commonly employed for accomplishing the "plumping" or distending of the hide for the reception of the tan liquor, as an acid is really used in both cases, the difference being that a vegetable substance (mostly gallic acid) is em- ployed in the first place, and sulphuric, a mineral acid, in the second. In this country sole leather is divided into the following varieties : — Hemlock. Buenos Ayres, light, non-acid ; middle weight ; overweight. California, light ; middle weight ; over- weight. Common hide, light ; middle weight ; overweight. Acid, all kinds, light ; middle ; heavy. Good damaged, all kinds and weights. Poor damaged, all kinds and weights. Prime export and jobbing leather, heavy. Calcutta buffalo, light ; middle ; heavy ; damaged. Oak Slaughter. Dressed backs, light ; middle ; heavy. Belting buts, rough. Bellies. Light Philadelphia and Baltimore tanned. Middle. Heavy. Louisville, no brands, X. A. Country tanned, light heavy. medium ; Oak Texas Hide. Good to best, middle and heavy i Common to good. weights. I Good damaged, best tannages. Light backs. Middle backs. Heavy backs. Damaged backs. Light crop. Union Slaughter. Middle crop. Heavy crop. Bellies. Heads. SOLE LEATHER. 483 The sole leather which will be described in the next section is that known as "oak slaughter," and the process which we shall give, is that emploj^ed at the large and well-known tan- nery located at Luray, Va. The tan-bark employed is known as chestnut-oak, and the hides are derived from Chicago, 111., St. Louis, Mo., Memphis, Tenn,, Baltimore, Md., and Washing- ton, D. C. Section II. Tanning and Finishing Oak Slaughter Sole Leather. The hides are placed in the " soaks," in which vats of water they remain three or four days, the period depending upon their condition, the water being changed with each pack of hides. From the "soaks" the hides are carried to the lime vats and are changed each day by means of a reel into stronger lime, and in these vats the hides remain until the hair is loosened. They are next unhaired, and afterwards fleshed, and then thrown into a vat of clear water and left to remain over, night. In the morning the hides are removed from the clear water and "grained," which process consists in scraping the hides on the grain side in order to cleanse them more thoroughly from the lime remaining in the pores. After being "grained" the hides are again placed in clear water, where they remain for three or four hours, which com- pletes the beam-house work. The hides are next suspended in the "handlers," which opera- tion is the first stage of the tanning process. They remain in the handlers for about three weeks, the liquor being at first quite weak, but is changed each day upon the hides, being gradually made stronger. After being properly "plumped" the hides are removed from the handlers, and are placed upon a truck, and conveyed upon a tramway to the "lay-away yard," where the tanning process is completed. The " lay-away vats" measure nine feet in length, seven feet in width, and six feet deep, and in these vats the hides are placed one by one, spread out flat, and a thin laj^er of dry. 484 THE MANUFACTURE OF LEATHER. ground bark is sprinkled over each hide, in order that the liquor may circulate uniformly. About eighty-five hides form a pack for each lay-away vat. After the hides have laid-away for a sufficient length of time to extract the tannin partially out of the "liquor," they are taken out and the liquor run off into a receiver through wooden pipes and pumped by steam power back to the leaches, where it passes through the bark and is restrengthened and then run as new liquor into the tan vats, and the hides are then put back as before. Each "pack" is usually " laid-away," ^. e., given new liquor five times, the whole operation of tanning extending over a period of about five months. From the "lay-away yard" the hides are placed on trucks and conveyed on a tramway to the scouring machine. The scouring machine used for this variety of leather is shown in Fig. 141 ; before the hides are scoured they are split into sides. Bach scouring machine will turn out one hundred and twenty- five sides of scoured leather per day. From the scouring machines the sides go into the drying loft, which is situated over the tanyard, and of course in a connecting build- ing with that in which they are scoured. The loft is heated by steam which circulates through a series of pipes connected with the boiler. In the loft the sides are suspended on sticks two by two inches and eight feet long, which sticks are partially rounded upon the edge that comes in contact with the side of leather. Two sides are suspended upon each stick about one foot apart, and a passage-way 6' 6" wide is maintained in the centre of the loft, and on each side of this passage-way two rows of sticks for holding the hides are placed. The steam pipes used for heating the loft are placed about 2' 6" away from the outside rows of leather, and are attached to the upright studding and pass around the loft. In drying sole leather it is very desirable that too much light should not be allowed to enter the loft, as it is injurious to the color. Around the base of the drying loft the weather-boarding is SOLE LEATHER. 485 hung ou hinges which can be adjusted to admit air without too much light; the windows in the loft admitting only sufficient light for the workmen. In the peak of the building are other openings so constructed as to be easily opened, and closed, thus creating a constant draft. The steam pipes are self-acting, and distribute heat more gently and uniformly than the old manner of drying with stoves. Experience has shown that the sides are the proper places to fasten the steam pipe, and the current of air from the outside is usually sufficiently strong to force the heated or dry air to the centre, and thus form a current towards the top open- ings. Without such openings the air forms a current up the sides of the building and does not reach the centre. The effect of side openings, other than the kind mentioned, is to create counter currents, thereby destroying the whole effect. With pipes for a circulation of steam properly arranged in connection with an intelligently constructed drying-loft, sole leather wet from the vats can be dried in forty-eight hours, ready for the roller. The sides of leather are not allowed to become entirely dry, sufficient dampness being allowed to remain in them for rolling, which operation is conducted in a building on a level with the drying-loft and opening into it, but in which a larger amount of light is admitted for the workmen than could be allowed in the drying-loft. The rolling machine shown in Fig. 225 is the kind generally employed for rolling sole leather. These machines are manu- factured by the Eureka Bark Mill Co. of Lancaster, Penn. The rollers on these machines are made of brass, and are six inches in diameter and six inches face or length, and are turned to a true surface and work into roller beds or concaves, which are also of brass and planed true to the radius or length of the vibrator or pendulum of each machine. The pressure of the rollers upon the leather is imparted by means of levers connected with the vibrator or pendulum of each machine, and controlled by a lever worked by the foot of the operator ; the hook to which the foot-piece is connected is shown in the drawing of the machine. 486 THE MANUFACTURE OF LEATHER. A list of patents for rolling machines, including those used for sole leather, is given on page 467. After the roller has passed over a portion of the side two or three times it is shifted by the hands of the operator until all parts are successively operated upon. Fiff. 225. The side is then placed in the loft, and on the following day it is again rolled and hung in the loft, and when dried the sides of leather are ready for market. From the time that the green hides arrive at the tannery until the finished sides are ready for use, the time consumed is about six months, two processes of tanning being completed each year. Section III. Tanning Inside Sole Leather. The term inside sole leather, though very old, is by no means correct, since this variety of leather is chiefly used for soles of ladies' shoes, only the offal (head and sides), with exception of hides much punctured by the larvae of gadflies, which are not fit for any other purpose, being employed for the manufacture of inside soles. The mode of tanning this variety of leather is nearly the same as that of ordinary sole leather, the principal difference being, SOLE LEATHER. 487 that the hides are seldom sweated, the hair being loosened bj liming. Dry hides are sometimes used, although thin domestic hides of cows and oxen, but weighing heavy, are generally employed for manufacturing inside sole leather. When green hides are em- ployed they are soaked for twelve to twenty-four hours, rinsed and freed from dung during this time, and placed, after final rins- ing and draining off, in weak milk of lime. Dry hides must be thoroughly soaked before placing them in the " limes." The hair of green hides, frequently handled, will become loose in from six to eight days, while about fourteen are required for dried hides. As soon as the hair can be easily pulled out depilating is pro- ceeded with. After being unhaired the hides are soaked for twenty -four to forty-eight hours with frequent rinsing, and then fleshed, which is done in the same manner as with sweated hides. After fleshing they are placed in a vat of water, fresh water being admitted every day and the hides handled tAvice daily. After six to eight days, according to the higher or lower tem- perature, scouring is proceeded with. In case the hides feel rough upon the grain side they are smoothed by forcibly driving the "stock stone" over the grain side, this being of advantage even if the hides feel entirely smooth. The hides possess a sufficient degree of softness when the ground and lime-slime is easily removed, and the impressions made by passing the fingers over them remain visible for some time. They are then placed in water for a few hours or over night, and finally brought into the " handlers." Inside sole leather can be raised in the liquors from which ♦sole leather has been removed. The treatment of the hides in the handlers and the after-pro- cesses are the same as those described for hides intended for sole leather. 488 THE MANUFACTURE OF LEATHER. Section IV. Bleaching Hemlock Tanned and Union Tanned Leather similar to Oak Tannage. This invention, which is that of E. W. Phillips, of "Waverly, N. Y., consists in bleaching hemlock-tanned and union-tanned leather similar to oak, and also has for its object to increase the percentage of leather from a given quantity of hides. To carry out this method proceed as follows: For fifty hides or one hundred hides, of average weight and tannage, prepare a mixture of five hundred and fifty gallons of pure cold water (soft water is the best), and six pounds of copperas, and suspend the sides or hides, if tanned whole, from rods in such a manner that they will be thoroughly immersed in the liquor, where let them remain for the period of thirty-six hours. The second step consists in removing the sides from the copperas-liquor and immersing them in a liquor composed by dissolving one hundred and fifty pounds of borax in five hundred and fifty gallons of pure water heated to 120° F., the sides being kept slowly moving in this liquor for the period of forty-five minutes, or until the leather feels slippery to the touch. In making the change into this liquor it it is best to put in at one time only so many sides or hides as can be convenientl}^ kept in motion for the period stated, after which the sides are removed from the borax liquor and immersed in liquor No. 3, which is a mixture of fifty pounds of oil of vitriol or sulphuric acid and five hundred and fifty gallons of pure water heated to 115° F., in which mixture the sides are kept moving for one and one-half minutes, or until the desired color is obtained, after which the leather is quickly removed from the liquor and placed in a pool of clear running water, where it is left until all trace of the liquor has been removed, when the process is complete and the leather may be hung up to dry. In making the change from the borg-x-liquor to the acid-liquor it is best to take only a few hides at a time, so that they can be quickly handled and not left to remain too long in the acid- liquor. After the number of hides or sides stated have been treated with the several liquors in the manner described, the old liquors SOLE LEATHER. 489 should be thrown away and fresh ones made for the succeeding tannage ; or, if preferred, the strength of the spent liquors may be raised to the standard by adding a sufl&cient quantity of the ingredients from which they are made. In order to insure the best results the strength of the different liquors, as also the length of time during which the leather must be left in them, should be slightly varied according to the weight of the leather and the degree of tannage. This must be left to the judgment of the bleacher, though the formula herein given, if strictly fol- lowed, will produce substantially the results claimed on any weight or tannage of leather. For the several liquors soft water or rain-water is best, although not indispensable. In all the processes of union-tannage, light liquors are used to obtain the desired color, and consequently the weight is less than if heavier liquors could be used, and an advantage claimed for the process which has just been described, is that liquor of any required strength can be employed. It is claimed that an expert cannot distinguish hemlock and union-tanned leather finished by this process from clear oak- tanned leather. Section Y. Artificial Sole Leather. Large quantities of artificial sole leather are produced at "Woburn, Salem, Peabody, and other places in Massachusetts, from leather scraps obtained from the numerous tanning and currying establishments in those places, and sole leather thus produced is much used in Lynn and other shoe manufacturing centres of New England, as well as in Chicago and other western cities, in the manufacture of cheap boots and shoes. In the different State penitentiaries where boots and shoes are manu- factured, artificial sole leather is also much employed. This material forms the inside sole, and when it is used for heels one or two layers of good leather are nailed on the outside. The following process for making from scraps and waste an artificial leather impervious to moisture, and to be used for soles and heels of boots and shoes, was patented in most of the Euro- 490 THE MANUFACTURE OF LEATHER. pean countries in 1882, and in the United States in 1883, by Emil Pollock, of Vienna, Austria-Hungary. In carrying this invention into practice, the leather scraps and waste to be used in the manufacture are first assorted, and those which had been dressed or treated with oil or grease sepa- rated from those not dressed with oil. The former are placed in a bath composed of ninety-five parts of water and five parts of soluble glass (potash or soda glass) of 35° Baume, or into a bath containing a proportionate quantity of soluble glass of 50° Baum^, as desired. The leather scraps or waste are allowed to remain in this bath, which may be cold or lukewarm, from one- quarter to one-half hour, according to the quantity of grease or oil contained in the scraps. The scraps are then drained off and placed in a solution of five parts of sulphate of zinc in five hundred parts of water. In this solution they are soaked for about half an hour. They are then pressed dry and ready for further treatment. In place of the soluble glass, any of the alkalies or any of the salts with alkaline reaction may be em- ployed, and in place of sulphate of zinc, any salt the base of which forms an insoluble combination with acids may be used. The so-prepared leather scraps or waste are now mixed with a paste that is formed by a thin solution of starch, to which solu-. tion, while in a boiling state, a small quantity of gum arable is added, and also to about twenty parts of the starch solution one part of a solution of alum consisting of five parts of water to one part of alum. The leather scraps are put into the starch and alum solution until they are thoroughly saturated. They are then, piece after piece, covered with a concentrated paste solution and placed in flat moulds in layers, one on top of the other, and beaten with hammers into sheets. The sheets thus formed are placed in a vessel containing a solution of soda soap, in the proportion of about one part of soda soap to two parts of water, and after having been well soaked therein they are sub- jected to hydraulic pressure, and finally dried, after which the sheets are ready for use. By the above process the oil and grease contained in the leather scraps are saponified, and the soluble soap transformed into an insoluble one, which dispenses with the removal of the SOLE LEATHER. 491 grease from the scraps and produces the utilization of the grease in the formation of the insoluble soap, by which the leather is rendered water-proof. The following chemical reaction takes place in the process described : The sulphuric acid of the alum combines with the soda of the soap, while the stearic and oleic acids, /C,3H,g02, stearic acid,\ V CjgHj^Og, oleic acid, J which were combined in the soap with the soda, become free to enter into a new combination with the argillaceous earths of the alum, the hydraulic pressure favoring the most direct mechani- cal combination of the two salts. Consequently, the leather becomes thoroughly impregnated with sebate of alumina, by which it is claimed to be protected against moisture so as to be water-proof. When leather scraps which contain no grease or oil are em- ployed the saponification of the grease is dispensed with, and the scraps are mixed directly with the thin paste of starch and alum, and are then worked up with thick paste into sheets and treated in the same manner as the oil-dressed scraps, and finally exposed to hydraulic pressure, forming a tough, and as it is claimed, a water-proof leather that can be used extensively in the arts. 492 THE MANUFACTURE OF LEATHEE. CHAPTER XXIX. HEAVY UPPER LEATHER — TANNING AND FINISHING THE "SIDE" - AND " split" — REMOVING EXTRACTIVE MATTER FROM TANNED LEATHER — PROCESS FOR WATER-PROOFING, DUBBING, AND V/HITENING UPPER LEATHER — IMPROVEMENT IN TAN PRESSES. Section I, Tanning and Finishing the " Side" and "Split." Under the head of upper leather are placed the soft and pli- able leathers which are employed principally, but notexclusivelj'' in manufacturing the uppers of boots and shoes. Upper leathers are produced from such hides and skins as Patna and East Indian kips, light and heavy cowhides, Buenos Ayres and Eio Grande hides, calf-skins, horse-hides, and split heavy hides. The processes of tanning and finishing are more rapidly com- pleted and less complex in proportion to the thickness of the hide treated, while at the same time, the percentage of tannin extract which the hide absorbs is likewise dependent upon its thickness. Lime is generally employed to soften the bulbous roots of the hair, and thus facilitate its removal by mechanical scraping with a blunt-edged knife or by machines constructed for that purpose, which have been explained in Chapter XVI. The lime used for upper leather must be removed in the preliminary stage of preparing the hide for tanning with greater thoroughness than is essential in the case of hides for sole leather ; and for this purpose the hides are subjected to various treatments and in addition go through the process of bating or " grainering." There is a great deal of obscurity surrounding the theory of the process of bating, but it has been explained on the suppo- sition that the uric acid of the hen dung employed removes the HEAVY UPPER LEATHER. 493 excess of lime, and that the ammonia generated by tlie putre- faction of the mixture tends to form an ammoniacal soap with any remaining fat of the hide ; but as the gelatin of the hide exists in two states — one the principal, hard, or fibrous portion, and the other contained between the fibres, and which is more soluble and easily affected by agents and putrefaction — this softer portion is removed by bating, and the leather when tanned is light and porous, and more readily permeable by water, which is sought to be obviated by the subsequent stuf&ng of the leather with oil and tallow. In the preparation of most kinds of upper leather the heavier hides are split into two, and sometimes more portions. In the case of a single split the por- tions form a grain and flesh side; when three sections or slices are made they result in grain, middle, and flesh splits ; the minor splits from shoulders, heads, etc., will be explained in the prac- tical part of this chapter as they are reached during the progress of the hide into upper leather. Some tanners split hides in the green condition, others after coloring, and in some cases the splitting is done by the currier, as a regular part of his operations, after the leather is fully tanned, this being particularly the case with imported tanned East India kips, and other fully tanned leather of foreign origin. The fact that machinery is now largely employed by some tanners and curriers for nearly every mechanical operation, while others still adhere to the old system of manual manipu- lations of the hide and leather, will of course make it impossible for this chapter to apply to every case. Then, again, some manufacturers employ machinery at one stage of the operation, while others reject it at that point and use it at some other stage. The machines described are those only that from personal knowledge we know to be acceptable in many instances by prominent tanners and curriers ; the basis of description will be at Salem, Mass., and the manufacture of heavy quality of hemlock-tanned upper leather is that which we will consider. In the city of Salem, and its adjoining neigh- bor Peabody, is produced a large quantity of upper leather, the hides used being mostly foreign, but some domestics in all con- 494 THE MANUFACTUEE OF LEATHER. ditions are also employed; they are kips, light cows, and heavy cows. A large number of hides have latel}^ been brought from China ; all the states of South America send hides to Massachusetts, east and west coast of Africa hides are also used, California hides are also employed, and Mexico sends them in moderate quantity, but South America furnishes the largest number. The bark used for tanning is usually hemlock, being derived mostly from Canada ; but Maine also ships hemlock bark in schooners, and it arrives in Salem in a less broken condition than that received from other localities. Pennsylvania also furnishes some bark to Salem, and extracts of bark are also employed there for tanning, but only in small quantities. In the State of Massachusetts the bark is nearly all bought by the cord, but some of the large tanneries purchase by weight. Preparation of the Hides, The hides first go into the " soaks" of clear cold water, and the period which they remain here is of course dependent upon the kind of hide, and varies from one to three weeks for those in a dry condition. Soft water is preferred for the " soaks" for upper leather, as the hides must not be swelled as much as those for sole leather, as otherwise the smooth cut would be injured. After they are split into sides, previous to which the hides are drawn into a pack, the hair side being placed uppermost, a knife is driven from the butt through the centre of the back. The sides are then placed in the hide-mill, which is a machine constructed similar to the fulling-mill used in woollen factories, and the time which they remain in the mill varies from one- fourth to three-fourths of an hour, the period being dependent upon their hardness or softness. Green salted hides are not of course worked in the hide-mill. From the hide-mill the sides are placed in clear cold water and remain over night, which period is sufficient if the first soaking has been properly done. Sometimes the sides are re- placed in the same water from which they were taken previous to going into the hide-mill, and this hastens the process of de- pilation ; but this results in loss in the end, as they cannot HEAVY UPPER LEATHER. 495 develop into properly plumped leather, and of course do not give profitable splittings. From the last water thej are removed to the "limes," and there remain until the hair is well loosened, after which they are unh aired, and this operation is now done either by hand or machinery. The style of machine commonly employed in Salem, Mass., for unhairing, is shown in Figs. 100 to 104. After the sides are unhaired they are placed in clear water and on removal are "green shaved," which is the removal of the loose flesh from the hide. Then the heads are run through the splitting machine, and the sides are next placed in the drench, and are worked about eight or nine hours in the bate, which contains hen manure. The object of the bating, as has been explained, is to neutralize the lime, open the pores for the admission of the tanning liquor, and also to render the leather more pliable. Pure cold water will extract the lime from the hide, but it leaves it much rougher and harder to finish than when hen manure is used. After being removed from the bate the sides are placed in the wash- wheel and worked for about fifteen minutes. The drench- wheels and wash-wheels are shown in Fig. 112. The period which the sides remain in the bate depends upon their thickness, the temperature of the bate, and the season, usually longer in winter than in summer. The sides then go to the hide-working machine, and here they are freed from lime and dirt, and are next thrown into clear spring water, where they remain over night. The style of hide-worker employed has an eccentric motion, and is shown in Figs. 114 and 115. The hide has thus, bv these preliminary operations of removing the portions not required for use and the cleansing, been prepared to receive and absorb the liquor in which the tanning matter is dissolved. Tanning. The sides are now placed in the handling liquor, which is a weak mixture, and remain in it for ten or twelve days for heavy upper leather, and during this period they are hung on sticks in the vats, and are afterwards twice " laid-away" in 496 THE MANUFACTURE OF LEATHER. ground bark, both lay-aways usually extending through a period of about two months, the first lay-away being for ten or twelve days, and the second consuming the remainder of the period. When removed from the lay-away the sides are hung on poles in the drying yard for a day to harden, and are then brought into the cellar and dampened. Fig. 226 shows the sides of leather hung over the poles, in the drying yard facing the finishing shops. The sides are next split. A day's work for one man on the union machine is about two hundred sides of leather. The operation of splitting the sides for upper leather consists in reducing them to a uniform thickness. Fig. 227. When the belt knife machine is employed the entire surface of the side is passed through in one operation, but the union machine usuall}^ requires two operations. The split is used for the tops of shoes or backs of boots, the splits are carried to a table and trimmed, which is the lopping ofi' of the rough edges, and they then follow the other leather through the process of HEAVY UPPER LEATHER. 497 tanning. The shoulder is also passed through the splitting machine ; but the shaving is not tanned, and is sold for stiffen- ing stock, and is also largely used in cheap or shoddy shoes by what are termed " pan-cake shops," which are places where boots and shoes are made for looks more than for wear, though the better part of these skivings are used for stiff'enings and the lighter ones for "insoles." The splitting machine, etc., are shown in Fig. 119, and are described in detail in Chapter XX. The sides next go to a " flatter," who levels off" the shanks and bellies with a currier's knife, as shown in Fig. 227, and they are then carried to the tanyard, and placed in a revolving wheel to be softened, twenty-five sides being placed in the wheel at one time and moderately strong gambler liquor poured over them, and in this wheel they are milled for about ten minutes. The result sought to be attained in placing the sides of leather in the mill after they have been split is to prevent the " glazing" or "crusting" of the raw parts from which the split has been taken. They next go back into the handlers and are drawn each day, and the liquor renewed ; they are not hung upon sticks in the handlers this time, the sides being pressed down and the liquor allowed to flow over them, and the period which they remain here is about fifteen days. Finishing the Side. From this last liquor the sides are carried to the shop and scoured, which may be accomplished by hand, as is shown in Fig. 137. The machines employed for this work, as has been stated, are the Burdon Scourer, the Fitzhenry, and the Lock- wood, each of which is fully described in Chapter XXI. From the scouring machines the sides are again taken to the poles or yard shown in Fig. 226, for hardening, and from thence are carried into the cellar to be dampened, about two days being occupied in the tempering. They then go into the stuffing wheel, as explained in Chapter XXII., and the sides remain in the wheel for about fifteen min- utes, the grease being here driven into the leather by heat. Fifty pounds of grease are used to two hundred pounds of leather, i. e., for heavy upper leather ; boot leather requiring a greater quan- 32 498 THE MANUFACTURE OF LEATHER. tity of grease, the leather must be warm and be kept warm uni- formly during the time the grease is being applied to it. The stuffing wheel in operation at the establishment of Thos. E. Proctor, located at Peabody, Mass., seems to do this work more thoroughly than any other that has been inspected by the author. This stuffing wheel is shown in Figs. 160 and 161. The leather, after being removed from the stuffing wheel, is then set out on the improved Fitzhenry or Lockwood machines, which have been illustrated and described in Chapter XXI. The number of sides of heavy upper leather which can be set out on the improved Fitzhenry machine is about two hundred and seventy-five per day ; but three hundred and twenty-five sides of lighter leather can be set out by the machine in the same time. The next step in finishing upper leather is that of whitening, which process can be performed by going over the leather on a table with the slicker, or the surface can be cut over with a currier's knife, or the whitening can be done by a machine, improved forms of which are shown in Chapter XXIII. The leather is then "stoned out" on a jacking machine, and if it requires softening it is next boarded by a machine, as shown in Figs. 177 to 182. The sides are now carried to the blacking loft and the flesh side is there " blacked" with soap blacking. This flesh blacking is made in two ways, sometimes with lampblack and soap, and at other times with lampblack and oil. When " soap blacking" is employed, oil is very freely applied afterwards in order to fasten the color and body of the black. It is claimed for soap blacking that it fills the flesh with a better body and hides defects in the leather which show through if oil and lampblack alone are employed. For other blacking compounds, see Chapter XXY., Section II. The disadvantages urged against soap blacking are that when this leather is crimped for boots, the blacking washes off leaving a coarse surface, while the alkali contained in the soap will, if allowed to lie for some time, neutralize the grease, thus impart- ing to the leather a harsh feeling ; pure oil blacking, on the other hand, will gradually grow softer with age. HEAVY UPPEE LEATHER. 499 Soap blacking is not now much used in foreign countries, and it is only used by us in the modified form to whicli attention has been invited. The blaclving is applied with a wet brush and thoroughly rubbed into the leather with a dry brush in the hands of the workman. There are machines for performing this work, as shown in Figs. 185 to 196 ; but they are not thought to answer so well for heavy upper leather as for softer and lighter leathers. The next operation is that of glassing, and this can be done either by hand or machinery, and when performed by a machine the same style is commonly employed as is used for rolling, pebbling, and finishing leather, but the improved Lockwood and Fitzhenry machines are also used. The Martin machine is largely used for glassing upper leather, and it is shown in detail in Figs. 200 to 203. After the side has been " tempered" it is again glassed, and then " pasted." Flour paste is used for the last operation, which is made from flour, with soap added, say in the proportion of about two pounds of hard brown soap to every pail of flour used, the soap being boiled with the paste. A piece of tallow about the size of an egg and a small piece of wax are also added to each pail of flour and also boiled with it. This composition is to " fill" the leather and make the stock "fine." After the leather is " pasted" it is dried and then " glassed in paste," which operation is also usually performed by the Martin Glassing Machine. The side is next " sized" with a preparation of gum paste applied to the flesh side with a sponge in order to finish. The " size paste" is made by dissolving four ounces of pure glue in warm water, adding a small piece of tallow, say half an ounce, and then diluting with water until the desired consistency is reached, when it can be easily spread with a sponge. After the application of the size the leather is hung up and dried, then assorted and finally measured, marked, and' bundled for market. An interior view of the finishing room of an upper 500 THE MANUFACTURE OF LEATHER. leather manufactory showing the pasting tubs and tables, horses for receiving and moving the leather and the blacked and pasted sides suspended from hooks in the ceiling racks, is shown in Fig. 228. There are several ways for measuring leather. The old style measuring frame is still largely employed ; but later inventions for measuring leather are illustrated and explained in detail in Chapter XXYIT. Finishing the Split. There are two processes for stuffing the split: if hand stuffed, it is taken from the scouring machine and stuffed; but if wheel stuffed it is handled about the same as the grain, after which it is struck out, dried, whitened, and trimmed. There are also two methods for finishing a split : if a flesh split it is whitened on the flesh side ; but if a waxed split it is finished on the split side. No preparation is applied to the back of the flesh split, it be- ing left plain; but the waxed or colored split is stained on the flesh side, and it is strictly known as the "colored pebble," of which there are two colors, the oak and hemlock, the first being a yellow and the second a red. The process of "fitting" the colored split is as follows: — 1. Coloring. 4. Grlassing. 2. Drying. 5. Pebbling. 3. Boarding. The machine shown in Figs. 206 to 208 is largely employed for the last-named operation. After pebbling, the colored split is ready for the "blackers," and the process from that stage is similar to finishing the "side," which has already been described at length. Head's Process for Soaking, Limi^ig, Tanning, Blacking, and Gumming Hides Intended for Upper Leather. Head's process is as follows : — ' The first step consists in soaking the hides, as they are re- moved from the animal, in a vat of water about eight feet long. IS 00 s= •73 ^ =^ HEAVY UPPEK LEATHEE. 501 four feet wide, and four feet deep, into which has been poured a mixture of one-half pound of saltpetre, one pound of potash, one pound of oil of vitriol, and twenty pounds of rook salt. This solution preserves the hides from decomposition, prevents the gelatine from dissolving, and assists in the liming process. Thej remain in soak from one to two hours. The second step consists in fleshing the hides after tliey have been soaked. The third step consists in placing the hides in a vat of water of about the dimensions given above, into which has been poured a mixture of one bushel of quicklime and one and one- half pounds of sal-soda. By the use of this mixture it is claim^ed that the time necessary to lime the hides is shortened to about six hours. This solution rapidly reraoves the albuminous sub- stances which hold the hair. After the hides have been taken from the lime above described, they are ready for the fourth step, which consists in soaking them in a vat of water at a temperature of about 110° F. They are allowed to remain in this vat about two hours, though a shorter time will accomplish the purpose as well. The fifth step consists in removing the hair and lime-shaving the hides. The sixth step consists in scouring them upon the grain side to remove all foreign substances, and prepares them for the color- ing liquor. It is seen that after the hides have been lime-shaved they are not placed in a bate, as is usually done, but are imme- diately scoured. This method, it is claimed, prepares them for the tan better than the process in common use. Seventh, the hides are placed in the coloring liquor, and re- main until they have acquired the desired color, which can be ascertained by watching them, and when removed from this' liquor the hides are immediately scoured, which removes all sediment and unnatural grain, and constitutes the eighth step of the process. Ninth, the hides are spread out on a table or floor, and the tanning solution well rubbed in with a brush or swab, and then laid away in a pile, which is the tenth step, the time which they remain in the pile being from two to fifteen days, according to 502 THE MANUFACTURE OF LEATHER. the character of the leather to be tanned. While in the pile the hides are handled once a da}^ or oftener, more of the solu- tion applied, and the hides returned to the pile. If, however, it is desired to retain the color upon either side of the hide, the tanning solution is applied to the opposite side from that upon which the color is to be retained, the solution is well boarded in upon that side, the hides folded together separately with the side which is to retain the color outward, and replaced in the coloring solution. If it is desired to retain the color upon both sides of the hide, the tanning solution is applied to both sides, is well boarded in, the hides spread out flat, and returned to the coloring liquor. The hides remain in this liquor from two to fifteen days, according to the character of the leather to be tanned. While undergoing this process the hides are handled once or twice a day, scoured, more of the solution applied, and returned to the liquor. The eleventh step, which consists in " sammying" the hides, is then carried into efiect. The twelfth step consists in scouring them on both sides, the thirteenth step in setting them out on a table or floor and flat- tening them with a slicker, and hanging them up to dry. When the hides have become dry they are taken down, placed upon a table or floor, and stuffed, which constitutes the four- teenth step. The fifteenth step consists in packing the hides down in a pile and covering them up to protect them from currents of air and from the light, which allows the stuffing to penetrate them without injury to the color. The length of time the hides re- main in the pile is optional, though the shortest time necessary to obtain good results is two hours. ■ The sixteenth step consists in dipping the hide singly in a vat of water at a temperature of about 120° F., which com- pletely drives in all the stuffing previously applied. After the hides have been dipped they are immediately struck out and hung up to dry, which is the seventeenth step. The eighteenth step consists in whitening, trimming, and boarding them after they have dried, and by which they are made ready for the blacking. HEAVY UPPER LEATHER. 503 The nineteenth step consists in blacking the hides, and the inventor does this with a composition of one pound of Limp- black, one and one half pounds of Babbitt's soap, boiled together in three gallons of water. The advantages claimed for this composition are that it softens and improves the texture of the leather, or, in other words, makes it " mellow." It is claimed that Babbitt's soap gives the best results for this purpose. The twentieth step consists in smutting the hides off and applying oil and gum tragacanth to them. The twenty-first step consists in glassing them down and hanging them up to dry. The twenty-second step completes the process, and consists in gumming them off with clear gum tragacanth after they have dried. Section II. Eemoving- Extractive Matter from Tanned Leather. In 1879 Plumer and Kernans, of Peabody, Mass., patented the following process for removing extractive matter from tanned leather: By this method leather tanned by the hemlock, oak, or other usual processes is subjected to a cleansing bath, which removes the extractive and tanning substances, grease, tannate of lime, etc., added to»the hide during the liming, bat- ing, and first tanning processes ; especially such matter as would tend to make the finished leather hard, or brittle, or which would interfere with giving to the grain-face of the finished leather a lisfht. even color. This the inventors claim to accomplish in the following manner: The tanned leather, say, twenty-five sides, containing from twenty to twenty-five feet each, are subjected in a mill to the action of diluted solu- tion of borax for from ten to fifteen minutes ; for the quantity of leather mentioned about six pounds of borax are dissolved in about thirty gallons of water. In practice the best results are obtained by the use of a closed circular or box-like wheel of about eight feet diameter bj^ two or three feet in width, and having a hollow journal for the en- trance of a water or steam pipe, and a side door for the intro- 504 THE MANUFACTURE OF LEATHER, duction and removal of the leather, the door to be suitably packed to obviate leakage. Having added the borax-water to the wheel, and placed the tanned leather therein, the wheel is rotated at tlie rate of about sixteen revolutions per minute for about fifteen minutes or until the objectionable matters referred to are loosened, when a hose or other water supply pipe is added to the hollow journal of the wheel to lead water into it, and in contact with the leather, so as to wash out the borax and other matters loosened or started by the first milling operation in the borax water. This treat- ment, it is claimed,, leaves the leather in proper and the best possible and most favorable condition to be retanned for all leather where softness and lightness of color are desired. Section III. Processes for Water-proofing, Dubbing, AND Whitening Upper Leather. Eady patented the following process for water-proofing, dub- bing, and whitening upper leather, the object being to give the leather a "satin finish." The process is as follows : A rough-tanned skin is first soaked, shaved, scoured, and then retanned, and next scoured and dubbed with oil and tallow, and then whitened, after which it is water-proofed by the following process — which is the first point of the combination where this invention commences. For the first p^art use a compound which consists of one part of dry gelatine (isinglass or other) dissolved in four parts of oil including a small quantity of sulphuric or other acid, and, when these are combined by means of heat, five parts of an alkaline solution are added, at a specific gravity of about 26"^ Baume, the whole being stirred while yet warm, and the result is a chemical combination designated as "the preparatory com- pound." For the second part of the process use the compound which is designated the "perfecting compound," prepared as follows: In one vessel prepare a strong solution of one of the alums (for instance, of the sulphate of alumina) with potassa, ammonia, or soda. In another vessel prepare a solution of the sulphate WATER PROOFING UPPER LEATHER,' ETC. 505 of zinc, and in a third vessel a solution of the acetate of lead. These solutions are each to be of the same density. When pre- pared, the two sulphate solutions are mixed in the proportions of about five parts of the first to one and a half parts of the latter, and to these are added about five and a half parts of the acetate-of-lead solution. By the chemical action that ensues sulphate of lead is formed, and when this has subsided the clear liquid is drawn off, and is reduced to the proper density, which is from 1° to 2° Baume, The manner of treating the material to be water-proofed is as follows : A bath is prepared with half an ounce of the prepara- tory compound dissolved in two gallons of hot water — that is, in about these proportions — and is used when cold. To treat leather, steep it in this bath till indued with its properties, and then drain it ; or the preparatory compound may be dissolved to about the consistency of cream, and then applied by hand before the "stuffing." Boots, shoes, and harness are treated before the final finish. The second part of the process is conducted as follows : When the goods have been removed from the preparatory bath, and are well drained, steep them in a bath of the "perfecting com- pound," where they remain from eight to twelve hours, and when well drained, they are gradually dried, which completes the water-proofing. After the water-proofing the side or skin is dubbed with tallow and oil, after Avhich it is whitened, and then finished. The final combination of dubbing, whitening, water-proofing, etc., it is claimed, gives -the leather a superior finish. S'ponhouse's Method for Manufacturing Water-proof Leather. In the selection of hides take those which are dry, as green hides are more porous. A solution of lime is made, care being observed not to make it too strong, for if too much lime is used it will swell the leather, and thus render it porous, soft, and spongy. The leather is then placed in the solution, as ordi- narily, and when all animal or extraneous matter has been ex- pelled therefrom, it is bated low in the usual manner with the proper decoction, in order to extract the lime as clean as 506 THE MANUFACTURE OF LEATHER. possible, so that the tannin will penetrate it. The upper leather and kip hides are handled in sweet liquor only, as sour liquor will swell them. When about three-fourths tanned, the leather is shaved and thrown into sour liquor and allowed to remain for a week. The leather during that time is handled everyday, and taken out and scoured a little, after which the flesh side is stuffed with dubbing applied milk-warm, composed of the fol- lowing ingredients: Tanner's oil, 4 parts; flaxseed oil, 1 part; tallow, 2 parts; care being taken not to staff the leather too thick or heavy with the dubbing. The leather is then folded up tightly and put into a close box and allowed to remain for 48 hours, so that the stuffing will enter the pores. A strong solu- tion of bark is made in a vat, in which the leather is then placed with the flesh side down, in order that the solution will tan in from the grain side. By this operation the stuffing and the oil will be tanned with the leather. It is then permitted to lie in the vat about 6 weeks, when it is taken out and scoured and allowed to get about half dry. The following ingredients, with the proportions of each given, are then mixed and applied milk-warm to the leather, viz: tallow, beef or sheep, 1 pound; tanner's oil, IJ pounds; beeswax, 3 ounces; castor oil, 4 ounces. The leather is then again tightly folded and put into a close Vjox and allowed to remain 48 hours. The same dubbing, composed of the above ingredients just mentioned, is stuffed on the grain side for wax finish, and the same again applied on the flesh side for grain finish, pure tanner's oil being used for this side. For the finish, or blacking for wax finish, take lampblack, one pound, and apply dubbing again on the grain side. The follow- ing ingredients are mixed with those herein above described, viz : beef gall, 1 ; India rubber, IJ ounces. Oil enough is added to make the same of the proper consistency. The rubber must not be dissolved in alcohol or spirits of turpentine, as it will injure the leather, but cut into strips and ignited, and the oil collected therefrom used. In the dubbing this will make a fine finish. The ingredients herein described, and as combined in the manner in which they are used and applied in the process of tanning, constitute Sponhouse's water-proof composition for TAN PRESSES. 507. leather. The composition is applied the same as other blacking to a boot or shoe, and will not only give a fine polish to it, but keep it soft and pliable, so as to make it easy for the foot. Section IV. Improvements in Tan Presses. In the present state of knowledge on the subject it may ap- pear idle to speak of the economy of a tan-press over drying the spent tan in the sun, or on the top of a boiler, or having it carted away as waste. By means of an elevator, consisting of buckets on an endless belt, the spent tan is taken from some convenient depository near the vats to a bin above the tan-press ; it feeds itself through, and is from there deposited in front of the boiler, where it is ready to be burned, thereby saving all labor except the little of getting the tan to the place where it is first taken up by the elevator. Thus there is obtained a good fuel convenient for use at almost no cost. Fig. 229. The furnaces in sole-leather tanneries are usually so con- structed as to burn wet spent tan ; but in upper-leather tanneries the material has to be treated so as to have it as dry as possible. The tan-press shown in Fig. 229 is manufactured by the estate of Charles Holmes, Boston, Mass., in two sizes, one size having 36 inch rollers and the other 28 inch rollers, the speed being about 165 revolutions per minute. This machine will 508 THE MANUFACTURE OF LEATHER. press from 15 to 18 cords of spent tan in ten hours, witli three horse power, and leave the material sufficiently dry for fuel. Fig. 230 shows a perspective view of the W. K. Daniels tan- press, which is manufactured in Salem, Mass. This press is made in two sizes, the smaller of which will press eight cords of spent tan in ten hours, and the larger, twelve cords. Fis. 230. Fig. 231 is a central vertical longitudinal section of the tan press invented by Thomas F. Weston, of Salem, Mass., and which is commonly known as the " Salem Tan Press." Fig. 232 is a front view of the forward rollers of the same. The gearing and driving-wheels are not shown in the draw- ings, as any arrangement of well-known mechanism may be adopted for rotating the several rollers as desired. A represents the frame of a machine, having on each side a forward, upright, slotted, or open standard, B, provided with suitable boxes, or otherwise arranged to receive and allow the rotation of the axles or ends of an upper pressure-roller, (7, and an under delivery-roller, D, provided with suitable gearing or other mechanism for rotating them in contrary directions with eath other. Provided with suitable gearing, or otherwise arranged to rotate in the same direction with the delivery-roller Z), is a feed-roller, .£/, the ends or axles of which turn in boxes connected with the sides of the machine. The roller J5'is located TAN PEESSES. 509 at a sufficient distance in the rear of and below the forward pres- sure-roller C to leave adequate space to receive the tan, and at Fiff. 231. Fig. 232. a sufficient distance from the upper rear portion of the delivery- roller Z), and rotating in the same direction with it is a supple- 510 THE MANUFACTURE OF LEATHER. mentary smaller roller F; between each roller i'^ and the pressure- roller G is left a sufficient space for the passage of the tan. The space between the feed and delivery rollers being filled bj the supplementary roller F prevents the falling through of the tan or other material, which is assisted in its passage and pressed against the pressure-roller G by the rotation of the roller F^ which is arranged to turn in the machine, and is provided with a gear-wheel meshing with the gearing operating the feed- roller E^ or otherwise provided with suitable mechanism for rotating it in the same direction with the said roller E. The gearing or other operating mechanism may be arranged to be actuated by steam or other motive power. The pressure-roller (7 is arranged to have a vertical movement in the standards B^ regulated by rubber or other suitable springs Q^ adjusted by screws ZT turning in the heads of the standards B ; or the pres- sure-roller G may be otherwise arranged, as desired, to have a yielding bearing or movement, or to be adjusted to admit of its operation on different thickness of material or matter. Any or all of the rollers may be corrugated or plain on the periphery, as desired. Z is a driving-shaft, and J a shaft carrying gear- wheels meshing with suitable gearing, operating the several rollers to carry the same in the direction required. The pressure-roller C is formed at each end with a lip, c, curv- ing up from the periphery of the roller to the rim of the lip, as shown, to close the space between the rollers G and D at the ends, and compress the tan or other material at the corners of the roller, so as to fill up the same and prevent the passage of liquid at these points, which passage is otherwise often apt to occur, owing to the tan not properly filling in at the ends of, as it feeds to, the roller. The operation of this machine is as follows : Power being applied to revolve the rollers, the tan is deposited at the top between the pressure-roller G and feed-roller E^ and carried between them, forming a sheet, which is taken by the supple- mentary roller F^ and carried along and against the pressure- roller (7, which presses it upon the feed-roller E^ between which rollers it is passed and delivered from the machine through a hopper, or into a receptacle, or as desired, comparatively freed GEAIISr SPLIT AND BUFFED LEATHERS. 511 of liquid, the supplementary roller F^ turning snugly between the rollers E D^ preventing the passage of the tan between the rollers, and assisting in its passage and pressure, and the lipped formation of the roller ends c preventing the back passage of the liquid, as will be readily seen by the above description, and on examination of the drawings without further explanation. The liquid expressed from the tan flows downward between the small roller F and rollers E D into a suitable receptacle, the narrow space between said rollers allowing the passage of the liquid, but not of the tan. CHAPTBE XXX. GRAIN, SPLIT, AND BUFFED LEATHERS — TANNING AND FINISHING GRAIN SPLIT AND BUFFED LEATHERS — COMPOUNDS FOR PRO- DUCING IMITATION OF GRAIN AND MOROCCO LEATHER. Section I. Tanning and Finishing Grain, Split, and Buffed Leathers. The above varieties of leather are produced in large quan- tities in this country, "Woburn, Mass., being one of the chief centres for their manufacture. The bark used at that place is hemlock, and is derived from Canada ; the sumach employed is both imported and native. The hides used are chiefly green salted, and are obtained from St. Louis, Mo., Cleveland, Dayton, and Cincinnati, Ohio. Boston, Mass., and other points in New England furnish a few hides, but the supply from the latter sources is small. The hides used for the varieties of leather under consideration are " buff hides," i. e., those obtained from cows, heifers, and steers, and weigh about 50 lbs. each. The first step in preparing them for the tanning liquor is to place the hides in the " soaks" of clear, cold well water, and here they usually remain for four days. 512 THE MANUFACTURE OF LEATHER. After being removed from the soaks, the hides are split into sides in the same manner as has been described for heavy upper leather, and after being split the sides are placed in the " limes," where they remain for six days, being reeled into a vat of stronger lime each day. The sides are next unhaired, which is accomplished both by the hand and -machine process, one hundred sides being a day's work for one man by the first method, while eight hundred sides of leather can be unhaired by two men in one day of'ten hours by the machine method. When unhaired by machinery the sides are passed through a McDonald or other suitable unhairing machine, and are then, by some large manufacturers of these varieties of leather, thrown into a vat containing sulphuric ac'd diluted with water, from which they are immediately dipped out by an oscillating framework of wood, the time which the sides remain in this dilute sulphuric acid bath being not longer than one minute. The sides are then passed through a second McDonald or other suitable unhairing machine, and any hair that may still remain upon the edges is dressed off' on a beam with an unhairing knife by a workman. In this way eight hundred sides are unhaired in a day, and the wages of six workmen are saved. The unhairing machines are fully explained and illustrated in Chapter XVI. When the sides are unhaired in this manner by machinery and subjected to the dilute sulphuric acid bath, as soon as they are dressed off" by hand at the unhairing beam, they are thrown into a vat containing clear, cold, spring water. After remaining in this cold water for a short time, the sides are removed, and tacked to sticks and placed in the " handlers." This seems to be pushing things a little too rapidly, but the method is pursued by some of the largest manufacturers of buffed leather in the State of Massachusetts, who appear to have difficulty in making sufficient leather to meet the demands of their trade, while other manufacturers, who give more care to the stock which they produce, find it difficult in competing for a market. There is no doubt that a much larger quantity of lime is GRAESr SPLIT AISTD BUFFED LEATHERS. 513 removed from the sides by passing them through the unhairing machines, which also scoar the sides, than conld possibly be re- moved by hand. Whether it is good policy to hasten the pre- paration of the side by the method which has been described, is of course not the province of this volume to decide, and should be settled by each tanner to his own satisfaction, taking indi- vidual experiences as a guide. Our large home consumption of leather and our constantly increasing export trade make it imperative to take advantage of every oportunity to hasten the production and lessen the price of this material, when it can be done without serious in- jury to the quality. If the method of unhairing by machinery and then subjecting the sides to a bath of sulphuric acid diluted with water, and then placing the side in cold water as described, answers all the requirements, then we think no objections should be urged against it. But to return to the point of divergence : After the sides are iinhaired by the hand process they are placed in a bate of hen manure in which they remain from twelve to thirty-six hours, but when the sides are worked in the bate with the England wheel shown in Fig. 112, the bating can be accomplished in six to eight hours, the time depending upon the weight of the hide and other circumstances, the object of the bate being to fully neutralize the lime, thereby allowing a smoother finish' to be applied to the leather. After being removed from the bate the sides are allowed to remain over night in a vat of clear, cold spring water, and are tacked to sticks and suspended in the '' handlers" containing hemlock liquor, which is increased from about 6° strength at the start to 12° strength at the finish. The sides are treated in these handler vats for about twenty-four days, being shifted every third day into stronger liquor. After being removed from the sticks they are hung over poles and dried in the open air, as shown in Fig. 226, and are next carried into the shop and skived usually by a belt- knife machine shown in Figs. 132 to 135 ; one man being enabled by means of a machine of this character to skive 400 sides in one day of ten hours. After being "fitted" or trimmed on a table 33 514 THE MANUFACTUEE OF LEATHEE. with an ordinary shoe knife they are next " split" usually by the same kind of belt-knife machine which has been mentioned. Two men will split 400 sides in one day of ten hours. About 4| ounce grain to the square foot is usually taken off the side in splitting it. The " split" is then trimmed by hand, and placed back in liquor of about 8° strength, which is gradually increased, and remains for from twelve to fifteen days. The part from which the " split" is taken, called the " grain," is shaved on a beam with a currier's knife in order to make the side of uniform thickness. One man will shave from 60 to 70 sides in a day, the number depending upon their size and con- dition. They are then " milled" with sumach liquor for about one hour in a revolving drum, which is commonly about seven feet in diameter. The sides are then placed in sumach liquor of about 8° strength, which is gradually increased, and remain for about sixteen days. For these leathers the American and Sicily sumachs are not mixed, as for Morocco leather, but are usnally employed separately. After being removed from the liquor they are next scoured, which is done either by hand or machinery ; if done by hand they are placed on a slate table, as shown in Fig. 137, and scoured first on the flesh, and then on the grain side. The tools used in this operation are the ordinary scouring brush, slicker, and stone, and by this method one man will scour fifty sides in a day. After being scoured, they are hung over poles and exposed to the air to harden, and are. then carried to the shop and stuffed in a revolving drum, such as has been explained and illustrated in Chapter XXII.; the operation of stuffing lasting for about fif- teen or twenty minutes. Fish oils, paraphine, oleine, and rosin are employed in the stuffing compound used for the "grains," and tallow, fish oils, and rosin for stuffing the " splits." The sides are next " set out," and after that are carried to the finishing-room and blacked on the grain side with a preparation GRAIN" SPLIT AND BUFFED LEATHEES. 515 of logwood and copperas for the " grains," lampblack and soap being used for the " splits." The "splits" are immediately "glassed" on a machine such as is shown in Fig. 199, and then placed on a horse for convenience of moving to the hanging up hooks, as shown in Fig. 228. One boy of nineteen or twenty years of age will glass six hundred " splits" per day. The " splits" are next " pasted" with a preparation of flour paste placed on the top of the blacking on the grain side. They are then hung up in the finishing-room and allowed to dry over night, and in the morning are reglassed, and are then immediately finished by gumming them over with gum traga- canth dissolved to about the consistency of jelly. Sometimes a preparation of fish oil and rosin is applied, which application depends upon the softness of the leather after being gummed. The " splits" are then assorted for different weights, and are measured and rolled up, ready for market. Finishing Grain Leather. The "grains" having been blacked, as has been described, are hung up in the finishing-room and dried, after which, if the Fig. 233. side is to be "pebbled," it is carried to the "jack" and pebbled on the grain side, after which it is grained on the grain side with an armboard shown in Fig. 243. The sides are next pol- 516 THE MANUFACTURE OF LEATHER. ished on the same side bj means of a revolving wheel ; the pattern shown in Fig. 233 being largely used for this purpose. After being polished, the sides are again grained with the arm board, and immediately oiled with a mixture offish oil and paraffine, and then measured for market. In graining " pebbles," the sides are " cut" four ways, the same as for Morocco leather. The " straight grains" are finished in the same manner as the "pebbles," except that a different roller is used in the "jacking machine," and in graining they are "cut" only from one direction. Finishing Buffed Leather. After the leather has been scoured either by hand or machin- ery, it is then hung on poles in the open air to harden, after which it is "set out" on the grain side with a stone so as to make it solid^ and free it from the grain, and it is then stuffed. This variety of leather is often stuffed by hand, and it is per- formed by laying the side of leather on a table, flesh side up, as shown in Fig. 137, and working over it with a steel slicker, after which a preparation of fish oil and tallow is applied with a brush to the flesh side. The sides are then hung up in the loft to dry, being placed on sticks in tiers, and in this manner they remain suspended usually for about three days. The superfluous grease is then removed from the flesh side by means of a slicker ; but sometimes this operation is per- formed by a machine, which is called by the curriers a " grease jack," and is shown in Fig. 164. The leather is now in condition for buffing, which, when done by hand, is performed by placing the side on a slanting table covered with leather, and removing the grain by means of a whitening or buffing slicker, which is shown in Fig. 165. One man will buff from fifty to seventy sides of leather per day, the number varying with the condition of the leather and the skill of the workman. The machines used for whitening and buffing leather are shown in Chapter XXIII. In order to improve the appearance of the edges, the sides after being buffed are next trimmed around with a common shoe knife. They are then placed on a flat table, fifty sides being piled GRAIN SPLIT AND BUFFED LEATHERS. 517 one on top of another with the grain up, and the batcli is then blackened with a composition of logwood and water boiled together, which is rubbed into the leather with an ordinary blacking brush, samples of which are shown in Figs. 18-t and 185, or the sides may be blackened by machinery. After the pack has been thus treated the sides are then blackened with another compound of irou rust and copperas. The sides are then replaced upon the table, flesh to flesh, and are, then "smutted," which operation is performed usually by working over the blacking with a woollen cloth in order to remove dirt and sediment, and improve the appearance of the blacking. Bryant's machine for " smutting" leather is shown in Figs. 196 and 197. The leather is next glassed in order to make it " fine" and remove all the creases, and. when the glassing is done by hand the side is placed on a table and the blacked portion worked over with a glass slicker. The sides are then hung up in the finishing-room for a short time, and then "pasted," which is an application of flour paste over the blacking, and commonly put on by means of a sponge. After being thoroughly dried, the sides are "soft-boarded" by working them with the flesh side up, and one man will soften about one hundred sides per day. The leather is then laid upon a table and slicked off clean on the flesh side, and then immediately glassed on the grain side, after which it is gummed with a preparation of gum traga- canth made of about the consistency of jelly, and applied over the paste. The sides, after being hung up and dried, are then assorted, measured, marked, and bundled, and the buffed leather is then ready for market. 618 THE MANUFACTURE OF LEATHER. CHAPTEE XXXI. GERMAN HARNESS LEATHER — VACHE-LEATHER — MACHINE BELT LEATHER GREASED WITH TALLOW. Green hides, if possible, are used for these varieties. As many hides as can be placed in the lime pit are, after cutting out the horns, soaked in running water six to eight hours with frequent rinsing, next cleansed from dung and placed in weak milk of lime for twenty-four hours. They are then taken out and replaced, after preparing fresh lime, for twenty -four hours more, when they are again handled. After this they are regu- larly handled. Depilation is eftected as soon as the hair can be easily pulled out, after which the hides are soaked in water for a few hours. Water-stripes and dots are produced by soaking the hides too long in running water, and allowing them to re- main stationary. After fleshing and soaking for twenty-four hours the hides are smoothed and placed in the bate for one to three days, according to their thickness and the state of the weather. They are handled three times everyday they remain in the bate. If the England wheel shown in Fig. 112 is em- ployed the bating can be accomplished in from eight to ten hours. Special attention should be paid to this process, as soft leather can only be produced by proper bating, while too much bating is injurious, as it destroys the skin fibres and the grain. After taking the hides from the bate and rinsing in fresh water they are again smoothed, and after soaking for several hours thoroughly worked upon the flesh side with a dull fleshing knife. They are then ready for tanning. Salted hides of cows and oxen are soaked three days, special attention being paid to remove all the salt before placing the hides in the lime pit. Dried hides after thorough soaking and bringing them back to their original shape by stretching, are GEEMAjS" haeness leathee. 519 treated in the same manner as green hides. By using the hide mill described in Chapter XIV,, much labor in stretching and smoothing may be saved, and for inferior hides, slicking also. The handling vats should be sufficiently large to allow of the convenient handling of the hides. It is generally preferred to place the leather in old liquor for one or two days, according to the quality of the liquor in the vat. The leathers are taken out and replaced and treated in the same manner as above, after ladling out the old tan and adding one third bushel of fresh tan. According to the state of the weather the power of the tan will be exhausted in four to eight days, it then becoming necessary to freshen the vats. After doing this twice or three times more the leathers are placed in the lay-aways, where they remain for about the same period as for sole leather, a longer period being as a general rule only required for stout harness and vache-leatlier, but it is absolutely necessary for belt leather. In order to see how far tanning has proceeded it is advisable to split the leathers after the second layer. The cut of a thor- oughly tanned hide will be uniformly brown, while a pale yel- low or white coloring is a proof of insufficient tanning. After splitting the hides into sides and numbering the two halves with the same number, the completely tanned leather is rinsed in old ooze and smoothed with a dull fleshing knife upon the beam. Where all three kinds of leather are made, the best hides are used for harness leather, the strongest for belt leather, and the poorest for vache-leather. The harness leather is gone over with a fine-edged knife and then greased upon the flesh side with a mixture of linseed oil and tallow, and hung up to dry. Yache-leather is also greased but only slightly upon the grain side and then dried. Preparation of Y ache- Leather . The dried hides are soaked in sufficient well-water to cover them in a vat, handled after an hour, then replaced and allowed to soak over night. The next day they are placed upon a wooden table, and after tucking in the hoofs rolled up grain side 520 THE MANUFACTURE OF LEATHER. in from the head to the tail, so that every half hide forms a roll. The rolls are tied together with strong twine or leather straps so that they will not become unrolled in the succeeding beating with fluted wooden mallets, which is continued until the hide feels soft to the touch. To soften them completely they are boarded, after beating, upon the grain side with a coarse graining board. After work- ing ten or twelve hides in this manner a thin shaving is taken from the flesh side. The best plan is to have two workmen perform the above operations and also the succeeding ones. In tanneries provided with a fulling mill a higher degree of sup- pleness can be imparted to vache-hides by fulling than is possi- ble by beating and boarding with the graining board. One-half of the hide is then placed upon a somewhat inclined table of wood, slate, or zinc, as shown in Fig. 137, as long as the hide and as wide as one-half the hide, and scrubbed with brushes constantly dipped in water until the flesh side acquires a mushy condition, which can be recognized by the impressions made by passing the fingers over the hide remaining visible. It is then turned over and, after placing the back part in a straight line with the edge of the table and passing the hand over the hide so that it sticks to the table, the grain side is treated in the same manner. The slicker is then driven first along the back to prevent the wrinkles which are formed from sticking, and then in the direc- tion from the back to the fore-hoof. After removing the wrinkles, which is absolutely necessary, more force may be used for the removal of tan depressions. As soon as one half of the hide is slickered it is immediately hung up in the drying loft. If this is higher than the length ot the hide, the latter is nailed through the hind hoof and root of the tail to short strong sticks, or incisions are made in these places, and after passing through the sticks the latter are placed between two poles. If the loft is not very high, the back part of the hide is nailed to straight strong poles, which after tying the front and hind hoofs with twine in such a manner that they cannot hang down and form wrinkles, are placed in the pole-rack. GERMAN HARNESS LEATHER. 521 After the hides are partly dry, they are phiced separately upon the table and, after wetting slightly such parts as have become too dry, one hide is placed above the other and the pile repacked. The hides moistened first are then replaced upon the table and after fitting the back exactly to the edge of the table it is fastened with a few wooden clamps, the impressions of which are removed later on. To remove all tan depressions and to give the leather a beau- tiful appearance and firm touch, the use of a roller is of great advantage, especially as it facilitates the currying and prevents the grain from being injured hy constant working. The tan impressions, etc., are then entirely removed, and after rubbing with a moist woollen rag the sides are stamped and hung up. Before the hides become entirely dry the halves are fitted together according to the numbers and placed grain side upon grain side and hide upon hide until a pile is formed, which is covered with planks somewhat loaded. After remaining here for twelve hours they are hung across poles and gradually dried. Each hide is then rolled up sepa- rately and about six placed in one bundle, which is secured with twine. It is scarcely necessary for us to say that scrupulous cleanliness must prevail during all these operations. By strictly following the directions given, an article fulfilling all demands will be the result, and one which is not only equal to the best Frankfurt vache-leather, but in most cases surpasses it as regards beauty and quality. After the harness leather has passed through all the above operations it is sorted into brown and black. The first acquires lustre by means of a glassing machine, or is sold without it. The black leather after grounding with decoction of logwood is blacked with iron black and, when nearly dry, passed through the press. The best qualities of light hides from Buenos Ayres, Monte- video, and Texas may also be used for vache-leather. The lime used for hides intended for vache-leather and inside sole leather is sometimes mixed with red arsenic. This has a better ef!'ect 522 THE MANUFACTURE OF LEATHER. upon the hide, also softening hard places found in these hides which are always dif&cult to soften. In using this mixture the hides require more frequent handling than in the ordinary liming process, and should be depilated as soon as possible. As the hides are not raised by the mixture it may also be recom- mended to subject them to the ordinary liming for a day after taking them from the arsenic and lime liquor. This method of liming can also be advantageously employed in preparing green hides and kips for upper leather, but the after-liming must ,be continued for a correspondingly longer time. Machine Belt Leather greased with Tallow. By greasing with tallow this leather acquires the desirable property of not becoming hard even if the belt cut from it has to pass, as is frequently the case, through water. This leather is tanned in the same manner as has been described for sole leather, complete tanning being the principal requisite. After dividing the hides into sides and rinsing off the tan, the sides are scoured either by hand or machinery so as to pre- pare them for the reception of the tallow. The sides are then treated differently from the leather that is to be used for uppers of boots and shoes, in that it is not dampened and tempered, as has been described for heavy upper leather. Bat the sides after being scoured are dried in heat ; in summer by spread- ing them out and exposing them to the direct rays of the sun, and in winter in a room having a temperature of at least 110° F. Pure tallow, best ox tallow, is melted in the meanwhile in a portable boiler, a temperature of 167° F. being the best for the purpose. This temperature should be kept up after the tallow is melted, which can be effected by keeping the boiler over a small coal-fire or, still better, by placing it in another boiler with hot water, which is kept hot over a fire while the work is going on. One of the heated sides is then placed upon the table and the fluid tallow applied with a brush. The hide sliould be so thoroughly saturated with the tallow as to be entirely permeated with it, and the tallow applied to the flesh side become visible GERMAN HARNESS LEATHER. 523 upon the grain side. Should the tallow congeal upon the sur- face before permeating, it is allowed to soak in by placing the hide in the sun or near a warm stove, but if the hide is already thoroughly permeated, the excess of tallow must be removed. Currying the Tallowed Leather. The sides having lost their good appearance and become dark by greasing with tallow, are soaked in water for twenty-four hours and then placed upon the beam, and the tallow still adher- ing to the flesh side removed with a blunt knife. After placing them again in water, each side is taken out separately, and after spreading it upon the table and covering with a layer of spent tan one-half inch thick, it is rolled up, and the roll, after secur- ing it with twine, beaten with a mallet, until the leather has again acquired a light color and its original suppleness. After rinsing off the tan the hides are again beaten, with frequent dipping in water in case they should feel too dry. They are next smoothed in the same manner as for the ordinary machine belt leather. It is recommended to have two men to do the work, it being too fatiguing for one. The manufacture of this variety of leather, though very laborious, repays doubly the work expended upon it, principally by the increased weight the leather acquires by the absorption of tallow. 52-i THE MANUFACTURE OF LEATHER. CHAPTEE XXXII. MOROCCO LEATHERS. Section I. Tanning- and Finishing Imitation of French Kid, Brushed Kid, Straight Grained Gtoat, Pebbled Goat, and Oiled Goat. By Morocco leather we understand that soft, pliable material so largely employed in the manufacture of the uppers of ladies' and children's shoes, and gentlemen's low cut shoes, and which also finds various secondary employments, such as bindings for books, linings for travelling bags, toilet cases, pocket books, etc. The finer grades of Morocco leather are produced from goat- skins, but an inferior quality is obtained from sheepskins, and split calf-skins. The usual commercial classification of Morocco leather, pro- duced in this country, is : — Imitation of French kid. Pebbles. Brushed kid. Straight-grained goat. ' Oiled goat. Caracal, or straight calf. Pony-glazed kid. Siamang. Glazed kid. The goat-skins employed in this country for the manufacture of Morocco leather, are classed as follows, and rank according to their position in the list : — Curacoa. Russians. South Americans. Capes. Madras. Arabians. Tampico. Macedonians, Patnas. Angoras. Mochas. Albanians. Kassan. Magadores. be = H MOROCCO LEATHERS. 525 Glove-calf and glove-sheep are also sub-names for Morocco leather, and are used principally for toppings for button, laced, and congress boots for ladies' and gentlemen's wear. Sometimes shoes for elderly gentlemen and ladies have the uppers made entirely of these leathers, which are desirable for this purpose, being soft and comfortable to the feet. When glove-calf and glove sheep are kept dry they continue soft, but when frequently wetted the tannin is drawn from the leather, which renders it hard and liable to crack. A large portion of the skins used in this country for the manufacture of glove-calf and glove-sheep ^re produced in the CJnited States; but South America and Russia also send us large quantities. The imitation French kid made in this country will remain pliable under continued wetting much longer than the genuine French kid. The tanning material usually employed for all the stock which has been mentioned is sumach, which is used in the proportion of about one-half Sicily or imported, and one-half Virginia or native. The process of preparing the skins for the reception of the tannin is about the same for all the stock that has been named. Preparing the Shins. When the dry skins are removed from the bales, they are placed in the " soaks," which are vats containing clear cold water, and remain for from three to five days, the period of course depending upon the condition of the skins, the hardest requiring a longer soaking than those that are softer. From the " soaks" the skins are removed either with hooks or tongs, and placed, usually 150 to 200 at one time, in the "pin- mill," which softening contrivance has been described on page 250, and when sufficiently softened the skins are next placed in the " limes." Fig. 234 shows a view of the lime-vats, in a Morocco tannery, and over one of the pits is shown a pile of skins which have been removed therefrom and placed upon planks to drain, while in the background is shown the " wash wheel." Above each lime-vat there is a small blackboard upon which are marked in 526 THE MANUFACTURE OF LEATHER. chalk the number and kind of skins in each vat and the date on which thej were put in. In large Morocco tanneries usually 1350 South American goat-skins are limed at the same time, and about 600 glove- calf, and 800 glove-sheep are placed in separate vats at once. The goatskins remain in the " limes" about 14 days, glove- calf 12 days, and glove-sheep 8 days. They then go to the unhairing beams and are unhaired by hand, and one man will " unhair, flesh, and slick" about eigb-ty skins per day. Fig. 235. After being unhaired the skins are placed in a mill and thoroughly washed to free them from adhering lime, and are MOROCCO LEATHERS. 527 next placed in the slightly heated bate of dog or pigeon manure, in which they remain over night. Upon removal from the bate the skins are " slated," which is the removal of the fine hair remaining upon the skins after the unhairing operation. The "slater" is a tool closely resembling a " slicker ;" but the edge of the " slater" is ground sharp. The skins are now passed into the bran drench, which is com- posed of bran and water, slightly heated, and in this they remain over night, and are then in condition to be sewed together. The sewing is usually performed on heavy chain stitch sewing machines, operated by women, who are paid at the rate of about ten cents per dozen skins. The usual form of machine employed is represented in Fig. 235, and it is made to sew either way, being one thus adapted to all classes of sewers ; it is strong, and thoroughly fitted for the hard and dirty work to which it is subjected, and may be run by foot or steam power. The skins are sewed in the form of a bag, the only opening left being one at the end of the hind shanks, which is to allow the spigots on the sides of the tan-tubs to enter and thus force the tannin into the interior of the bag. Tanning. The skins are sewed grain side out, and when placed in the tannin liquor the shanks are placed over the spigots, the skins tied to them with twine, and the liquor forced into the skins with a gentle pressure by means of a pump. The vats are filled with sumach liquor in which the skins are submerged, and three hours is usually sufficient time to complete the tanning. When it is desired to hasten the tanning process, the pressure from the pump is increased. Fig. 236 shows a view of the tan-tubs in a Morocco factory, and Figs. 287 and 238 show the manner in which the skins are attached to the spigots and a method by which the skin-baos are filled with the sumach liquor. The invention shown in Figs. 237 and 228 is that of John Gr. Baker, of Wilmington, Del., and it consists of a vat or tank with a feeding-pipe leading into a horizontal pipe at one end of the 528 THE MANUFACTURE OF LEATHER. tan-tub, connecting at each end with another pipe or tube pro- vided with cocks or spigots, set at regular intervals, to the noz- Fiff. 237. zles of which, facing the centre of the tan-tubs, are fastened by tying, the skin-bags to be tanned, so that the liquor will flow Fis. 238. into and suspend them in the liquor contained in the tub while under a pressure in combination with the tan-tub and its stand- pipe. MOKOCCO LEATHEES. 529 By this invention it is sought to provide an improved mode of filling and pressing sheep and goat skins while being tanned without their coming in contact with the sides or bottom of the tub or with each other. It is a well-known fact that if the skin-bags press against each other or against the tub, they will be but imperfectly tanned, and also that where skins are suspended by their necks in a vertical position their weight when distended causes them to break or tear away from the nozzle. In Figs. 237 and 238, A is the tan-tub ; B is the tube attached to the walls of the tub, and connecting with the feed-pipe ; G is the feed or supply-pipe for filling the bags from the vat or tank ; I) is the vat or tank ; E is one of the cocks of the tub, to the nozzle of which the skins are fastened ; and G is the stand-pipe or overflow-pipe to keep the liquor at a uniform height. The reservoir, feed-pipe, and tubes with their cocks are not a new idea, as they are described in the invention of Dr. Alexander Turnbull, of England, who obtained a patent in this country September 26, 1844, and also in the patent issued to Dudley and Brooks of Portland, Me., dated October 23, 1834, But the dif- ferences between both of the plans which have been named and the present one are plainly obvious, as the skins in both of those patents come in contact with each other, or with the floor or walls of the tan-tub. In Turnbull's plan the skins are laid upon the floor of the vat and partly submerged, and require turning, and in the other patent the skins are suspended by their necks, and are but partly submerged, and so hung as to come in contact with each other, while in the present instance they are so arranged and hung to the tubes or pipes, as to render contact almost impossible, and are buoyed up by the liquor. Warner's apparatus for tanning goat and sheep skins is shown in Figs, 244 to 249, and G, C. Walters's filling cup in Figs, 250 to 253, and Halsey's combined vat and wheel in Figs. 255 and 256. The skins are taken from the tan-tubs and when full of liquor are piled one upon the other in open vats provided for the pur- pose at each end of the tanning-tubs, and thus the liquor is 34 530 THE MANUFACTUKE OF LEATHER. gradually pressed oat and passes into a receiver, from whence it is pumped back into the tanning vats. After the liquor has been squeezed out, the bags are removed from the open vats and one end of the thread cut with an ordinary shoe knife, thus allowing the thread to be pulled out at one operation. The skins next go into the England wheel vat, which has been shown in Fig. 112, and are "wheeled" in sumach liquor of about 20° strength, which is the same as in the tanning vats. Striking Out and Drying. The skins are next "struck out" on mahogany tables, which are so shaped as to slant from the workman at an angle of about 45°. A steel " slicker" is used for this operation, and an average workman will " strike out" about 200 skins in ten hours. The object of this operation is to increase the size of the skins, remove the adhering " fleshings," tanning liquors, and water, and render the skins smooth and even, and this is accom- plished in some tanneries by the employment of machinery, shown in Pigs. 257 to 261. The skins after being "struck out" are hung up in the drying lofts and dried by the atmosphere ; the time required for this depending upon the condition of the weather. Fig. 239 shows the drying loft in a Morocco factory, the skins being hung on hooks which are shown on the racks placed at a convenient height from the floor. When sufficiently dry the skins are removed from the hooks and carried to a room on the same floor as the loft, and there assorted according to the kind of leather into which they are to be finished. This important point having been decided upon, the skins are removed to the cellar and wetted down in soap-water, and while wet the skins are carried to a currier's beam and shaved with a currier's knife on the flesh side, so as to make them of a uniform thickness, and also for the purpose of having them receive a better finish. From this point all the skins pass to the finishing-room, and as each kind of Morocco leather requires a different treatment. ►^ (n ^ ■ MOROCCO LEATHEES. 531 we will now describe each separate mode of finishing the various kinds. Finishing Imitation of French Kid. This class of leather has taken a high rank in our countiy, and it is now generally conceded to be much superior to the genuine French kid for wear. The skins, after being treated as above described, are carried to the coloring table and colored on the grain side, with an iron and nutgall-black having a logwood body which gives a clear and bright black, and after being blacked the skins are hung up in the loft. The skins, after the first blacking has dried, next pass into the finishing-room, and the second application of black is made, which is similar to the first, with the exception of the nutgalls, which are omitted ; bichromate of potash is some- times used in this black, but in small quantities. After this second application of color, the skins are hung upon racks in the finishing-room, and left until the color sets or dries, the blackened side being turned inward, as shown in Fig. 240, which shows a perspective view of the blacking tables and an interior perspective view of the finishing room. After being removed from the hooks they are next moistened with a solution of milk and water, and are then ready to be glazed, which operation is performed by machines of various constructions, and which have been heretofore explained in Chapter XXYI. Knox's machine, shown in Fig. 211, is much used for glazing this variety of Morocco. The skins are next softened by hand with a board and scraper, or, as it is termed, a " softening slicker." They are then oiled with the best sperm oil, which is applied with a rolled-up flannel cloth. The skins are glazed two or three times as the case requires, the oil is applied twice, and after the last application the imita- tion French kid is ready for market. In selecting skins for the production of this class of leather, their weight is regulated by the demands of the trade, at times being light, and at others heavy. The skins are also selected for their cutting qualities, those which are free from blemishes 532 THE MANUFACTURE OF LEATHER. or breaks being, of course, more valuable than those that are scratched. Finishing Brushed Kid. The finishers take the South American goat- skins from the shaving-beams and " put them out," and each man will put out and black five dozen per day, and after being thus treated they are hung in the loft and dried by the atmosphere. The skins are blacked and seasoned with the same prepara- tion of bullock's blood, iron, and vinegar black which is applied with a piece of flannel cloth made into a roll. They are then wet over with gum-water and brushed with a very soft brush, called a "kid-brush." After being hung ia the loft and dried, the skins are next "back-boarded," then glassed, and next rolled by a machine having a steel roller. The Knox machine shown in Fig. 211 is commonly used for glassing and rolling. The finisher takes the skins from the rolling machine and scrapes them with a steel slicker in order to loosen up the flesh, after which the grain side is oiled with the best sperm oil, which is applied by means of a roll of flannel cloth. The brushed kid is now completed and ready for market. Finishing Straight- Grained Goat. The first step after shaving in finishing this variety of Morocco is the " putting- out," which is performed by working over both sides of the skin with a steel slicker. This portion of the work is sometimes accomplished by machinery, such as is shown in Figs. 257 to 261. When done by hand about five dozen large skins or nine dozen small ones are put out by a skillful workman in one day. The skins thus treated in the morning are placed in the loft, and in the afternoon they are " put out the second way," which consists in smoothing the grain side. They are drawn oui and the stretch removed in the first operation. When the skins are placed in the loft they are spread out separately on the floor, as shown in Fig. 2-41, and are not allowed to become too dry, and in the afternoon when they are " set out the second time," no water issues from them. After being set MOROCCO LEATHERS. 533 out the second time thej are returned to the loft and placed on trestles, which are about two feet six inches high, and they re- main in this loft until dry, the period of course depending upon the state of the weather. The day's work of each man is kept separate from that of the others, and each workman hangs up his own day's work of skins, one on each hook, and so placed that none of them touch each other. When dry the skins are packed in piles, those that are in- tended to be stained on the flesh side being separated from those that are to be pebbled. They are next carried to the finishing-room and the rough part of the grained side is smoothed off with a piece of fine emery paper, rolled so as to expose the length of the paper to the skin. This portion of the work is sometimes accomplished by machinery; a revolving emery stone, such as is used in the manufacture of kid gloves, being employed, the dust being blown from the stone by a suitable fan. The skins are next seasoned, which is accomplished by coating them with a preparation of bullock's blood, logwood boiled, cow's milk, water, and a small quantity of vinegar black, made by treating iron with vinegar, one gill of the latter preparation being used for a bucketful of " seasoning," which quantity will season above five dozen straight-grained goat-skins. After the seasoning has dried they are regularly blacked and hung up in the finishing- room, as shown in Fig. 240, and after remaining on the hooks for about one and one-half hours, or until the dampness leaves the skins, they are rolled by machinery ; the machine shown in Fig. 211 being largely used for this purpose. After being rolled the skins are again hung up in the finishing- room and remain over night, and in the morning they are glazed on a machine having a glass roller, the one shown in Figs. 204 and 209 being much used for this purpose. The number of skins rolled or glazed is from 30 to 50 dozen per day for each machine, depending upon the speed at which the machine is driven and also upon the size of the skins and quality of the work. Some are glazed lighter than others, in 584 THE MANUFACTURE OF LEATHER. order to give a medium gloss, but when a high gloss is desired, extra pressure is applied. Fig. 242 shows a perspective view of the portion of the finishing-room in which the skins are being rolled and glazed. After the skins are glazed they are wetted in cold water by passing them through a large tub holding about 50 gallons, and the workman in accomplishing this takes two of them and places them grain to grain, and grasping hold of the butt of the skins draws them slowly towards him. They are next grained, which may be performed either by hand or machinery ; if done by hand, a graining board similar to that shown in Fig. 242 is employed. Fig. 243. These graining boards are made with a cork face, and in using them the arm passes through the strap and the hands grasp the handle. The object in using this tool is to raise the grain and to make the straight-grained goat-skins more durable, and also has the effect of rendering them more pliable as well as tougher. The skins are again hung in the loft usually above the finishing-room and dried by the atmosphere, which requires from 24 to 48 hours, according to the state of the weather. After this drying they are again grained, which has the tendency to raise the figure and further mellowing them. All the graining is done on the grain side ; but after the second graining they are " back-boarded" on the flesh side, which has a tendency to make the figure more uniform as well as to still further soften the skins. An application of best sperm oil to the grain side of the skins w oq S iTi MOROCCO LEATHERS. 535 completes the finishing of straight-grained goat, and as the oil is immediately absorbed by the pores, the skins are at once ready for market. From the time that they enter the finishing shop to the time that the straight-grained goat is ready for market, the period is about seven to ten days, being shortest in good drying weather and longest when the condition of the atmosphere is not favor- able. There is also a grade of Morocco leather known as " cara- cal," which is straight-grained calf, and its peculiarities are pliability, toughness, gloss, and superior finish. This leather has a fancy finish, and its introduction into the trade has been but to a limited extent. Finishing Pehhle- Grain Goat. The difference in finishing pebble-grain goat from that of straight-grained is that the first named is "cut" four ways in the process of hand-finishing, in the softening, and in the " spring- ing up ;" but in " back-boarding" it is cut two ways only. The skins are pebbled on the same machine, but not with the same roller that is used for straight graining. Finishing Oil Goat. In finishing " oil goat," after the skins have been " put out the second way" and blacked, they are then stuffed with dubbing on the flesh side. The dubbing is composed of one-half oil and one-half tallow when used during the winter time ; but in the summer more tallow than oil is used. They are then hung up to dry, after which they are grained three ways and then treated to a coat of dubbing on the grain side, after which they are flattened down on the grain side with a dull slicker, and after being treated with a coat of fine sperm oil which completes the finishing, the oil goat-skins are then measured and marked ready for the trade. This class of Morocco leather is more water-proof than the other grades, and is used for ladies' heavy wear, and sometimes boys' boots are made from it. The heaviest skins are used for this kind of leather, and the kinds commonly employed are Tampico, Capes, and Patnas, 536 THE MANUFACTURE OF LEATHER. Section II. Tanning Apparatuses for Goat and Sheep-Skins. Warnerh Aj^jjayntus. The apparatus shown in Figs. 244: to 249 for tanning goat and sheep-skins is known as Warner's Apparatus, and was invented in 1870 by William Y. Warner and James Crooks, of Wilmington, Del., and the fittings for it may be obtained from G. W. Baker, Wilmington, Del. Fig. 244. The first part consists in the combination of a feeding-trough for containing tanning-liquor, filling-hose with funnel-connec- tions, and valved ends, a gauge-box with slides for feeding tan- ning-materials into the skins or hides, operated by means of a rod and spring, having attached to it a tapering pipe, which receives the tanuing-material in its passage into the skins, and a smaller pipe, which leads the water from the liquor-feeding trough into this tapering pipe. MOKOCCO LEATHERS. 537 The object is to obviate tlie necessity of using a funnel and dipper in- the filling of the skins with tanning-material and Yisr. 245, Fig. 246. 538 THE MA^SrUFACTURE OF LEATHER. liquor, and to enable the workman to fill both at the same time, without waste. ' The second part consists of a valve, which is applied to the month or opening of the skin which retains the liquor, when distended or filled. The object of this is to dispense with the troublesome pro- cess of tying and untying the mouths or necks of the skins, in filling, and, at the same time, retaining the tanning-material. Fiff. 247. Fia-. 248. Fig. 249. Figure 244 is a front view of a machine embodying Warner and Crooks's invention ; Fig. 245 an end view ; Fig. 246 a longi- tudinal section ; Fig. 247, a section of the valve in the hose ; Fig. 248, a vertical transverse section, showing the end of the machine, which is at the right hand in Fig. 244 ; and Fig. 249 is a section through the centre of the gauge-box and its slides. MOROCCO LEATHERS. 539 A is tlie feeding-trough, wliicli is attached to the joists of the floor above the workman's head. B is the filling-hose, with funnel-head Cand valve D attached. -E' is the gauge-box with its slides S S, operated by means of the rod X and spring Y, for regulating the quantity of tanning- material used. F is the tapering pipe, through which the material passes into the skins. G is the pipe which carries the tanning-liquor from the feeding-trough A into the tapering pipe F, for the purpose of forcins; the tannino;:-material into the skins or hides. H is the valve, which is fastened to the mouth of each skin or hide. /is the bin for holding the sumach, or tanning-material. ^is the tan-tab, in which the skins are filled, and from which the liquor is pumped back into the feeding trough A, when re- quired. The skins to be tanned, after sewing, have the valve IT at- tached. The liquor is pumped from the tan-tub K into the trough A, which runs the whole length of the tan-tub. The sumach, or other tanning-material, is fed from the bin / through the gauge-box F. In filling, the skins or hides are taken to the tapering pipe F, the end of which is inserted in the mouth or neck of the skin, forcing open the valve H. The slides S S, in the gauge-box jE', are pulled forward, the tanning-material descends, the valves S S closing instantly, while the liquor which is constantly run- ning through the small pipe G, washes all into the skin, which is then removed, and passed to the workman stationed in charge of the filling-hose i?, who brings the mouth of the skin under the valved end of the hose, which forces up the valve D^ and the skin is entirely filled. Here, the operation is complete, and the skins or hides remain in the tan-tub until it becomes neces- sary to refill them. Walters' s Filling- Cup for Morocco Manufacturers. The filling-cup for Morocco manufacturers shown in Figs. 250 to 253 was invented in 1881 by George C. Walters of 540 THE MANUFACTURE OF LEATHER. Philadelpliia, Pa,, and the invention consists in the novel con- struction and arrangement of a valved cup having a valve-seat above the valve, an outwardly projecting extension, to which an extension on the rubber or other flexible valve is secured by screws driven outwardly from below at angles of about seventy degrees to the plane of the valve, and an encircling flange at the bottom of the cup, whereby the leg of the skin may be securely attached to the cup. The skins are first sewed in the ordinary manner at the edges, as has already been described, and the valved cup applied to an opening in the end of one of the legs of the skin by tying the cup therein. The old form of valve consisted of a circular cup with an outward projection in its inner edge or opening, around which the skin was tied. The valve rested on the outer surface of the inner edge of the cup and extended to the extreme edge. This construction permitted the valve to be dragged open when it came in contact with anything while handling the filled skins, and permitted the liquor to escape, which accident resulted in only partially tanning the skins. In the old form the projection to which the valve was attached was on the inner side of the cup. This construction lessened the opening in the cup, caused clogging, and produced an overflow of the filling material, which could only be replaced by guess-work. The screws were also passed through the valve at right angles to its horizontal plane, whereby it did not bear with suf&cient force on the edge of the cup when the skins were partially emptied, and from that cause the liquor would escape. By Walters's construction it is claimed that these objections are removed, as, in the first place, the valve is seated within the cup and cannot be displaced by accident in handling the filled skins; and, secondly, the projections on the cup and the valve in connection with the inclined screws, hold the valve more firmly, and the interior periphery of the cup is not obstructed, and is therefore not liable to clog, either during the filling or the emptying of the skin. A funnel is inserted into the cup and secured during the filling operation, and the sumach is placed therein, and a stream or drip of water from above falls thereon and produces a tanning-mixture of about the consistency MOEOCCO LEATHERS. 541 of cream. After filling, the funnel is withdrawn and the valve closed. The skins may then be piled for storage. Figure 250 is a representation of a perspective view of Walters's device. Fig. 251 is a bottom view. Fig. 252 is a sectional view, and Fig. 253 is a vertical section as applied. FiV. 250. Fig. 251. Fis. 252. FiR. 253. A designates the cup, of metal or other suitable material, having the valve-seat B at its lower edge, as shown. iV desig- nates a flanged projection entirely surrounding the cup, whereby the skin may be securely attached to the cup, and G the out- wardly-projecting extension, having the outwardly-inclined threaded holes a a for the reception of the screws Z>, which secure the valve D in place in its seat. The valve D is prefer- ably of rubber, and has an extension, ^, corresponding in shape to the extension C, to which it is secured by screws /), washers c being interposed between the valve and the screw-heads. Hayid Method of Tanning Morocco. In many of the small Morocco tanneries the skin bags are tilled with sumach liquor, as shown in Fig. 254, and after being inflated with the breath are tied with strings and made to float 542 THE MANUFACTURE OF LEATHER. in sumacTi Jiquor by constantly agitating them so as to facilitate the action of the tanning material. Fi?. 254. The process is repeated until the skins are tanned, when the bags are removed from the tub and piled upon one another and left to press and drain. After this the skins are unstitched and rinsed, then scraped lightly on the beam and hung in the drying loft. Tanning Morocco in a Combined Wheel and Vat. The apparatus shown in Figs. 255 and 256 was invented in 1883 by D. Halsey, Jr., of Newark, N. J. In the use of sumach in tanning goat-skins and Morocco, as has been explained in this chapter, the skins are commonly sewed up and the liquor and ground sumach placed inside of them, and are then placed in contact with the same substances in a tan-vat. By the use of this wheel the sumach is kept suspended in the liquor in the desired manner, and the skins are turned over and over in contact therewith, so as to produce satisfactory results, both in regard to the time consumed and the quality of the work per- formed. The sumach, however, settles to the bottom of the vat when the motion of the wheel ceases, and to remove it con- veniently the vat is constructed above ground and provided with the door J/, shown in Fig. 255, at the bottom for the con- venient removal and rinsing out of the sediment. Fig. 255 is a transverse section of this wheel and vat on the line x x in Fig. 256, the latter being a plan. MOKOCCO LEATHERS. 543 A is the vat; B the wheel; C a gear of ring form secured to the periphery of the wheel at one edge ; I) a door for the Fig. 255, Fig. 256. M-K insertion and removal of the hides from the wheel ; IE a pinion for driving the wheel, and F a shaft mounted in bearings G above the wheel, and provided with a pulley, H^ to receive a driving-belt, /. 544 THE MANUFACTURE OF LEATHER. The wheel is mounted by gudgeons e/in bearings K^ which are secured upon posts fastened to the sides of the vat at a suita- ble distance to make the bottom of the wheel clear the floor of the vat. L L are cleats fastened to the inside of the wheel's rim to move the hides, and J/ is a door in the side of the vat, near the bottom. iVis a clutch provided upon the shaft, in connection with the pinion E^ to stop and start the wheel at pleasure. The clutch would be moved by a handle, as is usual, and enables the opera- tor to disconnect any one of several tumbling-wheels, if more than one be driven by the shaft F. is a fastening for one end of the door D^ the other end being held in place by inserting it under the iron ring-gear C. P P are holes formed in the sides of the wheel for the free circulation of the tanning-liquor, so that the contents of the wheel will not be retained in contact with the same fluid con- tinuously ; but an automatic exchange of the fluids in the wheel and the tank will be effected by the movement of the wheel. The operation of the apparatus is as follows : About six feet in diameter- is considered a convenient size for the wheel, and the skins are placed in the wheel and rotated in the tan-liquor about three to six revolutions per minute by the application of suitable power to the shaft F. The skins, when stirred by the movement of the wheel, tend to float more or less in the liquor, and are constantly moved about in a current created by the movement of the Avheel. The liquor outside the wheel is raised a little by its contact Avith the periphery of the latter at one side, and correspondingly depressed at the opposite side, where the wheel's rim is descending, thus producing a change of level in the liquor at the front and rear of the tank. The liquor in- side the wheel is similarly affected, and thus tends to flow from the apertures P at one part of the wheel and into the apertures at another part, thus securing the circulation desired. When the operation is continued a suitable length of time, the door is opened and the skins are removed. The tan-liquor may be removed from the vat either before or after the removal of the skins, as preferred, and fresh liquor MOEOCCO LEATHEES. 545 may be furnished to tbe vat, without stopping the wheel, by drawing off a portion of the spent liquor at a time and supply- ing an equal amount of fresh. Section" III. Putting-out Machines for Morocco. The work of '' putting out" goat and sheep-skins in the pro- cess of manufacturing Morocco leather is commonly done by hand ; but during the past few years machines have been in- vented for this purpose that are steadily coming into use. The skin is "put out" after being taken out of the tanning- vat, and previous to being hung up to dry. The object is to press out the water and tanning liquor, and to scrape off the small pieces of flesh or other imperfections that adhere to the flesh side of the skin, and to render the grain side smooth and otherwise to improve its appearance. Mg. 257 shows a perspective view of Vaughn's machine for "putting out" skins, and it also claims to do other work, such as unhairing, fleshing, scouring, and "setting out" hides and skins. This machine is patented in all the principal countries. The machine is very efficient, and it leaves the skins dry, even smooth, and in a most desirable condition. Necks, butts, and shanks are also put out by it in a better manner than it is possible to perform the work by hand. The measurement of nearly all skins put out by this machine is increased fully live per cent, over hand work. Hoffman's Putting-out Machine is shown in detail in Figs. 258 to 261. It is a cheaper machine than the one shown in Fig. 257, and it may be used for goat, sheep, or calf-skins. Figure 258 is a back view of Hoffman's machine. Fig. 259 a side elevation, showing a portion of one of the pulleys broken away, so as to expose the pinion and spur-wheel on the other side of it. Fig. 260 is a cross-section through the machine, and Fig. 261 is a front elevation of the machine complete. The frame a of the machine is constructed of wood ; a' is the putting-out cylinder, provided with the spiral blades a^. The cylinder a' is usually made of wood, and the spiral blades are of thin strips of brass rigidly secured thereto. They are arranged, 35 546 THE MANUFACTUKE OF LEATHER. as shown, to meet near the centre of the cylinder, so that the spirals on each side rim in opposite directions. The object of Fiff. 257. this is to cause the skins to be stretched each way during the operation of the machine. This cylinder is provided with jour- nals a^ a\ arranged in boxes made in any well-known way. The driving-pulley a^ (see Fig. 259) is connected directly to the journal or shaft a*, and consequently with the cylinder. MOKOCCO LEATHERS. 5i7 a^ represents a small pulley rigidly secured to the journal or shaft a^. This pulley is connected by a belt, Z>, to a larger Fig. 258. pulley, v. On the shaft of the pulley S' is secured a. smaller pulley, h^^ from which a belt, If^ passes to the pulley ¥. On the 548 THE MANUFACTUEE OF LEATHER. inside of the pulley ¥ is a pinion, />°, which gears into a spur- wheel, W, which is connected to the shaft c of the wooden roller c'. (See Fig. 260.) Fiff. 260. Fig. 261. MOROCCO LEATHEES. 549 The object of the belts is to give a much slower motion to the roller c' than the motion of the cylinder a\ the motion of the cylinder being about three hundred and fifty revolutions, and the motion of the roller c' about twenty-five. On the inside of the frame is a pinion, c^, near either one or both sides of the frame. It is connected to the shaft of the roller c', and turns with it. (? represents a roller made of some yielding material — India- rubber for instance. This roller is mounted in boxes in the slotted arms c*, which are connected to the arms c^ by means of a bolt and nut, the bolt passing through the slots ,c° into the arms c^, so that the roller may be thereby rigidly secured to the arms and be capable of an adj ustment to or from them. The arms & are rigidly fastened to the shaft c?, which shaft is mounted in boxes d' . The boxes d' are set in place (see Figs. 259 and 260) so as to be capable of a movement up or down, and are kept down by a spiral or other spring, d^. The roller c' is made of a hard wood, and is secured in boxes in the frame. (See Figs. 259 and 260.) d^ represents a slotted arm secured to the arm e® by means of a bolt, a^, which passes through the slot d^. It will be seen that this arm is made adjustable. Its object is to secure the adjustment of the roller c^ to or from the putting-out cylinder, after which it is rigidly secured in place by the bolt d'^. There are two arms, c' — one at each side of the machine. At the outer ends of the arms is jointed by a pin, e, in the usual way, a con- necting-rod, e' — -one on each arm. The opposite ends of these connecting-rods are secured in a similar way by pins ^ to the arms e^ of the foot-step e^ The arms ^ are connected to a shaft e^ A counter-weight, /, on the shaft e' causes the foot-step to rise after the pressure of the foot is taken off of it. In operating the machine the skin is thrown over the roller & and the rollers started slightly by hand, until the skin is far enough in to be caught between the rollers & and c' . A pressure on the foot-step then brings the two rollers together, and still greater pressure brings the roller c^ and the skin against the cylinder by lifting the box d' up against the spring d^ ; this cylinder revolves rapidly and cleans off the small pieces of 550 THE MANUFACTUEE OF LEATHER. fiesli or other matter adhering to the skin. It also takes out the wrinkles or other imperfections, and stretches the skin both ways, as above mentioned, so as to leave it smooth and clear. This operation finishes one-half of the skin. It is then taken out and the opposite end treated in the same way, thereby com- pleting it. By this arrangement the skin is first gripped firmly between the rollers c' c^, which hold it and cause it to move with the required speed. By increasing the pressure slightly on the foot-step the roller c^ is brought toward the putting-out cylinder, and the skin is brought in contact with it, and is slowly carried past it, moving in a direction contrary to the movement of the putting-out cylinder. One advantage in thus being able to first bring the rollers c' & together is that it enables the operator to wring out the water from the skin, if at any time necessary, before bringing the skin in contact with the putting- out cylinder, which is often necessary on account of holes in the skin. It will also be noticed that as the rollers c' c^are brought together the wheels c^ g are brought into gear, and as the roller g' is continually turning it thereby imparts its movements to the roller c^ until released from it. The skin being put over the roller c^ is always in sight, and thereby enables the operator to let off the pressure of the skin from the putting-out cylinder when coming to a hole or a spot on the skin that may be tearing. List of all Patents for Putting-Out Machines, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Residence. 274,858) Mar. 27, 1883. J.W.Vaughn, Peabody, Mass. 274,859) 288,941 Nov. 20, 1883. W. M. Hoffman, Leather Flirffing and Grounding Machines. No. Date. Inventor. Residence. 235,249 Dec. 7, 1880. J. M. Jones, Wrexham, N. Wales, Great Britain. MOEOCCO LEATHERS. 551 List of all Patents for Machines for Evening or Making Leather of Uniform Thickness, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Residence. 69,219 Sept. 24, 1867. W. C. Joslin, West Thompson, Conn, 147,770 Feb. 24, 1874. C. Handy and C. E. Morrill, 152,811 July 7, 1874. J. Pu.llman and J. R. Edmonds, Wonercli, England. 270,964 Jan. 23, 1883. J. D. McDonald, Woburn, Mass. Section IV. Compounds for producing Imitation of Grain or Morocco Leather. This invention, wliich is that of Mr. Hugh Smith, Newark, N. J., consists in producing from split or buffed leather an imitation of grain leather or Morocco, made from any kind of skins or hides, by the use of certain compounds ; the first consists of glue, one-quarter to one pound, dissolved in one gallon of water, and boiled, after which is added thereto one- quarter to one pound of starch or flour, and the whole mixture is again allowed to boil, after which aniline colors or paints of any kind may be added ; also, use from one to four pounds of glycerine or other fatty substance, and mix therewith any desired colors of paints to correspond with the colors of the dyes. The whole is mixed together. Of this compound one or more coats may be used previous to graining or pebbling the leather under treatment, the object of which is to fill up the pores, and bind down the fibre or nap on the surface ; and if it is not required to be water-proof, it may be finished with one or more coats of a suitable varnish. The second compound, which is used to make the leather more flexible and water-proof, consists in a syrupy solution 'of the following ingredients, and in about the following pro- portions: One pound of gum-shellac dissolved in two quarts of alcohol, added thereto or used separately ; one pound of India-rubber or other equivalent gum, also dissolved in one gallon of naphtha (the latter should be dissolved in a separate vessel previous to mixing with the former), and adding thereto 552 THE MANUFACTUEE OF LEATHER. a sufficient quantity of glycerine to soften, together with the proper or desired coloring matter. If this mixture should be too thick, it may be reduced by adding wood-alcohol or its chemical equivalent until the desired result is obtained. These compounds are to be applied to the leather in the known manner, and for the purpose of coverings or coatings thereto. The leather is first split or buffed in the ordinary manner, and dyed, if preferred, any desirable color. It is then secured to frames, or spread or sticked out upon a table, preparatory to having the coloring matter and compound applied, which is done with a sponge, brush, swab, or any other suitable device, and well rubbed in upon the surface of the split or buffed side of the leather, one or more coats, either warm or cold, being applied, until a uniform color and smooth surface are produced, which, after being properly dried, is grained, to imitate the natural grain of the leather or Morocco or other design, as the case maybe, the first preparatory coating to be applied previous to the graining or pebbling process. Process for Finishing Lower Grades of Leather similar to Morocco. In preparing leather for market, metallic salts have been used, and with other chemical compounds and dyes been made to combine with the substance of the leather for the purpose of rendering the material impervious to moisture, and thus to strengthen the fibre and give it a suitable color and finish for the various manufacturing purposes. The fibre of leather not being readily absorbent of compounds containing metallic salts, the beneficial effect of the treatment has been confined to skins or leather of the higher grades of quality only. The material has been found not to retain permanently the metallic salts or color of the dye, and is liable to exude. The metallic salts and coloring-matter thus injure the appearance of the leather, caus- ing the color to fade and the leather to crack, thus rendering the usual methods objectionable on account of the higher grade of skins it is applicable to and the want of permanence in finish. The object of the present method is to provide a process for finishing leather which will render the fibre of the leather of MOROCCO LEATHERS. 553 all grades more absorbent of the chemical compounds and dyes, and will also set and retain the color and the metallic bases of the compounds used, and give a durable finish to leather of all grades, and make the lowest grades susceptible of a finish equal to Morocco leather. The process consists in the previous use of a certain prepara- tory solution and dyeing compounds, in combination with a secondary and a perfecting compound applied and used in the manner and order and composed of the ingredients as will be described, one essential requisite of this process being that the treatment shall be followed strictly in the order here designated. For the first part of this process, after the leather has been tanned and shaved in the ordinary way, saturate with a liquid compound composed of a hot solution of logwood made by boil- ing ten pounds of logwood-chips in forty-five gallons of water until reduced to twenty-five gallons, which is designated the "preparatory solution." Second, the leather is then put on tables for stretching and taking the water out, then hung up and partially dried. Third, sammy it, then put out on the tables the second time. Fourth, if it is Morocco and required to be straight-grained or pebbled, do so by the use of an arm-board or machinery. Fifth, it is then blackened by the use of a liquid compound composed of a solution of iron, vinegar, and animal- blood, either warm or coagulated, made by suspending eight pounds of iron in forty gallons of vinegar, thirty grains test, for three weeks; and to one quart of this solution add half a pint of animal-blood, either warm or coagulated, and this appli- cation is sometimes repeated ; then hang up the skins and allow them to dry ; or the leather may be blackened by dyeing in trays, by saturating with a liquid compound composed as follows: Say copperas, one pound ; nitrate of iron, one pound; verdigris, one-half pound ; chromate of potash, two ounces ; Sicily sumach, two pounds ; soda-ash, one-fourth pound ; pulverized nut-galls, two pounds ; water, forty gallons. To color leather bufi' and grain it, add to this last solution four ounces of animal-blood to the quart, and put it on with brush or sponge on the table. Sixth, if a bright finish is desired, glaze with the glazing- machine or on the table with a glass or flint. If a dull finish 554 THE MANUFACTURE OF LEATHER. is desired do not glaze, but brush on the face with a brush. Seventh, soften on the table by use of board or slicker. Eighth, oil the face of the leather, after which the process is continued as follows : — For the second part of this process use a chemical compound which consists of, say one part of dry gelatine (isinglass or other like substance) dissolved in four parts of oil, including a small quantity of sulphuric or other acid, and when these are combined by means of heat, five parts, or thereabout, of an alka- line solution of caustic soda are added at a specific gravitj^ of about 26° Baume, the whole being stirred while yet warm, and the result is a chemical combination which is designated the " secondary compound." For the third part of the process iise a chemical compound which is designated the " perfecting compound," and which is prepared as follows: In one vessel is prepared a strong solution of one of the alums — for instance, of the sulphate of alumina — with potassa or either ammonia or soda as equivalent. In another vessel is prepared a solution of the sulphate of zinc, and in a third vessel a solution of the acetate of lead. These solutions are each to be of the same density. When prepared the two sulphate solutions are mixed in the proportions of about five parts of the first to one and a half parts of the latter, and to these are added about five and a half parts of the acetate-of-lead solution. By the chemical action that ensues sulphate of lead is formed, and when this has subsided the clear liquid is drawn off and is reduced to the proper density, which is 1° to 2° Baume. The manner of continuing the treatment of leather to be finished is as follows : A bath is prepared with, say half an ounce of the secondary compound dissolved in two gallons of hot water — that is, in about these proportions. This is used when cold. To treat leather the patentees, Moses B. Tice and Nicholas O'Connell, steep it in this bath till endued with its properties and then drain it. When the leather has been re- moved from the bath of the secondary compound and is well drained, they steep it in a bath of the perfecting compound, where it remains from eight to twelve hours, and when well TANNING AND FINISHING SHEEP-SKINS. 555 drained it is gradually dried, wliicli completes the "finishing process. After the finishing process is thus complete the leather is again softened by use of board or slicker, then oiled to bring the color out and make it soft and pliable, and properly prepared and ready for manufacturing purposes. This finishing process gives to leather of all grades a satin finish which is very durable. The preparatory solution, by being first applied, and then the liquid compounds for coloring being afterward applied, fasten the color at once, and there is not required so much of coloring- matter as heretofore used, which is beneficial to the leather, for the reason that the less coloring-matter used the stronger is the leather, and by thus coloring before using the other finishing compound, which has not heretofore been done, the color is fastened, and will not fade or come out. CHAPTER XXXIII. TANNING AND FINISHING SHEEP-SKINS. Section I. Tanning and Finishing Sheep-Skin Fleshers FOE Linings, Binders, and Skivers. The manufacture of sheep-skins into linings, bindings, and skivers, for use in the production of boots and shoes of all grades, is an important one. In this country the majority of the sheep-skins used for this purpose are consumed in the State of Massachusetts, the large production of boots and shoes at Lynn and other places in that State creating the demand for this class of leather. The sheep-skins used are both domestic and foreign ; those derived from Great Britain are mostly " sheep-skin fleshers," and are treated with vitriol before shipment to preserve them. 556 THE MANUFACTURE OF LEATHER. The materials used for tanning this variety of leather are usually hemlock bark, sumach, and alum. These skins are finished in all colors ; hemlock is used for colors darker than its own, sumach is employed for white and fancy colors, and alum mostly for those that are to be dyed black. The compounds and machines employed for depilating and pulling wool from sheep-skins have been explained in Chapters XY. and XVI., and machines for splitting them are shown in Chapter XX. The sheep-skin fleshers are split from the sheep-skins while in a state of pelt, and special machines are required for this operation. The processes which we shall first describe are for those skins which arrive at the tannery from foreign countries, split, free from wool and which are green salted. Sometimes these skins are placed in clean water and washed ; but they are not uncommonly removed from the casks in which they were shipped and immediately soaked and placed in the tanning liquor, whether it be hemlock, sumach, or alum. In hemlock and sumach they remain about ten or twelve days, the strength of these liquors being gradually increased every thirty-six hours, and in alum the skins remain for a much shorter time. After being tanned, they are removed from the vats with a hook and piled, and left to drain, as shown in Fig. 263. The skins are then carried to the drying lofts and each one hung upon two hooks, but so placed that the skins do not touch. Fig. 264 shows an interior view of a drying loft in a sheep- skin tannery, with the skins hanging upon hooks to dry. Fig. 262 shows an exterior perspective view of a sheep-skin tannery, and the slat openings into the drying lofts for the free admission of air. After being dried the skins are removed from the hooks in the drying loft, and transferred to the "putting out depart- ment," where they are wetted and tacked to boards used for putting out. After this operation they are again hung up in the loft to dry, and then carried to the "finishing-room" and finished on the machines employed for that purpose, but if they siiii]iiffliiiiiii!iitiiiiii!ii!iiiiiiiii)]]iii)iiii]iiii)]iiiiiiiiiiiiii!)nniiiiiiiniimimiiiiiiiiinminniiiiiini ^imiiiiiiiiiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii •5d 3? = « =1 0, allowing the centre thereof to rest upon the oval upper surface of bar A, and place the wrench head upon the wrist y. Then turn the wrench downward, bringing the two arms of the joint toward or beyond a right angle, thereby increasing the distance between the bars A and D. When the skin is suffi,- ciently stretched, place a pin above the bar D in one of the 590 THE MANUFACTUEE OF LEATHER. apertures of the perforated plate, and permit the skin to dry, or be manipulated, as the operator may see fit. The hides are allowed to become perfectly dry on the frames before applying the compositions which are to finish the patent, japanned or enamelled leather. The first operation consists in treating the. hide to a mixture which is. intended to close .as much as possible the pores of the leather and thus obtain a ground ready to receive the varnish. The ground-laying mix- ture may be composed as follows : — White lead . . . . .10 pounds. Litharge . . . . . . 10 pounds. Linseed oil ..... 14 gallons. These materials are boiled together until they are reduced to the consistence of a syrup, and then there is added chalk or ochre, according to circumstances, and the material is then spread upon the hide with a steel tool called a " railike." The frame containing the hide is then placed in the driers with the face side downward as shown in Fig. 287. The driers have coils of steam-pipes arranged on the bottom and around the sides, through which there is a constant circulation of steam when all the racks are filled with frames containing the prepared hides. The steam to each drier is controlled by a suit- able valve, and when it is desired to admit the heat to the drier, the door is placed to the larger front opening, and the valve opened so as to give a temperature of about 80° F. to the interior of the drier, and from this point the heat is gradually increased to 160° F., which is about the greatest heat that the fibres of the leather will stand without injury. Sometimes it is desirable to subject the leather to a greater heat than 160°, and in that Case the fibres are protected by saturating the leather with a solution composed of: — Alum . . . . . . 2 oz. Borax . ... . . 2 oz. Water . . . . . . 1 gallon. The leather is immersed in the above compound for about two hours, and when nearly dry it is stretched in the usual PATENT, JAPANNED, OR ENAMELLED LEATHER. 591 manner on frames, and after japanning, it is placed in the oven as has been described, and the heat can then be gradually increased from about 80° to 230° or 250° F. The borax may be dispensed with if desired, as it is not absolutely necessary to produce the effect ; but is used to pre- vent re-crystallization of the alum. The leather is kept in the driers from six to ten hours, or until the composition is com- pletely matured and the surface perfectly dry. The ground is next rubbed with pumice stone to keep the surface smooth, and is then coated with from three to five layers of linseed oil colored with ivory black, and containing sufficient spirits of turpentine to enable it to flow evenly over the surface. After each application the hide is dried as has been described, ■ " ■■ Fig. 287. and it is after each application except the last one rubbed over with fine tripoli or pumice stone, applied with a piece of flannel. 592 THE MANUFACTUEE OF LEATHER. A varnisli is also used which is composed as follows : — Spirits of turpentine .... 10 lbs. Thick copal varnish . . . . 5 " Asphaltum . . . . . . J lb. Linseed oil . . . . . .10 lbs. The asphaltum can be replaced by an equal quantity of Prussian blue, or ivory-black, according to the finish desired, the one giving a reddish, and the other a blackish tint. The varnish is allowed to remain in the finishing room for fifteen or twenty days before being applied to the surface and is laid on with a brush as shown in Fig. 287, and the room in Avhich the varnishing is conducted is kept dampened and free from dust, similar to a coach-finishing or varnishing room. The variety of leather is not softened or boarded until it is japanned and been perfectly dried ; but in 1871 Franklin S. Merrill, of Boston, Mass., patented a process for boarding the leather while it is wet, by which manner of boarding it is claimed that the japanning is not cracked. Renewing the Surface of Japanned Leather. In 1863 Wm. Hoey patented in England the following com- pound for renewing the surface of japanned leather: Two ounces of paraffine, or rock oil, or a mixture of both in any pro- portion, to which are added one-quarter of a drachm of oil of lavender, one-quarter of a drachm of citrionel essence, and one- half ounce of spirits of ammonia. The mixture is applied lightly to the surface of the leather. Preparing the Cut Surface of Split Leather for Manufacturing Japanned or Enamelled Leather. The common way of buffing the hide or preparing it for japanning or enamelling is either by shaving off" the inequalities with a currying-knife, as explained on p. 586, or by taking of a light bufl&ng with the regular splitting machine. This light buff- ing, when finished, is of little value, bringing from one to three dollars. The way japanned or enamelled leather is often treated is by applying all the coats of the composition to the leather after PATENT, JAPANNED, OR ENAMELLED LEATHER. 593 being tanned, and when perfectly dry on the frames. The naphtha or turpentine in the composition is then absorbed by the dry leather, and it becomes dry and harsh ; but by applying the iEirst coat of the composition when the leather is wet and the pores are filled with tan-ooze, the naphtha or turpentine evapo- rates before the leather becomes dry, and is not absorbed by it, and the leather is left soft and flexible and more easily worked. If a heavy buf&ng be taken off, it leaves the surface fibrous and coarse, and it is necessary to have a smooth surface to finish on — that is, to japan or enamel. Stephen J. Patterson, of Bridgeport, Conn., in 1883 patented the following method for forming an artificial grain on the hide after it has been buffed or split with a regular splitting-machine. This process of treatment applies equally well to light buffings or splits, but is especially adapted to heavy ones by largely increasing their value. Patterson's improvement is as follows : When the split hide comes from the tan-liquor after the tanning operation is com- pleted, it is slicked out on a table and a light coat of oil spread over the surface with a sponge or soft brush. Then it is tacked on a frame, and while still wet the fibre or nap of the freshly- cut surface is brushed down smooth in one direction with a flexi- ble bristle brush (like a shoe-blacking brush, but larger), which simply gives direction to the fibre or nap; and then there is applied, while the hide is still wet, with the same brush or with a sponge, rubbing in the same direction, a coat of composition made from linseed oil boiled down to a jelly and reduced with naphtha or turpentine to the proper consistency. After this application repeat the brushing operation as before. The hide is now left to dry, and when dry the composition holds the fibre or nap in place, and the leather has a smooth surface to japan or enamel. When dry it is finished the same as other japanned or enamelled leather. The hide is not dubbed with a mixture of cod oil and tallow or other grease, as in the ordinary method of preparing heavy leather. For shoes and harness only a light coat of oil is applied as stated. It is buffed or split with the splitting- machine when about one-third tanned. For treatment by this process, Mr. Patterson takes off a heavy 38 594 THE MANUFACTURE OF LEATHER. buffing with the largest size improved "Union Splitting- Machine," shown in Fig. 227, making a buffing about three- fourths the size of the hide. This is thick enough to japan for shoe-leather or similar purposes, and will bring from four to eight dollars when finished. The extra expense will not exceed one per cent, of the cost of the hide. Japanned Leather in hnitation of Alligator Shin. The object of this process, which was patented bj Franklin S. Merritt, of Boston, Mass., in 1871, is to produce japanned leather in imitation of alligator skin. The leather is prepared by the ordinary process of currying for patent or enamelled leather. Afterward it is coated with a composition of linseed oil boiled with driers, viz., litharge, burnt or raw umber, sugar of lead, sulphate of zinc, Prussian or Chi- nese blue, mixed with naphtha, benzine, spirits of turpentine, or camphine, with sufficient lamp or ivory-black to give it color- ing. Fig. 288. / ux vv\^ W^fl^^ W^ ^ ^M\K' §M ^ % Fig. 289. The leather, after being coated with several layers of the composition, each being dried before the next is applied, is rubbed with pumice-stone to give a smooth surface to the coat- Finally the last layer is applied and dried without rubbing ms PATENT, JAPANNED, OR ENAMELLED LEATHER. 595 with pumice-stone, the whole making, thus far, what is usually called " patent or enamelled leather." The leather in this state is next wet sufficiently to soften it to admit of it receiving and retaining the impression of the die or rollers. Next the sheet of leather is passed between rollers or dies, or compressed by the same, so as to emboss it with the required figure or series of convexities. Next it should be softened while wet by " boarding," or by any other mode of effecting such as usually adopted by leather dressers and then dried. Figure 288 represents a face view, and Figure 289 a section of a piece of leather made as described. "When finished it may be used for many purposes in the arts, particularly in the manufacture of hand-satchels, shoes, etc. Substitute for Patent Leather. It has been proposed to make a substitute for patent leather by applying to the surface of the usual split hides employed for patent leather thin sheets of zylonite or a similar substance of a proper color. The zylonite is applied to the leather by dis- solving one side of the sheet in any of the well-known solvents and subjecting the same to pressure by passing the leather with the zylonite between a pair of rollers. A solvent such as collodion is then applied to the exterior surface of the sheet of zylonite, and the leather is progressively passed between a pair of rollers or compressing surfaces in con- tact with a plate of glass until the zylonite will be as finely polished as the surface against which it has been compressed. List of all Patents for Methods for Manrfacturing Enamelled, Japan- ned, and Patent Leathers, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Eesidence. 12,226 Jan. 9, 1855. H. L. Hall, Beverly, Mass. 13,819 Nov. 20, 1855. T. P. Howell and F. L. Blanchard, Newark, N. J. 19,583 Mar. 9, 1858. J. Rose, Newark, N. J. 42,584 May 3, 1864. F. Longhurst and A. L. Murdock, Boston, Mass. 58,733 Oct. 9, 1866. J. L. Newton, Boston, Mass. 70,176 Oct. 29, 1867. J. W. Dawson, Newark, N. J. 596 THE MANUFACTUKE OF LEATHER. No. Date Inventor. Kesidence. 114,586 115,083 282,664 May 9, May 23, Ang. 7, 1871. ]S71. 1883. } F. S. s. J. Merritt, Patterson, Boston, Mass. Bridgeport, Conn 289,241 Nov. 27, 1883 J. B. Edson, Adams, Mass. List of all Patents for Apparatus for Stretching Leather, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. 'So. Date. Inventor. Residence. 22,893 Feb. 8, 1859. A. W. Roberts, Hartford, Conn. 28,271 May 15, 1860. J. H. Haskell, Baltimore, Md. 59,292 Oct. 30, 1866. W. Strevell, Jersey City, N. J. 66,131 Jnue 25, 1867. " Reissues • J. W. Danson, Newark, N. J. 2,790 Oct. 29, 1867. 2,791 Oct. 29, 1867. . 66,565 July 9, 1867. V. Colvin, Albany, N. Y. 67,431 Aug. 6, 1867. T. P. Howell and C. P. Oliver, Newark, N. J. 67,996 Aug. 20, 1867. A. Marsli, Newark, N. J. 69,327 Oct. 1, 1867. W. Dunn, Newark, N. J. 69,630 Oct. 8, 1867. J. F. Coburn, 69,633 Oct. 8, ]867. J. F. Connelly and W. B. Hugbes, Newark, N. J. 77,615 May 5, 1868. T. P. Howell and C. P. Oliver, Newark, N. J. 82,063 Sept. 15, 1868. W. R. Andrews and R. Dingwell, Newark, N. J. 88,697 April 6, 1869. H. Danson, Baltimore, Md. 123,979 Feb. 17, 1872 . • Reissue S. D. Castle, Bridgeport, Conn. 6,252 .Jan. 26, 1875. J 135,836 Feb. 11, 1873. C. P. Oliver, Newark, N. J. 154,073 Ang. 11, 1874. C. P. Oliver, Newark, N. J. 178,36] June 6, 1876. W. Coupe, Soutb Attleborongh, Mass 184,352 Nov. 14, 1876. J. N. DuSy, Newark, N. J. 190,693 May 15, 1877. J. Sbarp, Cincinnati, 0. 207,508 Aug. 27, 1878. H. N. Dodge, Brooklyn, N. Y. 213,323 Mar. 18, 1879. Wm. Coupe, Attleborongh, Mass. 215,640 May 20, 1879. J. H. Leddy, Newark, N. J. 240,095 Apri 112, 1881. Wm. Coupe, South Attleborongh, Mass 287,009 Oct. 23, 1883. L. Dederick, Newark, N. J. PAET VIIL CHAPTER XXXIX. TAKNIISTG PROCESSES. A LARGE number of processes have been invented for facili- tating the tanning of leather; but on account of various circum- stances there are only a few that are of value to the tanners of this country. Many of these processes have been patented by persons who are not practical tanners and who possess but a limited knowl- edge of the art in all its branches. A good tanner must be able to judge the result of his work under various conditions. It is often possible to save in the tanning of leather; but if care be not observed the loss in currying and finishing will greatly exceed the gain so made. The fact that a claimed im- provement in tanning methods may have been invented bv a person outside of the business should not, of course, weigh against it. MacBride was not a tanner, but to him we owe the discovery of the use of sulphuric acid for plumping hides, and the same might be said in relation to various other improve- ments. Ninety -nine one-hundredths of all the leather produced in the United States is tanned by one of three methods : First, by placing the hides or sides in vats of ordinary construction with a layer of ground bark between the hides or sides and supplying fresh ground bark and tan-liquor thereto at stated periods; second, by placing the hides, sides, and skins in vats and agitating them gently by appliances that do not injure either the fibre or grain; third, by sewing the skins into bags 598 THE MAN'UFACTURE OF LEATHER. and forcing the tannin-liquor gently through the pores by pressure. In America the cheapness of hemlock and oak bark, bark extracts and native sumach, makes it quite unnecessary to so largely employ imported tanning materials, as is the case in many portions of Europe. All the above methods and materials for tanning leather have been enlarged upon in various portions of this work, and it now simply remains to give a synopsis of processes and materials not heretofore mentioned. Tanning Processes. A process consists of a series of acts performed in a definite and particular order in which each act or step co-operates with the other steps to produce a desired result. In tanning, these acts often consist in immersing the hide in different solutions. Where the substance of the invention consists in a single solu- tion only, the patents will be found under the head of "tanning materials." Where no bark or other tannin-containing sub- stance is used the patent will be found under " tawing," and where the novelty consists only in the apparatus or mechanical devices employed, look under the sub-class apparatus; for in- stance, if it is for facilitating the tanning process by agitating the hides and liquor in the vat, as by the England wheel, see list of patents for tan-vats, agitators, and handling appliances on page 358. Snyder punctures the grain or flesh sides of hides at any time before or after they go into the tan-vats in order to facili- tate the absorption of the tan-liquor, German employs any alkali, neutral salt, or other material that will cause fermentation of the bark so as fully to extract the tannin and allow it to enter into combination with the hide without becoming crystallized. Irving facilitates the absorption of the materials for liming and tanning hides by the application of electricity. HiBBARD, 1, depilates with lime and wood ashes ; 2, employs a composition of salt, sulphuric acid, sumach, oak bark, or any other tannin mixed together in water. Acetate of lead is used TANKING PROCESSES. 599 in the compound employed for tanning white and thin leathers for gloves, linings, binders, etc. This process is also claimed to be applicable to tanning goat-skins, for Morocco. The ingre- dients employed and the proportions in which they are used in this process will be found on page 559. Fulton, after having bated the hides, 1, U:ses2 to 3 pounds of muriate of ammonia and 7 to 10 pounds of nitre dissolved in sufficient water to cover the pack of 20 slaughter hides ; 2, places the hides in weak bark-liquor for one day, or until a fine grain is formed ; 3, places hides in strong liquor for from three to five days, until sufficiently plumped ; 4, lays-away in bark and liquor. Enos, after the sole leather hides have been properly pre- pared, 1, steeps them in a solution composed of 40 pounds of Sicily sumach, or 150 pounds of underground native sumach, in 250 gallons of water, to which are added 25 pounds of salt. 2. The hides after remaining in the first compound, kept at a tem- perature of about blood heat, have the liquor strengthened by 200 gallons of strong oak or hemlock liquor and 15 pounds of salt, and the hides allowed to remain in the strengthened liquor for from twelve to twenty-four hours. 3. The hides are with- drawn from the above liquor and placed in the same quantity of strong, cold oak or hemlock liquor containing 20 pounds of salt in solution, and remain for five or six days. 4. The hides are removed from the cold liquor and placed in same quality and quantity of liquor, except that it is at about a temperature of about blood heat, and in which they remain for about five or six days. The last described operation is repeated for six or seven times, after which it is claimed that the sole leather will be tanned. While passing through the different stages the leather should of course be repeatedly handled. Keeler introduces oil into the tanning-liquor and facilitates its incorporation with the leather, agitating the liquor and leather with the England wheel shown in Fig. 112. Wattles. 1. Depilates with soap combined with salt and lime. 2. Combines soap with the tan-liquor. Gould. 1. Uses a combined solution of catechu and saltpetre. 2. Employs a combined solution of catechu and alum. Other 600 THE MANUFACTURE OF LEATHER. tannin containing materials may be employed in place of catechu. Hatch. 1. Bates the hides in the usual way until the lime is thoroughly worked out. 2. Einses in clean water. 3. Hangs up in a tight smoke-room, butt and neck, grain side out, and smokes in such a manner that the hides do not become heated, upper and collar leather being smoked six hours, other varieties according to the thickness of the hides. 4. Takes them out and soaks one hour in clean water. 5. Puts the hides in tan- ooze of moderate strength, and stirs and handles until the grain is evenly struck through. 6. Increases the strength of the liquor from day to day, and handles until the hides are tanned. To obtain a light color in the terra japonica or hemlock-ooze, adds a little sumach in the first handler in such proportions as | pound per side for upper leather. For heavy leathers, such as harness and sole leather, after being prepared in the usual way it is smoked six hours, then soaked in clear water one hour, then smoked again six hours, and soaked, and put into tan as above described. Daniels. For 20 cowhides : 1. Steeps them, after they have been properly prepared in the beam- house, for one day in 15 pounds of catechu dissolved in sufficient water to cover the hides. 2. Takes out the hides and adds 15 pounds of catechu and 4 ounces of nitre or saltpetre, and in this liquor the hides are replaced and remain from three to five days according to thickness. 3. Prepares another liquor by dissolving 15 pounds of catechu in sufficient water to cover the hides and adds thereto IJ pounds sulphuric acid, which is thoroughly mixed, and in this they remain one day, when it is claimed that they will be tanned. In a later patent, Daniels combines the use of cream of tartar and bicarbonate of soda in making the liquor and using it for tanning. Kennedy makes a composition of 24 pounds of valonia or divi-divi, 8 pounds sulphate of soda, 4 pounds of sulphate of magnesia, or sulphate of potash, 1 pound of sulphate of alumina, 2 pounds of sal-soda (carbonate of soda), 1 pound borax or boracic acid, the ingredients being dissolved separately in hot water or hot decoction of tan-bark, which is preferable. The TANNING PROCESSES. 601 compound is then poured into a tank and thoroughly stirred to form the tanning-liquor, which may be drawn off as desired. The tanning-liquor thus formed is the most concentrated form, and on'ly suitable to be applied to hides in the advance stages of tanning, and must be largely diluted with water or bark-water before it is applied to hides at the commencement of the pro- cess, or else, before applying it to such hides, it should be partly spent by having had hides immersed in it that are in a more advanced state. The liquor is increased in strength as tanning progresses, the hides being handled frequently at first, but less handling will answer as the process advances. Hides intended for sole leather may, near the close of the process, be laid away with layers of ground bark, and then a liquid compound of 3 parts of the composition before mentioned, and 1 part of strong bark liquor poured over them until the hides are covered, and they remain undisturbed for twelve or fifteen days until tanned. Light skins are tanned by simply handling in the liquor. Noble. 100 calf-skins having been previously unhaired and bated, are: 1. Immersed in a preparation of 10 pounds of catechu dissolved in sufficient water to cover them, and kept in motion for two or three hours until well colored. 2. Then adds 10 pounds more of catechu, and allows the skins to remain for fifteen to twenty-four hours, handling occasionally. 3. Removes the skins, and adds to the liquor in the vat 15 pounds of catechu, 10 pounds of sulphate of soda, and 2 pounds common salt, 4. Immerses the skins in the liquor just prepared, and allows them to remain, with the addition of 10 pounds of catechu each day thereafter until tanned, which is usually from five to ten days. 5. Removes from the previous liquor and prepares a new liquor termed the " fixing bath," consisting of water suflScient to cover the skins, to which are added 1 ounce of commercial nitric acid and I ounce of glycerine to every 4 gallons of water. In this mixture the skins are placed and handled frequently for from ten to eighteen hours, or until they assume a bright, suitable color, which may be varied by the time of immersion to suit the fancy. 6. Rinses the skins so as to insure the removal of free acid, when they are dried, and, it is claimed, ready for the currier. 602 THE MANUFACTURE OF LEATHER. The skins during tlie wliole process are handled daily and freely exposed to the air. Heavy hides require more time, but the same relative proportion of the ingredients and order of their use is observed. Garge. After the hides have been unhaired and bated, to tan 100 sides of sole or harness leather : 1. To 300 gallons of water adds 20 pounds sal-soda and 8 pounds common salt. Immerses the sides in the above liquor for forty-eight hours. 2. Places the sides in a liquor composed of 300 gallons of water, 60 pounds of catechu or terra japonica, and 8 pounds of common starch, and in this they remain for two days, the object being to set the grain. 3. Puts them in a liquor composed of 300 gallons of water, 80 pounds of terra japonica or catechu, 8 pounds of starch, and 6 pounds of saltpetre, and in this liquor the sides remain until struck through. 4. Places the sides in a liquor composed of 300 gallons water, 80 pounds catechu, 8 pounds starch, and 10 pounds of alum ; the sides remain in this liquor for about six days, or till entirely filled and suflficientl}'' plumped to be solid and firm. Pag-e employs terra japonica or catechu, 3 parts; sulphate of alumina and potassa or alum, f part ; chloride of sodium, or common salt, 6 parts ; nitrate of potassa or saltpetre, 1 part; sulphate of soda or Glauber's salts, 3 parts. These sev- eral ingredients are separately dissolved in hot water and thor- oughly mixed together in a vat. Water is then added in the proportion of 2| gallons to every pound of catechu when in a dry state. After being prepared in the usual way for tanning, the hides or skins are immersed in this liquor and allowed to remain therein for about forty-eight hours. The strength of the liquor is then increased until it bears the proportion of only 1| gallons of water to each pound of dry catechu, and in this the hides are kept froi;n eight to ten days, according to their relative size and thickness, in which time, it is claimed, they will be thoroughly tanned. 12 pounds of catechu and a proportionate quantity of TANNING PROCESSES. 603 the otlier ingredients of this composition are sufficient to tan half a dozen calfskins, or an equivalent quantity of hides. EoBiNSON makes a terra japonica liquor, which we will call " No. 1," as follows: Puts 112 gallons of water in a suitable kettle heated over a fire, and adds 15 pounds of common terra japonica to it, and stirs until dissolved. Then adds 3 ounces of common sulphuric acid very cautiously, stirring the liquor rapidly. It is dangerous to pour strong sulphuric acid into hot water, therefore the sulphuric acid should be carefully poured in when the water is cold, or otherwise it should be greatly diluted. The acid precipitates the impurities contained in the catechu. The clear liquor is next racked off' from the cooling-tank into a vat (leaving the sediment behind), and is used as follows: For upper leather, add to the quantity of racked-off' liquor, No. 1, described above, about ^ ounce of dissolved carbonate or calcined magnesia and about -^q ounce of sulphate of potassa, and then add as much water as will reduce liquor No. 1 to f its strength, which will be sufficient for 10 good-sized hides. The whole is now stirred up and forms the tanning-liquor No. 2, and the hides are placed in this liquor and are moved frequently for the first two days. Fresh clear liquor No. 1 must always be kept prepared to maintain the strength of the vat-liquor No. 2, in which the hides are being tanned. About 35 gallons of No. 1 liquor and 1 ounce of sulphate of magnesia are added every second day at the early stage of the process, the hides being lifted out to put in the new liquor. The quantity of magnesia sulphate added to the liquor de- pends upon the amount of " plumping" which the hides require, which the practical tanner can judge by inspection. The No. 2 liquor is gradually increased towards the end of the process. At the completion of the tanning process the hides are lifted out of the liquor and treated the same as when tanned by the ordinary process. About 100 skins or 50 calf-skins may be tanned in the same quantity of liquor as for the 10 hides above described. Harness and sole leather are made harder and more firm than upper leather; but the liquor for cow and ox-hides to produce them is made up 604 THE MANUFACTUEE OF LEATHEE. exactly like ISTo. 2 described, and the process conducted in the same manner, with the exception that two ounces of sul- phate of potassa are employed or added to the first liquor which the hide receives. This salt, it is claimed, renders the sole leather hard and firm. The time required to tan harness leather is from four to eight weeks, and from six weeks to three months for sole leather. In making up new vats old liquors are used in place of water when they can be obtained. This method does not quicken the process of tanning, but it is claimed that the leather is made more flexible and durable than leather tanned by the ordinary process. Wyeth makes a soak of soft water, in which are dissolved 1 pound of caustic potash and 2 pounds of sal-soda, which is kept at a temperature of about 100° F., and in this the dry hides are softened. Then breaks flesh in the usual way and works out thoroughly. Next hangs in a suitable sweat-room which is kept at a temperature of about 60° F., and in this apartment the skins remain until the hair comes off easily. They are then unhaired in the usual manner and afterwards subjected to a thorough rinsing in fresh, cold water, and then worked on the beam. The skins are next again suspended in the sweat-room, the temperature of which is still kept at about 60° F., and sub- jected to the steam or vapor which rises from the combustion of equal parts of wet spent tan-bark, damp horse-dung, and damp rotten wood ; this vaporizing process being employed in place of bating the skins, and also to facilitate the tanning. After being vaporized, the skins are again worked thoroughly and then subjected to a compound tan-liquor composed as fol- lows : Steep 510 pounds of hemlock or chestnut-oak bark, 50 pounds of Sicily sumach, 25 pounds divi divi in a sufficient quantity of rain-water to receive 60 sides or 200 calf-skins. In this solution dissolve 5 pounds of alum. While the skins are in this liquor they must be handled frequently, and the strength of the first liquor kept up by the following compound : In a suf- ficient quantity of water dissolve 1 bale of japonica, 20 pounds Glauber's salts, and M pounds common salt, with which TANNING- PROCESSES. 605 strengthen the first tanning-liquor from time to time as re- quired, handling the skins frequently till fully tanned. PiCKARD employs the essence of turpentine with sumach, catechu, or other vegetable or mineral coloring essence for tan- ning hides and skins. Wheelock first soaks the hides or skins in a liquor made of fermented corn-meal, one pound ; common salt, two pounds ; soft water, eight gallons. In this liquor the hides or skins remain until they are soft, and are then placed in the unhairing liquor, which is composed as follows : soft water, eight gallons ; carbonate of soda, one pound; lime, three pounds; leached lye, two quarts. In this liquor the hides or skins remain from two to four days, until the hair slips easily. Then the hair is re- moved and the hide put in a bating-liquor, which is made as follows : soft water, eight gallons ; nitric acid, one- fourth pound ; common salt, one pound. ; corn-meal, one-quart ; hen-manure, two quarts. In this liquor the hides or skins remain from two to four days, until they are reduced to their natural thickness. After the hides or skins have been removed from the bating- liquor place them in the tanning-liquor, which is made as follows : nitric acid, one pound; salts of ammonia, one-fourth pound; common salt, three pounds; fermented corn-meal, two quarts; catechu, three-fourths pound ; sumach, one pound. In this liquor the hides or skins remain for three days (more or less), and then remove them -into the second tanning-liquor, which is composed as follows : soft water, eight gallons ; fermented corn-meal, three quarts; nitric acid, one-half pound; salt of ammonia, one-eighth, pound ; common salt, two pounds; catechu, one pound ; sumach, one and one-half pound ; carbonate of soda, one- fourth pound. In this liquor the hides or skins remain for six days ; then they are washed and scoured with soft water, and after the water has been slicked out as much as possible the hides or skins are stuffed with the following compound : tallow, one pound; straits oil, one pint ; castor oil, one-half pint ; bees- wax, two ounces ; alcohol, one-fourth pint ; corn-starch, one- half pound ; to which may be added, for polish, white glue, two ounces, and sufficient lampblack to produce a good black. 606 • THE MANUFACTURE OF LEATHER. The above quantities are sufficient for tanning one hide or four calf-skins. Kidder's method. To tan 12 hides of upper leather accord- ing to this method, use a sufficient quantity of water to cover the hides. Then dissolve 25 pounds of japonica or gambir. Then add the solution to the water. Then compound 3 quarts of the solution of potash or pearlash (the solution to equal the strength of strong lye) and 1 pound of sulphate of zinc. Dis- solve the zinc first in hot water. Then add the compound to the tanning-liquor. Then the liquor is ready for the hides. Place the hides in the tanning-liquor. Handle them up occa- sionally for two days. Then take them out and renew the liquor by adding 35 pounds of japonica or gambir, dissolved as before, and poured into the liquor. Then compound 3 quarts of the solution of potash or pearlash, 2 pounds of the sul- phate of zinc, 2 pounds of sulphur. Dissolve the sulphate of zinc and sulphur in boiling water before compounding with the alkaline. When compounded, add to the tanning-liquor. Then place the hides in the liquor. Handle them up for -i days ; then take them out and renew the liquor by adding 40 pounds of japonica or gambir, dissolved as before, two quarts of the solu- tion of pearlash or potash, 2 pounds of the sulphate of zinc, 3 pounds of sulphur, IJ pound of sugar of lead, to be dissolved and compounded as before, then added to the tanning-liquor. Then place the hides in the liquor thus compounded, and handle them up occasionally for 5 days, which completes the tanning operation of the 12 hides. Calf-skins, harness, and all other kinds of leather should be treated in quantities of ingredients and time proportionally. To tan with bark, to each cord of bark use two gallons of the solution of potash or pearlash, 5 pounds of sulphate of zinc, 5 pounds of sulphur, and 1| pound of sugar of lead. Before adding the above-named ingredients to the bark-liquor dissolve them in boiling water, then compound them and add them to the bark-liquor. For white-oak bark, double the quantities. Jenkins, for the purpose of liming the raw hides, say forty, takes 1 bushel of lime and 1 pound of potash, upon which he puts sufficient water to cover the hides by the liquor thus made. TANNIlSra PEOCESSES. 607 In this solation they must remain for from two to three days according to circumstances, after which they are removed to undergo the bating process in a solution compounded of 1 peck of stone lime and 4 pounds of sulphur by boiling such ingre- dients in water, enough of the latter being added to make the desired quantity of liquor. After a period of one day or one day and a half the hides are taken out of the bating solution and transferred to the tanning-vat, which contains the tanning com- pounds. The latter is prepared from the following ingredients: Take 20 pounds terra japonica, 5 pounds of wood-acid, 5 pounds of hops, 10 pounds of best sumach, to about 10 barrels of water, or enough of the latter to cover the hides. It is desir- able to subject the hides in the beginning of the tanning pro- cess to a solution somewhat weaker than the above will make. It is preferable to take only about two-thirds of the stated quan- tity of the ingredients above named to the required quantity of water, and add the remaining third as the operation progresses. After the hides have been in this liquor for about fifteen days, the tanning is claimed to be completed, and, after drying, the leather may be finished in any approved manner. Jluemelin's Tan Yat. In the process of tanning hides it is desirable to subject them to a weak liquor first, and gradually to increase the strength of the liquor until the process is completed. In practice, however, it is common to make the liquor of uniform strength, and apply it first at full strength to hides which have been so far advanced in the process as to require liquor of full strength. The liquor, in passing through one vat of hides, is reduced in strength thereby, w^hen it is of the required strength for the next pre- ceding vat. Ruemelin has therefore arranged the vats in a series as shown in Figs. 290 and 291, so that the liquor as it is reduced in strength will flow from the hides which are finished to those which have first been placed in the vats, so that by the time the liquor reaches the green hides, last introduced, it will become sufl&ciently reduced in strength as not to injure them. As the hides in the last vat are finished they are removed, and the hides in the next succeeding vat are moved forward into it, 608 THE MANUFACTURE OF LEATHER. and so on. All the hides in each vat are moved forward one vat at a time, from the first to the last vat in the series, every time a vat is emptied. Fig. 290 represents a vertical section, and 291 a top view of Eaemelin's tan vat. The hides are first Fig. 290. f II Fig. 291. K-- je: ^ JT r .JC K G^ JI ^ ^^ J ^ L^ r^ ^ K J) JT C .J' K JB ^ Jl Li. K placed in vat J., and from thence moved forward to vats BCD E F G H I J. The liquid is first introduced into vat J", from whence it flows from one vat to another, as indicated by the arrows, until it reaches the vat J., the liquor being so reduced in strength b}^ the time it reaches such vat A that it is adapted, as stated, to the condition of the hides in their fresh state. Each vat in the series is provided with a pipe, K^ reaching from its bottom to near its top. The upper ends of the respective pipes project through a closely-fitting hole in the partition between the vats, thus forming a duct through which the liquor passes from one vat to another. As the mouths of the respec- tive pipes extend to near the bottom of the vats, it is obvious that the liquor will rise in the pipe as the vats are filled, and when the liquor reaches the level of the passage through the partition it will commence to flow from the bottom of one vat to the top of the next. The passages through the partitions are formed successively lower from the first, J", to the last, J., so that as the liquor is admitted into the first vat it will gradually find its way to the last, and will, as stated, be caused to pass in at the top and out at the bottom of the respective vats in the series. TANNING- PROCESSES. 609 List of all Patents for Processes for Tanning Leather, issued hy the Government of the United States of America, fi^om 1790 to 1883 inclusive. No. Date Inventor. Residence. 866 Aug. 1, 1838. A. Hickman and E. L. Davenport, Abingdon, Va. 1,018 Nov. 25 1838. T. Chase, New York, N. Y. 1,160 May 30 1839. W. Herapath, Bristol, Great Britain. 1,741 Aug. 25 1840. A. H. Buzzell, Bridgetown, Me. 2,332 Nov. 10 , 1841. S. Guilford, Lebanon, Pa. 2,706 July 8 1842. A. Van Pelt, Bedminster, N. J. 3,614 July 5 1844. J. Cox, Edinburgh, Great Britain. 3,639 July 24 1844. Kettering and Vogle Hempfield, Pa. 3,993 April 10 1845. S. Snyder, Dayton, 0. 4,615 July 2 1846. W. Germar, Easton, Pa. 5,261 Aug. 28 1847. Dr. A. TurnbuU, London, England. 6,373 April 24 1849. E. Irving, New York, N. Y. 6,790 Oct. 16 1849. H. Hibbard, Henrietta, N. Y. 9,406 Nov. 16 1852. D. Kennedy, Reading, Pa. 9,840 July 12 1853. J. J. Fulton, Monongahela City, Pa. 11,325 July IS 1854. R. Enos, Woodstock, 111. 12,148 Jan. 2, 1855. R. Keeler, Rochester, N. Y. 13,443 Aug. 14 1855. 0. B. Wattles, Waddington, N. Y. 14,375 Mar. 4 1856. A. Steers, Medina, N. Y, 14,399 Mar. 11 1856. R. Gould, Whitewater, Wis. 15,157 June 17 , 1856. J. P. Williams, Salem, Mass. 15,303 July 8 1856. S. W. Pingree, Methuen, Mass. 15,736 Sept. 16 1856. G. W. Hatch, Princeton, 111. 15,896 Oct. 14 , 1856. S. W. Pingree, Methuen, Mass. 16,189 Dec. 9 1856. 0. Rich, Cambridge, Mass. 16,355 Jan. 6 1857. E. Daniels, Lafayette, Wis. 17,043 April 14 1857. D. H. Kennedy, New Alexandria, Pa. 17,868 July 28 1857. J. Carle, Kingston Township, Pa. 18,030 Aug. 18 1857. L. L. A. Elie de La Peyrouse, Paris, France. 19,201 Jan. 26 1858. B. G. Noble, Whitewater, Wis. 19,756 Mar. 30 1858. C. Daniels, Elkhorn, Wis. 20,502 July 8 1858. J. Morgan, Sumterville, S. C. 20,565 July 15 1858. H. G. Johnson, Cleveland, 0. 22,285 Dec. 14 1858. W. W. Garge, Rochester, N. Y. 23,360 Mar. 29 1859. T. T. Fergusson, New York, N. Y. 23,471 April 5 1859. H. Johnson, Farmersville, N. Y. 24,278 June 7 1859. J. Brainerd and W. H. Burridge, Cleveland, 0. 25,045 Aug. 9 1859. J. B. Read, Cold Spring, N. Y. 39 610 THE MANUFACTURE OF LEATHER. No. ] Date Inventor. Residence. 25,241 Aug. 30, 1859. J. Brainerd and W. H. Burridge, Cleveland, 0. 25,315 Sept. 6, , 1859. J. Brainerd and W. H. Burridge, Cleveland, 0. 25,522 Sept. 20, 1859. T. S. Page, Milan, 0. 25,671 Oct. 4, 1859. S. Pierce and F. E. Beardsley, Castle Grove, la. 26,966 Jan. 31, 1860. W. D. Bunting, Cleveland, 0. 27,088 , Feb. 7, 1860. P. Daniels, New York, N. Y. 27,177 Feb. 14, 1860. W. R. Webster, New York, N. Y. 27,259 Feb. 21, 1860. C. L. Robinson, Waukesha, Wis. 27,338 Mar. 6, 1860. D. Aldrich, St. Louis, Mo. 27,823 April 10, 1860. D. Needham, Oskaloosa, la. 27,961 April 24, 1860. M. A. Bell, Rushford, N. Y. 29,140 . July 17, 1860. D. J. Cochran, Centreville, Ind. 80,220 Oct. 2, 1860. R. Harper, Turnbull, 0. 30,367 Oct. 9, 1860. J. L. Wells, St. Louis, Mo. 30,390 Oct. 16, 1860. R. Crane, and W. Baldwin, Anamosa, la. 30,392 Oct. 16, 1860. A. Dietz, New York, N. Y. 31,640 Mar. 5, 1861. A. R. Wyette, West Middletown, Pa, 32,526 June 11, 1861. H. McKenzie, Talladega, Ala. 33,183 Sept. 3, 1861. J. Brainerd, Cleveland, 0. 34,005 Dec. 24, 1861. D. Mumma, Mt. Carroll, 111. 34,192 Jan. 21, 1862. M. Benas, New York, N. Y._ 34,688 Mar. 18, 1862. J. J. Johnson, Kalamazoo, Mich. 36,636 Oct. 14, 1862. Z. Baker, Erie, 111. 42,619 May 3, 1864. J. Burrill, Lynn, Mass. 43,013 June 7, 1864. W. Field and J. Townsend, Wilmington, Del. 43,346 June 28, 1864. H. Stratton, Jr., Leavenworth, Kan. 43,563 July 19, 1864. J. S. Boothby, Portland, Me. 48,740 July 11, 1865. W. E. Terry, Wyoming, Wis. 50,222 Oct. 3, 1865. 0. A. Coe, Charleston, S. C. 50,936 Nov. 14, 1865. J. J. Johnson, Kalamazoo, Mich. 50,945 Nov. 14, 1865. J. M. Muller, North Becket, Mass. 51,762 Dec. 26, 1865. W. H. Towers, New York, N. Y. 52,464 Feb. 6, 1866. B. F. Taber, New York, N. Y. 52,655 Feb. 13, 1866. B. Pickard,. Paris, France. 53,688 April [ 3, 1866. J. Scliultz, Ellenville, N. Y. 54,588 May 8, 1866. M. W. Page, Franklin, N. H. 56,643 Oct. 9, 1866. Gr. W. Hernsey, G-reeubush, Wis. 57,275 Aug. 21, 1866. G. Aymard, New York, N. Y. 57,409 Aug. 21, 1866. W. H. Towles, New York, N. Y. 57,795 Sept. 4, 1866. J. N. Sturtevant and H. E. Jones, McGregor, la. 59,109 Oct. 23, 1866. G. D. Wheelock, Freedom, 0. TANNING PROCESSES. 611 mo. Date. Inventor. Residence. 60,006 Nov. 27, 1866. A. Hill, Dubuque, la. 60,108 Not. 27, 1866. J. Wood, Woodstock, Vt. 60,472 Dec. 18, 1866. J. W. Calef, Sudbury, N. H. 60,701 Jan. 1, 1867. J. Davis and J. McKelvy, Pawtucket, R. I. 62,611 Mar. 5, 1867. J. C. Coultou, Buffalo, N. Y. 64,589 May 7, 1867-. Jersey Shore, Pa. 65,190 May 28, 1867.- 0. B. Evans, Buffalo, N. Y. 65,323 May 28, 1867: F. H. Wright, Richmond, Ind. 68,631 Sept. 10, 1867. G. L. Loverside, Burk Bank Gottages, En; 69,042 Sept. 17, 1867. r C. J. Gushing, St. Louis, Mo. 69,636 Oct. 8, 1867. } B. F. Walls, (w. A. Wood, > Hancock Gounty, Ky. 70,337 Oct. 29, 1867. A. W. Irish, Rochester, Minn. 76,015 Mar. 24, 1868. C. J. Weston, Gummington, Mass. 76,824 April 14, 1868. B. Schmidt, Hoboken, N. J. 76,957 April 21, 1868. D. Symonds, 78,256 May 26, 1868. F. J. Burcham, Racine, Wis. 78,672 June 9, 1868. E. Keith, Wabash, Ind. 80,693 Aug. 4, 1868. W. Windoes, Fond Du Lac, Wis. 81,237 Aug. 18, 1868. J. Wood, Woodstock, Vt. 82,517 Sept. 29, 1868. B. F. Gross, Trenton, Tenn. 82,763 Oct. 6, 1868. G. A. Starkweather, Waymart, Wis. 83,433 . Oct. 27, 1868. G. Tippe, New York, N. Y. 84,169 Nov. 17, 1868. C. J. Burgh, Eau Claire, Wis. 85,327 Dec. 29, 1868. C. 0. Swani, Tolentino, Italy. 87,325 Mar. 2, 1869. J. F. Bechraann, Abbott's Corners, N. Y. 87,894 Mar. 16, 1869. C. A. Williams, Jr., Alba, Pa. 88,764 April 6, 1869. E. Lynch, Georgetown, D. G. 91,504 June 15, 1869. H. L. Wilcox, Percival, la. 92,484 July 13, 1869. C. Smith, Bell Air, 0. 93,910 Aug. 17, 1869. N. C. Russell, Gloversville, N. Y. 98,916 Jan. 18, 1870. W. B. Brittingham, La Fayette, Ind. 100,520 Mar. 8, 1870. A. D. Fullmer, Buffalo, N. Y. 101,243 Mar. 29, 1870. E. England, Mossy Creek, Tenn. 104,276 June 14, 1870. G. W. Crabtree and J. G. Stoakes, Ghocoville, Ark. 104,734 June 28, 1870. J. Henry, New York, N. Y. 104,741 June 28, 1870. J. Kidder, Urbana, 0. 107,177 Sept. 6, 1870. G. L. Jenkins, Omaha, Neb. 109,714 Nov. 29, 1870. W. B. Brittingham, La Fayette, Ind. 110,562 Dec. 27, 1870. W. H. Fuller, Brockport, N. Y. 111,214 Jan. 24, 1871. F. A. Holcomb and S. B. Jenks, Grand Rapids, Mich. 111,583 Feb. 7, 1871. W. G. Stone, Derby Lane, Vt. 612 THE MANUFACTURE OF LEATHER. No. Date. Inventor. Kesidence. 112,285 Feb. 28, 1871. A. Rock, New Orleans, La. 114,596 May 9, 1871. G. Pile, Blountsville, Tenn. 116,578 July 4, 1871. L. Falkeman, San Francisco, Cal. , 118,089 Aug. 15, 1871. D. Woodbury, Peabody, Mass. 120,606 Not. 7, 1871. R. P. Wilson, New York, N. Y. 122,142 Dec. 26, 1871. B. F. Wright, Winchester, Mass. . 123,748 Feb. 13, 1872. C. J. Tinnerholm, Quiucy, 111. 125,020 Mar. 26, 1872. ^ J. Carter, t A. C. Keith, I Jersey City, N. J. 127,947 June 18, 1872. J. Bar ran, Cincinnati, 0. 128,246 June 25, 1872. J. Peters, St. James, Mo. 128,938 July 9, 1872. H. W. Southworth, Springfield, Mass. 133,021 Nov. 12, 1872. J. R. Enos, Peabody, Mass. 133,140 Nov. 19, 1872. S. Blanchard, Jr., Ashland, N. J. 135,214 Jan. 28, 1873. A. Fleischaner, Brooklyn, N. Y. 136,082 Feb. 18, 1873. W. Maynard, Salem, Mass. 136,488 Mar. 4, 1873. J.Carter and A.Keith, Jersey City, N. J. 138,138 April 22, 1873. J. Davis and J. Armstrong, Pittston, Pa. 139,892 June 17, 1873. C. Herveux, Islington, Eng. 140,040 June 17, 1873. J. B. Kite, Gyandotte, W. Va. 141,459 Aug. 5, 1873. ( Gr. Rawle, ( W. N. Evans, Bristol, Eng. Bedminster, Eng. 144,500 Nov. 11, 1873. R. Blake, Pontiac, 111. 146,742 Jan. 27, 1874. J. Anderson, Mount Pleasant, Pa. 149,954 April 21, 1874. H. Royer, San Francisco, Cal. 150,405 May 5, 1874. E. F. Dieterichs, Philadelphia, Pa. r L. M. Stockton, 1 D. Stockton, and ( W. A. Ward, > London, Canada. 153,464 July 28, 1874. 153,636 158,608 July 28, 1874. 1 Jan. 12, 1875. ) C. J. Tinnerholm, Keokuk, la. 160,440 Mar. 2, 1875. ( H. Klemm, ( C. Klemm, } Pfulliugen, Germany. 160,902 Mar. 16, 1875. R. Hart, Gloversville, N. Y. 162,140 April 20, 1875. G. A. Bartenbach and C. Richter, Detroit, Mich. 163,191 May 11, 1875. A. Haswell and J. C. Long, Webster City, la. 164,792 June 22, 1875. ( E. A. Baldwin, ( C. A. Holcombe, Phelps County, Neb. Lincoln, Neb. 165,314 July 6, 1875. A. D. Meritens, Paris, France. 165,348 July 6, 1875. E. Manasse, Napa, Cal. 167,866 169,076 Sept. 21, 1875. Oct. 26, 1875. J. Angus, E. Bauer, Calais, Me. Williamsburgh, N. Y, 169,102 Oct. 26, 1875. R. Hart, Gloversville, N. Y. TANNING PROCESSES. 613 No. Date. Inventor. Residence. 170,100 Nov. 16, 1875. H. W. Mirrill and J. W. Hoitt, Lynn, Mass. 170,623 Nov. 30, 1875. H. Ely, Ballston Spa, N. Y. 171,753 Jan. 4, 1876. H. W. Adams, Philadelphia, Pa. 174,761 Mar. 14, 1876. J. Bent, Lowell, Mass. 176,162 April 18, 1876. W. E. Brock, Philadelphia, Pa. 176,606 April 25, 1876. J. L. de Montoison, Manchester, Eng. 178,305 June 6, 1876. A. C. Krueger, San Francisco, Cal. 178,468 June 6, 1876. C. Ricliter, Detroit, Mich. 180,563 Aug. 1, 1876. P. J. Dussand and J. Duchez, Bordeaux, France. 180,947 Aug. 8, 1876. J. A. J. Schultz, St. Louis, Mo. 181,061 Aug. 15, 1876. W. Farris, Yarmouth, Me. 181,621 Aug. 29, 1876. A. M. Barnes and W. F. Yocom, Weston, Mo. 182,106 Sept. 12, 1876. Wm. Coupe, South Attleborough, Mass 182,198 Sept. 12, 1876. J. J. Johnson, Columbus, 0. 182,368 Sept. 19, 1876. J. Kent, Glqversville, N. Y. 182,684 Sept. 26, 1876. H. Loescher, Chicago, 111. 183,377 Oct. 17, 1876. S. A. Darrach, Orange, N. J. 184,114 Nov. 7, 1876. M. J. Soderberg, Malmo, Sweden. 185,799 Dec. 26, 1876. P. Sweeney, New York, N. Y. 187,492 Feb. 20, 1877. J. A. J. Schultz, St. Louis, Mo. 191,374 May 29, 1877. H. Royer, San Francisco, Cal. 196,672 Oct. 30, 1877. J. Kent, Gloversville, N. Y. 198,477 Dec. 25, 1877. J. Wells, Wilmington, N. C. 199,054 Jan. 1, 1878. G. Goodwin, Cookshire, Quebec, Can. 200,108 Feb. 5, 1878. C. J. Tinnerholm, Brooklyn, N. Y. 208,510 Oct. 1, 1878. H. Breisacher, New York, N. Y. 208,548 Oct. 1, 1878. E. Tivet, Philadelphia, Pa. 217,042 July 1, 1879. E. W. Avery, Plymouth, N. H. 221,187 Nov. 4, 1879. G. Plumer and C. P. Kerans, Peabody, Mass. 221,199 Nov. 4, 1879. P. Turner and J. Turner, Chicago, 111. 221,219 Nov. 4, 1879. M. L. Doty, Winterset, la. 223,200 Dec. 30, 1879. J. Wells, Wilmington, N. C. 229,928 July 13, 1880. T. P. Tucker, Independence Co., Ark. 230,225 July 20, 1880. S. Bloom, San Francisco, Cal. 230,841 Aug. 3, 1880. S. Ullmo, Lyons, France. 236,559 Jan. 11, 1881. R. F. Dobson, Darlington, Wis. 237,630 Feb. 8, 1881. J. S. Swan, Mongaup Valley, N. Y. 240,493 April 19, 1881. G. D. Zonca, Venice, Italy. 243,923 July 5, 1881. R. Koenitzer, St. Louis, Mo. 250,241 Nov. 29, 1881. W. Harris, Forrest City, Me. 254,962 Mar. 14, 1882. J. W. Hammond, Osceola, Pa. 614 THE MANUFACTURE OF LEATHER. No. Date. Inventor. Eesidence. 255,326 Mar. 21, 1881. J. M. Oardway and Jas. Oardway, Boston, Mass. 257,442 May 2, 1882. J. Head, Hornellsville, N. Y, 262,516 Aug. 8, 1882. M. Turley, Council Bluffs, la. 262,924 Aug. 22, 1882. J. B. Bollman, Dayton, 0. 271,804 Feb. 6, 1883. J. F. Crawford, Oak Hill, Ala. 289,588 Dec. 4, 1883. A. J. Weeks and J. E. Weeks, Littleton, N. H. List of all Patents for Processes Employing Leather^ issued by the Government of the V from 1790 to 1883 inclusive. Apparatus for Tanning nited States of America, No. ] Date Inventor. Kesidence. July 9, 1808. S. Parker, Oct. Dec. 9, 30, 1812. ) 1812. ) W. Edwards, Nov. 4, 1831. , A. Conwell, Dec. 16, 1833. Gr. H. Richards, 1,079 Feb. 9, 1839. W. Brown, Thompson, N. Y. 1,160 May 30, 1839. W. Herapath, Bristol, England. 1,455 Dec. 31, 1839. L. R. Palmer, Maryland, N. Y. 1,906 Dec. 17, 1840. W. Buchanan, Milford, Pa. 2,868 Dec. 5, 1842. D. H. Mason, Dahlonega, Ga. 3,614 June 5, 1844. J. Cox, Georgie Mills, Scotland, 3,632 June 15, 1844. R. Downey, New Albany, Ind. 3,688 Aug. 1, 1844. W. Brown, Manchester, Md. 4,253 Nov. 1, 1845. F. D. Parmele, Akron, 0. 5,165 June 19, 1847. L. C. England, New York, N. Y. 7,089 Feb. 12, 1850. W. H. Rosensteel, New Oxford, Pa. 7,192 Mar. 19, 1850. J. R. Innis, Easton, Pa. 8,500 Nov. 4, 1851. W. B. Milligan, Edinburg, Va. 9,555 Jan. 25, 1853. H. Britney, Springfield, 0. 11,061 June 13, 1854. N. Dodge, Oxford, N. H. 14,375 Mar. 4, 1856. A. Steers, Medina, N. Y. 19,211 Jan. 26, 1858. C. A. Shaw and J. Clark, Biddeford, Me. 21,126 Aug. 10, 1858. L. C. England, Owego, N. Y. .22,717 Jan. 25, 1859. L. C. England, Owego, N. Y. 23,360 Mar. 2a, 1859. T. T. Fergusson, New York, N. Y. 24,208 May 31, 1859. J. Gore, Milford, N. H. 24,457 June 21, 1859. J. Grore, Milford, Conn. 24,560 June 28, 1859. D. L. Hubbard, Glastenbury, Conn. 24,727 July 12, 1859. L. C. England, Owego, N. Y. 25,045 Aug. 9, 1859. J. B. Reed, Cold Spring, N. Y. TANNING PROCESSES. 615 No. Date Inveutor. Residence. 29,656 Aug. 21 1860. D. Aldrich, St. Louis, Mo. 30,062 Sept. 18 1860. W. H. Heald, Baltimore, Md. 33,448 Oct. 8, 1861. S. J. Patterson, Bridgeport, Conn. 34,815 April 1, 1862. W. Bush, Wilmington, Del. 40,575 Nov. 10 , 1863. V. E. Rusco, Chicago, 111. 43,013 June 7 1864. W. Fields and J. Towusend, Wilmington, Del. 43,258 June 21 1864. H. Leibermann, Paducah, Ky. 43,787 Aug. 9 1864. J. Mauren, Marseilles, France. 47,844 ^ Reissue > 2,519) May 23 1865. B. H. McNulty and Philadelphia, Pa. Mar. 19 1867. W. Kern, Mansfield, 0. 48,361 June 27 1865. 0. H. Brewer, Shannon, 111. 50,228 Oct. 3, 1865. C. R. Dean, Randolph, N. Y. 50,998 Nov-. 21 1865. H. W. Adams, Irvington, N. J. 51,655 Dec. 19 1865. H. Leibermann, Paducah, Ky. 51,870 Jan. 2 1866. T. Sharp, Nashville, Tenn. 55,333 June 5 1866. M. H. Merriam and E. L. Norton, Charlestown, Mass. 57,275 Aug. 21 1866. G. Aymard, New York, N. Y. 59,157 Oct. 30 1866. Bromfield, Me. 59,469 Nov. 6 , 1866. J. Snell, ,Tr., Patterville, Pa. 60,524 Dec. 18 1866. J. J. Johnson, Allegheny City, Pa. 63,869 Aprill6 1867. C. J. Dumery, Paris, France. 68,861 Sept. 17 1867. L. C. England, Owego, N, Y. 75,391 Mar. 10 1868. C. Doty, 76,134 Mar. 31 1868. H. W. Adams, Irvington, N. J. 76,777 April 14, 1868. L. L. Kelly, Delaware Station, Ind 76,784 April 14 1868. J. W. Lull, Glen Hope, Pa. 76,957 April 21 1868. D. Symonds, Marlow, N. H. 80,981 Aug. 11 1868. H. Lucas, Rousburgh, 0. 82,815 Oct. 6 1868. A. G. Eaton, Gouverneur, N. Y. 84,190 Nov. 17 1868. S. Hosmer, Concord, Mass. 88,764 April 6 1869. E. Lynch, Georgetown, D. C. 92,615 July 13 1869. J. E. Kanffelt, Shrewsbury, Pa. 92,776 July 20 1869. 0. W. Bean, Farmington, Tex. 101,213 Mar. 29, 1870. 0. W. Bean and W. B. Rowland, Tecumseh, Mich. 101,661 April 5 1870. L. T. Robinson, New York, N. Y. 101,812 Aug. 12 1870. Wilmington, Del. 105,169 July 12 1870. J. Champion, r J. Robijison, Woburn Centre, Mass. 106,209 Aug. 9 1870. } S. F. Robinson, (c. C. Putnam, > Skowhegan, Me. 112,285 Feb. 28 1871. A. Rock, New Orleans, La. 112,332 Feb. 28 1871. L. C. England, Philadelphia, Pa. 61-6 THE MANUFACTURE OF LEATHER. Wo. Date, 118,034 Aug. 15, 1871. 119,238 Sept. 26, 1871. 119,822 Oct. 10, 1871. 123,105 Jan. 30, 1872. 139,892 June n, 1873. 158,438 Jan. .% 1875. 159,510 Feb. 9, 1875. 180,563 Aug. 1, 1876. 218,539 Aug. 12, 1879. 23(5,659 Nov. 23, 1880. 242,954 June 14, 1881. 245,142 Aug. 2, 1881. 266,174 Oct. 17, 1882. 274,336 Mar. 20, 1883. 278,331 May 29, 1883. 278,981 June 5, 1883. 290,885 Dec. 25, 1883. Inventor. W. Masek, W. Morris, I W. Coburn, * F. Winslow, K. M. Jarvis, C. Harveux, H. Reed, C. Haserick, P. J. Dussand and J. Duchez, G. King, J. Davis, C. Michel, Jr., ' C. Kollen, . G. Hertzog, J. Davis, W. Masek, B. D. Hyam, D. Halsey, Jr., E. R. Locke, B. D, Hyam, Residence. Nashville, Ky. Philadelphia, Pa. East Walpole, Mass. South Dedham, Mass. Peabody, Mass. Islington, England. Atlanta, Gra. Maynard, Mass. Bordeaux, France. Washington, D. C. Allegheny, Pa. 1- Reims, France. Allegheny, Pa. Philadelphia, Pa. Washington, D. C. Newark, N. J. Keene, N. H. Washington, D. C. List of all Compounds and Materials for Tanning and also for Taw- ing Leather and for Preparing Raw Hides, that are especially claimed or mentioned in any Patent, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Kesidence. 836 July 12, 1838. A. A. Hayes, Roxbury, Mass. 4,007 April 22, 1845. G. C. Close and E. Field, Port Chester, N. Y. 9,181 Aug. 10, 1852. A. K. Eaton, Rochester, N. Y. 9,406 Nov. 16, 18.52. D. Kennedy, Reading, Pa. 12,102 Dec. 19, 1854. G. Reynolds, Bangor, Me. 12,139 Jan. 2, 1855. 0. Rich, Cambridge, Mass. 13,443 Aug. 14, 1855. 0. B. Wattles, Waddingtou, N. Y. 15,157 June 17, 1856. J. P. Williams, Salem, Mass. 17,043 April 14, 1857. D. H. Kennedy, New Alexandria, Pa. 17,867 July 28, 1857. J. Carle, . Kingston Township, Pa, 18,030 Aug. 18, 1857. L. L. A. Elie de la Peyrouse, Paris, France. 19,756 Mar. 30, 1858. C. Daniels, Elkhorn, Wis. 21,755 Oct. 12, 1858. B. Harrington and N. Russell, China, Me. 23,471 April 5, 1859. H. Johnson, Farmersville, N. Y. 25,241 Aug. 30, 1859. J. Brainard and W. H. Burridge, Cleveland, 0. TANNING PROCESSES. 617 No. Date Inventor. Residence. 25,522 Sept. 20, 1859. T. S. Page, Milan, 0. 26,800 Jan. 10, 1860. R. B. Thompson, Gailesburg, HI. 27,088 Feb. 7, 1860. P. Daniels, Le Roy, N. Y. 27,648 Mar. 27, 1860. J. Unessley, Gowanda, N. Y. 27,859 29.143 April 10, July 17, 1860. i J. Connell, Port Huron, Mich. 29,488 Aug. 7, 1860. A. Hill, Dubuque, la. 30,220 Oct. 2, 1860. R. Harper, Trumbull, 0. 30,367 Oct. 9, 1860. J. L. Wells, St. Louis, Mo. 30,390 Oct. 16, 1860. R. Crane and W. Baldwin, Anamosa, la. 30,392 Oct. 16, 1860. A. Dietz, New York, N. Y. 32,526 June 11, 1861. H. McKenzie, Talladega, 111. 33,314^ Reissue > Sept. 17, 1861. P. W. Thomas, Levee, Ky. 2,310 J 33,388 -^ Reissue > Oct. 1, 1861. G. W. Hatch, Princeton, 111. 2,384) 33,564 ^ Reissue > Oct. 29, 1861. W. Beach, Hamden, Conn. 2,560 5 33,790 Nov. 26, 1861. J. M. Muller, Richmondville, N. Y, 34,609 Mar. 4, 1862. .J. Brainerd, Cleveland, 0. 38,525 May 12, 1863. H. C. Williams, Lancaster, Pa. 41,666 Feb. 16, 1864. J. Wonder, Trucksville, Pa. 43,188 June 21, 1864. S. Dunseith, Philadelphia, Pa. 44,234 Sept. 13, 1864. J. W. Taylor, North Collins, N. Y. 46,443 Feb. 21, 1865. G. Bottero, Boston, Mass. 46,646 Feb. 21, 1865. C. Burton, Union, Me. 49,886 Sept. 12, 1865. E. Keith and B. Thorn , La Fontaine, Ind. 50,662 Oct. 24, 1865. J. Price, Edgefield District, S. 50,872 Nov. 7, 1865. S. A. Hickel, Roan Co., W. Va. 51,407 Dec. 5, 1865. J. E. Park, Seguin, Texas. 53,688 April 3, 1866. J. Schultz, Ellenville, N. Y. 57,409 Aug. 21, 1866. W. H. Towers, New York, N. Y. 57,795 Sept. 4, 1866. J. N. Stui-tevant and H. E. Jones, McGregor, la. 59,251 Oct. 30, 1866. H. Napier, Elizabeth, N. J. 60,472 Dec. IS, 1866. J. W. Calef, Salisbury, N. H. 60,548 60,549 Dec. 18, Dec. 18, 1866. 1 1866. ) J. A. Pease, New York, N. Y. 60,701 Jan. 1, 1867. J. Davis and J. McKelvey, Pawtucket, R.J. 65,323 May 28, 1867. F. H. Wright, Richmond, Ind. 65,934 June 18, 1867. W. H. Newby, Seymour, Ind. 618 THE MANUFACTURE OF LEATHEE. No. 66,432 67,563 Date July 2, Aug. 6, 1867. 1867. Inventor. J. Campbell, J. Melian, Residence. Leona, Pa. Newark, N. J. 68,335 68,511 Sept. Sept. 3, 3, 1867. 1867. A. Appleby, W. Johnson, Bi-ownfield, Me. Shirleysburg, Pa. 68,631 Sept. 10, 1867. G. L. Loversidge, rC. J. Cashing, ]b. F. Walls, and tw. A.Wood, Burry Bank Cottages Eng 69,636 Oct. 8, 1867. >- Hancock Co., Ky. 71,293 Nov, 26, 1867. C. Frank, Cincinnati, 0. 75,535 Mar. 17, 1868. J. Diehl, East Freedom, Pa. 75,794 Mar. 24, 1868. L. S. Robbing, New York, N. Y. 76,957 77,099 April 21. April 21, 1868. 1868. D. Symonds, L. F. Robertson, Marlow, N. H. West Farms, N. Y. 78,672 June 9, 1868. ( E. Keith and \a. A. Eylar, Wabash, Ind. Pontiac, HI. 80,693 Aug. 4, 1868. W. Windoes, Fond du Lac, Wis. 81,237 Aug. 8, 1868. J. Wood, Woodstock, Vt. 81,587 82,517 Sept. Sept. 1, 29, 1868. 1868. Gr. Bossiere, B. F. Gross, Paris, France. Trenton, Tenn. 83,073 Oct. 13, 1868. S. Lusten, Linesville, Pa. 84,169 Nov. 17, 1868. C. J. Bugh, Eau Claire, Wis. 84,734 Dec. 8, 1868. N. Cox, Salem, 111. 86,808 Feb. 9, 1869. J. P. Bridge, Boston, Mass. 91,504 June 15, 1869. H. L. Wilcox, Percival, la. 93,498 Aug. 10, 1869. N. A. Thornton, Conikee, Ala. 94,805 Sept. 14, 1869. J. Wood, Woodstock, Vt. 98,884 Jan. 18, 1870. F. P. Porcher, Charleston, S. C. 104,276 June 14, 1870. G. W. Crabtree and G. Stoakes, Chocoville, Ark. 107,713 Sept. 27, 1870. C. F. Panknin, Charleston, S. C. 109,714 110,562 111,562 Nov. Dec. Feb. ?9, 27, 7, 1870. 1870. 1871. W. B. Brittingham, W. H. Fuller, W. Parks, La Fayette, Ind. Brockport, N. Y. Meadville, Pa. 112,285 Feb. 28, 1871. A. Rock, New Orleans, La. 114,941 115,100 May May 16, 21, 1871. 1871. A. Hisey, F. P. Porcher, Tama City, la. Charleston, S. C. 117,241 July 25, 1871. A. T. Atherton, Lowell, Mass. 123,118 Jan. 30, 1872. J. M. MuUer, Cobbleskill, N. Y. 125,020 Mar. 26, 1872. J. Carter and A. C. Keith, Jersey City, N. J. 128,938 July 9, 1872. H. W. Southworth, Springfield, Mass. 132,269 Oct. 15, 1872. W. Farris, Yarmouth, Me. 140,040 143,105 144,500 June Sept. Nov. 17, 23, 11, 1873. 1873. 1873. J. B. Heite, W. Thilmany, R. Blake, Guyandotte, W. Va. Cleveland, 0. Pontiac, 111. 146,742 Jan. 27, 1874. J. Anderson, Mt. Pleasant, Pa. TANNING PEOCESSES. 619 No. Date. Inventor. Residence. 148,056 Mar. 3, 1874. G". W. Hatch, / T. M. Stockton, < D. Stockton, and (w. A. Ward, Lawrence, Kan. > London, Can. 153,464 July 28, 1874. 159,366 Feb. 2, 1875. W. R. Stace, Rochester, N. Y. 163,191 May 11, 1875. A. Haswell and J. C. Long, Webster City, la. 164,792 .June 22, 1875. E. A. Baldwin and C. A. Halcombe, Phelps Co., Neb. Lincoln, Neb. 165,348 July 6, 1875. E. Manasse, Napa, Cal. 165,731 July 20, 1875. G. Herrick, Kilbourn City, Wis. 165,822 July 20, 1875. G. W. Hatch, Lawrence, Kan. 169,076 Oct. 26, 1875. E. Bauer, Williamsburg, N. Y. . 174,110 Feb. 29, 1876. E. Bradley, St. Leonard, Can. 176,162 April 18, 1876. W. E. Brock, Philadelphia, Pa. 178,919 June 20, 1876. J. Foley, Montreal, Can. 182,368 Sept. 19, 1876. J. Kent, Gloversville, N. Y. 185,799 Dec. 26, 1876. P. Sweeney, New York, N. Y. 193,520 1 193,521) July 24, 1877. F. Knapp, Brunswick, Germany, 196,081 Oct. ]6, 1877. F. Funke, ^ G. De Cordova, ) M. Wise, ( H. D. Darrell, Detroit, Mich. / Brooklyn, N. Y. 196,339 Oct. 23, 1877. } New York, N. Y. (Brooklyn, N. Y. 198,478 Dec. 25, 1877. J. Wells, Wilmington, N. C. 200,108 Feb. 5, 1878. C. J. Tinnerholm, Brooklyn, N. Y. 230,841 Aug. 3, 1880. S. Ullmo, Lyons, France. 231,035 Aug. 10, 1880. P. Gondolo, Paris, France. 231,489 Aug. 24, 1880. J. Holtz, Berlin, Prussia, Germany, 235,923 Dec. 28, 1880. H. L. Wilcox, Lincoln, Neb. 236,115 Dec. 28, 1880. ) 4, 1881. ) H. Trenk, Berlin, Germany. 236,280 Jan. 237,007 Jan. 25, 1881. J. Foley, Montreal, Can. 260,322 June 27, 1882. C. Richter, St. Paul, Minn. 262,766 Aug. 15, 1882. C. T. Hayden, Whitesborough, Tex. 271,804 Feb. 6, 1883. J. F. Crawford, ^ E. Logue, Oak Hill, Ala. 283,798 Aug. 28, 1883. } M. T. Jones, and (c. E. MorriU, > Deering, Me. 286,491 Oct. 9, 1883. •T. Shaw, Hindmarsh, S. Australia. 287,255 Oct. 23, 1883. F. E. Dietsch, Woodbury Falls, N. Y. 620 THE MANUFACTURE OF LEATHER. CHAPTEE XL. TANNING AND COLORING HIDES AND SKINS WITH THE HAIR AND FUR ON. PiNGEE obtained two patents for tanning hides with the hair on, the first being for the process of shaving off" after the hide has been fleshed, the inner layer of the skin, or the same and a part of the coriura preparatory to immersing the hide in the liquors. The second patent relates to the preparation and use of the tanning liquors. 1. For 25 hides use 5 hogsheads of water, 1 peck lime, 5 pounds sal-soda, and 12 pounds soda-ash ; or, instead of the sal- soda and soda-ash, 15 pounds of soda-ash may be used. The hides remain in this solution for twelve or more hours ; but not long enough to start the hair. 2. Kinses in cold water. 3. Steeps in a solution composed of 5 hogsheads of water, 1 bushel of muriate of soda, and 12 pounds of sulphuric acid. In this solution they remain twenty-four hours or more, according to the thickness of the hide, and are frequently stirred. 4. Immerses in a solution composed of 5 hogsheads of water and 50 pounds Bombay catechu. 5. Steeps the hides in strong bark-liquor, in which they remain ten or twelve days. 6. Adds to the bark-liquor 50 pounds sumach and 25 pounds ground alum, and suffers the hides to remain one week longer in such solution ; but stirs them occasionally in the mean time, and the process is completed. Johnson. For tanning light skins with the hair on them — such as sheep, fox, coon, or minx-skins, etc. — 1. Soaks, fleshes, and cleans in the usual manner. 2. Makes a solution in the following proportions : to | bushel wheat-bran add 6 gallons of soft, hot water, and let it stand in a warm room, and agitate until it ferments. Then strain out the liquor and dissolve TANNING AND COLORING WITH THE HAIR ON. 621 therein 4 pounds of chloride of sodium or common salt, and then add 1| pounds sulphuric acid while agitating the liquor. This liquor acts as a mordant for settling a variety of colors, which are cheap and more durable than if made in the usual manner of sponging colors after tanning. 3. Light hides re- quire to be handled in the above liquor for one to three hours. 4. Rinse and hang out to dry in the shade. 6. Stuff', when nearly dry, with a compound of f fish oil, ^ alcohol ; to which add flour paste and melted tallow equal parts in order to thicken. To make this compound water-proof and India-rubber or bees- wax. 6. Dry the skins. CoE. 1. Soaks the light hide or skin with the wool, hair, or fur on. 2. Fleshes in the usual manner. 3. Makes a solution composed of 8 gallons soft water ; 1 quart potatoes, boiled and mashed ; 8 quarts rye or oat bran ; 5 pounds common salt : | pound oxalic acid. Stirs the potatoes and bran together with the water in the proportion above specified, and lets it stand in a warm room until it ferments. Then adds the salt, stirring until it is dissolved, and finally under continuous agitation adds the oxalic acid. This solution, which is termed the "first solution," imparts no color to the leather or fur. 4. For heavy hides or skins, such as calf-skins or cowhides, adds to the above solution a liquid made of the buds of sumach, melted catechu, and zinc mixed together in about the following proportions: 1 quart extract of the butts of sumach, 3 pounds melted catechu or Sicily sumach, ^ pound kino or cranes bill. It is claimed that this solution plumps and gives the leather a body. Light hides require to be handled from thirty minutes to one hour ; they are then rinsed in soft, warm water, and hung out in the shade to dry. 5. When the hides or skins are nearly dry they are stuffed with oil, tallow, and flour paste, and then hung in the air to dry. Carter and Keith's process is adapted for tanning hides and skins with the hair on, and for dressing furs. In carrying this invention into practice, prepare a solution composed of the following ingredients in substantially the pro- portions named : Carbonate of soda, three pounds ; nitrate of potash, three ounces ; chloride of sodium, three ounces ; prus- 622 THE MANUFACTURE OF LEATHER. siate of potash, three ounces; acetate of lead, three ounces; green vitriol, three ounces ; soft water, nine gallons. In place of the carbonate of soda, three gallons of common lye may be used, if preferred. Pulverize the ingredients and dissolve them in the water while hot. The skins to be tanned must be fleshed in the usual manner, whether green or dry. If dry, they must be soaked in water until softened. They are then immersed in the above solution, which is kept at a lukewarm temperature, and are handled or agitated to expose all parts equally to the action of the liquid. The time which they are required to re- main in the solution to become tanned varies with the kind and thickness of the skin from thirty minutes to two hours. After having been in the solution a sufl&cient time they are taken out, when it will be found that the hair or wool is loosened and the grain raised, so that they should be handled with care and im- mediately on removal from the solution rinsed in cold water, which will reset the hair and prevent depilation, and after being rinsed they are hung up in the shade to dry. The skins having been tanned and dried, must now be treated with the following composition : Soft soap, one gallon ; fish oil, one quart ; borax, one ounce ; chloride of soda, four ounces ; alcohol, four ounces ; all of which ingredients are thoroughly mixed in two quarts of hot soft water. The dried skins which are dressed with the hair, wool, or fur on must be washed with the composition on the flesh side only, and this repeated as many times as necessary to render them somewhat soft, and in a condition to be worked soft by rubbing or beating. The tan- ning-liquid does not affect the hand injuriously, and acts as a disinfectant of any fetid or oft'ensive odor that appertains to the skins, whereby the natural oil and impurities of wool are decom- posed and furs are cleansed and rendered fit for wear ; the treat- ment also serving as a preventive against the attacks of moth. Tanning and Coloring Beaver^ Otter^ and any other Shins with the Hair or Fur on. Bugh''s Method for Tanning Beaver^ Otter^ or any other Sldns^ loith the Hair or Fur on. — The skins according to this method should be soaked (if dry) from 12 to 16 hours, then thoroughly fleshed, then returned to the soak for from 6 to 8 hours lonsrer. TANNING AND COLOKING WITH THE HAIE ON. 623 They should then be washed as follows : — Take sufficient warm, soft water to wash them, to which add sal-soda until the water feels slippery, then wash thoroughly ; next wash them well in warm, strong soapsuds, then rinse well through 2 or 3 waters, and wring out as dry as possible. The skins are then ready for the tan-liquor, which is prepared as follows : — 2 gallons cold, soft water. 2 pounds Glauber's salts. 1 pound alum. 1 pound common salt. J an ounce sulphate of zinc. Melt 1 pound terra japonica in J gallon of the above prepara- tion, over a slow fire, then mix all together. All the ingredients should be pulverized, as they will dissolve much more quickly. Place the skins in the tan, and handle by pulling and stretch- ing thoroughly, then let remain 2 or 3 days ; if heavy furs, such as bear-skins, 4 or 5 days. Then rinse in 3 or 4 clean waters, wring out as dry as possible, and hang in the shade to dry. When nearly dry, work them occasionally by stretching, etc., or on the beam with the fleshing- knife. When dry, finish up on the beam, by working the middle or thick part of the skin down, until it is even, or as thin as the edges or flanks. A currying- knife, with a fine edge, is the best tool to do this with, or it may be done with coarse sand-paper, rolled on a round stick, using it the same as a knife. If it is desired to pluck the hides, after washing them through the alkali, and rinsing, lay them in clean, cold water for a day or two longer, or until the " guard-hairs" pull out without breaking. Care must be taken not to let the skin taint. If it does, it will loosen the fur, as the fur is only on the grain while the " guard-hairs" go through into the pelt. Muskrats have very tender skins, which should be treated somewhat differently from heavier furs. Soak in clean, cold water for 10 or 12 hours, or until all hard 624: THE MANUFACTURE OF LEATHER. spots are softened ; then flesh as well as possible ; then wash as directed to wash furs ; then put them in the tan-liquor for furs ; handle the same as other furs, and let remain for two or three hours ; then wring out, and flesh again, and return to tan-liquor for two or three hours longer; then wring and rinse, and finish up as directed for finishing furs. If the skins are well fleshed the first time, a second fleshing is not necessary. A rich, nice gloss will be formed on all furs, if tanned and finished as described. To Color Furs. After soaking soft, wash in a middling-strong sal-soda water, and rinse clean. Then apply with a brush, and rub well through the fur down to the pelt, half an ounce crystallized nitrate of silver, and one pint of soft water, and hang in the sun to dry. Again apply with a brush, and rub well through the fur, one ounce sulphate of potash, dissolved in one pint soft water, and hang in the sun to dry, and, when dry, rinse ofi*, and hang in the shade to dry, and work occasionally while drying. Method and Machine for Dyeing the Wool on Sheep-Shins. Alexander Jack, of Barnet, Yt., in 1875 patented the apparatus shown in Fig. 292 for dyeing the wool on sheep-skin, whereby the skin is kept perfectly cool during the operation of dyeing, thus preventing the skin from being injured, and at the same time there is no danger of cooling the dyeing-liquor. The invention also consists in a device whereby the apparatus, and consequently the skin attached to the same, are kept in the right position, so that the wool on the skin can be dyed a number of different colors during one operation. Fig. 292 is a perspective view of Jack's apparatus with a portion of one of the ends removed, and showing the sheep-skin in position after dyeing. ^ is a vat containing the dye -liquor. B B are the guide-rods attached to the vat A^ which serve to keep the apparatus, to which the skin is attached, in the right position. G is the wool TANXIJTG AND COLORIXG WITH THE HAIR ON. 625 of the skin after being dyed. D is a strip of cloth hooked on points, and to which the skin is sewed. E is a frame which is attached to the air-chamber. F is the air-chamber. Q- G are the clamps, by means of which the frame containing the skin is Fi£. 292. attached to the air-chamber. H H are the brackets attached to the air-chamber F containing guide-pulleys, which operate in connection with the guide-rods B B attached to the vat A. lis the space for the escape of the air after being used in cooling the skin, t/is a flexible air-tube to convey the air to the air- chamber. If is a metal plate to break the force of the wind upon the centre of the air-chamber, so that the air in the cham- ber will be of uniform density, and be distributed evenly through the perforated plate upon the skin. The skin upon which is the wool to be dyed is first sewed to the cloth Z>, and then hooked to the points. The air is then forced into the air-chamber, the wool is lowered and raised a few times in the dye-liquor until sufficiently colored, after which it is removed. By means of the air admitted to the skin, the latter is always kept cool, and pre- vented from being injured on account of coming in contact with the hot steam of the dye-liquor, so that it is unnecessary to remove 40 626 THE MANUFACTURE OF LEATHER. the skin from the vat until the wool is dyed. By the escape of the air without coming in contact with the dye-liquor no trouble arises in consequence of cooling the liquor. By the methods commonly in use but one immersion in the dye-liquor is permitted before taking the skin from the vat and cooling. It is then returned to the vat and once again immersed in the dye-liquor, and again removed from the vat, and this operation is continued until the wool on the skin is dyed. This- method of dyeing is necessary in the processes commonly employed in order to prevent the skin from being injured by being too long a time in contact with the heat from the dye- liquor. By means of the guides B B on the vat, and the pulley- brackets U H on the air-chamber, the latter, and consequently the skins attached to it, are always kept in uniform position in relation to the former, so that, instead of one vat containing only one color of dyeing-liquor, several vats containing different colors of dyeing-liquors, may be used to receive the air-chamber in succession, and the skins thereon be dyed accordingly. CHAPTER XLI. MINERAL TANNING. We understand by this name such methods of tanning as those in which mineral substances are employed as tanning material instead of vegetable tannin. Attemps to substitute mineral substances for vegetable tannin were made more than a hundred years ago. By consulting the English patent reports it will be seen that the use of mineral salts, especially ferraC salts, the tanning pro- perties of which were first observed, was already attempted at the commencement of the last century. Ashton as early as 1794 obtained a patent for tanning with ferric salts, which were pre- MINERAL TANNIISrG-. 627 pared bj treating iron rust or iron ores (pyrites) with sulphuric acid. Ashton also recommended the heating of other ores, such. as copper ores, calamine, etc., with an addition of sulphur, and to pulverize and lixiviate the hot mass. Bj heating ores of copper, zinc, and iron with, sulphur, sulphur combinations of the respective metals are formed which, when in aqueous solu- tion, are very likely converted into sulphuric acid combinations, in which state they exert a tanning influence upon the skin. The specification of the patent, which is very indefinite, directs the immersion of the skins in the solution of mineral salts prepared as above for five or six days with frequent handling. Jules Bordier, in 1842, obtained a patent for converting hides into leather by means of mineral and earthy substances, recom- mending especially ferric sulphate as the most important combi- nation. The ferric sulphate was to be prepared by treating solution of ferrous sulphate with manganese dioxide or nitric acid, with an addition of ferric hydrate. A red salt, not defi- nitely described by the inventor, which is separated by boiling the mixture, is used for preparing the tanning-liquor. Molac and Daniel Triedel, in 1855, obtained a patent, in which ferric salts were also described as the tanning material. The improvement claimed by them consisted in the neutralization of the sulphuric acid, separated in tanning by splitting off from the ferric sulphate by means of metallic oxides, such as ferric oxides, aluminium oxide, or zinc oxide. It is claimed that by this process the skin absorbs more iron salts than by using ferric salts alone, and that the injurious effect of the free acid is prevented. Triedel and Molac prepared their tanning-liquor by treating ferrous sulphate with manganese dioxide and sulphuric acid.^ To the solution of ferric and manganese salts obtained in this manner a varying quantity of ferric acetate was added. The depilated and cleansed skins were soaked for 3 or 4 1 The formula tliey give for this process is according to the old nomenclature : 4(SOs, FeO) + 2Mn02 4-S03 = 3S03Fe203-f 2(S03MnO)4-Fe203. In this they start from the incorrect supposition that the fluid contained free ferric oxide and neutral ferric sulphate instead of basic ferric sulphate. 628 THE MANUFACTURE OF LEATHER. weeks iirst in weak solutioDS of the above salts compounded at first with some fermented crushed barley, after which the strength of the solutions was gradually increased. To neutral- ize the free acid, some ferric oxide was from time to time added to the solution. By this process it was claimed that the thickest hides would in six weeks be converted into leather equal in appearance and quality to that tanned in the ordinary manner. The next advance in mineral tanning was made by Knapp, who, in 1861, obtained a patent in Germany for tanning with ferric salts and other metallic oxides. Hides tanned with mine- ral substances lost, like those tanned with alum, their tannin by immersion in water. Knapp tried to remove this evil by con- verting the metallic salts adhering externally to the skin into insoluble metallic soaps, by soaking and kneading the skin in a soap solution. In order to fix the tanning substance in the skin, Knapp recommended, instead of immersing the tanned skins in soap solution, the fulling in of insoluble soaps of ferric oxide, aluminium oxide, or chromium oxide. The solution of basic ferric sulphate Knapp used for tanning was prepared by com- pounding the solution with caustic soda until the resulting precipitate was again dissolved in the fluid. Next to Knapp, Pfanhauser obtained in 1864 a patent for the preparation of a basic ferric sulphate and its use for tanning. By his process ferric sulphate is heated to a red heat with con- stant stirring until the mass is converted into a reddish powder. The latter while hot is thrown into water, in which, with con- stant stirring, it is almost entirely dissolved. The resulting fluid is allowed to clarify by standing, and the clear liquor used for pre- paring tanning-fluid of varying strength.. The skins are first placed in a dilute solution of 0.5° Beaume, and then succes- sively in stronger solution. When thoroughly permeated they are washed ofi' and placed in a soap solution. The first use of bichromates for tanning was made by Cavalin. The skins, according to his method, are placed in a solution of 22 pounds of potassium bichromate and 44 pounds of alum in 396 pounds of water, where they remain for four or five days with frequent stirring, when they are placed in a solution of 2.2 pounds of ferrous sulphate in 22 pounds of water. In this they MINERAL TANNING. 629 remain for twelve hours, being in the mean while frequently stirred. The potassium bichromate is reduced to chromic oxide by the ferrous sulphate, and the ferrous oxide contained in the ferrous sulphate oxidized to ferric oxide, both oxides being pre- cipitated as such upon the fibre, or the ferric oxide together with alumina. The fixing of the chromium combination is effected by reducing the soluble chromate to chromic oxide. Cavalin's method may be considered as a combination of tan- ning with ferric aluminium and chromic oxides. But a practical application of the process is not possible, since the leather loses its tannin easily when immersed in water, and its grain is brittle. The use of iron alum and chrome alum was at one time pro- posed and actually introduced in practice. But the use of these substances was soon abandoned, as the leather prepared in this manner had no advantage over that tanned with alum and alumina salts. All the above-mentioned methods of tanning have been aban- doned on account of the defective quality of the product pre- pared by them. But this can scarcely be attributed to the properties of the tanning material, but rather to the errors committed in their preparation. By immersing leather prepared with these tanning materials in tan-liquor it was made closely to resemble that tanned in the ordinary manner. Tanners had almost become accustomed to reject all new pro- posals to use mineral instead of vegetable tanning substances, justifying their action by referring to former failures, until Knapp, in 1877, gave a fresh impetus to the matter by patenting in Grermany and other countries a new method of tanning with ferric salts. We will first describe Knapp's process as specified in the applications for patents. Knapp's Process of Tanning with Ferric Salts. In the use of the basic sulphate of iron as a tanning material, the hides or skins, having the hair and adherent fleshy portions removed in the usual manner, are placed in the cold solution of the ferric-oxide salt of the proper density, in which they are allowed to reniiiin for two, or, at most, four days, during which 630 THE MANUFACTURE OF LEATHER, time it is not necessary to handle the hides in any manner, all the laborious operations attending the use of tan-bark liquor, while the hides or skins are subjected to the action of such liquor, being obviated. At the end of the time named the hides or skins are removed from the solution of ferric-oxide salt. This salt is prepared as follows : To a boiling solution of sul- phate of protoxide of iron (greeu vitriol) is added as much nitric acid as will thoroughly oxidize the salt contained in said solu- tion. When the effervescence which ensues upon the addition of the nitric acid has subsided, the operation is reversed — that is, sulphate of protoxide of iron is added to the solution till said solution assumes a syrupy consistence — a. distinguishing char- acteristic aforementioned — and acquires a yellow- red color, also characteristic of solutions of this iron oxysalt, which, when slowly evaporated to dryness, has the appearance of an orange- red transparent varnish, also highly characteristic. In this condition, it is claimed, the ferric sulphate possesses qualities differing essentiallj^ from those attributed to it in chemical text-books, or found in the commercial article. The latter gives no syrupy solution, is of a yellow-brown color, and in aqueous solution is decomposed by boiling, while the prep- aration produced according to the above method remains un- decomposed by boiling even in a solution of 20° to 40° B. It is further claimed that the ferric sulphate prepared according to Knapp's method is more abundantly absorbed by the skin. After tanning, the skins are treated with fat solutions and a so-called iron soap. Greasing the skins by hand, hanging them up in the drying-room and scraping oft' the excess of fat is done away with. Stearine and paraflBne are suitable materials for the fat solution. The iron soap is separated in an insoluble form by precipi- tating soap solution with Knapp's ferric salt. The iron soap pre- pared in this manner is mechanically fulled into the skin, a fulling drum constructed by Knapp being used for the purpose. This machine, shown partly in elevation and partly in section in Fig. 293, consists of a drum A revolving around the hollow trunnions B B\ through which air can be forced into the barrel by means of the fan F. MIISTERAL TANNING. 631 The trunnions are fitted in suitable boxes or bearings G in or on a supporting-frame D. To one of the hollow trunnions is attached, by a suitable joint, a pipe or conductor, E^ which leads from a centrifugal or other blower or pump, F. From the inner extremity of the trunnion to which the conductor E is attached extend radially Fi?. 293, outward from the trunnion hollow arms, pipes, or conductors, (r, their ends being brought quite near the inner surface of the drum J., and their ends near the inner surface being open. The joint which connects the pipe or conductor E with the trunnion B' is of such a character as to permit the free turn- ing of the trunnion on its bearing without turning the con- ductor. When the apparatus is in operation the leather or tanned hides to be greased or treated with soap or other substance are placed in the drum A^ which has a suitable opening in its side, provided with a cover (not shown) for the reception of the hides to be treated, and the proper quantity of the substance to be thereto applied is also placed in the drum. The drum is then rotated by means of a pulley, gear, or other suitable means. At the same time the blower i^ is set in operation, and air is driven through the trunnion B' into the drum and discharged on the inner surface. The air then passes toward the centre of the drum through the interstice.s and pores of the leather in the 632 THE MANUFACTURE OF LEATHER. drum, exerting a rapid drying action on the same, the removal of the water in the wet or damp skins being followed by the rapid and thorough absorption of the grease or substance it is desired to incorporate into the pores of the leather. Finally the air issues from the trunnion B. A paste of iron soap described above is applied to the skin with or without an addition of fatty emulsions, or placed together with the skins in the fulling drum and mechanically fulled in. The skins are dried at the same time by the current of air passing through the fulling drum. The new and peculiar features claimed for this process by Knapp are as follows : — 1.^ The preparation of the ferric salt, especially the treatment of the ferrous sulphate oxidized by nitric acid by a further addition of the same salt. 2. The treatment of the skins and hides with solutions of iron and fat, 3. The use of stearin for the above purpose. 4:} The fulling drum connected with a fan by which a current of air is forced into it. 5. The iron soap and its use. The advantages of this method of tanning are, according to Knapp — 1. Greater cheapness (from 5 to 25 per cent.). 2. Considerable saving of time, the product being of an equal quality and durability. 3. The obtaining of as large a yield as by tanning in the ordi- nary manner. 4. The use of a tanning material of a constant chemical com- position by which the obtaining of a uniform product is assured. The leather prepared by Knapp's process has a brown-yellow color closely resembling that of leather tanned in the ordinary manner. It is, according to Knapp, not water-proof but capa- ble of resisting water, meaning by this that the leather does not lose its tannin by frequent contact with water. As far as we 1 By a decision of the patent office of the German empire, claims one and four have been set aside, as not being new. MINERAL TANNING. 633 know, this process lias thus far only been used for the prepara- tion of sole and belt leather, and we are unable to say whether upper leather has also been lately successfully produced. "We will say nothing further pro et contra, in regard to this method. Knapp has applied for an additional patent for a somewhat different method of preparing the ferric salts. Instead of add- ing, as formerly described, nitric acid to a boiling solution of ferrous sulphate, an equivalent quantity of sulphuric acid and sodium nitrate is added to the ferrous sulphate solution. The tanning with this is effected in the same manner as previously described, but can also be done by the precipitate which albu- minous substances, as for instance that of blood, produce with the ferric solution. Heinzerling' s Method of Tanning with Ghromates^ etc. In the years 1880 and 1881, Heinzerling obtained patents in the United States, and previously in other countries, for quick tanning with chromates with an addition of aluminium salts, sodium chloride, etc. The process is executed as follows : — The skins are cleansed, depilated, and swelled, and placed in a one-quarter per cent, solution of chromic acid or in a half per cent, solution of potassium bichromate, sodium bichromate, or magnesium bichromate or other neutral bichromates, or in a half per cent, solution of chromic salts, for instance chromic sulphate. It is advantageous to add to the solution one per cent, of alum or aluminium sulphate or other aluminium salts, and one per cent, of sodium chloride. According to their thick- ness the skins remain in the solution a shorter or longer time.^ During this time the solution is successively concentrated until it contains as much as GJ per cent, of chromates, 12 per cent. of alum, and 10 per cent, of common salt. The action of tanning-liquors gradually increasing in strength can also be effected in a more simple manner by placing the ' Calf-skins, for instance, four to six days, and lieavy bullock hides up to fourteen days. 63-i THE MANUFACTURE OF LEATHER. skins successively in more concentrated solutions and allowing them to remain a corresponding time in each of the solutions. When fresh skins are placed in the tanning-liquors, the tan- ning substance withdrawn by the skins taken out must be always supplemented, the quantity required being determined by analysis. Although experience has shown that the tanning process can be executed without the use of aluminium combinations and of common salt, it is advantageous to employ thera, since these substances possess also tanning properties and accelerate the process, and besides being comparatively cheap, reduce the cost of the operation. If leather is to be produced which is to be blackened after tanning, 2 to 3 per cent, of potassium ferric-cyanide or potas- sium ferro-cyanide is added to the solution. These substances, together with the iron black applied later on, give a deep dark- blue color to the leather. After tanning in the described solutions, the skins are placed in a 4 to 8 per cent, solution of barium chloride, acetate of lead, or soap, which effects a partial fixing of the tanning substance by the latter forming with the first insoluble salts or soaps. To effect a quicker absorption of the barium chloride, ace- tate of lead, or soap, the skins, while in the solutions, are vigor ■ ouslv moved or kneaded. They are next washed, superficially dried and stretched, and, while still feeling somewhat moist, placed for 36 hours in a solution of stearine, paraffine, w^ax, rosin, colophony, spermaceti, or of other hydrocarbons or fat, in benzine or other solvents having a similar effect. It is advantageous to heat the solution containing fat, paraf- fine, or other hydrocarbons to 96.8° P. in a water-bath. In place of stearine or the other substances mentioned, a mass resembling caoutchouc can be used, which is obtained by treating oils (linseed or rape-seed oil) with 10 to 15 per cent, of chloride of sulphur. If chromic acid is used in tanning, the parafi&ne em- ployed in the after-treatment is oxidized by the acid, the latter being at the same time reduced to chromic oxide. The paraf- fine appears to become oxidized to an acid-like combination which enters with the chromic oxide, formed into a combination MINERAL TANNING-. 635 insoluble in water which is firmly precipitated upon the fibre. When chromates are used, the chromic acid is split off from the chromates during the tanning process, either by the skin itself or, in case aluminium salts are employed, by the sul- phuric acid liberated from them. By the succeeding treatment with paraffine, etc., the insoluble combination described above is also formed. As a proof of the described action upon the paraf&ne taking place, we would mention the fact that the cut surface of leather prepared according to the described process is at first yellow but becomes gradually lighter, especially when exposed to the light, and turns finally to a nearly whitish-green. Metallic salts, for instance cupric sulphate and others, can be added to the solution of chromates formerly mentioned, partly on account of the tanning effect of these salts, and partly in order to produce certain shades of color upon the leather. The skins can also be placed, either before or after they Lave been treated with the described tanning-liquors, in solutions containing vegetable tannin. After the skins have been removed from the solutions of fat, paraffine or rosin, the leather intended for uppers and belts is greased in the same manner as leather tanned in the usual manner, with a mixture of tallow, train oil, or similar fat mix- tures. After greasing, the fat is either fulled in or allowed to soalv in by hanging the skins in a moderately heated room. The upper leather is, generally speaking, curried in the same manner as leather tanned by the ordinary process, a few points only requiring special precautions to assure a fine product. In preparing black grain leather, it is best to blacken the skins before placing them in the fat solutions. For blacking, on account of the yellow ground being more difficult to blacken, the application must be repeated once or twice oftener than for leather tanned in the ordinary manner. If the leather is to be blackened after greasing and currying, the fat must first of all be thoroughly removed by scouring with dilute solution of soda or ammonia, and rubbing with pumice stone powder, or wood ashes. The grain side thus cleansed is then blackened with logwood extract or iron black. Sole leather tanned by the above process, is, after removal 636 THE MANUFACTURE OF LEATHER. from the tanning-liquor, impregnated with solutions of fat, wax, or rosin. It is then dried and rolled. In working the upper and sole leather into shoes, the follow- ing directions should be observed : In order to be able to last the upper well, it should be placed in lukewarm soap-liquor for 10 to 12 hours and frequently kneaded. Lasting can only be accomplished in the ordinary manner after the fluid has thoroughly permeated the grain, which is more difficult to effect than with leather tanned in the usual manner. Chromium leather it is claimed is more water-proof. The property of the leather of not stretching after having been worked, deserves special attention, since a shoe made a close fit, as is generally the case with leather tanned in the usual manner, is apt to be too tight. For sole leather to be easily worked it is not sufficient to dip it simply in cold water; it should remain for some time in luke- warm water. As will be seen from a table on p. 88, experiments which have been made in regard to the absorption of water by leather tanned in the usual manner and that prepared with chromates, have shown that the latter absorbs water slower and a smaller quantity of it than the former. A further advantage of chrome leather is that it possesses the property of losing less tannin by repeated treatment with cold or warm water than leather tanned in the usual manner. We give here comparative experiments as regards the solu- bility of the tannin in chrome leather which were made by Dr. J. Clark, city analyst of Glasgow. In order to establish the total quantity of chromium contained in the leather and also the quantity of chromium which was under different conditions withdrawn by the action of water, he used six samples of chrome leather, namely : Foreign bends ; English bends ; heavy sole leather ; strips of sole leather ; bul- lock leather, and calf leather. The samples were cut into pieces of two inches square, and the resulting percentage of chromium calculated as potassium bichromate as follows : — • Total percentage of chromium calculated as potassium bichro- mate : Foreign bends 3.30 per cent., English bends 3.47 per cent., heavy sole leather 3.97 per cent., sole leather strips 4.80 MINERAL TANNING. 637 per cent., bullock leather 6.18 per cent., calf leather 3.50 per cent. The quantity of potassium bichromate withdrawn was as follows : — a. By boiling with water for half an hour: — Foreign bends, 0.005 per cent. ; English bends, 0.048 per cent. ; heavy sole leather, 0.006 per cent. ; sole leather strips, 0.018 per cent. ; bullock leather, 0.054 per cent. ; calf leather, 0.006 percent. h. By immersion in cold water for 12 hours : — Foreign bends, 0.004 per cent. ; English bends, 0.019 per cent. ; heavy sole leather, a trace ; sole leather strips, 0.006 percent.; bullock leather, 0.022 per cent.; calf leather, 0.060 per cent. c. By immersion in cold water for 24 hours : — Foreign bends, 0.005 per cent. ; English bends, 0.027 per cent. ; heavy sole leather, a trace ; sole leather strips, 0.007 per cent.; bullock leather, 0,043 per cent.; calf leather, 0.077 per cent. d. By immersion in cold water for six days: — Foreign bends, 0.014 per cent.; English bends, 0.091 per cent.; heavy sole leather, 0.025 per cent.; sole leather strips, 0.017 per cent. ; bullock leather, 0.135 per cent. ; calf leather, 0.123 per cent. A sample of good leather tanned in the nsual manner and obtained from one of the best English tanners on being treated in the same way gave the following results : — a.^ Withdrawn by boiling in water for half an hour=2.13 per cent, (containing 0.77 per cent, of tannic acid). b. By immersion in cold water for 12 hours=2.99 per cent, (containing 1.08 per cent, of tannic acid). c. By immersion in cold water for 24 hours=4.45 per cent, (containing 3 per cent, of tannic acid). d. By immersion in cold water for 6 days= 6.79 per cent, (containing 2.55 per cent, of tannic acid). ' That less extraction occurred by boiling than by immersion in cold water for 12 hours is probably explained by the fact that by boiling a part of the skin substance is converted into glue, which forms an insoluble precipitate with the tannic acid. 638 THE MANUFACTUEE OF LEATHEK. From the above results it will be seen that the quantity ot potassium bichromate extracted by immersion of chrome leather, even if continued for 6 days, is exceedingly small, and this quan- tity, small as it is, is in all probability still further decreased by the reducing action of organic substances upon the chromic acid. Dr. Clark concludes his report as follows: "I am firmly con- vinced that the remainder of the chromic salts cannot be with- drawn from the leather by any influence to which it may be exposed in use." We give in the two following tables the results of two Eng- lish experimental stations as to the stretching capacity of chrome leather and tan leather. MINERAL TANNING. 639 £^ ^ 5 1— I 1— I rH (M rH I— i rH (M T— I Tl Ti ni f5 fi fi 1) CD O- m W cq r£3 ^ fl pa pq i 2 ^ ^ ^ ^ .So Sc ^ ,2J ^ ^ f=^ fe fn pq cq pq pq H^'-i -ia;^r-i;-iaicL; n m « fl CO ft <1 ^ .SP 9 M Ph Ph :h S Ti 03 % ^ i» 'ji cB .^ ft crt g tc ft S a; ft OS t, ft » a 5 p:i g 640 THE MANUFACTURE OF LEATHER. ^ S 6 ^ « cc ^ 5^ ><; -« 5J5 1) s •O !- oi (yj .S ^ t>i s ^ fi ^ ^ o «D & CO § (M o 6 •^ a a ■^ ^ cq (M cq M< «D o CO o cq cq rx> S , ox- Oi 1:^ CD 1— 1 CN ^ Tf i-H 1—1 00 rt S cq ^ c4 o ^ ci oq Co' ai d t-- 1^ t— CO t-^ Pi I— 1 13 ^ 03 O 1^ 1 CO CO 00 o (?q cq cq o cq o cq CD cq " ^ ^ -^ (N !-( OS CO oo c/; i>; 00 CO CO J:^ 03 oD «5 oj 00 t-^ uri t^ IC O t;JH Tji ^ CO Tli P. 1 •^xinii Suiqo'ja.i^s •;irai^ Suup^8j|g 0) Is t^ CO cq iX' oi i-H u:5 cq cq t- CO CO th lO !3 oi o t— a: oD CO 1— 1 l>- lO J:^ O c^ tJi J^- -aS cq <^ t^ t-H o: o CO CO cq GO 1—1 lo lo lO .- o Ft, CO* CO CO •^' CO '^ CO cq' CO CO -^ CO CO CO ^~ s ri ® ^ "^ GO oi CO -Tfi cq ^ t^ -<* CO C5 CO CD 1— 1 lO o — 1>- C^l rH CO Oi 1^ t- •* O »« oo in CD lO |5 CO CD r^ CO C5 !■- 1-^ CO t^ Tt< cq i-i CO "* =w ^^ t-^ lO Tjl T;ji Cq 1-1 TJH urj co' •^' CO cq' i-i CO .« CL a O CO o o o o o o o o o o ^ ' cq to oi c t-- ^ O Tf m o o cq V ? "O rH rH 00 CD -^ 5 3i Cq' I-H l-H rH O O cq rA ,^ d d d W C . . o tl) ^ .J3 1 ^ ^ 1 bo be g h-l M CO CO lo CO in cq 03 in a; CO O O rH C3 s W SB cq oq cq ?q cq M d d o d d o 33 > I cq r^ cq CI cq cq <£ <£ d d- d><^ > W >>:.... c4 W ^. — . . s OS W oo CO la -TtH CO cq p 00 CO lo "^ CO cq c g o hJ o « K aj <1 o H a; o p^ o 0) ^ ■*-' 13 5)- o -a D 02 * ;^ o ^ r^ !5 MINERAL TANNING. 641 The foregoing statement indicates : 1st. that chrome leather excels in strength ; 2d, that after reaching the stretching limit with a corresponding load, it possesses still a considerable degree of elasticity which is of great value as regards the adhesion of belts to pulleys. Alum inium Ta nning . This patented method of tanning originated with Dr. Patz, of Passau. The skins are prepared in the usual manner and then completely tanned with a solution of aluminium sulphate or common salt. After tanning, the tannin, it is claimed, is pre- cipitated upon and fixed in the skin by fulling in an insoluble precipitate produced by boiling hair, horn, blood, and other substances containing albumen, with a solution of potash or caustic soda, and precipitating the resulting solution with alumi- nium sulphate or other aluminium salts. List of all Patents for Employing Mineral Substances for Tawing Hides and Skins, issued hy the Government of the United States of America, from 1790 to 1883 inclusive. No. Date. Inventor. Residence. 17,955 Aug. 4, 1857. H. Hibbard, Henrietta, N. Y. 21,168 Aug. 10, 1858. T. Klemm, Pfullinger, Germany. 46,443 Feb. 21, 1865. Gr. Bottero, Boston, Mass. 86,506 Feb. 2, 1869. F. Clozel, Paris, France. 159,366 Feb. 2, 1875. W. R. Stace, Rocliester, N. Y. 193,520 193,521 July 24, 1877. ) July 24, 1877. S F. Knapp, Brunswick, Germany. 231,797 238,389 Aug. 31, 1880. \ Mar. 1, 1881. ) C. Heinzerling, Biedenkopf, Germany, 260,322 260,418 June 27, 1882. \ July 4, 1882. ) C. Richter, St. Paul, Minn. 281,411 July 17, 1883. C. P. Smallridge, Sr. , Catlettsburg, Ky. 287,255 Oct. 23, 1883. F. E. Dietsch, Woodbury Falls, N. Y Note. — For a portion of the matter in this chapter the author desires to acknowledge his indebtedness to Heinzerling's Lederbereitung, BoUey's Tech- nologie, 35 (Bd. vi. 4). 41 642 THE MANUFACTURE OF LEATHER. CHAPTER XLII. TAWING — FRENCH OR ERLANGER METHOD OF TAWING — DAN- ISH GLOVE LEATHER — JENKINS'S METHOD OF TAWING — DE- FECTS OF ALUMED VARIETIES OF LEATHER- — MANUFACTURE OF OIL OR CHAMOIS LEATHER — PRELLER's METHOD OF TAWING — KLEMM's OIL LEATHER. French or Erlanger Method of Tawing. The manufacture of soft leather for gloves, i. e., the so-called French or Erlanger leather, which was originally a French industry, has also been lately brought to a high degree of per- fection in Germany and Austria, and especially in Prague. As these varieties of leather are intended for articles of fashion and luxury, they require all the properties of alumed leather in a higher degree, according to whether the articles manufactured from them are to be a pure uniform white, or a light delicate color. These demands can only be fulfilled by using the most scrupulous care in preparing the skins, great cleanliness, and avoidance of anything which might cause stains, such as the use of vessels of oak, water containing iron, etc. It is besides necessary that the gloves should possess a more than ordinary capacity of stretching, and a high degree of suppleness, while they must at the same time be strong and durable, and the grain sound and free from all injury. They must further adapt them- selves to the hand, and by their capacity for stretching supple- ment the natural inaccuracies of the pattern, and, what is the most difficult to avoid with such tender skins, not tear in the seams or the leather. The utmost care in working the raw material alone will therefore not suffice, since the quality and availability of the leather will largely depend on the quality of the skins. Besides conducting the tawing process with care and cleanli- TAWING. 643 ness, a manufacturer who desires to bring into the market au article answering all demands, should therefore know how to select and buy the skins to be worked. We will therefore, before treating of the tawing process itself, give a few practical hints as regards the buying and stor- ing of skins intended for glove leather. Buying and Preserving the Rata Skins. The skins most generally used for the manufacture of glove leather are those of lambs and kids, together with a few other light varieties such as skins of chamois, dogs, etc. The skins of unborn, or at least very young lambs, which are brought into commerce principally from England and Hamburg, furnish an especially fine material for glove leather. Generally speaking, kid-skins are preferred to all other varie- ties, as they furnish a more tender and a finer variety of leather than all others, with the exception of chamois-skins, which are also very highly esteemed. Skins of young lambs, especially of those not more than one month old, give also a very good and flexible leather, though this is not the case with old skins, which can therefore be only used for the manufacture of an inferior quality. Kid-skins being comparativel}' rare, skins of young lambs, the Silesian and Spanish being preferred to the Hungarian, Servian, etc., are almost exclusively used for the manufacture of glove leather. Large quantities of lamb-skins have also been recently imported from South America, especi- ally from Buenos Ayres, which, though equal in quality to the Hungarian skins, are inferior to the Silesian and Spanish articles. As regards dog-skins and cat-skins, which are less frequently used, much depends on the age of the animal, and the breed. A kid-skin should, in order to be classed as a commercial article, measure at least 10 to 10| inches square ; of the smaller skins three are generally counted for two, or even two for one. As regards lamb-skins, those from long-wooled species are the l?est. The skins of half- blooded breeds have but little value for the manufacture of glove leather, and those of full- blooded stock none whatever, as they are usually very thin and porus, and have but little strength, on account of the epidermis 644 THE MANUFACTURE OF LEATHER. being generally imperfectly connected with the true skin. The great difference in the quality of these skins is partly due to the sheep themselves, and partly to the food. It may, however, be laid down as a general rule, that the coarser the wool the better the skin for the manufacture of glove leather. By crossing he-goats and ewes a bastard breed is obtained, the skin of which, though bearing wool, approaches that of kid, and furnishes good material for glove leather. The price of lamb-skins, which varies very much, depends largely on the quantity and fineness of the wool, and the size and quality of the skin itself. After the lambs or kids are weaned, and commence to eat other food, the skin gradually loses more and more of its beauty and suppleness, and consequently its value for glove leather. The skin of a lamb fed partly on the milk of the mother and partly on other food, loses comparatively little in quality. A good skin should be smooth and lustrous, and slightly trans- parent without being too fat. After procuring the required stock of skins, the tanner pro- ceeds to sort them according to derivation, size, and age. A large stock of skins should never be stored away without previous sorting, since, after a lapse of time, it will not be possible to tell accurately the age of a skin nor its derivation, while it is of the utmost importance for the production of good leather to use for any tawing process only skins as uniform as possible. The skins, after sorting, are stored in a dry and airy loft or shed. While stored they are exposed to many dangers, espe- cially during the hot season of the year. Among the principal injuries to which skins are subjected while stored, we may mention such as arise from heating and the attacks of moths. Heating, to which kid skins are especially exposed, is actually nothing but the appearance of a superficial putrefaction attended, in consequence of the skins being closely piled, by a more or less strong heating which materially promotes the de- composition already commenced. As skins not entirely dry before storing are principally affected by this evil, special atten- tion must be paid to the thorough drying before piling upon TAWING. 645 eacli other. But even witli entirely dry skins, the tanner should assure himself from time to time, by an examination of the sep- arate ones, that heating has not made its appearance, and to stop the evil immediately, in case he finds the slightest indication of it, hy spreading the respective skins in the sun or in a dry and airy place. Although a slight heating of the skins, such as is frequently observed during damp weather, effects no material injury, too much of it will certainly cause considerable damage. Heating renders them soft, spoils the grain, and causes the wool to fall out. Although these injuries may frequently not be ob- served at once, they will be only too plainly perceived in the after-treatment of the skins. The damage by moths is caused by the deposits of larvae of certain moths in the wool of the skin. From the middle of spring to the end of summer small, silver gray butterflies are observed, especially in the evening, flying around in the houses. These are the genuine moths appearing most frequently in July and August. These nocticidse take no nourishment and possess no weapon with which they could cause damage. Their only object is to form a sexual union, and this being accomplished the female lays its eggs upon clothing, furniture, etc., but preferably upon wool or fur. The eggs are so small as to be scarcely perceptible with the naked eye. The larvae make their appearance in a few weeks, sooner in warm weather than in cold. Only the eggs and larvse can stand the cold of winter. Although the moths themselves are generally known, this is not the case with the larvae, as they live in hidden places and are so small and insignificant as to escape observation. It may, therefore, not be inappropriate to give here a short description of these enemies of wool. The extremely small grub of the moth, which externally does not differ materially from other larvae, is provided on the forepart of the body with three pairs of horny feet, which together with the mandibles and a part of the scutellum, form the only horny part of the body. The first business of the grubs after emerging from the eggs is the con- struction of a cocoon. For this purpose they weave first a thick, spindle-shaped tube around their centre, and enlarge this tissue, 6^Q THE MANUFACTURE OF LEATHER. consistiDg of delicate silk-like threads, by biting off with their mandibles the hair of the wool or fur surrounding them, and attaching them with a sticky substance secreted by them. This cocoon, which is open on both ends, has the same color as the wool or the hair of the skin, or the tissue in which the grub lives. In the same degree as the grub grows, the cocoon be- comes too short and narrow. When this is the case the grub projects the fore-part of its body from the cocoon and, after bit- ing off with its mandibles the wool or hair within reach, and enlarging the cocoon on that end by gluing the wool to it, turns around and performs the same operation on the other end. To widen the cocoon the grub gnaws through the entire length and inserts a new piece by gluing in wool or hair. When the grub has nearly attained its full growth, and the time of meta- morphosis approaches, it leaves its place of concealment and moves into the open air where, after attaching one end of the cocoon to a wall, woodwork, etc., it changes to a chrysalis. The perfect moth emerges after three weeks, during which time the chrysalis does not leave its place of abode. While the grubs of the genuine moth carry their cocoon with them, there are others, for instance, the ascarides, which build permanent cocoons in the form of passages of greater or less length on the base of the fur in which they live. The damage done to the skins by these insects not only consists in the destruction of the wool, which would be of little consequence, but in injury to the skin itself by the perceptible traces they leave upon it which damage the grain and quality of the leather. The best means of getting rid of these insect pests is to air the skins every eight or ten days during the hot summer months, and, if possible, beating them thoroughly in order to re- move any larvae alread};- in the wool. In cold weather beating every three or four weeks suffices. To be successful it is not sufficient to beat the bales, but each skin must be handled sep- arately. To avoid this work which, though sure, is very tedi- ous, many preservatives have been recommended, for instance, placing powdered pepper, the blossoms of Eoman camomile, leaves of patchouli, etc., between the skins, or sprinkling them with carbolic acid, spirits of camphor, etc., or scattering insect TAWING. 647 powder or sumach upon them. The best of these means, none of which is entirely effective, is perhaps carbolic acid or a mix- ture of birch oil and camphor, but they impart to the skins a penetrating odor which is not lost even by the succeeding treat- ment, and can only be got entirely rid of by long continued airing. Manner of Working the Shiyis. The principal difference between the ordinary and French method is in the actual tawing process and the means used to accomplish it, the preparatory labors being in the main the same. The work of tawing leather according to the French or Er- langer method is divided as follows: — 1. Soaking and Ritising. 2. Liming and Depilating. 3. Treating with hate. 4. Handling in the bran vat. 5. Tawing in the tawing comjoound. 6. Finishing . 1. Soaking and Rinsing. As previously mentioned, it is of great advantage for the manufacture of good glove leather to work skins in as nearly the same manner as possible, in order to obtain a nearly uniform pro- duct. This should be taken into consideration at the commence- ment of the work by soaking skins as nearly alike as possible and their differing not too much as regards age. Soaking and rinsing are effected either in running water, or if possible in the "soaks." The soaking is continued until all the skins are uniformly soft and freed from adhering dirt and blood, and thoroughly cleansed on the flesh side as well as on the wool side. In order to obtain clean wool, which is more salable, the wool side is frequently scrubbed with soap, though this labor is of course omitted in handling very young lamb-skins, the wool of which has no commercial value. In soaking and rinsing, special care must be had to have the water free from impurities, especially mud and iron, and not to use vats of oak, but of soft wood. In regard to the duration of soaking we will state that, as the skins of young animals, such as kids and lambs, have to be chiefly taken into consideration, 6i8 THE MANUFACTURE OF LEATHER. three days in winter, and at the utmost two days in summer should suffice for the process. After soaking and rinsing the skins are subjected to the breaking process, which is effected in the same manner and with the same tools as in ordinary tawing. A clean beam and a fleshing knife free from rust, and not too sharp in order to avoid injury, are required. In breaking the skins their great tenderness and susceptibility to injury must be taken into due consideration. After breaking and another rinsing, the skins are ready for depilation. In most places this is proceeded with at once, while in some taweries the skins are placed in bate for two to twenty- four hours to make them more susceptible to the action of the lime and accelerate the loosening of the hair. 2. Liming and Depilating. It is usual to consider 13 to 15 pounds of thoroughly burned limed, slacked to milk of lime, as being required for 100 goat- skins, or equally large lamb-skins. The process of liming is conducted either by using several lime-vats with lime water of different strengths, and putting the skins successively from the weakest lime-vat into the strongest, or what is more generally the case, by employing but one lime-vat and increasing gradu- ally the concentration of the lime water. For the latter purpose the entire quantity of lime to be used is generally divided into four equal portions, and the lime-vat, which is generally filled with lime water previously used, is charged for the first liming with one quarter of the entire quantity of lime. After thorough stirring throw each skin separately into the vat so that it falls with the wool side down upon the surface of the milk of lime, and push down with a pole. In this vat the skins remain, according to size and age, for one to three days, though in winter they are generally allowed to remain somewhat longer. The skins are then lifted out with wooden tongs — iron tongs must be absolutely forbidden — and hung upon the edge of the vat to drain off. After preparing milk of lime from a second quarter of the lime, with the avoidance of too great an excess of water, and TAWING. 649 adding tliis to the lime-vat, the skins are replaced in such a manner that those previously on the top come now on to the bottom. The skins after remaining in this vat for two to four days according to the season, are taken out and allowed to drain off. After converting the third portion of the lime into milk of lime and adding this to the vat, the skins are replaced. After 4 days they are again taken out, allowed to drain off, and replaced after adding the milk of lime prepared from the last portion of the lime. In this vat the skins may remain 6 to 8 days, but must be handled every 24 hours and replaced in reverse order. During this time the skins should be frequently examined, and those, where the hair or wool is found to yield, removed. After removal from the lime-vat and rinsing in clean water, the skins are placed in clean water and depilated successively, and after depilation thrown into a vat filled half full of water. In depilating the greatest care must be observed to avoid injuring the grain by too strong pressing, and to be able to do this, the skins should not be taken from the lime- vat until the hair or wool is thoroughly loosened. The method above described is principally employed for kid- or young lamb-skins. Frequently a mixture of orpiment and lime, or of gas-lime and lime, is used for loosening the hair. For depilating the skins of older animals, especially those over a year old, the sweating process previously described is generally employed. But in order to yield supple leather such skins must, after depilation, be placed in the lime-vat for 3 to 4 days. The skins are then topped or docked, and, after break- ing them upon the beam and cleansing, are thrown into a vat filled with water. To prevent the skins from becoming spotted, they must at no time be allowed to remain long oat of water. 3. Treatment in Bate of Dog Excrements. This work is frequently connected with the so-called fulling, and sometimes entirely replaced by the latter. As regards the preparation and use of the bate we refer to what has been said about it under tanning, only calling attention to the fact that 650 THE MANUFACTUEE OF LEATHER. the action of the bate must be shortened in accordance with the weaker texture of the skins.^ After removal from the bate, the skins are either at once broken and rinsed or first fulled. For the latter purpose 300 to 500 rinsed skins are placed in the fulling trough and pounded thoroughly with a rounded-off" wooden mallet. After a quarter of an hour a bucketful of clean water is poured into the trough and the fulling continued for twenty minutes longer, when an- other bucketful of water is poured in and the fulling again con- tinued for twenty minutes. The skins are then placed in a vat full of clean water for one to three days according to the season of the year. The fulling can also be effected with a washing wheel such as is frequently used by manufacturers of Morocco leather. A washing wheel much used in Germany and France is ar- ranged in the following manner: A wooden drum, with a diameter of ten feet and a width of rim of three feet four inches, lies with its horizontal axis in brass boxes, and motion is im- parted by means of a crank or driving gear. The drum is shown in Figs. 294 and 295, and the interior is divided by parti- tions into three or four compartments in such a manner that each compartment is accessible from the exterior through a large aperture, d, in the rim of the drum, which serves for the introduction of the skins and can be closed with the slide i. Short cross ribs projecting towards the centre are arranged on the arch of the compartments, i. e., on the inside of the rim, which is perforated with fine holes. The outside of the rim is provided with small laths nailed on zig-zag. The object of these, and of the laths on the edges of the rim, is to prevent as 1 In most taweries the bate is generally prepared by soaking dog excre- ments in water and stirring them to a uniform paste, of which 2^ to S^- gallons mixed with a sufficient quantity of water of 95° F. are used for 1000 young lamb-skins. The depilated skins remain in the bate for about 3 hours, or at the utmost until the remnants of flesh can be readily detached. The skins sufl'er injury by remaining too long in the bate. We would here call attention to the fact that dog excrements are frequently adulterated with human excrements. Tlie tanner should be very careful in regard to this, since the abundance of bilious coloring matter in human excre- ments is apt to cause the finished leather to be spotted. TAWING. 651 mucli as possible a waste of water falling from the rose A, which is placed above the drum. Fig. 294. Fi^. 295. The manner of using the drum for fulling is as follows : The drunx, after placing the skins in the different compartments and closing the slide, is set in motion and water allowed to fall continually through the rose upon the rim of the drum. The manner in which the machine works is self evident. The skins in the compartment occupying the lowest position during the revolu- tion of the drum lie upon the arch, i. e., the inside of the rim provided with projecting ribs. They remain here until by the upward movement of that part, they fall, by gravitation, towards the interior upon one of the partitions, and by the downward movement back upon the arch. By 652 THE MANUFACTURE OF LEATHER. this continual falling backward and forward, the skins are sub- jected to an action having the same effect as a gentle beating. During the upward movement they are at the same time con- stantly washed by fresh water falling into the drum from the rose, while the dirty water runs off on the compartment attain- ing its lowest position. These operations effect mechanically a complete removal of the lime soaps and other lime combinations from the skins and wash them thoroughly, and assist materially the action of the bate, the object of which is to produce the same results chemically.^ After removal from the bate or fulling drum, the skins are scraped upon the grain side with a dull scraping knife, and then rinsed in clean water, the latter operation being more effectively accomplished by another treatment in the fulling drum. The next operation is to break them upon the beam by working upon the flesh side with a sharp fleshing knife in order to re- move the last adhering remnants of flesh and fat tissue. They are then rinsed and finally scraped again upon the grain side, this being, if necessary, repeated after rinsing. Generally only heavy skins, especially goat skins, require this repeated scrap- ing and fulling. Light skins, such as kid, and young lamb- skins, cannot stand, nor do they require, scraping twice, allow- ing them to remain only for a short time in the bate and fulling drum being generally sufficient. A thoroughly worked skin shovild, on being taken from the water, fold together like soft cloth, be elastic and at the same time tough and have a uni- formly white or greenish-white appearance without spots. The next operation is — 4. Branning . The bran menstruum by means of which the skins are raised and the last traces of lime removed from the skin tissue, in con- sequence of the free acids formed by fermentation, is prepared and used in a similar manner as in ordinary tawing. Due con- 1 Manj' tawers add some soda to the water used for fulliBg the skins, or draw the skins, after removal from the bate of dog excrements, through a weak solution of soda. TAWING. 653 sideration should be given to the great tenderness of the skins and great care exercised to prevent too much raising and possi- bly total destruction. The bran used in preparing the menstruum should be as fresh and pure as possible, and especially free from sand and dust. For 100 medium sized skins, soak 2| pounds of bran in cold water, and let it stand 3 or 4 hours with frequent stirring. The water with a large part of the impurities floating upon the sur- face, or held in suspension, is then poured off. On to the washed bran pour as much water as will cover the skins to be treated, and, after thorough stirring, add 9 ounces of pure com- mon salt.^ In this steep the skins remain for 10 minutes when they are turned, and allowed to rest after securing their entire immersion by weights or cross-pieces of wood. The temperature of the menstruum should never sink below 50° F., nor rise much above 68° F. In the first case the temperature is raised by an addition of warm water, and lowered in the latter case by add- ing cold water. Great care should be observed in not carrying on the fermen- tation too vigorously, and in preventing the appearance of a putrid odor, as otherwise the raised skins would easily suffer destruction. When sufficiently raised, the skins are taken from the liquor and washed in fresh water, or placed upon the beam and scraped upon the flesh side, the latter being especially pre- ferable to mere washing in case the skins should be raised too much, it being possible to reduce this evil somewhat by scrap- ing.^ The next operation is — 5. Tawing. The object of this operation is not only to taw the skins but to treat them at the same time with the oil required to make them supple, and subject them to the action of flour, which im- parts to good glove leather its characteristic fulness and soft- ness. The tawing paste generally used consists of a mixture of 1 In many taweries this is omitted. 2 We would here remark that many tawers, in case they have treated the skins with a bate of dog excrements, do not use this bran steep. 654 THE MANUFACTURE OF LEATHER. solution of alum and common salt with yelk of egg and fine wheat flour. The following recipe for its preparation may be especially recommended : — For 100 medium sized skins dissolve IJ pounds of common salt, and 5J pounds of alum entirely free from iron, in 9 pounds of boiling water. Then make a paste by stirring gradually into 14J pounds of the best wheat flour, and a little cold water, the yelks of fifty fresh eggs. Knead the paste in small portions with a gradual addition of water, until it has become thinly liquid; the formation of lumps need not be feared when brought in contact with more water. Then add 9 pounds more water to the paste, stirring constantly and vigorously, and finally mix it with the hand-warm solution of alum, and com- mon salt. The skins are then placed in a vat, and after pouring the lukewarm paste over them, worked thoroughly with the hands to moisten them uniformly. When this is done a thor- ough penetration of the paste into the skin tissue is effected by a workman with bare feet stepping into the vat and treading the skins slowly but vigorously by alternate raising of the feet. This treading, for which no suitable mechanical appliances have thus far been invented as a substitute, is continued until the skins have absorbed most of the paste, which for thin skins will require 1 to 1^ hours and for thicker ones about 2 hours. The vat is then covered with a clean cloth, and, after allowing the skins to rest for 12 to 14 hours, the treading is repeated in order to make them thoroughly smooth and supple. To promote uni- form treatment it is recommended to turn the skins occasionally during the treading, and, to secure uniformity of the product, it is not advisable to subject more than 500 skins to the process at one time. After the second treading, during which it is customary in some places to pour off the remainder of the tawing liquor and replace it by lukewarm water, the skins are allowed to rest for a few hours, and are then stretched before drying. The object of stretching is to effect a uniform extension of the skins, which by the treatment in the tawing paste have become somewhat wrinkled. Two workmen, standing opposite to each other, take hold of each end of the skin and, after folding it grain side in. TAWING. 655 Stretch it as mucli as possible lengthwise. For drying, the stretched skins are suspended on poles, or fastened to strings by means of pins in such a manner that they hang free for almost their entire length. The latter method is preferable, as in the first the portion of the skin lying upon the pole will almost always turn out somewhat thicker, and besides become easily spotted in dyeing in consequence of the tawing paste piled up in these places. The principal point in drying is to effect it as quickly as possible, and for this reason the skins should be hung up in airy lofts which can be heated in damp weather. Skins drying slowly spot easily, or acquire a reddish shade difficult to remove. Instead of the yelk of egg many tawers use olive oil as an addition to the tawing paste. This gives also a very supple and soft leather, provided the workman understands how to divide the oil very finely and to mix it intimately with the tawing paste. This is done by rubbing together in a mortar, such as druggists use, 2^ pounds of the best wheat flour with sufficient water, or still better, thin gum mucilage, to form a stiff paste. Add to this drop by drop and very gradually, and stirring con- stantly with the pestle, 10 ounces of the best olive oil, and rub the mass until a sample mixed with a little water separates no globules of fat after continued standing. The mass, the prepa- ration of which is rather tedious, prepared in the above propor- tions contains an equivalent of about 100 yelks of eggs, and is mixed with the tawing paste in the same manner. A still more perfect emulsion is prepared by stirring gum arable finely pul- verized, instead of wheat flour, into a thick paste with water, and adding to this the oil with constant stirring and rubbing. About IJ pounds of gum arable will suffice for 9 ounces of oil. The use of this substitute for yelk of egg, though quite profitable, can only be recommended for inferior qualities of leather, and can only be rendered harmless by treading the skins a second time in clean water in order to remove the adhering gum substance, which otherwise would injure the softness of the leather in drying. Another mixture suitable for a substitute for yelk of egg, which is sometimes difficult to procure, can be prepared by 656 THE MANUFACTUEE OF LEATHEE. mixing intimately 8 J ounces of fresli almond oil, 8 J ounces of fresh casei'ne (such as is brought into the market under the name of curds), 12| ounces of dextrine, 1 ounce of borax. The mixture is effected by putting the caseine in a stone-ware mor- tar and pouring over it the borax dissolved in as little boiling water as possible. After placing the mortar in a warm place, the hot mass is rubbed together until the caseine is almost dis- solved and a tenacious liquid drawing threads is formed. To the borax and caseine then is next added, with constant rubbing, the pulverized dextrine, and after forming a uniform paste, the almond oil is added, drop by drop, and the rubbing continued until after about three-quarters of an hour the oil has been thoroughly mixed. The paste thus obtained can be diluted by slowly adding water, and the previously prepared wheat flour kneaded with it. A mixture of the above proportions answers as a substitute for 100 yelks of eggs, and can, as has been proved by many experiments, be used for the finest qualities of leather.^ Besides the above, many other substitutes for yelk of egg are used, and have been recommended. In Parisian taweries calves' brains, intimately mixed with wheat flour, are used as a substitute for yelk of egg, ^ oz. of brains being generally allowed for 1 yelk of egg. The brains of sheep and even of cattle are also used for this purpose, they being the more available the younger the animals from which they have been derived. In using such brain substance, it is recommended, in order to remove the bloodvessels, to rub it through a wire sieve with fine meshes, or to press it through large cloths. According to Knapp, paraffin also furnishes an available substi- tute. He uses crude paraffin oil intermixed with crystals of j^araffin. This, after heating until the crystals dissolve, is rubbed to an emulsion with starch-gum, and the resulting mixture compounded with salt, alum, and flour. This tawing paste imparts, it is claimed, a beautiful grain to the leather and suffi- cient stretching capacity. • In using tliis mixture it is recommended to substitute for the alum in the tawing -paste a corresponding quantity of aluminium sulphate. TAWING. 657 In many tavveries it is customary to substitute oil for a part of the yelk of egg by using about 2 tablespoonfuls of olive oil for each 20 yelks of eggs. In this case an intimate mixture of the yelk of egg with the oil, which can be easily effected by adding some flour, is absolutely necessary, as otherwise the spotting of the leather can scarcely be avoided. . In regard to the object of using a tawing paste such as plays a prominent part in the manufacture of French glove leather, the two never wanting constituents, alum and common salt, fuliill the same functions as in ordinary tawing, i. e, the alum is the actual tawing substance, while the effect of the salt is to promote the endosmose. But what eft'ect do the yelk of egg and the flour produce ? Every practical tawer knows that the object of the yelk of egg is to impart suppleness to the leather, and there can be no doubt that it fulfills the purposes. Researches have shown that 100 parts of yelk of egg contain — Water .... 48.4 parts by weight Albumen .... 20.6 " " Yellow oil of egg . . 31.0 a 100.0 " " As neither water nor albumen possesses the power of impart- ing suppleness to leather we must assume that the fat contained in the yelk, i. e, the oil of egg, is the effective agent. From the fact that yelk of egg has been shown to be decidedly the best means of obtaining supple leather, we might naturally come to the conclusion that the oil of egg is, on account of its constitu- tion, especially adapted for this purpose, or possesses properties not belonging to other oils. But this is by no means the case, and from the possibility of substituting other suitable mixtures for yelk of egg, it is clear that other fats properly prepared and used produce the same effect. The valuable qualities of yelk of egg are not found in a special constitution of the oil of egg, but are based upon other causes. We have already laid stress upon the fact that in preparing Erlanger or French leather it is abso- lutely necessary to have the fat finely divided before bringing 42 658 THE MANUFACTURE OF LEATHEE. it in contact with the leather. Fats mix with aqueous fluids with difficulty or not at all, and after an artificial mixing has been effected, a separation of the fat from the aqueous fluid will sooner or later take place. For producing a permanent mixture of fat with an aqueous solution, the latter must possess the property of preventing the union of the small globules of fat suspended in it without changing the constitution of the fat itself. This property is especially possessed by ropy and thickly fluid liquids, and for this reason it is possible to give water to a certain degree the power of mixing intimately and permanently with fat by adding gum and similar bodies, and also albumen, etc. But such artificial emulsions are not entirely permanent. Though gum mucilage, albuminous fluids, etc. render the running together of the globules of fat more or less difficult, they do not prevent it entirely, since the fat divided in such artificial emulsions separates from it after long standing. But this is not the case with yelk of egg which contains the fat in microscopically small globules enveloped in a film of albumen. As long as the envelopes are not removed or broken by artificial means, a union of the globules of fat is not possible, yelk of egg being therefore a natural and very complete emulsion of the oil of egg in an albuminous mass, which can be diluted with water without destroying the films enveloping the separate globules of fat. Independent of any other advantage the yelk of egg possesses that of being very convenient, since every other fat to be used for the same purpose requires tedious and time-consuming work for its fine division, while the former offers an emulsion ready made by nature. Having shown the advantages of the use of yelk of egg, it still remains for us to answer the question: What is the object of introducing fat into the skin tissue, and what effect does its presence produce upon the tissue of the leather? By assuming leather to be a skin tissue the fibres of which have lost all power of adhesion, and designating such leather as supple in which an easy shifting and moving of the tissue fibres, which are liable to friction on many points, are accomplished, the signifi- TAWING. 659 cation of fat in the tissue will be clear. The fibres, on the one hand, are rendered supple by the fat enveloping them, and, on the other hand, the friction produced by the moving and shifting of the fibres is reduced to a minimum by the intermediate layers of fat. By the word "/««;" we should of course not understand an unaltered substance, but rather the products of decomposi- tion gradually formed by the action of atmospheric oxygen. Independent of the specific action of the fat oil contained in yelk of egg, it would seem that the albumen of the latter, besides serving as a means of division and a carrier of the emulsion, ful- fills another function. This much seems to be proved by experi- ments of Knapp, who has shown that the precipitate produced by alum from solutions of albumen is easily and completely absorbed by the skin when kneaded with it, imparting to it a certain degree of tawing. According to this, the albumen con- tained in the yelk of egg would, on forming a combination with the alum or the alumina contained in it, pass into the skin tissue, and by depositing itself upon the separate fibres, assist not only in effecting a complete tawing, but increase at the same time the fullness and consequently the strength of the leather. The attainment of a certain fullness seems, however, to be essentially the task of the third constituent of the tawing paste, viz., the flour. The opinion was formerly entertained, that the object of adding flour to the tawing paste was to obtain as white a leather as possible. But this is only true in an indirect sense, since the actual part the flour takes in the tawing process is an entirely different one. Independent of some constituents, which are of minor interest to us, we have only to consider the more prominent constituents of flour, i. e,, the starch and so-called gluten. Of these, starch, a hydrocarbon found in small white granules in the cells of plants, is well known. Gluten being less known, we will mention here, that by this name is designated a constituent of the seeds of almost all varie- ties of grain, and it is a mixture of two albuminous bodies known as vegetable fibrine and vegetable glue. As, according to this, flour is a mixture of several bodies, the question we must pro- pose is, whether all the constituents of the mixture take part in 660 THE MANUFACTURE OF LEATHER. the tawing process, or, if this is not the case, which are of the most importance. The opinion was formerly generally entertained, that the availability of the flour depended on the starch, but at present there can be no doubt that the eftect of the flour is due to the gluten. Knapp has shown by suitable experiments that leather tawed in a paste containing flour contains no starch whatever, but that the combination of the gluten, or, as previously men- tioned, of albuminous substances in general, with the alumina of the alum, is absorbed by the skin and may even completely taw it. The action of the flour in the tawing paste is therefore easily understood. The albuminous bodies in the flour combine with the alumina in the alum added to the tawing paste, and the combination thus formed is deposited, after passing into the skin, around the fibres of the tissue in the form of a loose voluminous precipitate, which, by augmenting the body of the separate fibres, imparts to the entire tissue a certain degree of fullness. Although the principal effect of the flour must, according to- this, be attributed to the gluten, the starch is by no means an unimportant con- stituent. Knapp, in his manj^ experiments in regard to tanning and tawing, observed that certain combinations of alumina obtained as delicate voluminous precipitates by precipitating proteids with alum, form lumps when an attempt is made to knead them into the prepared skin and lose their capacity of penetrating into the skin tissue. To overcome this evil, the presence of another indifferent body is required which, by depositing its fine particles between the interspaces, prevents the particles of the combination from approaching each other and forming lumps. This is the part the starch has to perform, which, though it is not absorbed by the skin tissue, is capable of keeping the parti- cles of the combination of alumina with gluten apart until they have penetrated the skin tissue and taken their proper position. This explains why flour cannot well be replaced by other means. To recapitulate briefly what has above been said the object of the mixture of alum, common salt, flour, and yelk of egg or TAWING. 661 its substitutes is, besides tawing, which is due to tlie alum and the conaraon salt, to impart softness and suppleness to the leather and finally fullness, the yelk of egg serving specially the pur- pose of obtaining suppleness and the flour fullness. After treating with the tawing paste and drying thoroughly, the leathers can be stored without danger in a dry place. They require only 6. Finishing, the object of which is, on the one hand, to remove the last rem- nants of adhering tissue fibres, and, on the other, to impart as high a polish as possible and a delicate smoothness to the leather. The first operation is stretching the moistened leather. For this purpose the skins are sprinkled separately with water, and after stretching evenly upon a level table, they are piled upon each other and allowed to lay for some time until they are uni- formly moist. About 12 to 15 of these moist skins are then piled upon a linen cloth upon a straw mat, and after being cov- ered with a clean cloth or a large skin especially kept for the purpose, softened by a workman treading them. Each skin is then subjected to stretching by a workman holding it distended by both ends and drawing the flesh side in every direction over the stretching iron in order to remove as much as possible all remnants of adhering tawing paste. The skins are then stretched on poles, dried, and, after repeating the treading and drawing over the stretching iron, rubbed upon the grain side with a soft woollen rag to remove any adhering flour. Skins which are to remain white, or to be dyed a light color, are fre- quently bleached by exposing them to the sun for several hours. This is not required for skins to be dyed dark. Although leather finished in this manner is ready for the market, it is frequently subjected to glazing. The object of this operation is to make the grain side as smooth as possible, it being sufficient for sound and thoroughly tawed skins to pass them through the smoothing roller, although in large factories special smoothing machines are used. The polishing is generally accomplished with a polished steel or agate roller set in a crutch handle and revolvino; around its 662 THE MANUFACTURE OF LEATHER. axis, as shown in Fig. 296. After spreading the skin, flesh side down, upon a table with a smooth wooden or stone plate, the workman passes the roller repeatedly and forcibly over the grain side of the leather. By this operation any little irregular- Fig. 296. ities injurious to the appearance of the leather and making it feel rough to the touch, are removed from the grain side, and the leather rendered smooth and to a certain degree lustrous. The same effect is produced by the use of a large polished glass or stone ball, although, as the workman has to guide the ball with the hand, and cannot exert as strong a pressure as with the smoothing roller, the process is tedious, and consequently less suitable. The use of heated rollers is very advantageous. For this purpose the steel rollers are heated either by placing them in boiling water or by means of a spirit flame, care being had not to heat them too much, as otherwise the leather might be burned or become wrinkled. We had occasion to become acquainted with a polishing roller kept hot by a simple device, thus allowing the work to be carried on without interruption. The construction, as shown in Fig. 297, is as follows : In a hollow steel roller about four to six inches long and about two and a half inches in diameter fits exactly a piece consisting of two cross spokes connected by a shaft projecting on TAWIISTG. 663 both sides. To the spokes is fastened a sheet-iron cylinder of the same length as the roller, but about one-half inch less in diameter. Upon the perfectly round and polished shaft sits an oblong spirit lamp the wick of which can be regulated, and the bottom of which, in order to keep the lamp constantly in a ver- tical position, is weighted with lead. A handle with branches for the reception of the ends of the shaft and with an upholstered crutch serves for guiding the apparatus. For working with such a polishing roller it is only necessary to regulate the flame of the spirit lamp so as to heat the roll adequately, the remain- ing work being the same as with an ordinary roller. Instead of polishing rollers ordinary flat irons are employed in many small work-shops, the manner of using them requiring of course no further comment. As regards the construction of more complicated polishing and finishing machines, the use of which, compared with their cheapness, offers great advantages, we must refer the reader to the respective patents. For inferior qualities of leather, especially such as are obtained from the skins of diseased animals, the operation of smoothing is frequently preceded by that of glazing, by spreading the leather upon a smooth table and applying a thin coat of white of egg, gum, or mucilage of gum tragacanth. In using white of egg for the purpose it is best to beat it first to a froth in the same manner as cooks do, and then add, with constant stirring, double its weight of water. By allowing the whole to stand in 664 THE MANUFACTURE OF LEATHER. a warm place for about twelve hours, an available solution of white of egg is obtained, which is applied with a soft brush, or, still better, a small clean sponge. The best proportion for gum solution is 1 part of gum to 8 to 10 of water. The leather after glazing is dried and finally polished with the smoothing roller. Leather thus treated is known as glazed or ylace leather. The above described method of preparing French or Erlanger leather, although the most common, is by no means the only one employed. Many methods differ, in fact, essentially from the one described, and, although they are, generally speaking, antiquated, and offer no material advantage, we will give a short description of them. Aikins's method of working lamb-skins into glove leather is, according to Dr. 0. H. Schmidt, as follows : — ■ After soaking the skins in water for some time to free them from adhering dirt, blood, etc., they are laid upon a beam cov- ered with strong leather, and worked with the dull edge of a segmental scraping knife. A large number of them are then hung in a small narrow room heated by flues, and allowed to remain until an incipient putrefaction takes place. This is recog- nized by a strong odor of ammonia coming from the room on opening the door. The regular course of the putrefying process is recognized by a thick slime making its appearance upon the surface which loosens the roots of the wool so that it can be readily plucked from the pelt. The skins are then slimed^ that is, scraped upon the flesh side and stripped of the wool. They are then steeped in lime-water for a longer or shorter time, according to their condition. By this process further putrefaction is arrested and the skins con- siderably hardened and thickened. The skins are then worked upon the beam to remove the slime separated during liming, and cleansed and smoothed. These operations require much labor and care. The skin must not be injured by too long-continued putrefaction, as this would convert it into a non-cohesive pulp. Besides, every par- ticle of slime must be removed, as even the smallest remnant TAWING. 665 would unfit the skin for further working and for the reception of tlie dye. The skins are next placed in a vat filled with bran and water, where they remain for a time in a state of slight fermenta- tion. The hardening and thickening produced by the lime are then removed by working the skins upon the beam and scrap- ing them soft, by which the skin is actually converted into a thin, ductile, white membrane suitable for the succeeding opera- tions. The manner of treating chamois and goat-skins is nearly the same, except that the hair having no other value than for plasterer's use, the skins are limed before removing the hair. Chamois and goat-skins require, besides, a longer time for tawing. When taken from the bran steep, the skins to be tawed white are put into a bath composed, for 120 skins of medium size, of a solution of about 8^ pounds of alum and 4:J pounds of common salt in warm water, where they remain until they have absorbed a sufficient quantity of the liquor. This operation re-imparts to the skins a certain degree of thickness and tenacity. When taken from the ivhite hath, the skins, after washing in water, are allowed to ferment in a bran steep for some time in order to extract a considerable portion of the alum and salt and reduce the thickening acquired in the white bath. The skins are next dried by stretching them on hooks in an airy room in the centre of which stands a stove. When dry they will be found converted into a tough, flexible, and nearly white leather. To glaze the latter and remove any remaining roughness, it is again soaked in water, losing an additional portion of salt by the process. The skins are then placed in yelk of egg com- pounded with water in a wide vat and\rodden until they have gradually absorbed all the egg substance and the supernatant fluid is entirely clear. They are then dried in the air and pol- ished with a flat iron. As will be seen, the principal difference between this and the other method is that the tawing is effected with alum and com- mon salt alone, while the treatment with yelk of egg, to which in this case no flour is added, is executed after the skins are 666 THE MANUFACTURE OF LEATHER. tawed. "We doubt if this modification offers such considerable advantages as would justify the increased expense of labor and time. Another remarkable difference is that Aikins washes the skins after tawing in the white bath, and places them in a bath similar to the bran steep, in which they have to pass through a short fermentation. This treatment, the consequence of which, besides the reintroduction of raising, must be a retro- gression in tawing, produces no doubt a tough leather, but leaves much to be desired as regards softness and suppleness. The method of depilating lamb-skins, the wool of which is to be utilized, used by Aikins, is nearly the same as the sweating process previously described, and requires no further comment. Watts's method of working the skins of lambs, goats, and dogs into glove leather differs from the ordinary process only in the separation of the treatment in the tawing liquor from that in the yelk of egg. Schmidt describes this process as follows : — Soak the skins in clear water for 24 hours, then place them upon the beam flesh side up, and remove the fibres with the fleshing knife. Eeplace the skins in water, best in the same previously used, for 12 hours. Then scrape again with the fleshing knife, and stretch them in a loft or room until a slimy substance appears upon the flesh side, which remove with the knife. Then suspend the skins in the sweating-room until the wool can be readily plucked from the pelt, and when this state is reached, place the skins upon the beam and remove the wool in the ordinary manner. The depilated skins, after soaking in water for 5 to 6 hours, are dried and again placed upon the beam and scraped on the flesh side to remove all membranous substance, the neck and leg pieces being cut off at the same time. The skins are next replaced in clear water for 5 to 6 hours to soften any dirt adhering to them, and then dried by placing them in a wicker basket for about half an hour. When dry they are placed in the warm alum bath ; but in case they are to be colored it must be done before placing them in the alum bath. For 120 skins of medium size a solution of 12 ounces of ordi- TAWING. 667 narj alum in about a bucketful of water is required. To dis- solve the alum completely it is necessary to bring tiie liquor to the boiling-point, the temperature being afterwards reduced by pouring about one-half of the boiling liquor into the same quantity of cold water. In the alum liquor the skins are kneaded with the hand for about a quarter of an hour. The remaining portion of the liquor is then added, and, after working the skins for a quarter of an hour longer, they are dried in a wicker basket. When dry a workman treads the skins for a quarter of an hour in a blood-warm liquor, composed, for 120 goat-skins, of the yelks of 40 hen eggs and half a bucketful of water, and for 120 lamb-skins of the yelks of 30 hen eggs and the same quan- tity of water. After thoroughly absorbing the liquor the skins are stretched in the air to dry. When dry they are placed in a damp cellar for eight to ten hours. Finishing is effected in the "usual manner. We will finally describe M. Main's, of Niort (France), process of finishing alumed leather, which gives a very soft and ductile product. It is adapted to every variety of leather, provided it is strong enough, and, what is still more important, of a uniform thickness ; but it may be especially recommended for leather not readily salable in consequence of the grain being not clean, or, at least, injured or spotted. The modus operandi of the process is as follows : — Place the closest and strongest alumed skins in warm water, and, after soaking thoroughly, put them upon a smooth beam covered with thoroughly washed, unfinished calf, sheep, or buck-skin. Then scrape the alumed sheep-skin or goat-skin as strongly as you would buck-skin or oil-tawed sheep- skin, con- tinuing until all the membranous portions are removed. The workman, after passing the tool over the entire surface, suspends the skin by the hind legs to two iron hooks for dry- ing, or stretches it on a string. When dry, the skin is fulled and treated in the usual manner. In case a skin becomes drawn together by too quick drying it is only necessary to moisten it slightly. The skins are then turned over to the pumicer, who, after 668 THE MANUFACTURE OF LEATHER. placing them upon the beam, proceeds to rub the places from which the grain has been removed with pumice-stone. Skins which are to remain white for a time, and to be colored afterwards, are treated by applying very fine sea-sand, and rub- bing quickly and forcibly up and down, or backward and for- ward, with the pumice-stone held in the right hand, while the left hand grasps one end of the skin. For leather, which is to be of a pale-yellow color, a stone is prepared by pulverizing 6 parts of Mendon white (a variety of chalk) and 2 parts of yellow ochre. The ingredients are mixed, and, after moistening and kneading, the paste is moulded, and the resulting stone used for rubbing the places from which the grain has been removed. The workman presses the pumice- stone strongly upon the surface of the skin, and rubs as quickly as possible, adding occasionally some fine sand, and continuing the rubbing as long as for skins which are to remain white or are to be colored afterwards. By thorough pumicing the fineness of the skin imparted by the above treatment, and removal of the grain is augmented. It is rendered still finer and smoother by smoothing with a flat- iron after stretching, and can then be used for the best quality of gloves. Danish Glove Leather. In order to prepare supple Danish glove leather the method of finishing glace leather can be combined with the process of preparing tanned leather. By treating the skins with weak tan- liquors the desired color is obtained, though a complete tan- ning is not effected. The skins are then scraped upon the flesh side, and treated with a tawing paste composed, for 144 goat- skins, of 4J pounds of alum, 2 J pounds of common salt, 13^ pounds of fine rye flour, and the j^'elks of 300 eggs, to which is added some birch-tar oil to imitate the weak odor of Eussia leather, characteristic of Swedish or Danish leather. The skins are worked with the paste in the same manner as already described, and, after drying, placed in a damp cellar for some time, and finally rubbed upon the grain side with a woollen rag dipped in TAWING. 669 amianthus or tuffaceous limestone. If sucli Danish leather is to be used for gloves it is absolutely necessary to have the flesh side, which is worn outside, as smooth and uniform as possible. To effect this the skins, after scraping upon the beam, are rubbed in the above-described manner with pumice-stone, to which it is advantageous to add some fine sea sand. After rub- bing the surface as smooth as possible, the skins are finished by treating with a polishing roller or flat iron. Jennings's Method of Tawing. Jennings, in 1861, obtained a patent in England for a spe- cial method of preparing white leather, which differs not only from the ordinary method as regards the nature of the taw- ing substances used, but also as to the quality of the leather produced. The preparatory labors, such as soaking, rinsing, liming, and depilating, and working upon the beam, are precisely the same as in the ordinary method, though we will remark here that depilating is best effected by previous liming. If it is to be accomplished by the sweating process, it will be neces- sary to treat the skins afterwards with weak lime-water. To accomplish a loosening of the tissue and saponification of the fat, an after-liming for 24 hours will, on an average, be necessary. The process is available for all kinds of skins, though it is especially adapted for heavy ones. After liming and washing the skins are worked upon the beam to assist the removal of the lime soaps, and then placed in an acid bath composed of a mixture of 98 parts of pure water and 2 parts of concentrated hydrochloric acid where they remain, with frequent careful stirring, until the removal of the lime and raising of the tissue produced at the same time by the action of the acid, are as completely effected as possible, two or three hours being as a general rule required for the purpose. The skins are then taken from the bath, and, after draining off, subjected immediately to the tawing process. This is effected by placing the skins in two different tawing fluids prepared in two separate pits or vats. One fluid consists of a cold saturated solution of alum in water with an addition of about 2 per cent. 670 THE MANUFACTUEE OF LEATHER. of sulphuric acid, and the other of a cold saturated solution of crystallized soda with an addition of about 5 per cent, of dry sodium tungstate. The preparation of these fluids is readily accomplished. For the first pour cold water, not sufficient to dissolve it, over a large quantity of crystallized alum in a vat, and allow it to stand with frequent stirring until the quantity of alum not dis- solved no longer perceptibly decreases. Then run the obtained solution into the tawing pit or vat, and add, with thorough stirring, the corresponding quantity of acid. Tlie other fluid is prepared in the same manner, and the corresponding quantity of sodium tungstate previously dissolved in the necessary quantity of water is added.^ After filling the pits at least half full with the respective fluids, the skins are first placed in the one containing the alum solution. To facilitate the immersion of the skins and their removal from the pit Jennings makes use of a very convenient method. He employs for the purpose a perforated wooden frame large enough to spread upon it a large skin. Upon this frame he spreads out a skin, places upon this a hurdle of pealed osiers, upon this a skin, and so on until 10 to 12 skins are placed upon each other separated by hurdles. A hurdle is placed on top and fastened to the frame with cords so that the whole forms a bundle. By means of handles the bundle is then immersed in the pit so that it is entirely covered by the fluid. After remaining in the alum solution for six hours, during which time the fluid washing around the skins is renewed 2 or 3 times by repeated lifting and replacing the bundle, the skins are taken out, and, after draining off over the pit, placed in the one containing the soda solution, where they remain for 5 hours, and, after draining off, are replaced in the first pit. This alternate moving from one pit into the other is repeated until the skins are converted into leather, which is recognized by the opaque- ness of the cut surface and the fibrous structure. The time • In case determined proportions by weight are preferred it is necessary to tise for the alum solution 100 parts of water and 9^ parts of crystallized alum, and for the soda solution 100 parts of water and 16^ parts of crystallized soda. TAWING. 671 required for the operation depends of course on the size and thickness of the skins, but can be hastened somewhat by using the solutions lukewarm, say at about 96° to 100° F., which is recommended and necessary in winter. To increase the pro- ducing capacity it is of course advantageous to work with at least two frames, so that, while one bundle is in the one solu- tion, the other is treated in the second. After the skins are taken from the tawing fluids they are first placed in a bath of sodium tungstate and finally in one of soap. The first is prepared by dissolving the sodium tungstate in a sufficient quantity of water, allowing the solution to settle and pouring off' the supernatant clear fluid from the sediment. The skins remain in this solution, with frequent stirring, until they are completely saturated, the process requiring as a rule several hours. They are then taken out, and, after draining off", placed in the soap bath prepared by dissolving 15 to 20 parts of ordi- nary white soap in 100 parts of water. The skins remain in this solution until they have absorbed almost all the soap, which is recognized by the fluid feeling no longer slipperj', and ceas- ing to foam. The process can be considerably hastened by fre- quently working the skins in the bath. The final operation is rinsing the skins to free them from an excess of salts. As sim- ple rinsing is not sufficient for this purpose, the skins are soaked for 24 hours in water frequently changed, and after a final rins- ing in clean water, dried, and submitted to the finishing pro- cess. The color of leather thus prepared being not entirely white, it is more advantageous to use it for preparing colored varieties. If it is to be brought into commerce as natural leather, it is best to give it the appearance of tanned leather by placing it before drying in weak tan-liquor for 15 to 24: hours, according to the thickness of the skins. After the leather is thoroughly permeated with the liquor, which can be more readily effected by the use of pressure, it is dried and finished. Where a higher degree of softness and suppleness is desired, the finished leather can of course be greased, the process being the same as the one described for the Hungarian method of tawing. For obtaining fine and very white leather by Jennings's method, the use of the above tawing fluids alone is not sufficient. To 672 THE MANUFACTUEE OP LEATHER. give the tawed leather a proper degree of whiteness. Jennings recommends dissolving 5 per cent, of zinc filings in the acidu- lated alum solution, for which might perhaps be substituted a correspondingly larger quantity of oxide of zinc or sulphate of zinc. As regards the theory of this method of tawing we may make the following general remarks : It is, of course, self-evident that the action of the alum upon the fibres of the skin tissue does not materially differ from any other method where alum is used for tawing. But what is the object of the succeeding treatment with soda solution ? To understand this thoroughly we must consider the behavior of alum towards soda. Alum, ^. e., alu- minium sulphate on meeting soda, i. e., sodium sulphate, is decomposed and soluble sodium and potassium sulphates are formed on the one hand, and on the other insoluble aluminium hydrate. There can be no doubt that by the action of the soda solution upon the skin the fibres of which have absorbed a certain quantity of alum by the treatment in the alum bath, the same process of decomposition is introduced, and that the particles of alum present in the tissue are, on the one hand, converted into sodium and potassium sulphates, which being easily soluble are absorbed by the surrounding liquid, and, on the other hand, into aluminium hydrate which, being insoluble, will remain in the place formerly occupied by the particles of alum. In this man- ner the tissue of the skin will, by the repeated alternate im- mersion in the alum and soda baths, be gradually saturated with aluminium hydrate until finally not only the separate' fibres will be coated with the aluminium combination, but the interspaces will also be filled with it. The sodium tungstate, which under certain conditions can effect a sort of tawing, though not a complete one, might, as far as the matter can be judged from a theoretical standpoint, play only a subordinate role, and is very likely added to assist the tawing and perhaps make it more constant. A skin the tissues of which are filled with aluminium hydrate is no doubt genuine leather, but it lacks properties demanded of good leather, which must principally possess a certain degree of softness and suppleness. Dry alumi- nium hydrate being earthy and rough, its presence must oppose TAWING. 673 a considerable resistance by friction to ever}'- motion of the tis- sue fibres. To obviate this evil, and to decrease as much as possible the friction of the separate parts, the skins are treated in the soap bath, by the action of which upon the aluminium hydrate an alumina soap is formed, which consists of a slippery mass offering but little resistance to the shifting and moving of the tissue fibres enveloped by it. The treatment in the soap bath could thus only be omitted at the expense of softness and suppleness, and its continuation is therefore advisable. The object of adding zinc filings, or a soluble zinc salt, to obtain a higher degree of whiteness, is easily explained by the circumstance that by the action of soda solution upon soluble zinc salt, carbonate of zinc, i. e., a body of a pure white and great power of covering is formed, which, when deposited in the tissue alongside of the aluminium hydrate, imparts to it its whiteness. It is, therefore, of no consequence whether zinc shavings are added to the acidulated alum solution or a soluble zinc salt, for instance, sulphate of zinc ; in fact the latter is pre- ferable, as in case sufficient time had not been allowed for the zinc shavings to dissolve the skins coming from the soda solu- tion containing tungstic acid might assume a blue coloring, which, though only transient, would disturb the regular course of the work. We would finallv remark that the tawina; effected by Jennings's method is more constant than that by the ordi- nary process, and the leatlier resists the action of water much better. The cause of this phenomenon must be found in the fact that by Jennings's method the fibres are enveloped by an aluminium combination almost insoluble in water, while in the ■ ordinary method the tawing is effected by the absorption of a more or less soluble combination. Defects of Alumed Varieties of Leather. The defects are either natural ones, or originate from storing or the manner of working. Perforated skins are frequentl}^ found, the holes in most cases being made by the maggot of the large blue fly found so fre- quently in butcher shops, feeding upon the particles of fat and 43 674 THE MANUFACTUEE OF LEATHEE. flesli adhering to the stripped skin. The fly frequently deposits its eggs in the folds of the still moist skin, and the maggots on making their appearance and finding no other food attack the leather itself. The skins should therefore be stretched and dried immediately after stripping them from the animals. Lambs, and sheep still more so, are subject to diseases leaving their effects upon the skins, as for instance the small hard places, about the size of a pea, occurring principally on the back and neck, which must be classed among the worse defects, as they do not take the color. These lumps originate no doubt from chicken-pox, which frequently attacks entire flocks. Another similar disease produces smaller spots, and frequently only depressions, so that the skins can be at least used upon the flesh side. Such places are frequently found in goat-skins brought from hot countries. Another injury to the skin, chiefly found on the sides and upon the grain side, originates from not keeping the animals clean. By the dung, moistened by the urine, adhering too long to the animal, not only is the wool injured but the skin also. Such skins can only be used for dark colors and frequently only for black. Marks of varying shapes and of a wine-lees color, which do not disappear in tawing, are called hlood stains. They are very likely a kind of liver spot or mole. Actual blood stains are also found on the edges of large sheep-skins. They are caused by the blood adhering to the skins decomposing and producing indelible stains. The wool, or the hair of the skins of goats and lambs, is either white or reddish, or black, and sometimes spotted. The white skins, which are the most frequent, have after tawing a dull white color, while the black ones are more beautiful, but have a bluish-white color. Spotted skins are also more or less irregularly spotted so that they can never be used for white gloves, and frequently not for even light colored ones. Skins, the grain of which is only slightly connected with the grain side, and the tissue of which is loose and hollow and can be easily torn, are called swelled or distended. Such skins are only obtained from diseased lambs or sheep, or from flocks fed upon TAWING. 675 fat pastures. They are only used where more regard is paid to cheapness than to good quality. In reliable factories they are not worked, at least not upon the grain side. Skins of animals which have died of a kind of wasting dis- ease, are called dry skins. They are generally thin, without elasticity, have large open pores, and cannot be improved even by the most careful working. They are unfit for gloves. It is frequently found that the grain side becomes partly detached from the skin. This is caused by the skins becoming- heated while stored. This evil can be prevented by stretching and thorough drying of the skins before storing them away. Skins attacked by certain kinds of moths show, after tawing, the course the moth has taken in gnawing off the wool, while the small larvge of the genuine moth do not penetrate to the skin. The marks left upon the skin are not produced, as is erroneously supposed, by the bite of the insect, but by an acrid fluid running from the mouth of the insect while cutting the wool, and which very likely promotes the separation of the wool from the skin. Skins furrowed in the above manner were formerly frequently found in workshops where the wool was removed by means of a sharp slate, but scarcely ever occur since the general introduction of the scraping-knife for depi- lating. We have already spoken of the injury to which the skins are liable in branning in case the fermentation is too strong. It is frequently the case that small fissures or similar injuries are found upon the grain side, which are partly caused by the butcher inflating the skins and partly by the workmen, while tawing the skins, especially in depilating and scraping. The skins of young animals fed upon moist pastures^ as for instance the goats in the vicinity of Paris, require the most careful treat- ment in tawing as well as in coloring, to prevent them from receiving such injuries during the course of the work. The best skins will sometimes turn out hard if not thoroughly worked by the tawer, and especially if too little tawing paste has been applied. By treating such skins before tawing in the manner mentioned later on, they will be rendered sufficientl}'' soft. 676 THE MANUFACTURE OF LEATHER. Gases being developed in consequence of a fermenting pro- cess taking place in branning, it occurs occasionally that the gases developed by the fluid absorbed by the skins, cauDot find a suitable way of escape and are collected between the epider- mis and the true leather skin. By an increase of gas the re- spective portion of the skin is distended and a detaching of the epidermis from the other skin tissue is the result. Such skins have the appearance in a moist state of being covered with blisters. Though these blisters disappear in drying, the skins never acquire a perfectly smooth surface or, in short, a clean grain. The best way of preventing this evil is not to use the bran steep too strong, and avoid excessive fermentation by keeping up a moderate temperature, and also by frequent handling of tbe skins while in the bran steep. In case the detached skin is perfectly clean and free from other parts of the skin it is in much demand by manufacturers of artificial flowers, who use it especially for imitating orange blossom. The ordinary reddish bran stains are caused by the use of bad or impure bran. In dyeing such skins, the stained places form small grayish spots. These spots, which are also called rust stains, may be formed by filings dropping upon the skins in sharpening the stretching iron. To avoid them the workmen should never be allowed to sharpen their tools in the vicinity where skins are piled up. The appearance of similar grayish spots after coloring the skins is due to another cause. Portions of the tissue of skins stored in a damp place undergo decompo- sition, the formation of mould on the surface of such places being observed at the same time. The appearance of the spots is caused by the products of this process of decomposition. The spots are readilj detected by holding the skin,- before cleansing it for .dyeing, against the light. The skin hassuifered injury when blackish stains are observed in the interior. Such skins can only be utilized for verj'- dark leather. A very frequently occurring defect is technically called shading. It is YGxy plainly noticed especially in colored leather. One cause of this defect is that not sufficient care has been used in hanging up the skins to dry. By throwing the leather over the TAwma. 677 pole more tawing paste collects generally on those places resting immediately upon the pole, and the whole width of the leather shows a streak corresponding to the greater collection of tawing paste, which indicates a somewhat differently constituted sub- stance from the remainder. This difterence is not noticed in white leather, but in dyeing it will appear plainly, as such places will show a more intense coloring than the rest of the skin. This defect is also frequently caused by stretching the skins taken from the tawing paste, and can scarcely be avoided where the stretching is executed by drawing the leather back and forward over a wooden pole. By the pressure exerted upon the leather in pressing it against the wooden pole, a kind of streak or several streaks are produced if the work is not done uniformly, which after dyeing show a darker coloring. This evil can be avoided, on the one hand, by not drying them upon poles, but suspending them, as previously mentioned, their entire length, and, on the other hand, by stretching them only with the hands without the use of a wooden pole, or, if the latter has to be em- ployed^ by being careful to stretch the leather uniformly and drawing it over the pole not only crosswise, but also lengthwise and repeatedly in different directions. Another cause of shad- ing is subjecting the skins to too strong a lime-bath, or it may be produced by the grain of the skins in the lime-vat being partly injured or entirely destroyed by the action of the air, in consequence of which the finished leather will be without lustre and dull. The defect of what is called rotten or burned leather was formerly attributed to various causes, none of which is however correct. Credit is due to Prof. Knapp for having thrown light on this subject by a series of interesting experiments. Without entering into details, we will only give the conclusions Knapp has arrived at as to the cause of the rotteness of leather. There is no actual burning, as the fibre of the tissue is not injured or destroyed but remains entirely intact. The cause of the defect is due to the presence of certain salts enveloping the fibres and by forming a brittle coating depriving them of the power of re- sisting a tearing force. Knapp compares the condition of such fibres with that of the threads forming the wick of a stearine 678 THE MANUFACTURE OF LEATHER. candle which, though in a normal state, are broken in breaking the candle, the presence of a brittle substance enveloping them weakening their power of resistance. The cause of the rotten- ness of the leather must, according to this, be due to the fibres becoming, in the course of the tawing process, enveloped with a more or less brittle substance or at least a hard one, and the evil could be entirely avoided by removing such coating or pre- venting its formation. And this is actually the case. Knapp proves unequivocally that the formation of such brittle sub- stances is due to a remnant of lime either by itself or in combi- nation with the fibres, which by the succeeding action of the alum liquor is converted into calcium sulphate, the latter being deposited in the form of brittle crystalline masses upon the surface of the fibres. The most suitable means of prevention would therefore be to use the greatest care in removing the lime from the skins, which can be best eft'ected by thorough and repeated stretching of the depilated skins and by subsequent use of the acid bran steep, and, still better, by hydrochloric acid baths. Skins containing too much lime are improved by treat- ing them with a dilute solution of sodium phosphate, or, as Knapp recommends, with a soap solution. These agents do not remove the lime from the tissue, but produce the desired efi'ect by forming combinations with the lime not inclined to form such crystalline envelopes upon the fibres. A similar effect, although only within certain limits, is produced by the use of a bate of dog excrements, and also by such substances as flour and yelk of egg employed in the French mode of tawing, this being the reason why rotten leather will result more seldom by this process than in the ordinary method. Oiled leather also shows this defect very seldom, in fact, apparently rotten leather can frequently be restored by oiling, as the fat penetrating the tissue forces its way also between the crystals of the calcium sulphate enveloping the fibres, restoring, at least partly, their flexibility. We would finally draw the attention of our readers to a defect occasionally observed in colored leather and consisting of white spots which will take no color whatever. The occurrence of these spots has thus far not been satisfactorily explained nor a TAWING. 679 means found to prevent tliera, and it is simply a supposition to saj that their production might be due to small pieces of egg shell whicli adhere to the skins in treading them in the tawing paste. Manufacture of Oil or Chamois Leather. Oil or chamois leather has various employments, and under- goes a treatment which imparts to it a softness, suppleness, and woolly nature resembling that of woollen goods, and the property not possessed by any other variety of leather, of standing wash- ing without losing any of its good qualities. For this reason, it is also frequently called loash leather. As, on account of its denser tissue, the upper layer of the corium does not possess the same stretching capacity as the lower, the grain is generally entirely removed, especially in thick skins, so as to give both sides the same appearance. For making leather capable of standing washing, it is necessary that the fibre should not lose its tawing when placed in water, nor shrink to a horny mass in drying. The fibre acquires this property by treating the properly prepared skins with oils and fat. The tawing is, however, not efi'ected by the pure unal- tered fat, but is partly due to other factors the importance of which must not be underrated. Among the principal of these, we must class the action of heat and air, and especially the oxygen of the latter by the action of which the fats absorbed by the skin tissue undergo an alteration the products of which must be con- sidered as the actual tawing agents. The products formed by the chemical alteration of the fat not only unite the fibres so far as to give them all the characteristics of being thoroughly tawed, but prevent the fat contained in the leather from being detected by any external mai'ks. But although, the percentage of fat deprives more than any other means the fibres of the capacity of shrinking and sticking to- gether, it would be erroneous to suppose that it prevents water from penetrating the leather. This branch of the trade takes its name from the skins of the chamois, but, although the term is still retained, those of sheep, 680 THE MANUFACTURE OF LEATHER. deer, lambs, and goats, and even ox-hides and calf-skins, are now converted into it. The product obtained from the latter is almost exclusively used for military equipments, such as belts, etc., while the leather produced from the first is worked into pantaloons, bags, bandages, gloves, etc., though we would here remark that of late the use of chamois leather for these purposes has considerably decreased. The manufacture of chamois leather has undergone but little change in the course of time, nearly the same process being in use at present as in the last century. The operations may be divided under the following principal heads: 1. Soaking and rinsing. 2. Liuiing, depilating, and frizzing (removing the grain). 3. First liming of the frizzed skins. 4. Stretching and scraping. 5. Second liming of the frizzed skins. 6, Branning. 7. Squeezing or pressing. 8. Fulling in the oil. 9. Dressing and finishing. Soaking and rinsing and liming to prepare the skins for depilating being the same as used for ordinary alumed leather, require no further description. After thorough liming the skins are ready for Depilation and Frizzing. These operations differ materially from the method employed for alumed leather. The grain of the skin being, as previously mentioned, the densest part, is not adapted for such a high degree of softness and suppleness as is demanded in chamois leather, and besides prevents, on account of its density, a ready penetration of the fat. For the production of good wash leather it becomes therefore necessary to remove the grain, though it is done at the expense of lustre and smoothness. In depilating skins intended for chamois leather, it is therefore not necessary to be careful of the grain except with very weak skins of young animals, the solidity of which would be injured by the removal of the grain, and in case the wool is to be utilized for other purposes, as wool removed simultaneously with the grain has no value. In all other cases the depilation and frizzing are accomplished at one operation, i. e., the hair or wool and the portion of the skin in which they are imbedded are removed together, the TAWI^STG. 681 workman using for the purpose a sharp scraping-knife sirnilar to the one employed for skins intended for alumed leather. The treatment with the scraping-knife being generally not suffi- cient for complete frizzing, the remaining portions of the grain are removed with another sharp knife. After frizzing and rinsing, or without the latter, the skins are subjected to the First Liming, For this purpose they are placed in an ordinary lime-vat and subjected to the action of lime-water for 12 to 48 hours accord- ing to their size and thickness. The object of this treatment, which is equivalent to the raising of skins intended for alumed leather, is besides the saponification of the fat constituents of the skin, to loosen the skin tissue for the succeeding treatment. The next operation is Stretching and Scraping upon the Flesh Side and partly upon the Grain Side. This is accomplished upon the beam with a scraping-knife, the object being to free the flesh side from adhering particles of flesh and fat, and the substance of the tissue from the lye and lime-soaps which have been formed, thus preparing the skin tissue for the absorption of fresh lime-water in the Second Liming. This is generally accomplished by placing the skins for 24 to 48 hours in a vat charged with fresh lime-water prepared in the ordinary manner for raising skins. By this treatment the skins acquire the necessary degree of softness and sponginess required for the succeeding operations. After removal from the lime-vat, the skins are thoroughly rinsed in lukewarm water in order to free them from the greater portion of the adhering lime, and are then subjected to Branning. For this purpose the skins are placed in a bran steep acidu- lated by standing several days, for the preparation of which the same proportions in quantities are used as given for alumed 682 THE MANUFACTUKE OF LEATHER. skins. The acid steep should be warmed before pouring it over the skins in the vat. After a partial permeation of the skins, which is generally effected in a few hours, during which time they should be kept immersed by proper weights, a complete saturation is accomplished by treading them in a vat, in order to make the action of the steep uniform upon all parts of the skin tissue, and to accomplish a complete removal of lime from the fibres, which is the principal object of the sour steep. In place of treading, the object may be effected by pounding the skins in a low wooden vat or special fulling trough with a round wooden mallet. The pounding is continued, with an occasional addition of bran steep, until the skins have acquired a uniform milk-white appearance, and show, when held against the light, no dark spots, this being generally accomplished in winter in 2 days, and in summer in 12 hours. The skins are then squeezed or pressed in order to remove as much water as possible, this operation requiring no further description, as it does not differ from the ordinary method pursued in tawing. We will only mention that it is advantageous to use a wooden instrument in place of the usual iron one, especially for leather to be colored afterwards, in order to avoid spotting, frequently brought about by the skins taken from the bran steep coming in contact with iron instruments. After thorough wringing and swinging in the air the skins are again fulled and while still moist immediately oiled. Fulling in the Oil. Fish oil, obtained from seals, whales, sturgeons, dolphins, and herring, is preferred for this purpose, partly on account of being cheaper and partly because other fats do not give as good a pro- duct. The only oil worth mentioning besides the above is olive oil, while linseed oil, rape-seed oil, and poppy-seed oil must be designated as absolutely worthless, as they furnish a poor pro- duct even when used as an addition to fish oil. Oil of juniper deserves, according to Schmidt, consideration as the volatile oils free from oxygen dissolve the fat of the connective tissue and are oxidized much more quickly than fish oil and converted into soft resins, which form with the fats and the alkalies, a more solid TAWING. 683 resin soap enveloping the connective tissue fibres, than is the case with fish oil. But the introduction of this material has found but a limited use as might be expected from the material difference existing between this and other oils. The operation of tawing consists in spreading about 12 dozen skins, or as many as are required to fill the trough of the fulling mill, grain side up, upon a table, and after sprinkling upon them oil, distributing it uniformly over the surface with the palm of the hand. The skins are then rolled up in bundles of four, and subjected to the action of the fulling mill. This latter for this class of leather manufacture is generally driven by horse-power, and is the same as an ordinary cloth fulling mill. It has two hammers and two troughs capable of holding a gross of skins or more. The ham- mers give 15 or 16 blows per minute. The first fulling is continued for a period varying from 2 to 3 hours, the time depending partly on the temperature of the air and the more or less porous condition of the skins. They are then taken out, and after swinging in the air in order to unfold them, suspended to cords in the open air to cool off' from the heating consequent on fulling, and to allow of a better pene- tration of the oil by a partial evaporation of moisture. After half an hour to an hour the skins, after rolling them again into bundles, are fulled without oil for 1 or 2 hours, suspended in the air, oiled, again fulled, suspended in the air, fulled without oil, and so on, the process being repeated until the skins have been hung 6 to 8 times in the air, being fulled each time and receiving oil 3 to 4 times or oftener for poor skins. Fulling is the most important and at the same time delicate operation in oil-tawing, the smoothness and softness of chamois leather, so much admired, being entirely due to it. Formerly a fulling stock descending perpendicularly upon the skins was used, but more recent constructions are provided with a kind of hammer, the arrangement of which will be more plainly seen from the illustrations in Chapter XIV. The skins will be sufficiently oiled when a smell of mustard takes the place of that of flesh. The skins should gradually lose their water by repeated suspensions in the air, since the oil pene- trates more easily in the degree in which the water evaporates, 684 THE MANUFACTURE OF LEATHER. and thoroughly dry skin absorbs the oil with great difficulty and requires more frequently repeated fulling. The skins remain generally suspended until the surface appears dry. It is best to hang them in the open air or in case the weather is unfavor- able in an airy loft. Towards the end of the operation, when the skins have lost the greater portion of water, they are suspended, in damp weather, in a heated room. Chamois skins are given 12 fullings, other skins proportionably less. A dozen buck- skins absorb about 18 ounces of oil at each oiling, a total of about 9 to 10 pounds of oil being required for a dozen steep- skins, and about 13 to 13J pounds for a dozen buck-skins. Thus far the object of the operations is principally to thoroughly and uniformly impregnate the skins with oil, repeated fulling play- ing a principal part. By the repeated exposure to the air a part of the oil has, however, already undergone a partial altera- tion by the action of the oxygen of the air causing the forma- tion of various products of oxidation, which chiefly impart to the skin the property of leather. But the principal portion of the fat is still present in an unaltered state, and fills only mechanically the interspaces of the tissue. The object of the succeeding operations is to convert the unaltered fat so as to adapt it to form an intimate combination with the skin tissue, and to bring about a lasting tawing of the skin. This is effected by the oxidizing action of the air, best produced by the co-opera- tion of a gentle heating ; therefore, by the introduction of what has been erroneously called " a fermentation accompanied by heat." After the last fulling and thorough swinging in the air, the skins are piled in a cone-shaped heap upon the floor of a heated chamber previously covered with a linen cloth, and allowed to rest some time. In some workshops the pile is also covered with a linen cloth, though this is not absolutely necessary. In cold weather the skins must be heated before piling them up, which is effected by suspending them on poles arranged near the ceiling of the heating chamber. The interior of the pile soon becomes perceptibly heated by the oxidation of the fat permeating the skin tissue, which is caused by the admission of TAWING. 685 air, the color of the skins changing gradually into yellow as the process of oxidation progresses. To obtain a good product the heating of the skins must be carefully watched and special precaution taken to avoid over- heating of the pile, as otherwise a more or less brittle leather would be the result. The temperature of the pile should there- fore be examined from time to time by introducing the hand. If a considerable heat is felt, the pile, in order to avoid a failure of the process, is rapidly torn apart, and a new pile formed as quickly as possible to prevent too rapid cooling, by placing the skins previously in the interior, on the outside of the pile. After allowing the pile to rest for some time, it is again changed in a similar manner. This reforming of the pile and subsequent resting is repeated until the skins have acquired the right shade of color, which, as previously mentioned, takes place in consequence of the oxidation of the fat. When the latter pro- cess is finished, the skins will no longer become heated to any extent, so that the gradual decrease of heat may be considered as a sign of the process being finished. After passing through the process in the heating chamber the skins, in order to furnish available oil leather, must still be subjected to Finishing and Dressing. The principal object of these operations, besides the other mechanical treatment, is the removal of the excess of fat con- tained in the tissue. For this purpose the skins are first worked with the stretcher and then upon the grain side with a some- what dull round knife to remove any grain still remaining. This operation is especially required for skins of chamois, deer, and goats, whose upper skin is rather thick, and if any of the grain remained it would form, after drying, a stiff' and hard surface impairing the fine, woolly appearance of the grain side, which is worn outside in articles manufactured from the leather. Although the greater portion of the oil combines in an altered state with the skin fibre, the skins contain a considerable quan- tity of uncombined oil, which is removed by means of an alka- line lye, prepared by dissolving, for 1 dozen sheep-skins, about 686 THE MANUFACTUEE OF LEATHER. 1^ pound of potash in warm water, less being required for skins previously scraped. The skins are immersed in the bath and when thoroughly soaked taken out and wrung, the immer- sion and wringing being repeated three or four times until the leather is thoroughly cleansed. As a considerable amount of potash, which is comparatively dear, and frequently contaminated, is used in the manufacture of chamois leather, Hermbstaedt proposed, some years since, the use of soda as a substitute. This would be still more advanta- geous at the present time, since soda is now produced in immense quantities and of great purity, and is not only as effective as potash, as already proven by Hermbstaedt, but even superior to it. The proportions, for 1 dozen skins, are about 1^ pound of calcined soda, or 3f pounds of the crystallized article for the same number of skins. The use of a caustic lye has proved still more advantageous than either potash or soda, and experience has shown that only half the soda in the form of caustic lye is required as of potash. Caustic soda lye is obtained without difficulty by preparing first a clear solution of soda in lukewarm water and adding a paste of fresh slacked lime made by converting, for every 2| pounds of soda to be used, IJ pound of lime into a fine powder by pouring as much water over it as it will absorb. The powder is stirred into a thick paste with sufficient water, and added with vigorous stirring to the previously prepared soda solution. After standing for several days during which the fluid is frequently stirred, the caustic lye is ready. For use the supernatant clear fluid is drawn off. By scraping and treating with lye the skins lose about one half of the oil originally absorbed. The liquor running off' in wringing out the skins treated with lye, which is a solution of a soap-like body partly clouded by the mechanical admixture of fatty substances, is the so-called degras, an article of consider- able value, which should be carefully collected. The value of this liquor will be made plain by considering that it contains the greater part of the excess of oil from the skins and a small part of the products of the oil formed b}^ the process of oxidation. This product can in fact be used for TAWING. 687 moistening oil leather to be bleached and, after evaporating the water, for oiling other varieties of leather, especially tan- leather. The liquor can also be used in place of fish oil by neutralizing the alkali contained in the soap-like combination in solution, by means of hydrochloric or sulphuric acid, and skimming off the oil separating on the- surface of the fluid. This is effected by diluting the soap-like mass pressed from the skins by fulling with a quantity of water and adding with vigorous stirring small portions of sulphuric acid until the fluid has acquired an acidulous taste. By subsequent heating the fatty substance col- lects upon the surface. As strong heating takes place on mixing sulphuric acid with water, it is advisable to mix the acid drop by drop with 4 to 6 parts of soft water and add the diluted acid to the liquor. The simplest way is to use hydrochloric acid. In treating the liquor in the above manner with hydrochloric acid the latter combines with the soda or potash into the soap- like substance, and separates the pure fat which floats on the surface. The separation is promoted by heating the fluid. After freeing the skins from the excess of fat they are wrung and dried in the air, if the weather permits, or in the drying- chamber. When dry the skins are worked with the stretcher in order to restore to them =' the proper suppleness partly lost in drying. Small skins are worked in the usual man- ner. For strong leather a stretching iron rep- resented by Fig. 298 is used. It is fastened to the wall of the workshop. The leather is scraped lengthwise upon the blunt round edge c c?, and in width upon the dull curved edge e/, the latter being specially used for the thick places in order to make them supple. After this operation the skins are finished with the hone to give the surface the required uniformity, buck-skin undergoing this process on both sides, but sheep-skins on the flesh side only. 688 THE MANUFACTURE OF LEATHER. The leather is finally finished by passing a smoothing iron over the honed side in the same manner as in alumed leather. Chamois leather is generally of a buff color. To bleach it the skins are placed upon the bleaching ground in the sun and sprinkled with water, and when dry again sprinkled. When half white they are soaked in degras and replaced in the sun. In place of degras, soap water prepared from white soap can also be used. In bleaching the leather from chamois skins intended for gloves and that from skins of sheep, goats, and lambs for castor gloves, is at the same time pumiced. For this purpose the skins are trodden for one hour in a weak solution of potash, composed for 12 dozen skins, of 2^ pounds of potash in 79 pounds of water of 88° F. They are then wrung out, and after swinging in the air, placed upon the bleaching ground for 48 hours. The dry skins are then pumiced with white pumice-stone in the same manner as given for alumed leather, some fine sand scattered between the skin and the stone facilitating the work as the sand detaches the fine fibres. After pumicing and smoothing and moistening the skins with degras they are spread upon the bleaching ground to bleach entirely. When dry they are alternately sprinkled with pure water and degras, the latter restoring to them their original softness. For leather intended for white gloves, the sprinkling is repeated 8 to 10 times, while 3 to 4 times are sufiicient for leather to be worked into yellow or colored gloves. The required shade for buff- colored leather intended for panta- loons, gloves, etc., is prepared by mixing with water to a thin paste the requisite proportions of yellow ochre, whiting, and some Dutch or English pink, adding a little starch paste to prevent the color from dusting when dry. Apply the color with a stiff brush, stretch the skin when dry and finally remove the loose dust by vigorous shaking. To clean dirty leather proceed in a similar manner. After washing with a brush and soap-water mix the above buff color with sufficient olive oil to a ball, dilute this with the requisite quantity of water and apply with a stiff brush to the moist TAWING, 689 leather. When dry rub with a dry brush. For white leather use fine whiting in place of the buff color. A variety of oil leather which has been colored black on the flesh side, and the grain of which has not been scraped off, is pre- pared for shoemakers' purposes. It is manufactured from calf- skins scraped smooth upon the flesh side and blacked in the manner given later on. The so-called tioisted leather^ which is much used in some countries for straps, may also be called a variety of oil leather. It is said to excel in durability and suppleness. For manu- facturing it, depilate cowhides, which are generally used, by scalding with boiling water, and, after softening sufficiently, cut them into strips. Sew the strips into one long piece, and then sew the two ends of this together. After saturating with oil hang one end of the material on a hook and suspend a weight to the other. Then insert a stick between the two strips and after twisting them together, allow them to untwist in the opposite direction, repeating the operation several times and applying fat. By this operation the leather becomes heated and gradually saturated with fat. This method, as can be readily seen, will only serve as a partial substitute for fulling in oil. Peeller's Method of Tawing. Preller, on the 8th of March, 1852, obtained a patent in Eng- land for a peculiar method of preparing leather, but the merit of the invention is claimed by Theodor Klemm, of Pfullingen, who states that Preller bought the patent from him. Here- with we give a description of the process as patented by Klemm in Germany in 1849, which is substantially the same as the process patented by him in the United States in 1858. According to the specification, the process consists in impreg- nating the skins or hides with a mixture composed of certain animal, vegetable, and salty substances. The animal substances used are bullocks' brains, butter, milk, and animal fats ; of vege- table substances those are preferred which contain most starch and but little gluten, for instance, barley flour, rice flour, or starch by itself. The salts used are common salt and saltpetre. The fol- 44 690 THE MANUFACTURE OF LEATHER. lowing mixture gives good results: Barley flour 26 parts, bul- lock's brain 23, common salt or saltpetre 4, unsalted butter 6J, milk 12|, animal fat, such as neat's-foot oil or horse fat, 28. After mixing the butter and bullock's brain, add the flour grad- ually, then the fat, and finally the milk. The salt, the object of which is to preserve the butter and brain, can be added in the beginning. After depilating, soaking, and partly drying the skins or hides to be treated, place them in a cylinder and set the latter revolv- ing. The skins remain in the cylinder until by the motion imparted to them, the water still contained in them is uniformly distributed. The above mixture is then applied to the flesh side, and after replacing the skins in the cylinder, the latter is set in motion. The application of the mixture and revolving in the cvlinder are repeated until the desired success has been attained, thick skins requiring of course a longer time than thin ones. The skins while revolving in the cylinder may also be heated by the introduction of warm air. In place of a revolv- ing cylinder other means may be employed to impart to the skins the requisite motion. The succeeding operations to which the skins are submitted are the same as in the ordinary process, though the finishing is considerably facilitated by the foregoing treatment. The owner of the patent erected a factory in Southwark (London), in which the above process is used. The establish- ment has been considerably extended since the products are said to be much in demand. The mixture used is the one stated in the specification of the patent. The skins are spread out upon a table to receive the tawing mixture upon the flesh side. They are then placed in revolving stuffing-wheels, 8 to 9 feet in diameter and 5 feet deep. The skins are placed in the interior of the stuffing-wheels and removed through openings in the sides. The interior surfaces are provided with strong pegs, radiating from the centre, the object of which is to beat the skins vigor- ously to promote an equal distribution of the water contained in them, and a uniform absorption of the paste. The drums are driven by steam power, and can be made to revolve TAWING. 691 quicker or slower according as the course of the operation re- quires it. To effect a drying, which is frequently required, the exhaust steam is conducted into a large receiver from which runs a pipe along the floor of the room. The pipe is connected with the interior of the stuffing-wheels by means of pipes and hollow shafts, the connections being opened or shut by means of cocks. The skins, after being revolved for a few hours (the time de- pending on their thickness), are taken out and examined, to ascertain whether the absorption and partial drying has been thorough and uniform. Skins not thoroughly saturated are, after hanging in an airy place for a short time, treated with a new application of the paste, and after replacing in the cylinder treated as before. The entire operation is repeated once more, after which cuts made in the skins should show by their uni- formity of color that the conversion into leather is complete. The skins, after a slight drying, are ready for finishing. Leather prepared according to Preller's process is called H B Groiun, and has proportionally less weight and thickness than tan leather. Experiments have shown that while 220 pounds of green hide tanned with bark give 110 pounds of leather, the same weight tanned by Preller''s process yields only SIJ pounds. The greater weight of tan leather is partly due to moisture, and as many tanners frequently produce intentionally thick and heav}^ leather by a peculiar mode of working, the smaller weight of crown leather would not be against it, and besides which, weight and thickness are not a criterion as to the quality of the leather. The greater strength of crown leather is due to the fibrous structure remaining unaltered. In tearing a piece of tan leather the structure is found to be more felty, while in crown leather the fibres lie in their natural position, closely pressed against each other. Experiments have shown that crown leather is far superior to tan leather as regards strength. A piece of crown leather ^ inch thick resisted a pull which tore tan leather f inch thick. A strip of crown, leather about J, inch wide, \ inch thick, and 2 feet 7 inches long, tore only with a load of 682 pounds, while a strip of bullock's leather tanned with oak bark, and of the same dimensions, resisted only a load of 550' 692 THE MANUFACTUKE OF LEATHER, pounds. A strap, consisting partly of crown leather and partly of tan leather, will always tear first in the part composed of the latter. Crown leather, on account of its strength with less thickness, is especially adapted for the manufacture of machine belts. Such belts being thin and pliable can be placed upon pulleys of small diameter, and are very durable. By using thick leather for belts the fibres on the outside must alternately expand, caus- ing an alteration in the original condition of tension, and con- sequently formation of cracks. Belts of a single thickness of crown leather are manufactured by simply joining the bevelled ends of the separate strips by means of a plastic mass. Belts for the transmission of greater power are made by placing two, three, or sometimes four thicknesses of crown leather upon each other, and sewing them together. In using these belts the motion is very gentle, Preller's method requires considerably less time than the ordinary tanning process. Calf-skins can be prepared by two operations in the wheel, each requiring about eight hours with a short interval between the two workings. The conversion into leather of the thickest bullock hide can be accomplished by Preller's process in two and a half days, while under the most favorable circumstances five to six weeks will be neces- sary by the ordinary method. As regards the capacity of- crown leather to resist water all experiences thus far seem to be favorable. Belts of it used in the open air and damp buildings have stood the test very well. By boiling ordinary leather in water, it becomes gradually- hard and inflexible, and by continuing the operation for half an hour it becomes brittle, or it frequently dissolves and becomes gelatinous. Crown leather subjected to the same experiment approaches gradually to the nature of horn, but only after several hours. The softness of crown leather makes it very suitable for the soles of house shoes, this quality and its strength with little thickness .recopimending it also for many other purposes. The back part of horse hides, which in the ordinary method is gene- rally cut qft' o.n a,Qcount of its thickness and not used, can by this TAWING. 693 process be brought to such a state of softness, that it can be used together with the rest of the hide. Preller manufactures in this manner beautiful horse leather for carriage tops and boots, which is exceedingly soft and of great lustre. The theory of the process is easily understood by assuming that the fatty substances used, such as neat's-foot oil, horse- fat, and butter, on the one hand, and bullock's brain and milk on the other, play the same part as in the preparation of Erlanger leather and, that in a certain sense, as is the case in preparing oil leather, the other substances, such as flour con- taining gluten and starch, and common salt or saltpetre, have no other material function than the same substances in the taw- ing liquor for alumed leather. But excellent as no doubt the leather obtained by Preller's process is, it cannot be denied that its preparation does not excel in cheapness, and this is the point which every practical man has to consider. Butter, milk, and flour are commonly too expensive for the manufacturer to expect to be able to cover their cost by the price obtained for the leather produced, and this is very likely the reason why Preller's process has not been more gene- rally introduced. Preparatio:^^ of Klemm's Oil-Leather. This process is, so to say, an intermediate method between alumed and oil leather, alum being used in common with the first, and that of fats with the latter. According to the descrip- tion given in the patent,^ the process is as follows: — a. Manner of preparing the hides. — The hides are depilated by liming. A second liming as for alumed or tan leather is not required. To remove the lime, the hides are thoroughly washed and scraped and then placed in the bran steep until all the lime is removed, the raising of the hides being effected at the same time. They are then rinsed in fresh water and scraped clean upon the flesh side. h. Tanning is effected in the following manner : Prepare ' Wiirtemberg'sches Gewerbeblatt, 1855, 9. 694: THE MANUFACTURE OF LEATHER. warm alum liquor of the proportions previously mentioned, pour it over the hides, and, after thorough treading, allow them to remain in it for twenty-four hours. Then wash and com- pletely remove the excess of alum and salt by treading. Make a paste, composed for one hide of 8.8 pounds of brains, 15.4 pounds of barley flour dust and about 8| ozs. of cod oil or melted horse grease, and dilute sufficiently with lukewarm water to allow of the hides being drawn through it. After immersion tread the hide until it has completely absorbed the fats and the gluten of the flour. After allowing the hide to remain in the vat overnight, hang it up the next day until it is half dry and then take it on the horse and remove the bran of the flour. After drying completely, and taking it once more on the horse, the leather is ready for coloring. It is suitable for all colors. By the removal of the alum and subsequent treatment with the tanning paste, this leather on exposure to water does not become fleshy like alurned leather. Beside it combines Avith all the desirable properties of oil and tanned leather the advan- tage of being stronger than the best tanned leather in consequence of the texture of the hide not being injured by liming, and that of resisting water better than ordinary tanned harness leather, and being more durable, as it contains no tannic acid. The further advantages of this process consist in that tan- ning is effected more quickly and fewer utensils and smaller outlay for tanning materials a-re required. Skins of deer, goats, sheep, and chamois tanned by this pro- cess combine all the advantages of glace leather with less con- sumption of tanning paste. Prof. Eeusch, who made experiments in regard to the strength of this leather as compared with the best harness leather, found the bearing strength of harness leather =7.100 pounds, of Klemm's oil leather= 13.112 pounds. The leather is colored in the same manner as glac^ leather. After coloring, the hides are once more greased with tallow or fish oil, and then finished with a hot plate. It will be seen that this process, which corresponds in many points with Preller's, does not differ materially from the more rational methods previously mentioned in speaking of the TAWING. 695 manufacture of glace leather, and it is only natural that it should excel in strength. Prof. Fehling, who has made many conscientious experiments in regard to the matter, finds Klemm's statements entirely correct, and draws especial attention to the fact that Klemm's leather when dried after boiling for 12 hours, showed the perfect cut of the leather, having only be- come somewhat more brittle. We have in the chapter on Mineral Tanning drawn the atten- tion of our readers to a method of preparing leather proposed by Dr. F. Knapp, who is well known through his valuable researches in regard to tanning processes. Knapp proposes to effect the tanning by the alternate use of salt solutions and soap baths. For preparing the salt solutions, alumina salts, aluminium sul- phate, or alum are employed, or ferric oxide, or chromium salts, the leather obtained by using the last two being of course more or less colored. For practical purposes alumina salts could only be recommended, as they, besides leaving the leather white, have the advantage of being found in commerce of an always uniform quality and great cheapness. Commercial potash-alum is with- out doubt the best material for the purpose. As regards the coDcentration of the solution, Knapp recommends 1 part of alum to about 20 parts of water. The soap bath is best pre- pared by dissolving 1 part of white soft soap in 20 or 30 parts of water. The soft soap, if not otherwise obtainable, can be prepared by boiling good clean fat or tallow with potash lye. The soap bath may also be prepared with ordinary white soda soap, but before using it, it must be heated to 96° to 98° F. The hides to be tawed b}'" this process, after depilating and preparing them in the usual manner, are placed in the salt solution, and after thorough handling are taken out from time to time and allowed to drain oft'. This is continued until they are thoroughly permeated with the salt solution, the process requiring, according to the thickness of the hides, and the .manner of preparation, 24 to 48 hours. After removal from the salt solution the hides are allowed to drain off, and then, while still moist, placed in the soap solution for 24 to 48 hours, being during this time frequently handled. After removal from the soap bath the hides, which are now thoroughly tawed, 696 THE MANUFACTURE OF LEATHER. are rinsed in clean water and dried. Finishing and dressing are the same as for ordinary aluraed leather. The resulting pro- duct corresponds in all respects with that obtained by the ordinary process, but excels the latter in softness and supple- ness and greater permanence of the tawing. According to the same principle, a product resembling in many respects oil or chamois leather, is obtained by treating the thoroughly prepared skins in an acid bath, for the preparation of which hydrochloric acid diluted with 20 to 30 times its weight of water can be advantageously used. The best mode of pro- ceeding, according to Knapp's researches, is first to expose the hide to the action of the acid bath and then place it in the soap solution, repeating the operation twice or three times, or until a cut made in the hide proves it to be thoroughly tawed. After drying, the leather is freed from adhering soap with a sponge. A more simple and sure method, and one which is at the same time rational and in accordance with the theory of the tawing process, can scarcely be devised. The nature of the method is readily understood. As soap undergoes an alteration with solutions of alumi- nium salts, ferric and other salts, and a formation of a more or less voluminous precipitate of sebate or oleate of alumina, iron, etc., which is alm.ost insoluble in water, takes place, it will be readily understood that a complete tawing is effected by the formation of such combination, which by being formed in the skin tissue itself, must envelop the separate fibres of the tissue. The result obtained by the use of liquors and tawing paste, not very rationally composed, and transmitted to the tawer from remote ages, is by this process reached in a not only more simple but also surer way. And if we inquire about the expense the answer must cer- tainly be in favor of this process, for nobody can pretend that the tawing paste is cheaper than the soap solution. By trying this process once and seeing the results obtained from it, it will scarcely be possible to understand why this simple and easily managed method has not been more generally introduced, TAWING. 697 though known since 1858. Progress in tanning appears to be much slower than in other branches of industry. A beautiful, white glazed leather of great softness and sup- pleness, can, according to Knapp, be prepared by macerating thoroughly cleansed skins of lambs or goats in a lukewarm saturated solution of stearine in spirit of wine and drying after thorough permeation. Though we are assured by experiments that this process furnishes an excellent product, especially as regards delicacy of color and suppleness, and a less pure and consequently cheap variety of stearine can be used, it seems to us that the use of spirit of wine as a solvent is too expensive for the purpose, especially as a part of it could only be regained by special utensils and apparatuses. If this defect could be remedied, the process might be used with profit and success. Note. — For matter in this chapter, the author desires to acknowledge his indebtedness to Gintl's Weissgerberei. PAET IX. CHAPTBE XLIII. DYEING LEATHEB. Section I. General Eemarks. Light is the source of all color, and it is the result of the vibrating motions of a very subtle substance, whicli the natural philosophers term "ether." The ether receives vibrations from self-lighting bodies, such as the sun, and spreads them in the same manner as the air spreads sound, with this difference, that the oscillating motions called "light" are brought forth many million times quicker than those of sound, because the ether is many million times finer than the air ; consequently, its vibrations are more rapid and intensive. The light entering our eye excites the optic nerve, producing a sensation called " vision," and thus light renders objects visible. Light itself is not a simple body, but is composed of various colors, of which we distinguish seven by separate names. All the colors observed in the organic and inorganic world around us are derived by reflection from the different colors, of which the white light, or sunlight, is composed. When we admit a ray of sunlight into a dark room, and there split it by means of a triangular glass, called a " prism," we can see, upon the screen opposite to the hole, as shown in Fig. 299, a series of bright colors, consisting of violet at the top, indigo, blue, green, yellow, orange, and red. This phenomenon is a "spectrum." DYEING LEATHEE. 699 Apparently there are seven colors; but there are only three primitive colors, namely, red, yellow, and blue, from which all others are derived. In fact, if we look very attentively at a spectrum, we soon realize the fact that violet, indigo, green, and Fig. 299. orange are the products of amalgamation of either two of the three primary colors, viz., violet and indigo from red and blue, green from blue and yellow, orange from 3^ellow and red. This is, in fact, the only natural explanation of this wonderful phe- nomenon. When speaking of primary colors hereafter, it must be borne in mind that we refer to the colors of the spectrum. There ex- ists no primary color substance, that is to say, a color represent- ing nothing but itself, in the true sense of the word. In fact, if we compare all known dye stuffs, we find that they always contain, besides the principal ones, more or less of some other color. This is not, of course, by bodily mixture, but their inti- mate atomic construction is such as to reflect more or less of the others, too, which are the components of the white light. For a man who studies the manifestations of nature, all the beautiful colors in which nature dresses plants, flowers, and trees, are simply wonderful objects of admiration. Uncertain colors there are none in the organic world ; wherever we turn our eye, we discover harmony and purity in the composition of colors and shades. To imitate this wonderful artist, nature, in coloring, should be the ambition of every dyer. 700 THE MANUFACTUEE OF LEATHER. Of all the arts, none require such thorough knowledge, theoretical as well as practical, as the art of dyeing. Ohaptal, the great French chemist, therefore considers the dyer's art as the most useful and admirable of all. Indeed, if there is a call- ing which could make justly proud the man who practises it as an art, it is certainly that of the dyer. Chemistry is the abstract science, the part of which in devel- oping the art of dyeing consists in ascertaining, framing, and pre- senting the invariable rules, upon which all the dyer's operations must be based. The dyer is the practical, artistic executant of these rules ; all his operations are strictly chemical. The sim- plest mixture, the composition of the commonest mordant, in- volves chemical processes, the knowledge of which is indispen- sable to insure success. Of all his operations, a dyer should know the result in advance with mathematical accuracy; of his doings nothing should be left to blind haphazard. The scientifically educated dyer observes ; studies facts, always endeavoring to bring the chemical and physical phe- nomena occurring to him back to scientific principles, in order to ascertain their cause ; such studies constituting his ex- periences, which in all cases serve as guides. Such knowledge allows him to very quietly confront any problem which he may in the course of his operations encounter, giving at the same time an astonishing accuracy to his calculations for the elemen- tary composition, as well as for the production of colors and shades, which he desires to imitate. In composing our shades, there are, in fact, only the three primary Colors at our disposal, that is, red, yellow, and blue. The modifications, which these three colors are capable of under- going, and the limitless combinations into which they can enter with each other, enable us to reproduce any required color or shade. The part which water plays in all these modifications and combinations makes this element one of the most useful agents in the hands of a dyer. Indeed, water is for the dyer what the white color is for the painter; the more it is used in composing a dye-bath, the lighter becomes the dye; for the dyer, water means '' white," that is, absence of coloring. We shall try to illustrate this assertion by an example, for DYEING LEATHER. 701 instance, a quart of concentrated solution of scarlet. "Concen- trated" means that we have dissolved in boiling water so much of the djestuff as the water was capable of dissolving, and de- canted the clear liquor from the sediment, if there was any, after cooling down to 50° F. If leather is dyed with a quart of this solution, there is produced a deep, nourished scarlet ; but for the next dye we will take only -^-^ of a quart of this solution and add yig- of a quart of water, so as to have again 1 quart of dye- liquor. The color thus produced is also well nourished, but has -jIq less depth than the former one. The addition of water and the reduction in the quantity of coloring solution have already produced a modification which is not likely to escape a dyer's eye. If we continue reducing the quantity of concentrated solu- tion at the rate of 10 per cent., and increasing the quantity of water at the same rate (that is, making the quantity of dye- liquor=l quart), we will arrive at a point where our dye-liquor consists of only jL- quart of the original concentrated solution of scarlet red, and -^-^ quart water. The color of the material dyed in such a bath is, of course, proportionately lighter. Each time that we have reduced the quantity of concentrated solution of dyestnff by j^q, and added yig- more water instead, we have altered the original color, and have produced nine modifications of the first, or ten grades of scarlet-red altogether. The result of such an experiment is what is called a "gradu- ated line of a color," and each degree of it is called a " modified color" of such a line. A close examination and dissection of a spectrum discloses the fact that there are not only seven, but actually twelve, colors contained in it, viz : Red at the bottom, and following in suc- cessive order upward, red-orange, orange, yellow-orange, yellow, yellow-green, green, blue-green, blue, blue- violet, violet, and red-violet. If we take three very bright artificial dyestuffs (red, yellow, blue), products of coal-tar, better known as aniline colors, whose chemical composition allows of their perfect union by mixing their solutions with one another, we can produce these twelve colors of the spectrum by mixture, out of three we can form twelve, nine of them being binary colors, so called from being 702 THE MANUFACTURE OF LEATHER. composed of two of the three primary colors. There is no difficulty in producing such a representation of a spectrum upon leather. The measure is for a leather dyer what scales and weights are for the chemist — they are proof and evidence. A quart re- presents a unit, which can be divided, and of which we can take only one hundredth part or any fraction we desire or require — where figures corroborate, error is not probable. One quart of concentrated solution of scarlet-red is mixed with one quart of concentrated solution of a yellow dyestuff. If these dyestuffs represent the true elementary colors, and this bath is applied to dyeing leather, properly prepared, the product must be a true orange, this color being composed of red and yellow in equal pro- portions. But if only 0.25 of a quart of yellow dyestuff solution is mixed with 0.75 of red, the compound will be red-orange. If, on the other hand, these proportions are reversed, that is, 0.25 of a quart of red dye-liquor mixed with 0.75 of yellow, the pro- duct will be yellow-orange. As red and yellow in equal pro- portions form the true orange, it follows that red-orange lies on one side of this binary standard color (toward red), and yellow on the other (toward yellow). We call a " binary standard" that compound color which is obtained by mixing together the liquors of two primary colors in equal proportions. By operating in the same manner with the solutions of a yellow and a blue dyestuff, yellow-green, green, and blue-green are produced. The solution of a true blue dyestuff, such as is spoken of in enumerating the prismatic colors, being brought together with that of a pure red, in the above proportions, the blue-violet, violet, and red-violet of the spectrum are produced. It should be borne in mind, however, that in all cases the dyestuffs which are used for such operations must be of such a nature as to allow of their combination, that is, of their perfect embodying one into the other, if mixed in solution ; so that, after dj^eing, no separate colors can be distinguished upon the material. If in the transition from one prismatic color to another we were at each step to exchange only one hundredth part of the DYEIXG LEATHER. 703 one for an equal quantity of the other, it is evident that in- finitely more colors might be produced; but these slight modifi- cations would be hardly distinguishable. To our eye the whole scale would appear as an amalgam, like the spectrum of the white light. But if it is considered that either of the two colors can be graduated, that is, progressively changed from very dark, nearly black, to light and very light, nearly white, it may readily be imagined that thousands of colors can be pro- duced by this very simple means. We say purposely colors, because we mean not shades,^ of which we shall speak later. The slightest alteration of "white is at once perceptible; while a considerable proportion of any other color can be added to black, before the modification becomes apparent to even the trained eye. Transition of colors through their countless modifications can be very properly illustrated by a so-called color-ball, having for its equator, as it were, a zone consisting of the primary and binary colors, white for its north pole and black for its south pole. But to return to our circle of normal colors : All colors growing out of a primary color must be classed under that denomination, until they reach the compound of the primarv with the nearest binary standard color. For instance, all colors originating in red are to be classed as reds, until the red-orange is reached, with this difference, however, that they are distin- guished at first, second, third, etc., reds, according to the degree of modification the red has undergone. Thus, if red is denomi- nated as No. 15 on the side toward blue, it would signify that this red contains 15 per cent, of blue ; as only with the addition of 25 per cent, blue the red becomes red-violet. The same nomenclature ought to be used for blues and yellows. From the above it is easy to see that a precise knowledge of this circle is suf&cient to determine a color at once, thus enablins; the dyer to reproduce it. The series of modifications of which any primary or binary color is susceptible is collectively called the "category" of that color, and we wish it here to be under- stood that the category is not identical with "shades," though 704 THE MANUFACTURE OF LEATHEE, the erroneous application of this term is quite general and popular. We know what a simple (or primary) color is, of which there are only these three : red, yellow, and blue ; we know also, that either two of these simple colors combined with one another form a binary (or secondary) color. But a " shade" is the result of the combination of one binary color with one or two other binary colors not belonging to the category of the former. Brown, for instance, is a shade. All the browns are oranges shaded more or less with blue or violet. When a dyer is called upon to reproduce a certain brown, the first thing he has to do is to ascertain what kind of orange is the base of it, whether red, pure, or yellow orange. By contrasting various browns with another, it is easy to determine Avhether the particular brown in question belongs to the reddish or yellowish category; the category once defined, there is no further difficulty in decid- ing upon the base of the dye-bath, whether reddish or yellowish- orange. This base is then to be composed, then to be shaded, and the bath is ready for dyeing; if the diagnose of the orange is correct, and the shading carefully done, the dyer cannot fail in producing the exact brown. From this it may be seen how indispensable for a dyer it is to thoroughly understand his binary colors; upon this knowledge depends, in fact, the whole art of producing the various shades. The whole variety of binary colors are so many bases for all imaginable shades. The shades, in their turn, are again susceptible of infinite modification, that is, of being rendered light by the addition of water, or darkened by the chemical action of various salts, such as sulphate of copper, bichromate of potassium, etc., added to the dye-bath. The whole range of such modifications, from the lightest to the darkest hue, is called the "categorj^ of a shade." In reproducing a given shade, the practical dyer will rather from the beginning sadden a little less than too much, because he has it always in his power, and it is easier to increase the saddening, than to diminish it, after it has been once produced. The manufacture of dye-stufi's from coal-tar, the so-called aniline colors, has attained a high state of perfection, although DYEING LEATHEE. 705 this fraitful field of manufacturing chemistry is, as yet, only partly explored and still less practically cultivated ; and we are daily greeted by the news of improvements, inventions, and new and astonishing discoveries in this line. There are now already a number of such artificial dye-stuffs in the market, which directly produce a variety of desirable shades, relieving the dyer of the trouble and the cost of experiments to compose them. Still, it is very often necessary to mix these colors for the production of certain shades. In such cases it ought to be borne in mind that the base of every shade is a binary color, which must be ascer- tained and defined before beginning the mixing operation, in order to save trouble, time, waste, and positive loss. Dyeing with aniline colors will be enlarged upon in Section V. of this chapter. Section II, Mordants. Mordants in the widest sense are bodies having the power of fixing certain coloring matters upon materials to be dyed. But in the narrower sense mordants are also certain bodies which possess the power of changing the natural color characteristic to coloring matters, thus leading to the production of several shades with one and the same substance. In as far as many bodies available as mordants can produce, on meeting with other sub- stances partly organic and partly inorganic, characteristic colors, they may be designated as color-yielding substances. The mordants generally used can be divided into three groups, viz., acids, bases, and salts. Acids. Acids are generally compound bodies sour to the taste, and capable of changing blue vegetable colors to red. By combin- ing with bases they furnish combinations which have neither the external characteristics of the acid nor those of the base combined with it, in fact are new bodies. Such combinations of acids with bases are called salts. In the process of combination the acids are neutralized by the bases, the same being true in a 45 706 THE MAiSrUFACTURE OF LEATHER, reverse sense as regards the bases. Acids are divided into mineral and organic acids. Sulphuric, nitric, and hydrochloric acids are the principal mineral acids employed in dyeing leather, and they will be described separately. Sulphuric Acidj or oil of vitriol, is a combination of sulphur with oxygen. In a concentrated state it is a caustic substance, which energetically attacks organic bodies and destroys them under a black or brown coloring, and is best kept in glazed earthenware or glass ves- sels hermetically closed. Sulphuric acid is mixable with water in all proportions, and by sufficiently diluting loses its strong caustic property and yields a fluid more or less clear. Diluting the acid with water requires to be done carefully, as the great attraction which this acid has for water causes a strong develop- ment of heat, in consequence of which phenomena resembling explosions of steam take place, and with careless handling the workman might be injured by the caustic fluid. Many have suffered permanent injury to health or have lost eyesight by carelessly diluting sulphuric acid. With the exception of dis- solving indigo, which requires concentrated sulphuric acid, only dilute sulphuric acid is used in dyeing leather. The best method of diluting is to place the water in a clay or porcelain vessel, or very diluted acid in a wooden vat, and to pour the concen- trated acid into it in a thin stream, a glass rod being used to mix the acid with the water as it flows in. Under no circum- stances should water be poured into concentrated acid. Nordhauseu, or fuming sulphuric acid, differs from common sulphuric acid in its mode of preparation and that it contains less water, and is in a certain sense more concentrated than ordinary sulphuric acid, which is due to its percentage of anhy- drous acid. For all other purposes except for dissolving indigo, the use of ISTordhausen sulphuric acid would be sheer waste, as the cheaper American acid, when diluted with water, furnishes the same product as fuming acid, and besides has the advantage of being less contaminated. DYEI^^G LEATHEE. 707 Nitric Acid Is a product of the action of sulphuric acid upon nitrates, and is generally prepared by distilling nitrate of potash or of soda with sulphuric acid. The strongest nitric acid emits thick gray fumes when exposed to damp air, because its vapor, though itself transparent, readily absorbs water from the air, and con- denses in minute drops of diluted nitric acid which compose the fumes. Nitric acid exerts an energetically oxidizing influ- ence upon all organic substances, and is best kept in vessels of glass or earthenware. It is mixable with water in all propor- tions, and in a diluted state furnishes a colorless fluid of a strongly acid taste. Nitric acid suffers decomposition when exposed to the light, and it frequently happens that bottles filled with concentrated nitric acid burst on exposure to light, in consequence of the pressure of the accumulation of gases in the upper part of the bottle. Such acid, decomposed by the action of light, assumes a red-brown, and under certain circumstances, green color, and acquires the property of emitting, when exposed to the air, brownish- red vapors of hyponitric acid, etc., which violently irritate the respiratory organs. Such acid, known as red or fuming nitric acid, is very serviceable for certain purposes, and is especially manufactured and brought into commerce. Ordinary, as well as fuming, nitric acid is exclusively used by the dyer for sharpening certain baths, and in the preparation of some mordants ; for all other purposes it can be replaced by other and cheaper acids. The characteristic property of nitric acid of coloring nitrogenous, organic substances, yellow, which is utilized in silk and wool dyeing, cannot be made use of in coloring leather, as the acid would act too strongly upon the leather substance. Hydrochloric Acid Is a solution of the gaseous combination of chlorine and hydro- gen in water, and is a yellowish fluid which emits white fumes when exposed to the air, and has a suffocating odor. It is 708 THE MANUFACTURE OF LEATHER. rnixable with water in all proportions, and when sufficiently diluted yields a colorless fluid of a perceptibly acid taste. On account of its cheapness, hydrochloric acid can be advan- tageously used where only the action of an acid is required, as, for instance, in neutralizations, etc. Of organic acids, the following are of interest to the dyer: — Acetic Acid Is found in nature as a constituent of salts, occurring in some juices of plants, and also forms a constituent of certain combi- nations of the animal body. It is a combination of carbon, hydrogen, and oxygen. Yery concentrated acetic acid is slightly caustic, but diluted with water it is entirely innoxious. Pyroligneous acid — obtained by the dry distillation of wood, ■and as a by-product in burning charcoal — is dilute acetic acid. It is much used, especially for dyeing leather, in consequence of its containing certain empyreumatic substances. It possesses the property of imparting to the black color, produced with the assistance of the so-called black vat, a pure tone of color, this being the reason why it is almost exclusively used for iron liquor for black, vlcetic acid, whether produced by the oxidation of alcohol, or dry distillation of wood, is mainly used for the preparation of the various acetates employed in dyeing, and as it attacks the leather substance less energetically than mineral acids, is preferably used for acidulating dye-batbs. Oxalic Acid, Known also by the name of acid of sugar, is, like acetic acid, a combination of carbon with hydrogen and oxygen. It is a constituent of many plant juices, being found in the leaves of the wood-sorrel, in the stalks of rhubarb, in some seaweeds, and in certain lichens. Oxalic acid, like acetic acid, is used for preparing dye-baths. It is very poisonous, the antidote being chalk of magnesia. DYEING LEATHER. 709 Citric Acid and Tartaric Acid. Citric acid is a constituent of plants, and occurs in the juice of lemons, currants, gooseberries, and other kinds of fruit. Tar- taric acid is prepared on a large scale from crude tartar, which is deposited in wine casks. Both acids are occasionally used as additions to dye-baths, though they probably possess no special virtues entitling them to preference before the other acids. In commerce both acids are found in the form of colorless crystals, or crystalline masses, readily soluble in water, and yielding solutions of a pure acid taste. Bases. Bases comprise all compound bodies capable of combining to salts with acids. Bases soluble in water have in common the property of re-coloring vegetable substances blue after its color has been changed to red by acids. Considering bases in the above sense that they can combine with acids to salts which show neutral reaction under certain circumstances, we may speak of a neutralization of acids by bases and employ thein for that purpose. The majority of bases, which are either metallic oxides (mineral bases) or combinations containing nitrogen, hydrogen, and carbon, and sometimes oxygen (organic bases), are insoluble in water but soluble in acids, while, on the other hand, bases with insoluble acids and soluble in water will gene • rally yield solutions containing the newly formed salt. On account of the dissolving effect which bases exert upon many insoluble substances by reason of the nature of the acids, they are as such of but little importance to the dyer. These are the following: — Potassium Hydrate and Sodiura Hydrate. The first body is almost exclusively obtained by the action of caustic lime upon solutions of potash. It dissolves very readily in water, has a strongly alkaline reaction, and exerts a powerful caustic effect by reason of its capability of dissolving many organic 710 THE MANUFACTUEE OF LEATHER. substances (among others animal skin). Caustic potash can generally be replaced by the cheaper potash, soda, or ammonia. The action of sodium hydrate, or, as it is commonly called, caustic soda, is very similar to that of caustic potash, and is frequently used as a substitute for the latter substance, which it resembles in appearance. Ammonia, In a pure state ammonia is a colorless gas of a pungent odor. It is a combination of nitrogen and hydrogen, and is produced by heating a mixture of caustic potash or caustic soda, or, what is cheaper, caustic lime, with sal ammoniac. Although ammonia is a cheap article of commerce and is in general use in dyeing, urine of human beings and of carnivorous animals is almost exclusively used in the so-called English method of steam dyeing. Besides there are other dyers opposed to progress who still make use of antiquated receipts and retain the disgusting use of urine, although the employment of ammonia is not only cheaper but also better. We consider it unnecessary to enter into a discussion of this antiquated substitute for ammonia, and will only remark that putrefied urine can only be used as it only acquires the properties of a substitute for ammonia in that state. Urea, a characteristic constituent of the urine of carnivorous animals, undergoes decomposition in the putrefaction of urine, in consequence of which ammonium car- bonate, i. e., the active principle of putrefied urine, is formed. . Lime. Caustic lime, or burnt lime, is the oxide of calcium. The purest product is obtained by burning white varieties of marble, while ordinary limestone yields lime contaminated with alumina, silicious earth, iron, etc., the quality of the lime depending on the quantity of these impurities. The fewer impurities lime contains, the better it is for dyeing purposes. Lime-water, or milk of lime, is much used, not only for neutralizing purposes, but also for separating acids from solutions; the preparation of caustic lyes being, for instance, a process in which the power of lime of precipitating carbolic acid in the form of insoluble DYEING LEATHER. 711 carbonate of lime is utilized for separating the carbonic acid from the oxides of potassium or sodium. Other bases by themselves are not used in dyeing, only the combinations of a few with acids, i. e., their salts, being employed. Organic bases, which are generally derivatives of ammonia, and closely allied with it, are also not used by themselves as mordants, though in certain combinations they furnish highly valued coloring matters. Salts. Salts are combinations of acids with bases, no matter whether the acid or the base is of organic or vegetable origin. The salts can be divided into acid, neutral, and basic salts, according to whether their acid is incompletely or completely neutralized, and the base is also completely neutralized, or whether a non- saturated part of the latter is present in excess. Acid salts are such as contain an excess of acid, basic salts, such as contain an excess of base, while the terra neutral salts is applied to those which contain exactly the quantity of base necessary for the neutralization of the acid. Soluble acid salts have generally an acid reaction, and basic salts mostly an alkaline one, while the majority of the actually neutral salts have also a neutral reac- tion. Exceptions to this rule seldom occur. While the actual salts consist, as stated, of acid and base, and are, therefore, oxygenous combinations, there is another class of salts which contain no oxygen, and must be considered as pure combinations of metals with another element or with a combination. They are called haloid salts, chlorine, bromine, iodine, etc., being instances of this class. One of the most com- mon examples of these salts is common salt, which is composed of the metal sodium and the element chlorine, and is, therefore, chemically known by the term sodium chloride. In the following we give a compilation of salts of greatest importance to the dyer. Sulphates. Ferrous sulphate^ or green vitriol^ is a combination of ferrous oxide with sulphuric acid. It is used for making mordants, 712 THE MANUFACTURE OF LEATHER. especially for black, gray, and violet, and for preparing the indigo vat. For the latter purpose, it should be as pure as pos- sible, while for preparing iron liquor, ferrous sulphate, even if turned strongly brown, can be employed. It is also used in the production of Berlin blue. Capric sulphate^ or hlue vitriol^ contains cupric oxide and sul- phuric acid, besides water. It is brought into commerce in transparent or semi-transparent prisms of a dark-blue color, wdiich have an acid metallic taste. They are soluble in -i parts of cold water and 2 parts of boiling water. Under the name of Salzburg vitriol, double eagle vitriol, etc., a variety of cupric sulphate is brought into commerce, which, besides being mixed in various proportions, contains sul- phate of zinc. Both varieties are used in dyeing glove leather. Cupric sulphate is very poisonous ; a small quantity taken inwardly produces severe vomiting. White vitriol, or zinc sulphate, is a combination of oxide of zinc with sulphuric acid, and is obtained by crystallization from a solution of zinc in dilute sulphuric acid. The crystals are clear as water, and have a nauseously metallic taste. They are readily soluble in water. White vitriol, which is very poisonous, is almost exclusively used in the so-called English method of steam dyeing. Aluminium sulpihate consists of sulphuric acid and aluminium. It is found in commerce in the form of bricks or plates of a white or grayish-white color and an acid taste. By boiling aluminium sulphate with water, it is gradually and completely dissolved, and yields a colorless fluid, with an acid reaction. The solution can be advantageously used in all cases where alum was formerly employed, especially as it contains no excess of sulphuric acid, and constitutes the only component part of alum which makes the latter valuable for dyeing purposes. Alu7n, in the narrower sense of the word, is such a double combination of two sulphates, which will always contain alumi- nium as a sesquioxide, when solutions of aluminium sulphate are brought together with sulphates of suitable simple oxides. According to the nature of the sulphate combined with the aluminium sulphate, the following principal distinctions are DYEING LEATHEE. 713 made in the varieties of alum: Potasli-alum, ammonia-alum, and soda-alum. Soda-alum is more readily soluble in cold water than the others. For dyeing purposes potash-alum is most generally used, or as a substitute for ammonia-alum, or a mix- ture of both in varying proportions. It is of little importance which variety is used, only in buying his supply the dyer should be careful not to be overcharged by paying the same price for ammonia-alum, which is always cheaper than potash-alum. For the purpose of recognizing whether potash-ahim is pure, rub a piece of it together with caustic lime and moisten the mixture with water. The presence of ammonia will be readily detected by its characteristic odor. It is also worthy of consideration that alum frequently contains iron, which renders it unsuitable for many purposes, as the percentage of iron frequently produces with the coloring matters other shades than those intended. In order to obtain a pure red with madder, alum containing iron must be especially avoided. It is, therefore, well to subject the alum to a test before using it. This is readily effected, accord- ing to Prof, Eange, by throwing a piece of the alum to be tested into a solution containing 15J grains of potassium cyanide in 7 ounces of water. If the color of the surface of the alum remains unchanged, it is free from iron^ but contains iron in case blue spots make their appearance. This test is entirely reliable for alum in pieces ; it is claimed to be equally reliable for pulverized alum and alum solution. A variety of potash-alum which is especially highly esteemed is the so-called cube alum. It is distinguished from the ordi- nary alum by the form of its crystals, and has the further advantage of its solution being entirely free from iron. "Burnt alum" is almost exclusively used for fixing coloring matters which by themselves have not sufficient capacity to ad- here to the fibres. But it is not generally used in the above form, but rather by preparing first a solution in which by adding acetate of lead to alum solution, aluminium is present as aluminium acetate, and using the solution as a mordant (red liquor). Chromium alum is also sometimes used for dyeing purposes, especially in dyeing with aniline colors. It is found in com- 714 THE MANUFACTURE OF LEATHER. merce in dark violet crystals, which yield with water a solution of the same color. On heating, the aqueous solution turns green, but gradually reassumes its original color. Nitrates. Ferric nitrate and lead nitrate are the only ones of the series which have any importance for the dyer. Ferric nitrate is formed by dissolving iron in nitric acid. The commercial article is a brown liquid of the consistency of syrup, has an acid reaction and a strong taste of ink. It is mixable with water in all proportions, the diluted liquid yielding a strongly colored fluid. This salt, which can also be prepared in a solid form, can be advantageously used for black and blue colors, in the latter case with the assistance of yellow prussiate of potash. • Lead nitrate is prepared by dissolving litharge in nitric acid. It forms white crystals of a nauseously metallic taste, which are difficult to dissolve in cold water, but readily so in boiling water. Lead nitrate, like all other soluble lead combinations, is poisonous. This salt, Avhich is not generally used in leather dyeing, lead acetate being mostly substituted for it, has only become of importance since the introduction of aniline colors. Chlorides. Sal ammoniac comes into commerce either in fibrous cakes (sublimated sal ammoniac) or in small crj^stals (purified sal ammoniac). It is readily soluble in water, and yields a colorless solution of a neutral reaction and a peculiar salty taste. In dj^eing it is used as an addition to the so-called tin composition. Ferric chloride is similar to ferric nitrate, and is used in a like manner. Stannous chloride (tin salt) is of but little importance to the leather dyer, as leather, especially alumed leather, is not im- proved by it. Stannic chloride forms the most active constituent of the solu- tion of tin in nitric and hydrochloric acids, or in nitric acid and sal-ammoniac, which is known by the name of tin composition or physic. Pure stannic chloride is soluble in water, and yields DYEING LEATHER. 715 an almost colorless solution of a strongly acid reaction, which can be successfully used as a substitute for all the various tin compositions. Common salt (sodium chloride) is so well known that it requires no description. It plays a more important part in tawing than in dyeing. Acetates, Ferric acetate in a pure state forms a reddish-brown liquid of an ink-like taste. It is never used in this form for dyeing pur- poses, but it constitutes the active principle of the various essences used under the name of iron liquors, which are ob- tained by dissolving iron in vinegar, sour beer, sour wine, or wood vinegar. The following directions for the preparation of a black, vat can be recommended: Place a barrel upright and provide it with a perforated false bottom six inches above the true one. Upon the false bottom pile a layer of old iron or iron filings, and upon this a layer of iron, which should be rusted as much as possible. Upon the iron place a layer of young alder bark with the addition of a few nutshells and a few buckthorn berries. Upon this bring another layer of old iron, upon this a layer of alder bark, nut-shells, and berries, and continue the layers alternately until this barrel is full, and then fill the barrel with an acid liquid such as vinegar, sour beer, juice of unripe fruit, etc. The first liquid is generally heated before pouring it into the barrel. A part of the fluid is drawn off from time to time through a cock near the bottom of the barrel and poured back over the material, whereby a movement is originated in the barrel which exerts an advantageous effect. Some leather dyers use, besides the above-mentioned materials, some verdi- gris, which has by no means an injurious effect. The black vat cannot be successfully used before it is six months old, and can only be called good after it is one year old. The black vat is not only used for dyeing oil leather, but also for coloring alumed leather upon the flesh side. The iron solu- tioD prepared in the above manner is, as a rule, something over 2°B. Aluminium acetate forms the actually active constituent' of the 716 THE MAXUFACTUEE OF LEATHER. red liquor, which is generally prepared by mixing hot solution of alum, or better of aluminium sulphate, with plumbic acetate. 'The resulting solution, which is as clear as water, can be imme- diately used after adding some sodium sulphate in order to com- pleteh^ separate the lead. According to Leussen, the following- are the best proportions: Dissolve 191^ pounds of aluminium sulphate and 15 J pounds of soda in 37 gallons of water, and add to this solution a solution of 228f pounds of plumbic acetate in 18J gallons of water. After settling and removal of the white precipitate of plumbic sulphate by filtering, the mordant can be immediatel}'" used. Aluminium acetate is an indispensable mordant for the calico dyer, but is of less importance in dyeing alumed leather since the skins, on account of the percentage of aluminic salts worked into them by the tawing process, do not especially require a mordant. In dj^eing oil leather this mor- dant can be advantageously used. Plumbic acetate (sugar of lead) is prepared by dissolving litharge in vinegar and evaporating the resulting solution. It is chiefly used for preparing the red liquor and for the produc- tion of chrome yellow upon leather. For the latter purpose it is better to use the basic acetate of lead, it being less injurious to the leather. It is prepared by boiling solution of plumbic acetate with an excess of litharge and is found in commerce in solution under the name of vinegar of lead. Both salts are violently poisons, and when taken inwardly or even handled carelessly produce symptoms of colic. Cupric acetate. In commerce this salt is known as verdigris, crystallized verdigris, distilled verdigris, etc. It is but slightly soluble in alcohol and requires five times its weight of boiling water for a complete solution. It forms bluish-green crystals of a nauseously metallic taste, which represent the actually neu- tral salt, i. e., the crystallized or distilled verdigris. Under the general name of verdigris a basic acetate comes into commerce in two varieties differing widel}' in appearance. One forming a mass of a pale blue color sprinkled through with a quantity of cr3'stalline spangles, while the other is a greenish mass in which the cr3^stalline spangles are less perceptible and DYEING LEATHER. 717 have a more earthy appearance. The difference in appearance is caused by the presence of different basic salts. Verdigris can be used as a substitute for crystallized verdi- gris in all cases, it being only necessary to use a larger quantity of it, or, what is preferable, to dissolve it with an addition of acetic acid which effects a ready and complete solution. In- dependent of being the material used for the manufacture of Schweinfurth green, verdigris is only used as a mordant in dye- ing with garancine or as a ground for the production of brown shades in dyeing with potassium ferrocyanide. Tartrates. Of this series of salts, the only of any importance to the dyer is the 'potassium, hitartrate. It forms a crust in the fermenting vessels, and after reaching a certain degree of thickness is broken out and brought into commerce as crude tartar. It forms grayish-brown masses, which, when derived from red wine, have a dirty red color. Cream of tartar is found in commerce either as colorless, transparent, and hard crystals, or as a powder. It dissolves in 200 parts of water of 158° F., and in 20 parts of water of 185° F. It is insoluble in alcohol. Tartar is used in leather dyeing for the purpose of increasing the durability of the colors. Tartar used at the same time with ammoniacal liquids gives a good mordant. The ch(3mical action of tartar in the different dyeing pro- cesses is not yet thoroughly explained. Its power of keeping lime salts and many metallic oxides in solution, is of especial importance as a protective against the injurious effects of hard water which has frequently to be used, and exerts a disturbing influence upon the progress of the dyeing process on account of its richness in lime salts. Carlonates. Of this series of salts only tAvo are of importance to thc'dyer: Potassium carhonate (potash) is almost exclusively obtained by lixiviating wood ashes and evaporating the resulting lye. It forms a mass of a dark-gray, blue-gray, or bluish color, which 718 THE MANUFACTURE OF LEATHER. readily becomes moist on exposure to air and deliquesces. It is easily soluble in water, yielding a solution of a lye taste and strongly alkaline reaction (crude potash). Purified potash, on the other hand, is always white and also soluble in water. Different varieties of potash are known in commerce and desig- nated by various names according to their quality and derivation, such as pearl ash, Russian potash, lllyrian potash, American potash, etc. As potash is always used in solution it is recommended that the dyer subject it to the inexpensive purifying process, which consists in pouring over it about the same quantity of water. The carbonate passes into solution, and by placing the vessel in the air and pouring off the solution, it can readily be separated from the larger portion of sulphates and chlorates which form tlie most common contaminations. The residue is washed out with water, which can be used for purifying a fresh quantity of potash. Potash is partly used for cleansing the skins before dyeing, and partly as an addition to aluminium sulphate whereby the sulphuric acid is saturated. It serves also to remove any excess of oil used in preparing many skins and frequently for the neutralization of acid liquids, whereby effervescence, caused by the escape of carbonic acid, takes place. Potash is also used as mordant in the English method of dyeing glove leather. Sodium carbonate (soda) is used by the dyer chiefly for neutral- izing purposes, for dissolving coloring matters, and as a consti- tuent of mordants. In most cases it can be employed as a substitute for potash. It remains to mention a few salts of other acids of importance to the dyer which could not be included in the above groups. Potassium hichrom,ate is composed of chromic acid and potas- sium. This salt, which is very poisonous, is chiefly used with dye-woods for the preparation of black colors, the development of which from the coloring matter of the dye-woods is due to the oxidizing action of the chromic acid. By mixing potassium bichromate with lead salts (nitrate or acetate of lead in solution). Lead chromate is obtained as a yellow, pulverulent precipitate, which is highly esteemed as a color (chrome-yellow). In dyeing DYEING LEATHER. 719 leather it is most conveniently used by subjecting the leather previously mordanted with lead acetate to the action of a solu- tion of potassium chromate. By heating potassium chromate with concentrated sulphuric acid, a green solution is obtained from which separates the previously described chrome-alum in the form of crystals. Yellozv pj'ussiate o/'potesA (potassium ferrocyanide) is brought into commerce in the form of yellow crystalline masses more or less saturated, which yield a white powder. The salt is readily soluble in water, especially if previously heated, and is distin- guished by its bitter salty taste and neutral reaction. It is not poisonous. Yellow prussiate of potash is not used as much as a mordant for fixing other colors, as for a coloring matter by itself, since it possesses the power of yielding at once a beautiful blue color, known as Berlin blue, on coming in contact with iron salts. This blue, which can also be prepared by the action of yellow prussiate of potash upon sulphate of iron and simultaneous exposure to the air, is convenient for dyeing leather, since nothing further is required than brushing the skins previously mordanted with yellow prussiate of potash with a weak solution of nitrate or acetate of iron, or, vice versa, treating skins mor- danted with iron solution with yellow prussiate of potash. Another somewhat different method of dyeing with Berlin blue is to saturate the articles to be dyed with a solution of ferric salt and ammonium oxalate (obtained by saturating oxalic acid with ammonium), to treat them next with prussiate of potash, and finally to pass them through a weak acid bath. Berlin blue prepared according to any of the above methods is entirely fast, and is not changed by acids, but is destroyed by alkalies. The coloring matter is, however, not soluble in water. With prus- siate of potash and a cupric salt, a beautiful brown is produced, the formation of which is due to the precipitation of cupro-ferric- cyanide upon the leather. Hed prussiate of p)oiash (potassium ferric-cyanide). This com- pound crystallizes in large, dark-red, monoclinic crystals soluble in water with a brownish-green color. It is poisonous. Its employment in dyeing is due to the fact that with ferrous salts, 720 THE MANUFACTURE OF LEATHER, it yields a blue, the so-called Turnbull blue, which is similar, as regards behavior and appearance, to Berlin blue. It is an ex- cellent oxidizing agent especially in the aniline color industry, where it is chiefly used for the preparation of aniline black. For producing blue colors the cheaper yellow prussiate of potash is, however, to be preferred. It only now remains to mention in a general way the sub- stances which can be obtained by the action of alkalies upon fats and oils, and which are known as Soaps. The product of saponification, which is known as soap, must be classed with the salts. Soap of every kind, and especially that used in dyeing, which result from the saponification of a fat or oil by an alkali, must chemically be considered as a mixture, more or less pure, of the stearate, palmitate, and oleate of the alkali used, containing besides water and frequently an excess of alkali and some glycerine. Soaps are generally divided into potash and soda soaps accord- ing as the fat has been saponified with potash or soda. Potash soaps are generally soft and readily soluble in water, and soda soaps hard and more difficult to dissolve. A further difference in the quality of the soap depends on whether the soap is sep- arated by the addition of salt or prepared by simply evaporating the solution obtained by boiling the fat with the alkali. Soaps have the peculiarity of being precipitated from their solutions in water by an addition of common salt, and this peculiarity is taken advantage of, by throwing into the boiler a quantity of common salt, in order to separate the soap from the lye. The soap rises to the surface when the spent lye is drawn off" and the soap is brought into a solid form either by further boiling or by being transferred to iron moulds. Independent of the fact that such soaps are generally soda soaps, they have the . advantage of being purer than soaps not separated by salt, and are especially free from an excess of alkali. Generally speaking, good hard soda soap is the best to be used for dyeing purposes, it being only necessary to see that it is as DYEING LEATHER. 721 white as possible and not too strongly alkaline. The variety known as Marseilles soap, which is a combination of olive oil and soda, and also the finer grades of white castile soap, can be especially recommended. A good quality of tallow soap or palm-oil soap can also be used with equal success. In dyeing leather soap is partly employed for preparing the skins to be dyed, and partly for giving lustre to the dyed leather. Section III. Mechanical Work of Dyeing Alumed Leather and Directions for Preparing and Applying Various Vegetable Dyes. Glove leather is dyed either upon the flesh side or upon the grain side. The latter process, which is the usual one, is ex- ecuted either by dipping or painting. In order to obtain uniform coloring the skins must in all cases be cleansed, ^. e., uniformly moistened by fulling in a drum or treading in lukewarm water. For this purpose the skins are placed in a vat with sufficient warm water to allow of their being thoroughly worked, and trodden with the bare feet of a workman, until they show no white spots. As by this treat- ment they lose a part of the egg substance and flour previously imparted with the tawing paste which has been .described in the preceding chapter, it is restored either only with yelk of egg (1 yelk for each skin) or with an addition of flour (100 yelks of eggs and 2^ pounds of flour for one gross of skins). If several lots of skins are to be cleansed in succession, a saving of yelk of egg is effected by adding warm water to the liquor re- maining from the first lot and using it for treating the second lot, and so on. Dyeing the shins upon the flesh side, — After brushing whiting upon the flesh side the skins are smoothed with the hone. They are then cleansed, wrung out and after drying worked with the stretcher. The skin is then spread upon a table with a bed of zinc, such as is shown in Fig. 300, and the color applied as uni- formly as possible with a long bristled brush. Immediately after applying the color the skin while still moist is stretched in 46 722 THE MANUFACTURE OF LEATHER. a frame and pumiced. In executing this operation the work- man holding the lower end of the skin with the left hand rubs with the right from top to bottom, pressing the pumice-stone as hard as possible upon the skin. After turning the skin and pumicing the portion not touched in the first operation, the skin Fig. 300. is dried in damp weather in a heated room. After drying and working with the stretcher it receives a second application of color and is again dried and worked with the stretcher. Should the color not be sufficiently intense, a third application is re- quired. The skins being already sufficiently mordanted by the alum contained in them, the only requisites for dyeing are simple decoc- tions of dye-woods, barks, and berries, such as logwood. Brazil- wood, Avignon berries, quercitron, etc., which are compounded for the different shades. A chestnut color is obtained by a de- coction of fungi, such as grow on the trunks of apple and yjear trees, prepared by breaking the fungi into small pieces, and after soaking them over night in water, boiling in water for two hours, and repeating the boiling in fresh water. To impart a black color the skins, after working them with the stretcher, receive a coat of iron liquor (acetate or methylate of iron) of about 2° B., and, after drying, a strong application of logwood decoction, and, finally, one of acetate of iron. Pumic- ing is omitted. To oxidize the iron the skins are exposed to the air for a few days and then brushed with a brush moistened DYEING LEATHER. 723 with pure olive oil or almond oil, in order to give the black color the required lustre. To avoid spots, moisten the palm of the hand with the oil, and after passing it over the brush, take the oil from this brush with a second, and rub the oil into the skin with the latter. To prepare by this method of dyeing alumed leather, an imi- tation of Swedish leather, apply, after cleansing the skins, a color of oak bark, decoction of fungi, and Brazil-wood, and after giving yelk of egg, stretch, dry, and work them with the stretcher. Then apply the second coat of color, stretch, and work them with stretcher, and finally brush the leather upon the flesh side. Dyeing the skins upon the grain side. — For glazed leather and glazed glove leather the skins are first sorted into dif- ferent classes, the finest and whitest being reserved for white gloves, while the others are selected for light or dark colors, according to the cleanness of the grain. The skins are prepared in the same manner as those to be dyed upon the flesh side. Dyeing hy Dipping, To dye glazed skins by dipping, pour after cleansing and taking the skins from the vat, one- third of the dye-bath, the temperature of which should not exceed 77° to 86° F., into a vat, and work the skins in it with the hands to make the absorption of color uniform. Then beat them with the feet until the color of the bath is exhausted. After ten minutes remove the skins from the vat, and after pouring in the second third of the dye- bath, proceed in the same manner as before, and after that with the last portion of the dye-bath. Including cleansing, dyeing is accomplished in Icvss than an hour. The remaining dye-bath is poured into a vessel and used for another color. The dyed skins, after treating with yelk of egg, wringing out, swinging in the air, and stretching, are suspended by the lowest ends of the hind shanks, and quickly dried. As the flesh side is also dyed by dipping, this process is gene- rally only used for delicate and light colors. Berries are still often used as a dye-stuff'. For yellow Avignon berries, for gray dwarf elderberries, for sea-green privet dog-wood berries, and 724 THE MANUFACTURE OF LEATHER. for Other green shades buckthorn berries. Yery dilute decoc- tions of dye-woods are also used. For canary-yellow weld, for rose color Brazil-wood, for lilac logwood, and for other shades mixtures of these decoctions. A peach color is, for instance? prepared by boiling 1 pound 2 ounces of Avignon berries, 2^ ounces of ground Brazil-wood, and 1 pound 2 ounces of dwarf elderberries in 21 pints of water for two hours. It is not ad- visable to use astringent substances, such as quercitron, sumach, oak tan, etc Dyeing ly Painting. Dyeing glazed leather by painting can be accompl'shed either according to the Grenohle or the English method. By the Grenoble method the skins are first cleansed, i. e., soaked. After removal from the cleansing water they are placed upon a smooth board and smoothed with a horn tool, so that they lie closely to the board, and then brushed to remove any adhering dust, etc. After the skins have become dry, three or four coats of color are applied in succession, and the skins allowed to dry upon the boards. When dry they are taken from the boards, put in a damp place and worked with the stretcher. Lixiviated boards of linden wood joined with glue compounded with linseed oil are used for the purpose. After use they are thoroughly washed with water, or, if necessary, with weak lye or diluted acid. Every time before being used they must be painted with a decoction of flaxseed, this promoting partly the clinging of the skins to the boards and protecting them from dirt. The colors used are as a rule the same as used for dyeing by dipping. For violet apply a gray ground with dwarf elderberries and upon this a decoction of logwood. Chamois and nankin are obtained with Avignon berries and Brazil- wood; hazel-color by an addition of dwarf elderberries, and chestnut color by a further addition of logwood decoction. For olive-green apply lirst a mordant of acetate of iron or copper, and then a color prepared from Hungarian yellow berries with more or less logwood decoction, etc. For black a decoction is used prepared for 1 gross of skins, by boiling 2 pounds 3 ounces of Hungarian yel- DYEING LEATHEE. 725 low berries, 2 pounds 3 ounces of sumach, 11 pounds of logwood in 4| to 5| gallons of water until reduced to one-half the quan- tity. After filtering apply the fluid to the skins, and when dry give a coat of liquor of acetate of iron of 2° B,, and repeat the alternate application twice more. When the skins are thoroughly dry, wash them with a brush and water, and then work them with the stretcher. Should the color be wanting in intensity give another coat of logwood decoction only. After drying, a lustre is imparted to the skins by brushing them with a strong solution of white soap into which the yelks of a few eggs have been stirred. A good lustre is also obtained by using a mixture prepared for 6 dozen skins, by boiling 10| ozs. of soap, 1^ ozs. of lard, and If ozs. of soda in a sufficient quantity of water, and adding a decoction of 10| ozs. of flaxseed. After polishing, the skins are rubbed with a woollen rag and worked once more with the stretcher. The English method^ which is now generally used, has the advantage of furnishing more durable colors than the other methods, though very delicate shades such as by dipping can only be produced with difficulty or not at all. The process con- sists in giving the skins first a ground with a potash solution and applying upon this the dye liquor. Firing required for some colors is effected by an application of green vitriol. The principalobject of the alkaline ground is that by preventing the dye-liquors from penetrating, a greater saturation of the surface with dye is effected, which may possibly be due to the decom- position of the free alum still present in the skins. The mode of executing the process is as follows : — After cleansing and moistening the skins in warm water until they show no white spots, the water is poured off' without wring- ing the skins. Then take one yelk of egg for each skin, stir all the yelks together with some warm water, and after pouring the liquid over the skins, beat with the feet until all the egg sub- stance has been absorbed. Then take each skin separately from the vat, and, after rinsing thoroughly in cold water, spread it upon a table so that it has no wrinkles. The table is somewhat higher on the end where the workman stands, and is provided with a zinc top and a ledge open on the lower edge where the 726 THE MANUFACTURE OF LEATHER. fluid runs off. The spreading out of the skin is effected with a tool of horn. The alkaline mordant consisting for dark colors of a solution of 1 part of ordinary blue potash in 15 parts of water, and for light colors of 1 part of potash in 30 parts of water, is then applied with a brush. Instead of the potash solutions, solutions of 1 part of soda in 10 parts of water or 1 part of soda in 25 parts of water may be used. After applying the solution quickly and smoothing out the wrinkles, a second coat is given. The thoroughly cooled dye is then immediately applied with a somewhat stiff'er brush than is used for laying on the ground. The work should be done as quickly and uniformly as possible. Eubbing with a full brush upon one spot must be avoided. After applying the color, the skin is washed upon the table with well water, and then smoothed to remove the wrinkles. Applying color and washing is repeated until the water runs off clean. For colors requiring firing, a solution of y^ths to 1 oz. of Salzburg green vitriol and 4:^ to 5^ pints of water is applied after the second coat of paint and washing. Paint the skin thoroughly and uniformly with the solution, and, after allowing it to soak in somewhat, proceed with the washing with well water and smoothing as before. French Method. — In France a somewhat more alkaline mor- dant is used. It is generally composed of one quart of old urine which has become oily, 1\ ozs. of sodium carbonate, and 2 small liqueur glasses full of liquid ammonia. By applying this mor- dant carefully a beautiful yellow color is obtained with fustic of prime quality. By adding a little red to this color, chamois is produced, and orange-yellow by increasing the proportion of the red color with an addition of some Avignon berries. Hazel- nut and chestnut-brown are obtained by adding more red and some violet. Before proceeding with the dyeing the skins are sorted ac- cording to the colors for which they are best adapted. The best quality is used for light brown, mixed brown, olive-brown, sap-green, and olive-green ; the medium for lemon color, orange, violet, dark brown, dark gray, and nankin color; and the poor- est for dark green, iron gray, and black. DYEING LEATHER. 727 With the exception of spirituous tinctures, which can be kept in well-stoppered bottles, it is best to mix the colors fresh and use them immediately after cooling. Scrupulous cleanliness and order should prevail everywhere. The cloth or sieve for straining the color, the vessels for the latter, the brushes, and especially the dye-table must be kept as clean as possible. The mechanical portion of the dyeing of alum leather is divided, according to the French method, into five parts : — 1st. The assorting of the skins into the different colors and shades, and if for gloves into ladies' and gentlemen's. 2d. The washing, cleansing, that is to say, the preparation of the skins for dyeing. 3d. The dyeing itself (a) on the table ; grain and flesh dyeing (b) by dipping the whole skin in the dye liquor; viz. : plonge, suede. 4th. The drying of the dyed skins. 5th. " Boarding" the same ; that is, to render the dyed and dried skins soft and smooth again. The first thing to do is to assort the skins into the different classes, as it is impossible to take alum skins and dye them just as they run. Into the first class we put all the skins of a very fine grain, the smoothest and freest from air, lime, or iron spots. On these skins there can be dyed shades such as Havana, Bismarck, Bore, light chestnut, or leather brown, light terra-cotta, old gold, steel gray, mais, etc. The second class embraces skins on the grain of which we can recognize the marks left from the black hair of the living animal. Such skins are reserved for light chocolate, brown, medium olive, smoke gray, Eussian green, dark terra-cotta, Car- melite, etc. The third class consists of skins on which the alum or salt, while drying after tawing, has formed a kind of a marbled face ; skins with a partially open or coarse grain. On these skins there is usually set a dark olive color or bronze, dark grays, bottle-green, or black; also the very dark brown; in general such shades in the composition of which an iron salt is used, such as sulphate of iron, as a striker. 728 THE MANUFACTUEE OF LEATHER. The fourth class of skins are those the grain of which is too much damaged. These skins should be dyed on the flesh side (undressed kid), provided this part of the skin proves consistent enough in its structure to support the emery wheel or pumice- stone, in order to give it an even velvet-like face. When the skins are thus selected, mark each class on the neck with a little cut ; the first class with one cut, the second class with two cuts, etc., so that they can be recognized again should the whole lot be washed together in a drum or tub. The dyeing of alum leather is a very unthankful task. Even with the greatest care the skins often do not turn out as they ought to do. But one thing is certain, if we are not very care- ful, as in this case, our work is condemned beforehand, and we must not wonder if we spoil the skins or produce uneven dyeing. We entered upon a full explanation of the assorting and pre- paring of the skins for dyeing, because it is, so to say, the prin- cipal operation of the dyeing itself; on badly-prepared skins, a dyer cannot set an even color. Suppose the skins we assorted belong altogether to the first three classes, that is to say, they are skins to be dyed on the grain and in fancy colors. We marked the different classes with little cuts at the neck; now that they are washed, we have to assort them again. On class No. 1 we will set a leather- brown; class No. 2 we will dye in a medium olive; of class No. 3 we will dye one-half of the lot chocolate-brown, and the re- maining skins bottle-green. In the morning, while the brusher (that is, the man perform- ing the mechanical work of dyeing the skins) is cleaning the dye table, bowls, dye brushes, and assorting the prepared skins into the different classes again, the head dyer is preparing and mixing the colors. For this purpose, he needs the so-called mother dye-liquors — red, yellow, and blue. If it is not advisable to prepare the dye liquors by boiling the dyewood chips our- selves, which preparation requires at least three hours' boiling, it may be equally as good to have the extract of such dyewoods on hand, in which case the boiling lasts only a quarter of an hour. Many dyers say they cannot depend on the extracts of DYEING LEATHER, 729 dyewoods. This Avas probably true before we bad the improved machinery to produce good and pure dyewood extracts. In preparing the three mother dye liquors, the dye stuff's used for this purpose are : For No. 1, extract Brazil-wood {Ceesalpinia christa); for No. 2, extract fustic {Morus tinctoria)] for No. 3, extract logwood [Hsematoxylon campeachianum). To prepare the Brazil-wood mother dye liquor, put 20 gallons of clear water in a copper kettle, if boiled by open fire, or in a wooden tub or barrel if boiled by steam. To produce a strong dye liquor, 5 pounds extract Brazil-wood are allowed to boil for about 10 minutes. After this time add, always under stirring, one ounce of potash and one ounce of soda, in small quantities, and continue to boil it for 5 minutes longer. Now this mother dye liquor is ready, and must be drawn off' in a separate barrel and covered. The fustic mother dye liquor is prepared exactly in the same way, the same quantity of water, dye wood extracts and chem- icals being used. For the logwood mother dye liquor, use onlj^ 4 J pounds ex- tract for 20 gallons of water. To this add 1 gallon old urine. After boiling 10 minutes, add 1 ounce soda and 2 ounces potash, and continue to boil for 5 minutes. Then the liquor is drawn off' into a barrel and ready for use. Clean the kettle or tub thoroughly after each color is boiled, so that one color will not interfere with the following one. Besides these mother dye liquors, there are also required the so-called strikers. These are solutions of metallic salts, mostly sulphates. To dye our intended four shades we need three of them : striker No. 1, alum 3 pounds dissolved in 40 gallons of water ; striker No. 2, sulphate of copper, 3 pounds, dissolved in 40 gallons of water; striker No. 3, sulphate of iron, 1 pound, dissolved in 40 gallons of water. Now that the skins are ready for dyeing, the mother dye liquors and strikers prepared, we can proceed to compose our shades. The first is — Light-Leather Brown. — Take fustic dye liquor 12 gallons, Brazil-wood dye liquor 1^ gallons, logwood dye liquor 3 quarts. Use striker No. 1. The second shade is — 730 THE MANUFACTURE OF LEATHER. Olive. — Take fustic dje liquor, 6 gallons, logwood dye liquor 6 gallons, Brazil-wood dye liquor \ gallon. Use striker No. 2, The third shade is — Mi-fonce Brown. — Take fustic dye liquor 4 gallons. Brazil- wood dye liquor 6 gallons, logwood dye liquor 4 gallons. Take striker No. 2 and striker No. 3 in equal proportions; mix well and use. The fourth and last shade is — Bottle Qreen. — Take fustic dye liquor 4 gallons, logwood 8 gallons. Use striker No. 2. The dye is applied with a suitable brush. The hair of such a brush should be pretty stiff, and about 1| inches long, so that it may hold a proper quantity of dye liquor by dipping it in the bowl which is placed on the sideboard near the dye table. The wet skin is spread on the table which is shown in Fig. 300, flesh side down, and stretched out with a wooden or rubber " slicker." The skin must, of course, lie evenly on the table, so that no fold can be seen. Now apply consecutively two brushes full of old urine on the skin, brushing with each brush full of liquid two or three times around the skin. It is unnecessary to say that, for the urine (mordant), as well as for the dye liquors and strikers, an extra brush is used. Never change the brushes, nor use a dye liquor brush for striker, or vice versa. After the mordant is applied to the skin, put the color on it immediately. Each skin must be brushed four times at least, taking each time a good brush full of dye liquor (or two if necessary), brushing the skin on all its parts for about one and a half minutes with each brush full of dye liquor. In brushing the skin, while dyeing it, it is necessary to be quick, always trying to keep the dye liquor as much as possible on the surface of the skin. The weak part of the skin, as for instance the flanks and the neck, where the dye does not take very well, should be brushed a little more than the middle of the skin, that is, the back. The method of brushing the dye liquor on the skins is indi- cated in Fig. 301. A dyer should never commence to dye a lot of skins before being certain that everything is right. Consequently it is best to dye one of the prepared skins in the regular way with the DYEING LEATHER. '31 dye liquor prepared for the whole lot of skins; dry it and stretch it out, in order to see the shade and compare it with the sample, so that we may discover the error, if there is any, and correct it. Then, but then only, the brusher can continue to Fiff. 301. dye the whole lot. The imitation on paper of these shades is not quite so nice as are the leather samples. On leather, of course, these shades appear fuller, that is to say, better nour- ished. After the skin is well nourished with dye liquor, put the striker on it. This striker it is convenient to have also in a bowl on the table, so that it can be reached when required. Two brushes full of striker applied in the above-mentioned way are sufficient for each skin. Now the skin is dyed and ready to be rinsed with water out of a barrel kept near the table — that is to say, a dipper full of water is poured over it ; then turn the skin flesh side downward and drive all the superfluous water out of it by means of a copper slicker. After this take the skin from the table and hang it up, clean the table with water and recommence the same manipulation with another skin. As soon as four skins are dyed, hang them up in the dry-room or in the open air, in the shade, as the wet skins must never be hung in the sun. When the skins are dyed and dried they appear hard and stiff' and require to be softened again. For this purpose lay them in damp pinewood sawdust, in pairs, with the grain inside, so that the sawdust touches only the flesh side of the skins. When they have absorbed sufficient dampness, take them out of the 732 THE MANUFACTURE OF LEATHER. sawdust and press them in a basket. Now they are ready to be " boarded," that is to say, softened again. If the skins which it is desired to soften are not damp enough, it will be hard work to soften them perfectly; if, on the contrary, they are too damp, there is the risk of cracking the grain while boarding them. After the skins are softened they are, of course, too damp to bring into the market. It is necessary then to hang them up, in order to get rid of the dampness. When entirely dry overlet them on the board again — that is to say, pull them in the length and width, to get rid of any hardness remaining, occasioned by the last drying. After the manipulation of overletting, the skin must stay altogether in the width, not in the length, and it is in this shape that they are in condition to go into the market. Fig. 302. The French knee contrivance employed for " boarding" or softening, and overletting the skins is shown in Fig. 302 ; the armboard is shown in Fig. 243. Section IV. Receipts for Various Vegetable Colors, and FOR Coloring Leather with Mineral Pigments. We give in the following a number of receipts taken partly from PrechtVs " Technological Encyclopedia^'''' a work which, though somewhat old, contains many valuable items. DYEING LEATHER. 733 Dark hroion. — Boil 8 parts by weight of Hungarian fastic, 1 part of logwood, 2 parts of Brazil-wood, 1 part of sandal-wood, and I part of quercitron in sufficient water to cover the ingre- dients about 2 inches deep, for 1 hour. Strain the liquor through linen, and when cold use for dyeing after an application of green vitriol. By boiling the ingredients with water for a second time, the resulting decoction can be used for a similar color. Light hroiim. — By applying a thin ground of potash solution and omitting the coat of green vitriol, the above color can also be used for this. Olive-hroion. — Boil as above 2 parts of Hungarian fustic, 1 part of quercitron, and \ part of logwood. Apply the color upon a strong ground of potash solution, and then give a coat of green vitriol. Catechu hroiun. — Apply a decoction of 1 lb. 2 ozs. of catechu in 10| gallons of water, and 2 ozs. of green vitriol to the slightly grounded skins. Catechu gray-hrown is obtained with the above color and an after application of solution of green vitriol. Coffee hrow7i. — Apply to the moist skin a ground composed of a solution of 2| lbs. of acetate of copper in 13|- gallons of water, and after draining, wet immediately with a solution of yellow prussiate of potash in slightly acidulated water. DarJc green. — Apply a decoction of 4 parts of quercitron and 1 part of logwood upon a strong ground with an application of green vitriol. Some dogwood berries may be added to the decoction, and for fining a like quantity of blue vitriol to the green vitriol. Olive green. — Decoction of 2 parts of quercitron, 1 part of Hungarian fustic, and some dogwood berries. Apply upon a strong ground. Omit the vitriol. Light olive green. — Give the skins a light ground with Berlin blue, and apply upon this a liquor obtained by boiling 2^ lbs. of fustic, and 10| ozs. of archil in 5 J gallons of water. Picric green. — Apply a solution of picric acid in water to the skins previously grounded with Berlin blue. Lemon color. — After digestion 1 part of turmeric in i parts of 734 THE MANUFACTURE OF LEATHER, ordinary spirit of wine at a moderate heat or in the sun for 24 hours, and diluting with ordinary whisky apply the mixture uniformly with a clean sponge kept especially for this purpose. After drying upon the boards rub the skins with a woollen rag dipped in Spanish chalk, without previous application of a coat of green vitriol. Quercitron yelloio is obtained in various shades by applications of decoctions of quercitron bark. Barberry yellow. — Apply a liquor obtained by boiling 2| lbs. barberry root and 7 ozs. of alum in 8 gallons of water. RustyelloTu. — Apply a composition obtained by boiling 2^ lbs. of annotto, 7 ozs. of soap, and 4 ozs. of potash in lOJ gallons of water. Orange. — Digest 1 part of Brazil-wood shavings in 8 parts of spirit of wine, and after diluting with whisky add more or less of the above lemon color. Apply the mixture to the slightly grounded skin, omitting the application of green vitriol. Orange is also obtained with annotto and decoction of madder. Violet. — Digest 1 part of dry shavings of logwood in 8 parts of spirit of wine, and after diluting with whisky, treat the slightly grounded leather as above. Mixedhrown. — A beautiful brown of various shades is obtained by mixing different proportions of the three foregoing colors : lemon color, orange, and violet. Apply upon a slight ground without an application of green vitriol. A darker color is obtained by repeating the application. Sap green. — Digest 1 part of buckthorn sap in 4 parts of spirit of wine, and apply upon a slight ground in the same manner as given for lemon color, omitting the application of green vitriol. Nankin yellow. — Digest 1 part of madder in 4 of spirit of wine and apply in the same manner as lemon color, without applica- tion of green vitriol. Dark blue. — Use a concentrated decoction of logwood upon a strong ground without application of green vitriol. A better and faster blue is obtained by applying a solution of indigo carmine. Red. — A magnificent shade of red is obtained by an applica- tion of cochineal color prepared by tying the cochineal in a DYEING LEATHER. 735 small linen bag and boiling in water to wliicli has been added about 2 per cent, of spirit of sal ammoniac. Alazarine red {a pale flesh color) is produced bj rubbing the cleansed and trodden skins with a solution of alazarine or ex- tract of madder in weak soda lye and rinsing in water. Scarlet is produced by an application of extract of carthamus, especially upon skins with a weak annotto ground. The ex- tract of carthamus is dissolved in a solution of 1 part of tartaric acid in 60 parts of water. Red of any other shade is obtained by applying spirituous extract of sandal -wood upon a weak ground. Dark gray. — Decoction of 1 pound 2 ounces of Indian fustic, 9 ounces of tan-liquor and ^ to | ounce of concentrated decoc- tion of logwood. Apply upon a strong ground and give a coat of green vitriol. Iron gray. — 9 ounces of tan-liquor, 2^ pounds of solution of green vitriol, and |- to jounce of logwood extract. Apply upon a strong ground, omitting the application of green vitriol. Black. — Boil 1 part of logwood and | part of quercitron for two hours. Apply upan a strong ground and follow with an application of green vitriol. A black color is also obtained by boiling, for one dozen small skins, 2J pounds of logwood, 21 ounces of fustic, J ounce of Hungarian yellow berries, J ounce of pulverized gall-nuts and 1 ounce of sumach in 8 gallons of water for two hours, or until reduced to about one-half the quantity. Apply upon a strong ground and follow with an application of green vitriol. A lustre is imparted to the leather by the process previously given. Mineral Pigments. Leather may also be colored by mineral pigments. The color is more durable and resists air and moisture better than that obtained with vegetable coloring matter, but the process is more troublesome on account of the difficulty of obtaining a uniform coloring. The manner of execution is essentially the same as in calico printing. The skins, after cleansing and wringing out, are 736 THE MANUFACTUEE OF LEATHER. placed upon the board, and the respective dye-solutions applied. Thus sky-blue is obtained by first applying a thick coat of solution of 9 pounds of yellow prussiate of potash in 16 gallons of water so that the skin is thoroughly permeated, and then a weak solution of acetate of iron, containing not more than ^ to ^ ounce of the salt to one quart of water. Brown is obtained by using, instead of the iron solution, one of acetate of copper. Before applying the solution of yellow prussiate of potash it is made slightly alkaline by adding potash. Chrome yellow is produced by applying a thick coat of a solution of one ounce of red calcium chromate in one pint of water, followed by an application of a solution of one ounce of sugar of lead in one pint of water. Section Y. Dyeing Chamois or Oil Leather. The dyeing of this variety of leather differs from that of alumed leather in being executed almost exclusively by dipping, and the skins generally requiring to be treated with a mordant before applying the color. The process is as follows: Skins to be dyed a light color are first exposed to the sun, and then uniformly moistened by tread- ing in lukewarm water in the same manner as given for alumed leather. The skins are then placed and thoroughly worked in a warm mordant composed, for 20 skins, of a solution of 2 J ounces of alum and ^ ounce of tartar in about 20 times the quantity of water. After thorough soaking and slightly wring- ing out, the skins are immediately passed first through a weak dye-bath, and after wringing out, through a more concentrated one, the process being repeated until the desired shade is ob- tained. After thorough wringing out, the dyed skins, especially those intended for glove leather, are treated with a paste of alum and yelk of egg, shaken out, dried, and finally worked with the stretcher. As oil or chamois leather is, as a rule, used for articles to be washed, it is of course self-evident, that only fast colors can be DYEING LEATHER. 737 used in dyeing. We will here briefly discuss the most impor- tant coloring matters used in this branch of the industry. Madder red upon oil leather is obtained in the following man- ner : Dissolve, for every 10 to 12 skins, 2 pounds and 3 ounces of white sugar, and 13 pounds of alum free from iron in the re- quired quantity of water, and add 4z\ pints of spirit of wine, and tread the skins in the solution for 2 hours. Before sub- mitting the skins to the process, they should be thoroughly fulled with lukewarm water and washed with boiling water, and after passing through dilute sulphuric acid (1 part to 60 parts of water) subjected to a final washing. After working the skins thoroughly in the solution, remove them from the vat and after slight wringing, draining off", and rinsing in water, dry them in the shade. After partial drying replace them in the same bath, to which in the mean while some warm water and about one quart of spirit of wine have been added, and allow them to remain for one hour with occasional working. After the skins b}^ repeated wringing out and replacing in the bath have been thoroughl}^ soaked through, and passing them once more through the bath, spread them in piles upon a table for 2 to 3 hours. The skins thus prepared now receive the actual mordant for madder red. This is prepared by mixing 20 pints of the above mordant with one pint of tin composition and 20 gallons of water. After stirring the mixture thoroughly, full or tread the prepared skins in it for one hour. After removing and allow- ing to drain off beat and roll them upon a smooth stone for some time, drav^^ing them from time to time through the mordant. Then hang the skins up in the shade to dry, and when air-dried place them in a room heated to 86° F., where they should re- main for at least 12 hours. The skins are then ready for dye- ing. After taking them from the drying-room rinse them first in cold water, and after fulling in cold water, air and rinse them once more. To obtain a better color they are frequently trod- den, before actual dyeing, in a bath composed of If to 2 ounces of madder and 26| gallons of water. The madder bath is prepared by adding 8f pounds of good madder to 37 to 42 gallons of water in a boiler and heating gradually to a temperature not exceeding 118° to 122° F. 47 738 THE MANUFACTURE OF LEATHER. Place the skins in the bath one by one, and after allowing them to remain until the above temperature is reached, 5 to 6 hours being generally required, place them at once in running water, and after thorough rinsing and repeated fulling upon the stone hang them up to dry. In order to give the dyed skins more lustre, they are placed in the fining bath prepared by mixing 26| gallons of water, J pint of spirit of wine, and ^ pint of olive or almond oil. After treading the skins thoroughly in this bath, rinse once more and dry. A solution of 2 pounds and 3 ounces of soap in 13^ gallons of water may be used in place of the above fining bath. Blue in all shades is obtained upon oil leather by dyeing in the indigo vat. The skins require no special mordant for this, but must, like for all other colors, be thoroughly trodden in water and moistened. Oil leather not thoroughly cleansed from free oil or- fat, will not take the color uniformly, and must before dyeing in the vat be passed through a bath composed of 1 part of potash and 15 parts of water, and rinsed. Green upon oil leather is obtained either by dj^eing the skins, after giving them a ground in the blue vat, in decoction of quercitron, or, according to the old method, Avith buckthorn berries. The following receipt will answer for the latter pur- pose : Dissolve, for 12 dozen skins, 2 pounds and 3 ounces of green vitriol and 1 pound and 2 ounces of alum in 8| pints of water, and after adding 1 pint of this solution to the warm water required for treading the skins, work them thoroughly. After wringing, place them in a fresh bath of warm water some- what colored with a decoction of 26J pounds of quercitron bark, 8| pounds of logwood, and 2 pounds and 3 ounces of Hun- garian yellow berries. After treading them in this, replace them in the first vat, charged in the mean while with fresh water and some green vitriol. Tread them in this for some time, then replace them in the second vat, containing fresh water with a larger addition of the above decoction, and beat thoroughly with the feet. This process is repeated three or four times, adding every time an increased quantity of green vitriol and decoction. To the last dye bath add a decoction of ripe buck- thorn berries, or the commercial sap green, increasing the quan- DYEING LEATHER. 739 tity, with vigorous stirring, until the desired shade of green is obtained. The skins are then allowed to drain off, and finally placed in a mordant, prepared by dissolving 6 ounces of ace- tate of copper in the required quantity of water. Rinse the skins thoroughly in the solution, and after rinsing in cold water dry them slightly in the air. To restore softness to the dyed skins, tread them in a mixture of 100 yelks of eggs, 1 pound and 2 ounces of alum, and the necessary quantity of water, and after wringing and drying work them with the stretcher. Yellow. — This color if not produced with yellow ochre is obtained by means of a decoction of quercitron and previous mordanting with alum. Chrome yellow is seldom used. The latter color, which makes the leather weighty, can be best applied as has been described under mineral pigments. For this purpose the skins to be dyed are first thoroughly failed in a bath of sugar of lead, and then thoroughly worked in a bath composed of 1 part of potassium chromate and 8 to 10 parts of water. The}" are next rinsed and dried. Brown upon oil leather can be obtained by using the catechu bath mentioned for alumed leather. A beautiful red-brown is produced by dyeing the leather previously mordanted with acetate of copper, in a solution of yellow prussiate of potash and final rinsing in dilute acid. This brown is very fast and in many respects preferable to one produced by decoction of fungi, etc. Black upon oil leather is conveniently produced in the following manner : After moistening the skins uniformly, apply to the side to be dyed a decoction prepared by boiling 10 parts of logwood, 10 of sumach, 2 of pulverized gall-nuts, and 2 of quercitron bark, in about 60 parts of water until reduced to one-half the quantity. Spread the moistened skins one over the other and apply the decoction to each one in succession with a soft brush. After all the skins have been brushed over give a second coat, commencing in the same manner, and finally a third one which will generally be sufficient. Next apply to the prepared skins two coats of black liquor, and when this is absorbed, a coat of the decoction, and upon this, if necessar}^, a third coat of black liquor. To obtain an intense black give a final 740 THE MANUFACTUEE OF LEATHER. coat of pure decoction of logwood. To give lustre to the dyed skins, brush them lightly over, after drying, with olive oil in the same manner as alumed skins. To make the leather more salable it is recommended to black the uncolored side. Section YI. Dyeing with Analine Coloes and the Methods of theie Peepaeation. Having given in the foregoing sections of this chapter the iKiiOst important methods of dyeing formerly in general use and stj.ll ,so in some places at the present time, it remains to give the process of dyeing with aniline colors. Aniline colors, excepting the actual rosaniline colors, are espe- cially suitable for coloring leather partly on account of their brilliancy of color frequently combined with a high degree of fastness, and partly on account of their being absorbed with avidity by the leather substance. A special mordant to prepare the leather for the reception of the coloring matter is but seldom required, a simple application of the color either in aqueous or spirituous solution being generally sufficient. Colors which can be used in aqueous solution are, as a rule, preferable to those only soluble in ethyl or methyl alcohol, especially as alumed leather will not stand strong alcoholic solutions. If colors only soluble in alcohol have to be used, care should be had to dilute the dilution with as much water as it will bear without sepa- rating the coloring matter. It is of course self-evident that the dyeing with aniline colors can be accomplished in the same manner as with other dye stuffs either by dipping or painting, though the latter method is with few exceptions to be preferred. If it should happen that the leather will not take an aniline color or does not dye uniformly, recourse must be had to a mordant. The most convenient and effective method of mor- danting leather for aniline colors, is to apply a ground with a fluid containing tannin, it being of course necessary to use a composition which will not color the leather perceptibly. The best plan is to apply a solution of ] part of tannin (pure gallo- tannic acid) in 20 to 25 parts of water with a sponge. After partly drying the leather apply the first coat of color, using a DYEING LEATHEE. 741 weak solution, and stronger ones for the succeeding coats until the desired shade is obtained. For dark colors, such as orange yellow, brown, or even green, a cheaper solution containing tannic acid will answer the purpose just as well, a weak decoc- tion of sumach being especially suitable. In using an aqueous solution of picric acid, which is also very good for giving a ground to leather to be dyed with aniline colors, the fact that the shade of the latter is frequently changed must be taken into consideration. A fast black can be produced with aniline colors, and in this and the next chapter we shall give the dif- ferent modes in which it is accomplished. Oil or chamois leather can also be dyed in the same manner as aluraed leather with aniline colors, without requiring special preparation. Beautiful brown and blue colors can especially be produced with aniline colors, but for red it is better to use the process for madder red, as the color obtained with fuchsine or coralline, though very brilliant, is not particularly fast. Aniline colors are especially valuable for dyeing parchment, since brilliant colors can be obtained without the parchment losing its transparency as is the case with other dye stuffs, especially such as require a mordant. Aniline Violet. Perldns's violet in a pure state is either a dark violet paste, or, what is more frequently the case, a dry green crystalline powder of a metallic lustre. It is but moderately soluble in cold water but readily in hot, and also, in the presence of an acid, in alcohol, wood spirit, glycerine, acetic acid, etc. From its solutions it is precipitated by alkalies and alkaline salts, and from spirituous solutions by water. Parisian violet is insoluble in water, but dissolves readily by adding an acid. Hofraann's violet, pre-eminent on account of its purity and beauty, is but moderately soluble in water but readily in alcohol, wood spirit, etc. In commerce, Hofmann's violet, of which there are two varieties, a reddish violet and a blue violet, occurs in bronze colored grains or crystals. Rosaniline violet \q a brownish blue powder with a weak lustre. 742 THE MANUFACTUEE OF LEATHER. and is scarcely soluble in water but readily in alcohol and acetic acid. Dahlia (dahlia imperial) is probably a by-product obtained in the manufacture of aniline red. It is a beautiful violet color- ing matter of rare purity of color and is readily soluble in hot water. It differs from the ordinary aniline violet in assuming a brownish-red color when treated with concentrated sulphuric acid while the latter is colored blue. , Aniline Blue. Bleu de Paris (soluble aniline blue) is a black-blue powder with a slight copper lustre. It is soluble in water, and may be precipitated from its aqueous solution with acids or common salt. This blue, on account of its solubility in water, may be especially recommended for coloring leather. Bleu de Lyon. — This color does not differ chemically from the foregoing. It is difficult to dissolve in water, but readily in alcohol, and gives a beautiful blue color. It comes into com- merce in lustrous masses of a copper-red color. Ordinary aniline blue (also rosaniline blue) is insoluble in water, but soluble in alcohol, A¥Ood spirit, etc. It is also solu- ble in concentrated sulphuric acid, and can be precipitated in an unaltered state from such a solution prepared cold, by an ad- dition of water. But by heating a solution in concentrated sulphuric acid to 266° to 284° F., even for a short time only, the blue precipitated by an addition of water and washed, is entirely soluble in boiling water. There are two principal shades of this aniline blue, the bleu de lumih^e^ which shows a pure blue color by candlelight, and a darker blue, bleu de Parme, with a violet tinge and having a difi'erent color by candle- light. Aniline Green. Aldehyd green (rosaniline green) occurs in commerce either in the form of a paste or as a green powder. The article in paste form is the picrate of a base which has not been much ex- amined. The paste is not soluble in water, but in alcohol and acids, while the powder dissolves in boiling water. DYEING LEATHER. 743 Ethyl rosaniUne green dissolves with difficulty in water bat readily in alcohol. Emeraldine, a green patented in England by Calvert, Lowe, and Clift, is insoluble in water, alcohol, and acids, but dissolves with a blue color in concentrated sulphuric acid. It is constant in the light ; but it is difficult to utilize it for coloring leather. Aniline Yelloio. Ordinary aniline yelloio is scarcely soluble in cold water but readily in alcohol, wood spirit, etc. Zinaline is found in commerce in the form of a cinnabar- colored powder, which is insoluble in water but dissolves in warm solutions of borax, sodium phosphate, or sodium acetate. It is also soluble in alcohol and w^ood spirit, but is precipitated from these solutions by water. It gives reddish-yellow shades. Chrysaniline is a yellow powder entirely insoluble in water, but soluble in alcohol, and gives a beautiful yellow color. Generally the hydrochlorate of chysaniline, found in commerce under the name of aurin, is used, it being tolerably soluble in water and yielding beautiful golden-yellow colors. Hydro- chlorate of chrysaniline forms beautiful red-yellow needles. Aniline Red. The different red aniline colors known by the names of fuch- sine, roseine, azaleine, mauve, solferino, magenta, tyraline, rubine, etc., are, no matter how different their mode of production, without exception the salts of a base termed by Hofmann " rosaniUne.'''' The product is brought into commerce either as red powder or, more frequently, as green granular crystals with a metallic lustre and sometimes several millimeters in diameter. The acetate, known in England and the United States by the name of fuchsine, forms especially beautiful crystals. In Germany the acetate is termed roseine and the hydrochlorate, fuchsine. Aniline red occurs but seldom in the form of a paste or in solution. In buying crystallized fuchsine great precaution should be exercised, as it is frequently adulterated, especially with sugar crystals. Pure fuchsine is sparingly soluble in water 744 THE MANUFACTURE OF LEATHER, of an ordinary temperature, but dissolves readily in hot water and very readily in alcoliol, wood spirit, acetic acid, or in a solution of tartaric acid. It yields beautiful purple-red solutions which are discolored by an addition of alkalies or strong acids. The red color of solutions discolored by an addition by alkalies is, however, restored by adding acid, and that of those discolored by strong acids by an addition of water. The nitrate of rosaniline, which is known by the name of azaleine, occurs but seldom in commerce, and is distinguished from the other varieties of aniline red by the pronounced cherry- red color of its solution. The article known in commerce Si&diamond 'magenta or fuchsine^ is produced in large crystals with a greenish lustre. It has the same properties as fuchsine, but has the advantage of being non-poisonous, Tyraline is another aniline red with nearly the same proper-' ties as fuchsine. Aniline Brotun. Havana hrown is soluble in water, alcohol, and acetic acid. It is purified by precipitation from its solution with common salt, Bismarck hroion is a tarry, black-brown mass not soluble iu water but in spirit of wine. The spirituous solution can, after mixing with water, be directly used for coloring brown. Similar coloring matters known as aniline brown consist fre- quently only of by-products obtained by overheating the com- position in preparing fuchsine. A special coloring matter discovered by Jacobsen, forms a black pulverulent mass insolu- ble in water, but soluble in spirit of wine, and gives quite a beautiful brown. Aniline Black. Aniline black is not an actual coloring matter, and does not occur as such in commerce, but is best produced directly upon the materials to be colored by the action of oxidizing agents upon the fabric prepared with an aniline salt (best aniline ace- DYEING LEATHER. 7-i5 tate). The resulting color, which is actually a very dark aniline green, is by reason of the insolubility of the product of oxida- tion formed upon the fibre itself very fast, and resists more than any other black color the action of the most energetic acids and bases. To prepare this color numerous receipts have been given. Taking the nature of leather into consideration, which does not allow of the use of every oxidizing agent, the only one of the older receipts available for our purpose is Cordillot's, who uses ammonium ferrocyanide as an oxidizing agent. But the more recent process discovered by Persoz, Jr., might be still more available for leather. The best mode of applying Persoz's process to leather is to treat it, after moistening, with a solution of 75 grains of potassium bichromate, 45 grains of blue vitriol, and 30 grains of sulphuric acid in 2|- pints of water. After thorough saturation wash the skins, and after passing them while still moist through a dilute solution of oxalate of aniline and rinsing them in a bath of tartaric acid, wash them again. They will acquire a beautiful black color immediately after passing through the aniline bath. Coloring by aniline black might also be readily produced by applying, after soaking the skins in a solution of sugar of lead, a coat of solution of potassium bichro- mate in water and, after washing the painted side which has now a yellow appearance, applying to it a coat of solution of oxalate of aniline in water to which some sulphuric acid has been added. By this process the black color appears also quite quickly and remains unchanged by the rinsing in water to which the skins must be finally submitted. A product recently introduced in commerce under the name of " Lucas aniline Mach,^^ offers no special advantages, as the semi-liquid black paste consists mainly of hydrochlorate of aniline and acetate of copper, and can be readily produced by anybody. Aniline black is without doubt a very valuable coloring matter, and its introduction for coloring leather would be very desir- able, a fact of which every tanner would be convinced if he would take the trouble of testing its availability by experi- ments. In connecti,on with aniline black we would mention the aniline 746 THE MANUFACTURE OF LEATHER. gray as one of the more important aniline colors. This coloring matter sometimes called murein, in manj respects approaches aniline violet, is soluble in boiling water, and yields a pretty gray. Another gray produced by the action of aldehyde upon aniline violet in the presence of sulphuric acid is, on account of its present high price, not adapted for general use. Besides the aniline colors which, with the exception of the actual rosaniline colors which are not fast, are now doubtless permanently introduced into the workshop of the dyer, partly on account of their ready application, and partly by reason of their brilliancy and freshness of color', there are other colors derived from coal tar which are equally valued. To this series belong first such as being direct products of the creasote in coal tar, are known as 2^henol colors. The most important are the phenol red or coralline, or peonine, ■phenol blue or azuline, and phenol brown. Coralline, a magnificent red coloring matter which several years before the analysis of Kolb6 and Schmidt, was discovered by Persoz, and manufactured on a large scale in a Lyons factory, is a red powder scarcel}^ soluble in water but readily in alcohol, yielding a scarlet solution. It is also soluble in alkalies, but the solutions change readily. It is not changed by acids. Coralline gives to alumed leather a beautiful orange-yellow color. To color with it dissolve it in alcohol and after adding some caustic soda mix the alkaline solution with water acidulated with sufficient acid to neutralize the soda. Unfortunately the fiery color which coralline yields does not stand exposure to light. Another variety of coralline {coralline yellow) differs from coralline red by giving a color with an orange tinge. The orange color ob- tained with it is very brilliant but will not stand exposure to the light. Azuline. This blue coloring matter, with a shade resembling ultra- marine, is a coarse-grained powder with a slight copper lustre, and insoluble in water but soluble in alcohol. By heating it DYEING- LEATHEE, 747 with concentrated sulphuric acid for some time, it is, however, changed into a product of a like color soluble in water resem- bling in this respect aniline blue, which it is greatly like in appearance. Azuline may, like coralline, be dissolved in alcohol, and after diluting with water containing tartaric acid, be used for coloring leather. Phenol Broivn. The discovery of this beautiful and fast coloring matter was made by Roth. It is found in commerce as a delicate brown pow- der sparingly soluble in water but readily so in alcohol, acetic acid, and alkalies, especially with an addition of some tartaric acid. Phenol brown is readily absorbed by leather, and imparts to it an agreeable brown color. By adding oxidizing substances, such as potassium chromate, to the solution of coloring matter, different shades from dark wood-brown to light brown are obtained. * Another series of colors belonging to this class are the so- called naphthalene colors. They are derived from a constituent of coal tar, naphthalene, a white crystalline body belonging to the hydrocarbons. Although many beautiful and valuable colors have been derived from naphthalene they have thus far not been so generally introduced as the aniline colors. We shall, therefore, only mention the following as samples of this series: najyhthylamine violet, naphthylamine red, naphthyl hiue resembling alizarine, naphtharazine, and several yellow coloring matters, among which that prepared by Martins, deserves special consideration. This magnificent yellow, known chemically as dinitro-naphtha- lene, forms small crystals of a brilliant yellow color and is scarcely soluble in water, but dissolves in alcohol and alkalies. It is also partly soluble in boiling water. It is not only one of the fastest colors, but furnishes also the finest shades, and is easily applied, as it is readily absorbed by the fibres. All the shades from the lightest lemon color to the darkest golden yellow can be produced with it without anything further being- necessary than a corresponding concentration of the bath. The above-mentioned colors are by no means all that have 748 THE MANUFACTURE OF LEATHER, been brought to our knowledge by recent researches, and we could fill page after page in enumerating them, but as many of those not mentioned have not been generally introduced into practice, and are not regular articles of commerce, we omit them here. Note. — For portions of the matter contained in the foregoing sections of this chapter the author desires to acknowledge his indebtedness to Gintl's Weiss- gerberei und Beller's Glacelederfdrheri. Section VII. Dyeing Sumach-tanned Skivers with Aniline Colors.^ We present herewith twelve samples of sumach-tanned skivers dyed with a few of the products of the Badische-aniline and Soda Fabrik at Ludwigshafen, Bavaria, and sold by W. Pick- hardt & Kuttroff", New York, Boston, and Philadelphia. The skins shown in the sample* are bleached by acetate of lead and sulphuric acid. The Nos. of the patterns correspond with those of the first twelve following receipts. For each color, the receipt for which is here given, the dye-bath is calculated for one dozen skivers, viz., 20 gallons of water. •*, ISTo. I. Methylene Blue (9, Patented. Mordant. — Dissolve 8 ozs. white tartar in 6 gallons of water. Enter skivers ; turn 6 times ; lift on the horse. Now take : " -, , , 1 T x^i r\ • ^ \ W. Pickhardt & Kuttroflf. New li oz. methylene blue O, pat. \ ^ ^, .' ( York, Boston, and Philada. Boil in 2 quarts of water. When boiling, add 30 grains com- mon salt. Prepare dye-bath at 110° F, Add one-half of the prepared ' blue. Enter skivers ; give 6 turns ; lift, and add balance of pre- pared blue. Ke -enter skivers, turn to shade, lift and rinse in plenty of water. Stretch on frames and dry. 1 The author desires to acknowledge his indebtedness to the Textile Colorist, published at 50(5 Arch Street, Philadelphia, for the receipts comprised in this section. II III IV VII VIII VI IX XI XII Page 748. DYEING LEATHER. 749 No. II. Azohenzole Fast Crimson RR^ Patented. Mordant. — Dissolve 1 oz. borax in 10 gallons of water. Enter skivers ; turn 6 times ; lift on the horse. Now take : \\ oz. azobenzole fast crimson j W. Pickhardt & Kuttroff, New ER. pat. \ York, Boston, and Philada. Boil in 2 quarts of water. Prepare dye-bath at 110° F., and add one-half of the above prepared crimson. Enter skivers ; give 6 turns ; lift, and add balance of prepared crimson; re-enter skins; turn to shade; lift and rinse. Stretch on frames and dry. No. III. Naijhthol Yelloio Z, Patented. Mordant. — Dissolve 1 oz, white tartar, 1 oz. tannic acid, in 10 gallons of water. Enter skivers; turn 6 times. Lift on the horse. Now take : 1 ^ i W. Pickhardt & Kuttroff, New 1 oz. naphthol yellow L, pat. \ ^^ ^ ^ ^ ^_' ( lork, Boston, and Philada. Boil in 2 quarts of water. Prepare dye-bath at 110° F. Add one-half of the dissolved yellow. Enter skivers; give 6 turns; lift, and add balance of dissolved yellow. Re-enter skivers ; turn to shade ; lift and rinse. Stretch on frames and dry. This is a very fast color. No. IV, Leather Broivn. Mordant, — Dissolve 3 ozs, white tartar, -1 ozs. alum. Enter skivers ; give 6 turns ; lift on the horse. Prepare foundation by boiling for 15 minutes 2 gallons of water with : 5 ozs, ext fustic, _ ( ^^ Pickhardt & Kuttroff, New 1 oz. ext. hy pernio, ■{ -^^ ^ -d ^ j -m -i i ■^ ^ ' ) 1 ork, Boston, and Philada, f oz. ext. logwood, (. Make a bath of 10 gallons altogether, at 110° F. Enter skivers ; give 6 turns ; lift on the horse. 1| oz. Victoria green, j 750 THE MANUFACTURE OF LEATHER. Now take : n ^ .u \. f W- Pickhardt & Kuttroff, New IJ oz. leather brown, < ' ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Add one-half of the prepared brown to foundation bath. Enter skivers ; give 6 turns ; lift, add balance of prepared brown. Ee-enter skivers, turn to shade ; lift, rinse, stretch on frames, and dry. No. V. Victoria Green. Mordant. — Dissolve 3 ozs. white tartar, J oz. tartaric acid in 10 gallons water. Enter skivers ; give 6 turns ; lift on the horse. Now take W. Pickhardt & Kuttroff", New York, Boston, and Philada. Dissolve in 2 quarts of boiling water; add 1 oz. indigo paste; let boil five minutes. Prepare dye-bath at 110° F. Add one-half of the prepared green. Enter skivers; give 6 turns ; lift, and add balance of prepared green. Ee-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. YI. Bark Rose Pink B. Mordant. — Dissolve 6 ozs. alum in 10 gallons of water. Enter skivers; give 6 turns; lift on the horse. Now take : o . 1 -n ( W. Pickhardt & Kuttroff', New f oz. rose pink B, ^ ^ ' ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared pink. Enter skivers; give 6 turns ; lift, and add balance of pre- pared pink. Ee-enter skivers ; turn to shade, lift, rinse, stretch on frames, and dry. No. VII. Orceine B. Mordant. — Dissolve 1 oz. borax in 10 gallons of water. Enter skivers; give 6 turns; lift on the horse. DYEING LEATHER. 751 Now take : U oz. orceine B, ] ^^- Pi«khardt & Kuttroff, New ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-balf of the prepared orceine. Enter skivers ; give 6 turns ; lift. Pass back through mordant-bath ; give 6 turns ; lift, and add balance of prepared orceine to dye-bath. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. VIII. Orange BR. Mordant. — Dissolve 2 ozs. tannic acid in 10 gallons of water. Enter skivers; give 6 turns; lift on the horse. Now take : R -DT? \ W. Pickhardt & Kuttroff, New I oz. orange BK, 1 ^- ( 1 ork, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared orange. Enter skivers ; give 6 turns ; lift, and add balance of dyestuflf. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. IX. Bismarck Broivn B. Mordant. — Dissolve 3 ozs. tartar, ^ oz. borax, in 10 gallons of water. Enter skivers ; give 6 turns ; lift on the horse. Prepare foundation by boiling for 15 minutes 2 gallons of water with : 4 ozs. ext fustic, ^ j ^^ Pickhardt & Kuttroff, New 1 oz. ext. hvpernic, ■{ v „i t? ^. i tdi -i i ^ " ^ / ) York, Boston, and Philada. \ oz. ext. logwood, I Make a bath of 10 gallons altogether, at 110° F. Enter skivers; give 6 turns; lift on the horse. Now take : -, -D- 1 -D -p S W. Pickhardt & Kuttroff, New 1 oz. Bismarck Brown K, ^ ' ( York, Boston, and Philada. Dissolve in boiling water. Add one-half of the prepared brown to foundation bath. 752 THE MANUFACTUEE OF LEATHER. Enter skivers ; give 6 turns ; lift, and add balance of dyestufif. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry, No. X. Fast Brown. Mordant. — Dissolve 3 ozs. tartar, 4 ozs. alum, in 10 gallons of water. Enter skivers ; give 6 turns ; lift on the horse. Now take : T 1 P , 1 ( W. Pickhardt & Kuttroff, New 1^ oz. last brown, ^ ^ , ' ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared brown. Enter skivers ; give 10 turns ; lift, and add balance of dyestuff. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XI. SoluMe Blue R. Mordant. — Dissolve 1| oz. borax in 10 gallons of water. Enter skivers ; give 6 turns ; lift on the horse. Now take : W. Pickhardt & Kuttroff*. New 1^ oz. soluble blue R, ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared blue. Enter skivers ; give 6 turns ; lift, and return to mordant- bath ; give 6 turns ; lift, and enter dye-bath, to which has been added dyestuff ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XII. Fast Red R, Patented. Mordant. — Dissolve 1 oz. borax in 10 gallons of water. Enter skivers ; give 6 turns ; lift on the horse. Now take : -, , f ^ . A Tf + i W. Pickhardt & Kuttroff New 1^ oz. last 1 eQ XV), pat., ~i ( York, Boston, and Philada. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared DYEING LEATHER. 753 red. Enter skivers; give 6 turns; lift, and add balance of dje- stuff. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XIII. Brilliant Green. Mordant. — Add 1| ozs. sulphuric acid to 10 gallons of water. Enter skivers ; give 8 turns ; lift on the horse. Now take : 2 ozs. brilliant green crystals, j Kalle& Co., Biebrich-on-Rhine, 2 ozs. tartar, I New York and Philadelphia. Dissolve in |- a gallon of boiling water. Prepare dye-bath of 20 gallons of water at 120° F. Add one- half of the prepared brilliant green crystals. Enter skivers ; give 6 turns ; lift, and add balance of prepared green. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XIV. Russia Green. Manipulate the same as receipt No. XIII., after dyeing with brilliant green crystals. Then prepare a fresh bath of: Nitrate of iron, 2° T., i ^- ^^.^^" ^ ^^•' ^^^ ^ork and ( Philadelphia. Enter skivers ; give 6 turns ; lift, rinse well, stretch on frames, and dry. No. XY. Bose Bengal. Mordant. — -Dissolve 6 ozs. alum in 10 gallons water. Enter skivers ; give 6 turns ; lift on the horse. Now take : Heller & Merz, New York. Dissolve in 2 quarts of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared rose Bengal. Enter skivers ; give 6 turns ; lift, and add balance of the prepared rose Bengal. Re-enter skivers; turn to shade; lift, rinse, stretch on frames, and dry. 48 2| ozs. rose Bengal, AT, ■< 754: THE MANUFACTUEE OF LEATHER. No. XVI. Scarlet, No. 2. Mordant. — Dissolve 8 ozs. alum in 10 gallons of water. Enter skivers ; give 6 turns ; lift on the horse. Now take : 8 ozs. scarlet, No. 2, ( Kalle & Co., Biebrich-on-Rhine, 1 oz. white tartar, | New York and Philadelphia. Dissolve in J a gallon of boiling water. Prepare dye-bath at 110° F. Add one-half of the prepared scarlet. No. 2. Enter skivers ; give 6 turns ; lift, and add bal- ance of prepared scarlet. No. 2. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XVII. Nanheen Broivn. Mordant. — Add IJ oz. tartar and J oz. tartaric acid to 10 gallons of water. Enter skivers; give 8 turns; lift on the horse. Now take : . 1| oz. nankeen brown, j I. Levinstein, Campbell & Co., 1 oz. tartar, I New York. Dissolve in one-half gallon of boiling water. Prepare dye-bath at 120° F. Add one-half of the dissolved nankeen brown. Enter skivers ; give 6 turns ; lift, and add balance of the dissolved nankeen brown. Re-enter skivers ; turn to shade ; lift, rinse, stretch on frames, and dry. No. XVIII. Dark Nankeen Brown. Manipulate the same as for receipt No. XVII., except in dye- bath use : 3 ozs. nankeen brown, j I. Levinstein, Campbell & Co., 2 ozs. tartar, ( New York. Sectiok VIII. Dyeing Russia and Moeocco Leathers WITH Aniline Colors. In Jacobsen's Chemisdies Repertoriiim, W. Eitner gives direc- tions for the use of aniline colors produced by the Aniline Color Manufacturing Co., of Berlin. DYEING LEATHER. 755 The various shades obtained with it are pure and brilliant, being not only equal to, but surpassing those obtained with decoction of dye-wood. Thus far we believe only three shades are manufactured. They are known as Eussia leather red G light, Eussia leather red Gr E medium, and Eussia leather red E dark. But all three, even E, are light as compared with other products, but their tone of color is pure and fiery, instead of yellowish. The coloring matter which is soluble in water is dissolved in boiling water in a clean boiler, the best proportion being 1 part by weight of coloring matter to 100 of water. Allow the solution to stand quietly for 2 to 3 hours to give any impurities a chance to settle. For dyeing, mix more or less of the solution, according to the size of the skins to be dyed, with warm water. The first pair of skins is first brought into a very diluted dye-bath, then into a somewhat more concentrated one, and finally into the third, which is the most concentrated of all. The second pair of skins is brought into the second dye-bath used previously for the first pair, and then into the third bath previously used, and finally into a fresh dye-bath. In this manner each pair of skins receives two dye-baths previously used, and one fresh one, the coloring matter being by these means thoroughly exhausted and a uniform coloring of the skins efiiected. After dyeing, the skins are rinsed by drawing them through pure water, and are then stretched, and slightly oiled during the latter operation. If, in order to produce the odor of Eussia leather, birch tar is added to the oil, it is neutralized with soda in case of acid reac- tion. For the production of yellow and yellowish-brown shades, phosphin-orange — composed chiefly of hydrochlorate of chrys- aniline and chrj'-sotoluidine — is the most suitable of all tar colors. Boil 1 part of coloring matter in 500 parts of water until a per- fectly clear solution is obtained which serves directly for the dye-bath. The color is very fiery and constant, and loses nothing in drying. For many purposes the fiery color of the dyed skins is dulled in a bath of potassium bichromate. For 756 THE MANUFACTURE OF LEATHER. dyeing leather golden orange, dissolve 1 part of " Philadelphia jellow," manufactured bj the above concern, in 200 parts of water, and dilute the solution suflEicientlj for dyeing, or dissolve 1 part in 300 parts of water, which will give a dye-bath of proper concentration. This color, as well as the one previously described, does not spot unsound places in the grain, and is constant, pure, and fiery. The reddish shade of this group of colors is produced in precisely the same manner with Berlin blue G, and is not inferior as regards purity, constancj^, and brilliancy to the above color. The three colors mentioned are specially suitable for brightening dark dye-wood colors by placing the leather dyed with Brazil-wood and black in a weak batli of one of these colors, the choice depending on the more red- dish or yellowish shade desired. Besides the yellowish-brown shades, a pureorange, produced with corallin, is also much liked. The proportion is 1 part of coloring matter dissolved in 150 parts of water. But as corallin upon leather has a tendency to fade, the leather must be quickly handled and dried after dyeing. A half-dark pale blue, the so-called marine blue, is produced by dis- solving 1 part of marine blue in 300 parts of water. Before dyeing the leather is not drawn through a bath of very dilute sulphuric acid, as is the case in dyeing with other aniline blue colors. For pale blue with a pure blue shade, the water blue B B is used, and for pale blue with a reddish shade the water blue B. Dark blue, which was generally produced in the indigo vat and after dyeing with a red coloring matter, is obtained by coloring the leather first with blue R or marine blue, and finishing dyeing in a second bath prepared by boiling nigrosin in 300 parts of water. The previous dyeing with blue is necessary since nigrosin applied directly to the leather colors badly and not uniformly. A beautiful bright green is obtained with methyl-green in crystals which is readily soluble in water. Its comparatively low price makes its use available for dyeing inferior qualities of leather, or at least for brightening leather dyed green in the ordinary manner with indigo and fustic. The green leather produced in the vat, or as is more frequently the case with sulphate of indigo, is washed in cold water in order to remove the acid w^hich would alter the methyl-green, and DYEING- LEATHER. 757 receives then a weak bath of methyl-green which will consider- ably brighten the originally dull and impure color. For produc- ing violet color methyl-violets are the best, as they cover excellently, so that the most impure skins can be used for these colors. By a proper use of aniline colors, all the inconveniences of producing the light shades from yellow to orange so much liked at present, with dye-wood colors, are removed, and besides much more beautiful tones of color are obtained. The so-called Martiii's yellow {hinitronaphthol as calcium or sodium salt) is best adapted of all tar colors for the production of pure yellow tones of color. It is an orange-red powder which dissolves completely in hot water to a pure yellow fluid, and is one of the most con- stant and durable colors. Dissolve 1 part of Martin's yellow in 100 parts of boiling water in an earthen or wooden vessel (all contact with metal must be strictly avoided), accelerating the solution by stirring with a wooden spatula. After cooling, the solution is ready for use. For the production of orange tones of the reddest shade, such as are in demand for harness leather, a solution of 1 part of aurantia (the ammoniacal salt of hexani- trodiphenylanine) in 120 parts of boiling water is used. Phos- phin-oranye is also suitable for reddish-orange shades. Dissolve 1 part of the coloring matter by boiling in 40 parts of water, and after allowing the solution to stand quietly one day pour off the supernatant clear fluid from the sediment. For use, dilute the solution with 50 parts of water. The intermediate shades from pure yellow to the reddest orange are produced by mixing a solution of Martinis yellow with that of aurantia^ the desired shade being determined by experiments. This operation is much facilitated by noting down the different proportions and adding to the notes a piece of leather dyed with the respective mixtures. All the coloring matters mentioned dye directly,, requiring no grounding or mordant, and are fast and do not rub off". The dyeing is accomplished by spreading the dry leather upon a large table and applying the cold color uniformly with a long-bristled brush, the latter operation requiring, of course^ some skill and care. It is very difficult to color the entire skin uniformly and without streaks by one application. It is, there- fore, best to dilute the solutions of color given above with an 758 THE MANUFACTURE OF LEATHER. equal part of water and to apply two coats, the second being given after the first is dry. Two coats will be suflicient in all cases. Harness leather receives generally a more or less intense lustre, this being accomplished by rubbing with flannel, or by glazing with or without the assistance of wax, cerine, or stearine. To give leather straps at the same time color and lustre, a single application of orange fat color prepared at the above factory is sufficient, 1 part (for very sad color 2 parts) of coloring matter is dissolved in 100 parts of boiling water to which 1 part of soda has been previously added. Apply the lukewarm solu- tion, which gelatinizes on cooling, to the leather with a brush or sponge. By rubbing the dry leather gently with flannel, the desired lustre is produced. CHAPTEE XLIY. COMPOUNDS FOR COLORING AND POLISHING LEATHER. A Black consisting of an Ainmoniacal Solution of Shellac^ and the Aniline Color hnoivn as ^^ Pourrier''s D Blue Aniline.'''' This composition, patented by Martyn, is composed of water, shellac, spirits of ammonia, and the aniline color, known as " Pourrier's D blue aniline," and which, when used in with the ammoniacal solution of shellac in proper quantity, produces a black. To make the composition, take, for 24 ounces of shellac and 6 gallons of water, 1 pound of spirits of ammonia and 8 ounces of the aniline color, and thoroughly mix or stir the whole together, the water being heated to about 212° F. Use boiling water plentifully with the shellac, the spirits of ammonia, and the aniline color in order to combine the ingredients quickly and to advantage. COMPOUNDS FOK COLOEING AND POLISHING LEATHER. 759 Protochloride of Iron in Solution as a Basis for Black for Slcins. This method, patented bj Brainerd, may be used for coloring either partly tanned or fully tanned skins. The iron liquor is prepared by dissolving metallic iron in pure hydrochloric acid of the shops, at a temperature of about 80° F., until all effer- vesence ceases, leaving metallic iron in excess. Of this saturated solution of iron take a fluidounce, and dilute it with pure soft water, and if the skins are only partly tanned, immerse them therein for a period of four or five minutes, keep- ing them in constant motion. The dilute iron liquor may be applied to the grain of the fully tanned skins with a brush. From the iron liquor bath, immediately transfer the skins to a bath of clean water, and thoroughly wash, in order to free them from any hydrochloric acid that may have been formed by the decomposition of the protochloride of iron, by this latter element entering into a new combination with the tannin. If preferred, the skins may be subjected to the action of a bath made slightly alkaline with ammonia, in order to neutral- ize any free acid formed. The strength of the iron liquor, as above given, will be suffi- cient to make a jet black, but a day or two of exposure to the air may be necessary to produce the finest tone. A weaker iron liquor will give a correspondingly lighter shade of color. Skins that have been thoroughly tanned, may, by immersion in this iron liquor, be colored through their entire thickness. If it is desirable to color only the surface of the skin, it should be set out upon the table, while wet, and the iron liquor applied with a brush. Preparing Raio Hides and imparting Blacky Maroon^ and Purple Colors. The object of this process, patented by Merrill and Hoitt, is to prepare and color raw hides in such a manner that they will be permeated by the materials used, and thus rendered more dura- ble and neat in appearance for the various purposes to which prepared hide is applicable in the arts, such as for tips and shields for boots and shoes. 760 THE MANUFACTURE OF LEATHER. The hides are unhaired, fleshed, and rinsed in the usual man- ner, and being removed from the rinsing-vat are prepared for coloring by being passed through lukewarm logwood liquor, made by placing a third of a bushel of logwood, in chips or coarse powder, in a bag, in which it is boiled in about twelve gallons of water until the strength is extracted. A sufficient quantity of the liquor is made for use, as wanted. The hides are laid flat, one above the other, in a vat containing sufficient logwood liquor to cover them, the temperature of the liquor being preferably lukewarm. This liquor may, however, be colder than lukewarm, and in such cases the hides must remain longer in it. The hides are kept in this liquor for two or three days, and are frequently turned until the strength of the logwood is extracted and the hides saturated. The hides having been treated as described, are then blacked in a dyeing liquor made from the solutions here designated for convenience of description as Nos. 1 and 2. No. 1 is made by boiling together for five or ten minutes four ounces each of pulverized nut-galls and blue vitriol in a gallon of hot logwood liquor, and afterward adding four quarts of vine- gar saturated with iron in any well-known way, or the chemical equivalent of the vinegar and iron may be used. Solution No. 2 is an iron- set, made by dissolving iron chips in aqua fortis or other acids, the iron being added until a satu- rated solution is obtained. For the purpose of blacking about half a dozen hides, or two or three dozen medium-sized skins, place the hides, previously soaked in logwood-liquor, in about twenty-four gallons of log- wood-liquor such as first described, to which have been added two quarts of the solution No. 1 and one pint of No. 2 solution, the latter having a tendency to set the color. The hides should be allowed to remain in this dye-liquor from one to three days, according to their thickness, being frequently turned to secure a thorough penetration. The exact quantities above given are not arbitrary, as the in- gredients vary in strength, and some hides will take color more easily than others. The quantities mentioned will generally be sufficient to thoroughly black two dozen calf-skins or a half COMPOUNDS FOR COLORING AND POLISHING LEATHER. 761 dozen kips or light cow-hides ; but the heavier hides require to remain longer in the compound. The dyeing-liquor requires to be replenished as its strength is exhausted, by the addition of fresh material, to keep it in substantially the proportions described. Maroon and purple colors may be made by working in the logwood-liquor and finishing by using aqua fortis and tin, with solution of logwood, instead of the dyeing-liquor. Eawhide, after being subjected to this treatment, in which it is only partially tanned, is rendered a deep and permanent color throughout its entire surface, and is susceptible of a high polish, giving it a finished appearance similar to that of hard black rubber. It can be prepared at exceedingly low cost, does not become discolored by use, but retains its original neat appear- ance until worn out, and is thus of great value in the manufac- ture of tips or shields for the toes of boots and shoes, and of similar or other articles liable to rough usage. Logwood has been described as the base from which the solu- tion is obtained. It is selected because it is the cheapest and most readily obtained ; but it is evident that more expensive materials — as nut-galls and other equivalent dyes from wood or vegetables — may be used instead of logwood. In the preparation of ISTo. 1 solution we have described that the blue vitriol and nut-galls were placed in hot logwood-liquor. This is preferable, but instead of logwood-liquor hot water can be used, increasing the quantity of nut-galls. An Intense Black, etc., jjrepared from Aniline Colors, mixed loith Alcohol, etc. This compound, patented by Humphrey, is made of aniline- red, aniline-blue, and aniline-brown, mixed with alcohol, sul- phate of iron, or muriated tincture of iron, water, oil, and amber, which, when applied to leather, or other suitable material, imparts an intense and durable black color. In preparing: Take aniline color one and one-half parts; alcohol, one hundred and twelve parts ; sulphate of iron, or muriated tincture of iron, sixteen parts; oil, eight parts ; oil of 762 THE MANUFACTURE OF LEATHER. amber and water to suit, usually about two parts of the former and eight parts of the latter. The aniline colors which the inventor employs, by preference, are red aniline, blue aniline, and brown aniline, and he generally takes equal quantities of these colors. The aniline color is dissolved in the alcohol, and, by the addi- tion of oil and sulphate of iron, a compound is obtained which will readily combine with the fibres of leather, the oil serving to penetrate the material, and to open its fibres, while the sul- phate of iron, or muriated tincture of iron, acts as a mordant, whereby the color is firmly bound to the fibres. In order to reduce the expense of this compound add to it a quantity of water, and the inventor also adds amber, for the purpose of disguising the smell of the alcohol. The color produced on leather is a jet-black ; but, by chang- ing the proportions of the aniline colors, different shades may be produced. Black Staining Gorapound for concealing defects in Leather and for applying to Pocket-hooks , composed of Aniline Colors, Nap)hthaline^ etc. The object of this process, patented by Wolff', is to produce a liquid compound which, being applied to the surface of leather, will impart a deep, indelible, black color. To prepare the compound: Take 0.94 part of blue aniline, 0.26 part of yellow aniline, 0.48 part of naphthaline, and 0.32 part of red aniline, which are dissolved in 74 parts of alcohol in a suitable vessel by agitation. After being dissolved the liquid resulting is passed through a filter. It is applied to the leather with a brush, and dries rapidly, and, when dry, presents a bronzed appearance, which will be converted into a deep black by the application of water with a cloth or sponge. This staining material can be used in connection with other organic substances than leather ; but it is chiefly intended to be employed on the latter for the concealment of defective places in the blackened surface. After application, the leather may be dressed with liquid COMPOUNDS FOR COLORING AND POLISHING LEATHER. 763 blacking or paste, or such materials as are commonlj^ used ; in this event dispense with applying water, which is superfluous, as the bronzed appearance will be displaced upon the applica- tion of such dressing. Its effects will be the same on every description of leather ; but in classes of leather having a very close grain, such as pebble goods and those qualities used in the manufacture of pocket-books, etc., two coats of the compound should be applied the one upon the other, in order to obtain the desired intense black. The yellow and blue anilines, by their union, form a green, which, by the addition of the naphthaline, is converted into a very deep green, so that, by the addition of red, it will produce a black. Of itself the mixture of the yellow and blue anilines would produce a light green of insufficient depth when mixed with the red to produce a deep black. Another compound patented by Wolff' consists of the same aniline colors as above, but is dissolved only in alcohol and is intended to form a base for a black coloring composition for leather. To prepare this compound : take 0.87 part of blue aniline, 0.84 of yellow aniline, and 0.29 part of red aniline, and dissolve them in 74 parts of alcohol, preferably methylic alcohol, the composition, after the complete dissolving of the several ingredients, being passed through any appropriate filtering medium. The result of this combination is a very dense coloring com- position possessing great power of penetration. The proportions given may be varied to some extent to accord with variations in the strength or density of the aniline colors employed. The compound may be used as a black-varnish ingredient by dissolving in it shellac. The composition may be used as a base for admixture with other materials in order to produce compounds for different purposes, such as coloring leather, compound for renovating harness, shoe-blackino;, etc. 764 THE MANUFACTUEE OF LEATHER. Compound for iynparting a lustrous Black Gloss to Leather. Quinland has patented the following leather dressing com- pound for boots and shoes, carriage-tops, harness, trunks, satchels, etc., designed to impart to the same a lustrous black gloss, as well as to preserve and protect the leather. It consists of alcohol, shellac, castor oil, ivory-black, and turpentine, in or about the proportions named. In preparing : Take one gallon of alcohol, and dissolve in it two and a half pounds of orange-shellac. To this add one pint of castor oil, one-half pound of ivory-black, and one gill of turpentine. In adding the ivory-black it is thoroughly incorporated and imparts to the liquid a dirty-black color, which, however, when applied to the leather surface, becomes, by reason of the evapo- ration of the alcohol and turpentine, a rich, lustrous black gloss. Dyeing Leather.^ containing Tannic or Gallic Acid, Black, hy subjecting it to the action of a Yanadic Compound. This process, patented by Soerensen, relates to a method of dyeing leather black by means that are claimed to be more convenient, cleanly, and eft'ectual than when the ordinary methods are employed. The leather to which this manner of dyeing applies is such as has been tanned, and contains tannic acid, or gallic acid, or any of those derivations or combinations of or with which such analogous acids as turn black when acted on by compounds of vernadium. The dyeing can be effected at any time after the leather has been tanned. The action of the vanadic compound or preparation — which is employed in solution — on the surface or body of the leather treated is to turn it black. It will be well understood that in order not to in any way in- juriously affect the qualitj'- of the leather it will be most advan- tageous to employ a neutral vanadic solution, and the inventor claims to have successfully used a neutral solution of vanadiate of ammonia containing one per cent, of the latter salt. In order COMPOUNDS FOR COLORING AND POLISHING LEATHER. 765 to bring out a full black color the moderate use of heat is bene- ficial. Blackening leather by vanadium preparations is claimed to be especially advantageous in the treatment of manufactured articles, such as boots and shoes, as the risk of damaging the upper portions of the same is avoided, and in the case of orna- mental stitching in saddleryware the leather is rendered black, while the stitching retains its proper color. It also allows the operation to be performed without soiling the hands. Gilding and Ornamentiny Leather for Suspender Ends^ etc. The method patented by Walker consists in gilding or bronz- ing leather used for suspenders' ends with gold leaf, metal foil, or with bronze, either in the form of leaf or in powder. The gilt or foil or leaf is applied by means of stamps or dies contain- ing any suitable ornamental design, and may be applied by any of the means now used, for imparting ornamental designs to leather by means of gilding and bronzing. The processes, being well understood by the workers in this method of ornamenting leather, need not be particularly described. If the leather is dyed, it should be with fast colors, so that no stain will be imparted to the clothing. When artificial leather is used, it can be treated in the same way as real leather. Gilding Leather. The Papierzeitung gives the following method described for gilding leather. It is first moistened with a sponge, then stretched and tacked on a board. When dry it receives a coat of thick isinglass solution, then one of white of egg that has been beaten and allowed to settle. Upon this are laid lightly with a brush sheets of silver foil, which are then pressed down with a wad of cotton-wool. When this is dry it is painted over with yellow leather varnish, which gives it a beautiful golden appearance. Bronze Dressing for Leather. The object of this method, patented by Fennessy, is to pro- vide a cheap and brilliant bronze dressing for leather, to be used 766 THE MANUFACTURE OF LEATHER. particularly for bronzing boots and shoes; and consists in a preparation composed of aniline red, blue, violet, or purple, or a mixture of two or more of these colors, dissolved in a suitable acid, and brought to the desired consistency by the addition of an acid solution of gelatine or a gum soluble in water. To prepare : Take six ounces of aniline red and two ounces of aniline blue, violet, or purple, dissolve them in one quart of acetic acid, heating the mixture slightly in order to accelerate the operation, after which it is allowed to become cool. Then dissolve in a separate vessel thirty-two ounces of gelatine in one gallon of acetic acid, and add this mixture to that first described, after it has become cool, to give the required consistency to the compound. The whole is then thoroughly stirred together, when it is ready for use. Any suitable acid other than acetic acid may be used ; and in lieu of gelatine, a gum soluble in water— for instance, gum arable, or gum tragacanth — may be employed, if desired. The proportions of aniline color or acid above stated may be varied somewhat according to the shade of bronze required ; and any one of the aniline colors above referred to may be used singly instead of a mixture of these colors ; but the inventor prefers the mixture first described, as it produces a more desirable shade of bronze. The quantity of gelatine or gum used may also be varied, according to the consistency required. The dressing is applied with a soft brush, and gives a brilliant bronze finish to the leather. Aniline Bronze Colors of Various Shades applicalle to Leather. This method, which is that of Fiorillo, consists, broadly, in the admixture of benzoic acid with aniline colors, for the pur- pose of producing a bronze paint or color, the shade or tint of which may be varied according to the aniline colors used and the detailed treatment to which they are subjected during the process. To compound this bronze proceed as follows: Dissolve ten parts of aniline red, or so-called diamond fuchsine or roseine, and five parts of aniline purple (known in commerce as " Hof- man's violet" or methyl violet) in. one hundred parts of alcohol COMPOUNDS FOR COLORING AND POLISHING LEATHER. 767 of 95° strength, placing the vessel containing the mixture in a hot-water or sand bath, to promote the dissolution. As soon as the aniline*ha^ been dissolved in the alcohol add five parts ben- zoic acid, boil gently, then add thirty-two parts of gum benzoin, and continue boiling from five to ten minutes, until the can- tharide-green color of the mixture disappears, changing into a bright golden bronze color. The color thus produced is of a very high lustre, of great durability, and will adhere firmly to leather, and, in fact, to nearly all substances. It is readily applied with a brush, and dries in a few minutes. It will answer equally well on white and colored grounds ; and may be used, on account of its durability and the facility with which it is applied, upon ladies' boots, slippers, shoes, or other articles of leather, to which it imparts a bright golden bronze hue. . Producing wpon Leather Various Shades of light broivn, and darker colors^ hy the combination of Oxalic Acid, Salt of Tin, and Potash, with Nut-gall and Sulphate of Iron. The process patented by Jager consists in washing the leather with the solution of salt of tin and oxalic acid to prepare it for receiving the color. Potash, nut-gall, and sulphate of iron are the ingredients of the compound for coloring. The proportion of ingredients composing the wash for pre- paring the leather is one part of oxalic acid to three parts of water. With this solution the inventor washes all kinds of grain leather. With the solution of one part of salt of tin and three parts of water he washes all split leather and leather without grain. After the leather is perfectly dry it is ready to receive the color. The compound used to give the leather the various shades of light broAvn is composed of one part of potash and three parts of water. To get the various shades desired increase or decrease the strength of the solution. It is applied with an ordinary brush. For dark colors use the following compound : one part of sulphate of iron, one part of nut-gall, and three parts of water. This is also applied to the leather as stated. For the purpose of shading the color on the leather a solution of oxalic acid is prepared and slightly applied with a 768 THE MAISrUFACTUEE OF LEATHER. sponge till the shades suit the operator. After the paint is well dried a mixture of starch and the white of egg is used for coat- ing the leather. After the coating has well dried the leather is ready to receive the varnish. Coloring Leather voitli Aniline upon a Starched Surface and produciny an appearance similar to Marhled Paper. This process, which is that of Koppitz and Mayer, is carried out by mixing the ground color with starch ; as, for instance, if logwood is used as a ground color, the inventors boil it in vinegar until the color is sufficiently extracted, and after having stained the solution there is mixed with it a quantity of starch, generally one pound of starch to one quart of the solution, although the proportions are to be varied according to circumstances, For further coloring the leather the inventors use various aniline pigments, each of which is prepared as follows : First dissolve the color in alcohol, using for each ounce of the aniline pigment about one pint of alcohol. To this add about three quarts of vinegar, and next boil the solution for a few minutes, after which it is ready for use. Next, the preparation of ground color is sprinkled on the leather or the latter is covered with the preparation to the necessary extent, after which the other color or colors or prepa- ration of aniline, as above explained, is to be sprinkled or thrown upon the leather to the extent required. The starch of the first preparation will cause it to resist the aniline color or colors, or second preparation, whereby there will result a soft- ening or shading together of the spots of ground and other colors at their edges in contact. This softening or blending of the masses or spots of colors at their edges with the ground colors produces a very 23leasing effect, and although the leather has an appearance much like that of marbled paper, used in book-bind- ing, no bath is required to produce the effect, as in the process of marbling paper. Furthermore, the preparation of the aniline color, by the employment of alcohol and vinegar, in manner as described, renders the color stable, or not easily oxidizable by light, the preparation being peculiarly fitted for coloring leather COMPOUNDS FOR COLORING AND POLISHING LEATHER, 769 with one plain color without first employing a ground color prepared with starch, as set forth. We would observe that, generally speaking, whenever the ground color prepared with starch, as explained, becomes cov- ered with the aniline color, the latter becomes readily remov- able by water, so that, after a skin may have been sprinkled with the ground and aniline dyes or colors, and is afterward washed, the aniline colors will remain fast in such portions of the skin not covered by the ground or starch color, but will be mostly if not entirely removed from the parts on which the starch color or ground may have been thrown. By this process it is possible to color leather or other substances for use in the arts with great economy, and with excellent practical and orna- mental results. Forming a Solution for Staining Tawed Leather^ consisting in , mixing Clay, Water ^ Comm^on Salt, Sulphuric Acid, Brewer's Yeast, Ahcrn, Hemlock Extract, and Terra- Jaiponica. This process, patented by Eichter, is carried out as follows : Prepare a clay mixture by filling a barrel or other vessel half- full of clay (preferably clay suitable for making bricks). Then add water sufficient to thoroughly reduce the clay, destroying its adhesive qualities and forming a mixture of thick or semi- liquid condition. Then mix therewith the following ingredients, in substantially the following proportions, viz : To every thirty-two gallons of the clay and water mixture add four quarts of common salt, one pint of sulphuric acid, and presently add one quart of brewer's yeast, and thoroughly incorporate them. An effervescence Avill ensue and continue for about twenty-four hours, and when it ceases the liquid compound will begin to precipitate. Then remove the impurities deposited and leave the supernatant water, and fill the barrel or other vessel with water and dissolve therein six ounces of alum to every thirty- two gallons of liquid. Then add to this mixture one pound of hemlock extract and one pound of terra-japonica thoroughly dissolved in hot water. Apply to the hides, after being tawed and dressed, by pouring the mixture over them when in a close 49 770 THE MANUFACTUEE OF LEATHEE. vessel, so as to cover them, and keep about tliirty-four hours in solution. Preparing^ coloring^ and poll sliing Light Skins for Car Seats^ Trunk Covers^ etc. This process, patented by Djar, relates to the preparation of leather for the purpose of imparting a finished or ornamented surface to the same, having particular reference to converting cheap or light skins into material for car seats and linings, boot and shoe linings, trunk covers, etc., where light stock may be used to advantage, if it has a finished and uniform surface. In accomplishing this object the surface of the skin to be prepared is first filled with a composition (using a compound which can be polished by friction), and the dead or lustreless surface of the leather left by application of the composition is next printed (by any one of the ordinary printing processes) with any suitable design or figures, and in any desired colors. The surface is then solidified and polished by working a tool over the skin, laid upon a bed, as in ordinary levelling, solidifying, or polishing machines. The skin to be prepared is preferably in a dry condition when treated, and the composition the inventor prefers to use is made up of a mucilage or pulp obtained by soaking flaxseed in water, and straining oft" the pulp, and dis- solving in the pulp, freed from the seed, white soap, adding also a little linseed or other oil. This composition is thoroughly worked into the surface of the leather, and the leather subse- quently dried. Then the pattern or design is laid or printed on the prepared surface, after which the leather is subjected to the action of the- polishing tool, the mucilaginous and saponaceous surface so combining with the imprinted colors that a uniformly polished and hardened surface is imparted to the whole skin, the tool gliding over the printed characters without moving or spreading them. Deer, neat, goat, calf, and sheep-skins maj'- all be prepared in this manner, and upon either the grain or flesh side, as circumstances may make desirable. COMPOUNDS FOR COLORING AND POLISHING LEATHER. 771 Composition of Olycerine^ Resinous and other Substances afford- ing a Base for inipartinx] a High Polish to Leather. The composition patented by Farnbam, is intended for appli- cation to leather- work, for the purpose of rendering the leather impervious to water, and at the same time affording a base which is susceptible of receiving a high polish, preserving, also, the flexibility of the leather. The employment of resinous substances as a coating for leather has been objectionable, because such resinous substances, on becoming dry, would crack, and cause the leather to break. It is claimed, that by mixing glycerine with a resinous compound, an article will be produced meeting all the requirements, viz., the exclusion of water, the preservation of the softness of the leather, and the susceptibility of the compound to receive a high polish. To make this preparation take of alcohol (ninety-four per cent.) one gallon; Venice terebinthina, one pound; gum-shellac, one pound; glj'cerine, one pound; myrtle-wax, one-fourth pound, and of fine lamp or ivory-black, enough to give the requisite color and consistency. Digest the gum in the alcohol until thoroughly dissolved. A portion of the glycerine is used in grinding the myrtle-wax, and a portion in grinding the blacking, so as to make it perfectly soluble in the alcohol. The ingredients, after being mixed, must be stirred until a perfect union is effected. The composi- tion is to be applied to the leather with a brush or sponge, in the usual manner. Castor oil ma}^ be used with the glycerine resin, for carriage- tops and other work where a brilliant polish is not required. Composition for Polishing, Water-proofing, and' Coloring Leather. In making this composition, which is the invention of Martyn, proceed as follows : To one imperial gallon of water add three ounces of nut-galls, and heat the water and' maintain it at a sim- mering temperature for about half an hour, so as. to thoroughly extract the tannin from the galls.. Next remove the liquid from the galls, and raise it to a boijirjg. heat,, and while at this 772 THE MAKtlFACTtrJlE OF LEATHER. boiling terapefattire introduce two ounces of strong spirits of ammonia, borax, or other suitable alkali, and one and one-half pounds of gum-shellac, and stir the whole until thorough solu- tion of the shellac takes place, Next add to the solution one drachm of aniline color in crystal, using generally " aniline- blue," or violet, or both, or an aniline-black, for instance. Next add to the solution three ounces of vegetable, ivory, or lampblack. After stirring until the latter addition is well incorporated, the composition will be complete and ready for use. It is to be applied to the leather, boot, shoe, or other article by means of a brush or sponge, and when dry will be found to impart to it a brilliant enamel surface, one impervious to water. The proportions of the ingredients may be varied somewhat, more or less, without materially changing the character of the process. , The vegetable, ivory, or lampblack will, by the gum, be held in suspension in the liquid, but the compound should be thoroughly stirred every time before using, Polish for Leather used for Bags, Satchels, etc. This polish, patented by Bddlemon and Walker, is in the nature of a blacking, and to prepare it mix the following ingre- dients in the proportions stated, viz: 1 quart alcohol, 4J ounces gum shellac, 3 ounces English rosin, 1 ounce oil of sassafras, 1 ounce castor oil, 1 ounce lampblack, and f of an ounce beeswax. These ingredients are placed in a tin vessel over a slow fire, stirring frequently until the shellac, rosin, and beeswax are dissolved, and the whole mixed thoroughly, which will require from twenty to thirty minutes. It is then removed from the fire, and, after cooling oS", is ready for use. This polish may be used for bags, satchels, harness, boots, shoes,, and all other leather goods, as it will not rub off', but gives it a fine and lasting gloss, besides softening the leather and rendering it water-proof by filling the pores. It may be applied with a brush or soft rag (a piece of flannel is the best), or a sponge may be used, if desired. Several of the ingredients named have been used before separately or in different combi- COMPOUNDS FOR COLOKIISrG- AND POLISHING LEATHER. 773 nations in the manufacture of leather-polish, notably the combi- nations of alcohol, gum-shellac, rosin, and lampblack, or other coloring matter, and these combinations are not claimed in this patent; but only those ingredients in the proportions above set out. Coloring partially tanned Hides and Skins by the employment of a Bath of Tin, Acid and Water, and Turmeric. In carrying out this process, which is that of Woodbury, sub- mit the skin or hide, after its outer and inner layers have been, tanned sufficiently, to the action of a bath composed of a solution of nitrate or muriate of tin, or nitrate or muriate of tin and a coloring matter, such as turmeric, for instance. In this bath allow the skin or hide to remain from twelve to twenty-four hours or thereabout, when it will be found, after removing the skin from the bath and washing it, that the tannin in the outer layers, or much of it, will have been thoroughly driven or forced into the inner layer, and a uniform or practically uniform tan- ning of the whole skin or hide will have taken place ; also, that the tannin or coloring matter will have penetrated the entire skin so as to color or modify the color of it, as may be desirable. In preparing the bath of nitrate or muriate of tin take for each gallon of nitric or muriatic acid about one pound of the metal tin. The acid is to be poured upon the tin, or the latter is to be immersed in the acid, and the two are to be al- lowed to stand until the tin may have been dissolved or destroyed by the acid, after which there may be added to the solution the necessary amount of water, say about 140 gallons, and the tur- meric or coloring matter. Compound for changing the coloi; of Leather, especially the color of the soles of Boots and Shoes. This process, patented by May, relates to a compound to be applied to leather in the manufacture of boots and shoes, and for leather used for other purposes, for changing the color of the leather, designed more especially for changing the color of the soles or bottoms of boots and shoes, but not confined thereto; and it consists in the following compound : Take 2 gallons rye- 774 THE MANUFACTURE OF LEATHER, flour paste; 2 gallons tragacantli paste; 1 pound American isinglass; IJ pound oxalic acid; ^ pound gum gamboge; 3 pounds pipe-clay, united with water sufficient to make 10 gal- lons of the compound of the proper consistency for use. The mode of preparation is substantially as follows : While the rye paste (made in the usual way) is hot, add the isinglass and stir until all is dissolved ; then add the tragacantli paste ; then let the mass cool, and, when cold, add the oxalic acid, gum gamboge, and pipe-clay and water. Let the composition stand for the space of a week or so before using. This composition fills the pores and makes the leather bright and hard. By the use of a revolving brush, or of friction applied otherwise after the application of the composition, the complex- ion or color of the leather may be changed, as desired. The bottom of a boot or shoe or other leather may be made of a very light color, or of a dark red or other complexion or shade. The color, it is claimed, will not fade, and the application of the compound, it is also claimed, improves the wear or durability of the leather. Compound for Whitening Leather. Tinnerholm's process for whitening leather is as follows: He takes — Acid, tartar., crys. 2 ounces Acid, muriatic, crys. 2 " Cream tartar 2 " Sulphur . . 2 " Water . . 20 gallons The above ingredients are mixed and placed in the vats with the hides, and in it they remain for two hours. COMPOUNDS FOR COLORING AND POLISHING LEATHER. 775 List of all Patents for Compounds for Coloring and Polishing Leather^ issued by the Government of the United States of America, from 1790 to 1883 inclusive. No. Date Inventor. Residence. 5,327 Oct. 9, 1847. W. Mc Adams, Albany, N. Y. 33,331 Sept 24, 1861. J. Braiuerd, Cleveland, Ohio. 46,804 Mar. 14, 1865. X. Karcheski, Bellville, N. J. 62,120 Feb. 19, 1867. S. Dyar, Charlestown, Mass. 77,021 Apr. 21, 1868. T. M. Farnham, Tully, N. Y. 118,089 Aug 15, 1871. D. Woodbury, Feabody, Mass. 121,375 Nov. 13, 1871. G. Jager, Indianapolis, Ind. 124,965 Mar. 26, 1872. T. C. May, Cochituate, Mass. 130,958 Aug. 27, 1872. G. W. Walker, Lowell, Mass. 142,797 Mar. 29, 1873. J. Koppitz and F. B. Mayer, Boston, Mass. Canibridgeport, Mass. 147,337 Feb. 10, 1874. H. Martyn, Martha's Vineyard, Mass 158,608 Jan. 12, 1875. C. J. Tinnerholm, Keokuk, la. 164,678 June 22, 1875. E. H. Fennessy, Newton, Mass. 165,129 June 29, 1875. H. Smith, Newark, N. J. 167,183 Aug. 31, 1875. H. Martyn, Boston, Mass. 170,100 Nov. 16, 1875. H. W. Merrill and J. W. Hoitt, Lynn, Mass. 171,787 Jan. 4, 1876. Otto Fiorillo, Baltimore, Md. 179,560 July 4, 1876. A. S. Humphrey, Poughkeepsie, N. Y. 190,660 May 8, 1877. Geo. S. Wolff, Pliiladelphia, Pa. 194,754 Aug. 28, 1877. Geo. S. Wolff, Philadelphia, Pa. 203,498 May 7, 1878. N. Quinlaii and J. H. Quinlan, Glens Falls, N. Y. 225,772 Mar. 23, 1880. M. B. Tice, Newark, N. J. 243,000 June 14, 1881. N. G. Sorensen, Stockholm, Sweden. 265,041 Sept, 26, 1882. J. F. Eddlemon, and W. L. Walker, Witcherville, Ark. INDEX. ABIES CANADENSIS, 118 Abraham and Lot, rich in cattle, silver and gold, 34 Acacia bambula, 118 catechu, 114 Acetate of potash, 105 Acetates, 715-717 Acetic acid, 708 use of in separating coriin, 97, 99 Acid, acetic, 97, 99, 101, 708 iesculotannic, 120 arsenic, 105 arsenious, 52 carbolic, 48, 50, 53, 344 carbonic, 105 cashew-tannic, 101 chromic, 53, 61, 62, 107, 134 citric, 709 colfee-tannic, 101 digallic, 108 ellagic, 107 formic, 120 gallic,.^ 08 gallotnnnic, 101, 103, 108, 109 hydrochloric, 82, 83, 97, 99, 105. 107, 707, 708 iodic, 106 lactic, 112 li(pors, depilating with, 265 metagallic, 105 mineral, the principtd ones em- ployed in dyeing leather, 706 morintannic, 101 nitric, 83, 86, 707 oxalic, 107, 708 phosphoric, 105 phyllocitannic, 120 physiological and pathological tannic, 102 picric, 138 propionic, 112 protocatechuic, 120 pyrogallic, 105, 113 pyroligneous, 52, 708 Acid — quercotannic, 110 quinotannic, 101 rufigallic, 109 rufitannic, 110 suberic, 107 sulphuric, 86, 105, 706 tannic, 97, 99, 100, 113, 114, 116 tannomelanic, 1 09 tannopinic, 109 tannoxylic, 110 tartaric, 709 Acids, 705, 706 in sour liquor, 360 mineral and organic, 706 depilating with, 265 organic, which are of interest to the dyer, 708 the action of, on tannin, 106, 107 the swelling influence of, on skin, 100 Adamson's bating process, 349 Adipose tissue, lobules of, 95 Adler's compound for depilating and swelling hides, 273, 274 ^sculetin hydrate, 120 ^^ivsculotannic acid, 120 tEscuIus hippocastanum, 120 Africa, goat-skins of, 42 African kino, 114 Agamemnon, the boots of, 57 Agitators, patents for, 358, 359 Aikin, 58 Aikins's method of working lamb-skins into glove leather, 664-669 Air bath for the determination of water in leather, 82 Alaska, seal-skins of, 43, 44 Alazarine red, 735 Albumen, use of in bating, 346 Alcohol, extracting resinous substances from leather with, 127 its employment in determining fats and resin in leather, 82 use of, for dissolving tannin, 103 778 INDEX. Alcohol — use of, for exhausting gall-nuts, 104 Aldehyde green, 742 Alder 'bark. 121 Aleppo fir, bark of, 121 Algarohia f/landuloxa, 122 Alkalies, action of the, on tannin, 107 Alkaline carbonate solution, 137 chromates, neutral, 134 mordant, 726 sulphates, 131 Allen and Wai-ren's hanging sprinkler, 208 sprinkler leach, 203, 204 system of leaching with little or no heat, 223 Alligator leather, 582-585 uses of, 582 skin, japanned leather in imitation of, 594, 595 of the, 36 skins, bate for, 584 packing, shipping, and trade in, 5"82, 583 tool for softening, 584 treatment of, 583-585 whence obtained, and their uses, 44 Almond oil for tawing, 65G Aloes, 52 Alum, 712, 713 absorbed by a complete saturation of the skin tissue, 132 according to Knapp and Reimer is split in being absorbed by the skin tissue, 132 ammonia, 131 chromium, 132 concenti-ated, 130-132 cubic, 131 for bating, 386 formation of, 131 formula of, 130 for tanning, 628 for tawing, 654 iron, 132 iron and chrome in tanning, 629 leather, 69 manganese, 132 potash, 131 Kunge's test of, 713 tanning properties of, what prin- cipally due to, 132 Alumed leathers, defects of, 673-67-9 leather. Main's process of finish- ing, 667, 668 Alumina, 53 Aluminium acetate, 132, 133, 715, 716, chloride, its use for increasing the weight of leather, 86 salts, ammonium hydrate as a reagent for, 86 in tanning, 633 sulphate, 130-132 to test, 131 tanning, 641 American hemlock extract, 119 leather, high rank of, 78 patent system, 54 potash, 51 sumach, 116 Ammonia, 107 alum, 131, 713 and blood for bating, 285 carbonate of, for accomplishing the purposes of the bate, 336 muriate of, for bating, 336 Ammoniacal solution of zinc acetate, use of in determining tannic acid, 143 Ammonium hydrate as a reagent for aluminium salts, 86 its use in determining the percentage of lime in leather, 83 nitrate, its use in determining the percentage of ash in leather, 82 oxalate, its employment in deter- mining lime in leather, 82 Analyses of vegetable tanning mate- rials by various processes, 138-164 Analysis, qualitative, of water, 169 Anderson's depilatory of cRarcoal, 277 Aniline, 746, 747 black, 7 44, 746 blue, 742 ordinary, 742 bronze colors, application of, to leather, 766, 767 brown, 744 colors and alcohol, compound of, for imparting an intense black to leather, 761, 762 colors, dyeing Russia and Moroc- co leather with, 754, 755 dyeing sumach-tanned ski- vers with, 748-754 dyeing with and the methods of their preparation, 740- 748 especially suitable for leather, 740 for dyeing parchment, 741 INDEX. 779 Aniline colors — for oil or chamois leather, 741 high perfe(!tioii of this indus- try, 704, 705 naphthaline, etc., for making a black staining compound, 762, 763 on Morocco, advantages in using, 757 upon a starch surface on leather, producing an ap- pearance similar to marble paper, 768, 769 gray, 745 green, 742, 743 red, 743, 744 violet, 741, 742 yellow, 743 ordinary, 743 Animal charcoal, extraction of, with hydrochloric acid, 156 kingdom, 36 skin, 93-100 construction of, 93 Anthon on the quantities of various tannins required for the conversion of one pound of skin into leather, 125, 126 Antiseptic substances for preserving hides, 50 Apparatus for stretching leather, patents for, 596 Apparatuses for blacking leather, patents for, 449 for tanning goat and sheep-skins, 536-545 " Applying the dye, 730 Areometer, the, 139, 14 7 Arsenic acid, 105 Arsenious acid, 52 Art, the improvement of an, 56 Artificial leather, of what made and its uses, 72, 73 Russia leather, 581, 582 sheep-skins for linings, 561, 563 sole leather, 489-491 by Pollock's process, the chemical reaction "which takes place in, 491 impervious to water, 489, 490 large quantities produced in Massachusetts from leather scraps, 489 Artificial — tannin of resin, camphor, and sul- phuric ac"id, 137 tannins, chemical nature of them not thoroughly investigated,. 137, 138 Artificially prepared tanning sub- stances, 136-138 Ash, percentage of in leather, deter- mination of, 82, 83 Ashton's process for tanning with fer- ric salts, 626, 627 Asia Minor, goat-skins of, 43 trade of in lamb-skins, 42 Aspidosperma quebracho, 122 Aspidospermin, 122 Astringent principle of hemlock and oak bark alike, 481, 482 Australia, kangaroo leather in, 583 Avens root, 122 Azaleine, 743 Azobenzole, fast crimson E, R for skivers, 749 BACTERIUM ANTHRAX, poi- soning by, 48 Badische aniline and soda fabrik ani- line colors, 748 Baker's improved glazing machine, 462, 463 improvement on Coogan's board- ing and graining machine, 438, 439 pony glazing machine, 463, 464 vat with feeding pipe for Morocco tanning, 527, 528 Ballamy, 59 Bahamokarpon hrevifolium, 122 Bamboo, silica in the epidermis of, 175 Bantsia serrata, 121 Banks's discovery of the tanning pro perty of terra japonica, 58, 59 Barberry yellow, 734 Barber's bark mill, 188-190 Barium, 134 chloride, its use for increasing the weight of leather, 86 of, 61 of, how determined in the percentage of ash, 82 sulphide of, for softening, plump- ing, and depilating hides and skins, 282, 283 780 INDEX. Bark, 174-183 bought in Massachusetts by the cord, 494 chestnut oak, 119 contrivance for cutting prepara- tory to peeling the same, 178- isl conveyer, 200-202 cutch and gambir, exports and imports of, 79 epidermis of, 174 extracts, 494 of, purifying, 227-231 removing resinous gums and floating particles from, 227 use of in the United States, 598 grinding and leaching of, import- ance of in tanning, 184 mill, Barber's, 188-190 one of the prime require- ments of a, 184 safety, coupling of, to prevent breakage should a foreign substance get into it, 186- 188 Troy or Starbuck, arrange- ment of, 185 Weston's horizontal cylinder, 185 with rotary cutters, 190-195 mills, different varieties of Ameri- can, 185 patents for, 195-197 oak, chemical examination of, 159-163 to obtain a correct sample of for analysis, 160 peeling, and the most convenient time for it, 176, 177 quantities of oak and hemlock, consumed in the United States, 75 rock oak, 1 19 rossing, 181, 182 machines, patents for, 182 the, from which tannin is obtained, 181 the more unevenly ground the more unevenly it is leached, 184 the nature of, 174-176 the outer coating of, loses its tan- ning properties, 181 used for grain, split, and buff leathers, 511 Barking, influence of seasons and place at the time of, on the richness in tannin, 177 tools used in, 177, 178 Barkometer, the, 221, 226 Barks used in tanning, 118-121 Barley dressing, 300 raising by, 300 Barrentrapp-Will method of analysis, 84 Barron's process for softening dry hides, skins, and peltries, 244, 245 Bartenbach and Richter's process for lace and whip leather, 569 Barton & Co., splitting machines of, 380 Base for a high polish to leather, 771 Bases, 709 Basic acetate of iron, 98, 99 of lead, 98, 99 ferric sulphate for tanning, 135 sulphate of iron for tanning, 629 Bassora gall-nut, 116 Batchelder's leather blacking, color- ing, and dressing machine, 441- 44^6 Bate in taweries, preparation of, 650 stone, 586 Bating, 262, 335-351 and final prejiaration for the ooze, 335-341 compound of muriate of soda, SLiper-tartrate of potassa and tartaric acid, 342, 343 compounds, 341-351 for glove leather, 649-652 hides and skins, patents for com- pounds for, 351 in what it consists, 335 objections to the present method of, 336, 337 period at which the hides and skins remain in, 335, 336 process, Adamson's, 349 Mullen's, 349 Soderberg's, 349 Swan's, 350 Tucker's, 350 Tnrley's, 351 Wilson's, 350 the theory of, 492, 493 usual practice of, 337 various substances used for, 336 vats and wheels for, 337 INDEX. 781 Bating — when used, 335 Avith blood and ammonia, 285 with bran, oil of vitriol, and salt, 345, 346 with carbolic acid, muriate of am- monia, and alum, 343, 344 with glucose and dried sour cheese, 346 with liquor composed of water, impregnated with sulphur di- oxide previously employed in softening and soaking hides, 346-349 with muriate of ammonia, either alone or with dung, 341-343 with sulphuric acid and the lime liquor in which the skins have already been treated for remov- ing the hair, 344 Bauxite, 130 Bavarian calf-skins, 41 Bazil, 69 Beam for whitening, 423, 424 German form of, 304, 305 house, 304 arrangement of in France, 307 iinhairing, 304-306 Beaver, otter, and other skins, tanning or coloring with the hair or fur on, 622-624 Beech bark, 121 Beetling, implements for, made from very heavj' hides, 43 Belt knife machine in operation, 496 splitting machine, 378, 379 Cummings's improve- ment m, 380-383 Belts, machine, leather for, 692 Bennat's description of Persoz's method of analyzing tanning materials, 141 suggestion for analyzing tanning- materials, 142 Berry's process for softening hides, 245, 246 Bichromate of potash, 53, 61, 107 Bichromates, use of, for tanning, 628, 629 Binary colors, 701, 702 Birch oil, distillation of, 579-581 manufacture of, 578-581 products of distillation of, 581 use of, in the manufacture of Eussia leather, 576 Birch oil — poplar, and alder barks, where used for tanning, 125 Bismarck brown, 744 R for skivers, 751 Black, 724, 735 aniline, 744, 746 an intense, imparting to leather, Humphrey's compound for, 761, 762 color, 722, 723 coloring for partly or fully tanned skins, Brainerd's, 759 gloss to leather, compound for imparting, 764 maroon and purple colors to raw hides, Merrill and Hoitt's pro- cess, 759-761 Martyn's, compound for leather, 758 on alumed leather, 722 on oil leather, 739, 740 staining compounds for concealing defects in leather, and for ap- plying to pocket-books, 762, 763 Blacking and smutting appliances, 440- 449 brushes, 440, 441 coloring and dressing machine, Batchelder's, 441-446 compounds, 449-451 for leather, patents for, 451, 453 Hayward's flesh, 449, 450 leather, 440-453 patents for apparatuses for. 449 Blackings, oil and soap, 449 Bleaching hemlock tanned and Union tanned leather similar to oak tannage, 488, 489 the leather from chamois skins for gloves, 688 Bleu de lumifere, 742 de Lyon, 742 de Paris, 742 de Parme, 742 Blood, advantages claimed for, in de- pilating with, 285 and ammonia for bating, 285 lime, and water for depilating, 284-286 "Blood stains" on leather, 674 Blue, aniline, 742 for skivers, 748 782 INDEX. " Blue-blaok" tannins, 101 dark, 734 for skivers, 752 on Morocco with aniline, 75(5 on oil leather, 738 pale, on Morocco with aniline, 756 vitriol, 712 Boarding and graining before the in- troduction of machinery, 431, 432 by machinery, 431-440 machine, 432-434 for Morocco, 438, 439 Hovey's, 434-438 machinery, advantages of, 432 machines, patents for, 439, 440 Boettger's proposal to depilate with hydi'osulphate of lime, 288 proposed use of lime that had served for purifying gas as a depilatory, 275 Bollman's depilatory compound, 284- 286 Bones of the ox, how utilized, 39 Bonneville method of making artificial leather, 72 Borax, 52 Bordier's patent, 1842, for tanning by means of ferric sulphate, 135 process for tanning with mineral and earthy substances, 627 Botchford's process of distilling sour liquors to get rid of the decaying and animal substances in them, 360, 361 Bottle green, 730 Boudet's proposal to depilate with caustic soda, 290 Boxes for exhaust steam and direct steam, 216, 217 Boy den, Seth, early inventor of a split- ting machine, 369 the first to make japanned leather in the United States, 70 Bradley's apparatus for purifying ex- tracts of bark, 227-231 Brainerd's compound for coloring partly orfully tanned skins, 759 depilatory, 276 Brains of calves and sheep for tanning, 656 Bran drench for goat-skins, 527 oil of vitriol, and salt, bating with, 345, 346 Branded hides, 55 Branning for chamois leather, 681, 682 injury to skins in, 675, 676 skins for glove leather, 652, 653 Breaking hides, list of patents for, 261 Bromine, 106 Bronze colors on leather, 766, 767 dressing for leather, 765, 766 Brown, aniline, 744 coffee, 733 dark, 733 light, 733 light leather, 729 mi-fonce, 730 mineral pigments, 736 mixed, 734 olive, 733 on oil leather, 739 Browns, catechu, 733 for skivers, 751, 752 Brush for scouring, 385 Brushed kid finishing, 532 Brushes, blacking, 440, 441 Brusliing the dye liquor on the skin, 730, 731 Bryant & King's tannery, Woburn, Mass., setting machines in use at, 388 Bryant's machine for smutting leather, 447-449, 517 " B. S." oil for stuffing compounds, 419, 420 Bublah, 118 Buchner on tannomellanic acid, 109 on Wagner's method of determin- ing tannic acid, 152 Buenos Ayres hides, sweating, 297 the best hides come from, 40 Buffido hides, 45 tanned with chromium com- pounds, 61 Buff' color on leather for pantaloons, 688 "Buff" hides," 511 Buff" leather, 69 Buffed, grain, and split leathers, 511- 517 leather, finishing, 516, 517 Buffing and whitening machine, 428, ^429 the hide for japanning or enamel- ling, 592, 593 wheels, 43 whitening, and shaving leatlier, patents for machines for, 430 INDEX. 783 Bugh's method for tanning beaver, otter, and other skins with the hair or fur on, 622, G24 Building for sweating hides and skins, 293-295 round leaches, 209-219 Burdon machine for dressing, setting out, and scouring hides, skins, and leathers, 401-405 Burnt alum, 713 Butea frontosa, 122 gibsonis, 122 C.^SALPmiA CORIARIA, 117 Caesar on the reindeer clothing of the German tribes, 37 Caillelet on the determination of fat in leather, 83, 84 Calcium and sodium as a depilatory, 27G, 277 bichromate, 134 chloride of, how determined in the percentage of ash, 82 hvdrosulphuret as a depilatory, 275 preparation of, 288-290 sulphide and sulphuret for depi- lating hides and skins, 283 sulphuret of, and soda for depi- lating, 287 Calf-skin the best material for parch- ment, 68 uses of, and whence derived, 41 Calf-skins, dried, 41 salted, liming, 264, 265 split, sometimes used for Mo- rocco, 41 tanned with chromium com- pounds, 61 treating in the limes, 264 California tanning, interest in, 75, 76 Calves' brains for tawing, 656 Camphor and resins, tannins from, 138 Canada, bark obtained from, 494, 499 Canary yellow, 724 Cape, goat-skins of the, 42 Carbolic acid, 53 for bating, 336 for preserving hides, 50 muriate of ammonia and alum as a bating compound, 343, 344 used for disinfecting tanner- ies, 48 Carbolic acid — valuable as a wash against in- fection, 48 Carbonate of ammonia employed by Warrington, 1841, for the pur- poses of the bate, 336 of potassa, 52 Carbonates, 717-720 Carbonic acid, 105 Carbuncles produced by handling hides of diseased animals, 48 Carpene-Barbieri's method of deter- mining tannic acid, 143, 144 Carriage tops, leather noAv and for- merly used for, 70 Carter and Keith's depilatory process, 270 process for tanning hides and skins with the hair on, and for dressing furs, 621, 622 Cashew-tannic acid, 101 Catechu brown, 733 discovery of the tanning proper- ties of, 58, 59 gray-brown, 733 or terra japonica, 114 Category of a color, 703, 704 of a shade, 704 Cattle breeding one of the principal industries in the United States, 35 ranches in the United States, 35 the hides of the improved breeds of, less thick and less useful for leather, 39, 40 Caustic lye in the manufacture of cha- mois leather, 686 lime, 710, 711 soda, depilation by, 290 Cavalin's process for tanning with bi- chromates, 628 Cellar of an upper leather tannery, showing the piles of sides and the ma(,'hinery, 368 , (Jhalk, ground, 69 Chamois- and goat -skins, Aikens's method of working into glove leather, 665 color, 724 leather, color of, 688 colors for, 736-740 depilation and frizzing for, 680, 681 operations in the manufacture of, 680 the most famous, 64 784 INDEX. Chamois — or oil leather, manufacture of, 679-689 qualities necessary in, 679 or royal leather dyeing, 736-740 shamony, or shamoy leather, 69 Chaptal, 58 Charcoal, depilating with, 279 Cheese and glucose, bating with, 346 Chemical compounds, saturation of leather with, 553, 554 examination of vegetable tanning materials, 138-164 reaction which takes place in Pol- lock's process of making artifi- cial sole leather, 491 Chestnut bark and quebracho bark used for tanning in Eng- land, etc., 125 and quebracho, tanning with, 129 where used in tanning, 125 color on alumed leather, 722 oak bark, 119 tan-bark, 483 Chinese gall-nuts, 115 Chloride of barium, 61 how determined in the per- centage of ash, 82 how used in detecting fraudu- lent increase in the weight of hides, 49 its use for increasing the weight of leather, 86 of potassium, 61, 62 of sodium, 61, 62 Chlorides, 714, 715 Chlorine, 106 Chromate compounds, 62 neutral alkaline, 134 salts, deoxidizing effect of organic matter on, 61 oxidizing power of, 6L Chromates, etc., Heinzerling's method of tanning with, 633-641 Chrome alum in tanning, 629 leather and tanned leather, stretch- ing capacity of, 638-640 effecl; of boiling in water, 62 of steeping in cold water, 62 of stuffing with fat or parafline, 62 oxide, 62 Chrome — tanned leather, effect of Immer- sion in water, 636-640 yellow, 736 Chromic acid, 53, 61, 62, 107, 134 oxides in tanning, 629 salts, conclusions of Dr. Clark on the power of leather to retain, 638 sulphate, 134 Chromium alum, 132, 713, 714 the most important of the chromium salts thus far used in mineral tanning, 1 34 compounds, tanning and tawing with, 61-63 in chrome tanned leather, 636, 637 salts, 133, 134 sulphate, 131 withdrawn from chrome tanned leather by the action of water, 636-640 Chrysaniline, 743 Circles of normal colors, 703, 704 Citric acid, 709 Clark, Dr. J., comparative experi- ments of, as regards the sol- ubility of tannin in chrome leather, 636 conclusions of, on the power of leather to retain chromic salts, 638 on the " degrees of hardness" in water, 173 Clark's modification of Wagner's me- thod of determining tannic acid, 153, 154 process of determining the hard- ness of water by soap solution, 170 Classification of sole leathers in the United States, 48 2 Claus's depilatory, 276 Cleansing and moistening skins for dye- ing, 725 Clements' s leather whitening machine, 423-426 Climate, effect of, on the hides of cat- tle, 40 Clothing for man, origin of, 33, 34 Coal, tannin from, 138 Coe's process for tanning, 621 hides and skins Avith the wool, fur, or hair on, 621 INDEX. 785 Coffee brown, 733 tannic acid, 101 Cold sweating process, 291-293 Color, graduated line of, 701 modified, 701 of leather, compound for chang- ing, 773, 774 Colored leather similar to our Morocco prepared by the ancient orientals, 65 spolten of by Ezekiel, 56 various phices in which it has been manufactured, 66 Color! metric method of determining tannic acid, 142 Coloring and polishing leather, com- pounds for, 758-775 compounds for, patents for, 775 and tanning beaver, otter, and other skins with hair or fur on, 622-624 hides and skins with hair and fur on, 620-626 blacking, and dressing machines, 441-446 Klemm's oil leather, 694 leather with aniline upon a starched surface, witli an appearance sim- ilar to marble paper, 768, 769 pai'tially tanned hides and skins, 773 polishing, and water - proofing leather, composition tor, 771, 772 preparing, and polishing light skins for car seats, etc., 770 Colors all derived by reflection from the different colors of which the white light or sun light is composed, 698 aniline, used in aqueous solutions preferable for leather, 740 normal circle of, 703, 704 of the spectrum can be artificially produced by three artificial dye- stnlis, 701 requiring firing, treatment of, 726 transition of through their count- less modifications, 703 Composition as a base for a high polish to leather, 771 for impregnating hides and skins and preserving them in condi- tion to be unhaired by immer- sion in water, 50-52 50 Composition — for polishing, water-proofing, and coloring leather, 771, 772 for treating japanned leather and producing an imitation of alli- gator skin, 594 Compositions for patent japanned or enamelled leather, 590, 592c Compound for changing the olor of leather, 773, 774^ for finishing upper leather. 450 for renewing the surface of japan- ned leather, 592 for whitening leather, 7 74 Compounds and materials for tanning and for tawing leather and for preparing raw hides, especially claimed or mentioned in an^- patent, 616-619 for coloring and polishing leather, 758-775 for producing imitation of grain or Morocco leather, 551-555 for stuffing and currying leathei', patents for, 420 Conductors to the leaches, 218, 219 Connective tissue of skin, behavior of, toward certain sub- stances, 99 formula of, 99 qualities of, 99 Contagious diseases, hides of animals having died of, dangers in handling, 48 _ Contrivance for cutting bark prepara- tory to peeling, 178-181 Conveyer, bark, 200-202 Coogan's boarding and graining ma- chine, 432-434" Copal varnish, 69 Copper, 53 suljjhate of, 52 Coralline, 746 on« Morocco, 756 Cordovan leather, 65. 66 whence the name is derived, 65 C.ordillot's process for coloring blac]*: with aniline, 745 Coriin, 94 formula of, 84, 85, 98 qualities of, 97, 98 to obtain, 97 Corium or leather skin, composition of, 94 Counter fleshing the hides, 310 786 INDEX. Coupe's stretcLing machine, 568, 569 Cream of tartar, 717 Creasing machines, patents for, 465- 467 Creasote, 53 Crimson, aniline for skivers, 749 Crockett, David, of Newark, N. J., the first to manufacture enamelled leather in the United States, 70 Crown leather, capacity of, to resist water, 692 for machine belts, 692 softness of, 692, 693 strength of, 691, 692 weight of, 691 Cryolite, 130 Cube alum, 713 Cummings's improvement in belt knife splitting machines, 380-383 Cupiic acetate, 716, 717 its use in precipitating tannic acid when testing for grape sugar, 86 chloride, 98 sulphate, 712 Curing hides. Rock's liquid for, 52, 53 Curriers' knives, 423, 424 patents for machines for sharpening, 430 slickers, patents for, 430 Currying business in twelve States, 80 establishments in the United States, 79 leather, patents for compounds for, 420 tallowed leather, 523 Cutch, gambir and bark, imports and exports of, 79 where used in tanning, 1 25 Cuticle or epidermis, 93 Cutlery manufacture, buffing wheels for, made from very heavy hides, 43 Cutting bark preparatory to peeling, contrivance for, 178-181 surface of leather a test of tan- ning, 85 D'ARCET'S recommendation of tanning with ferric salts in the last century, 135 Daheny's table for leather scouring machines, 405-407 Dahlia, 74 2 imperial, 742 Daigneaii's contrivance for cutting bark preparatory to peeling, 178-181 Damaged hides, 55 Daniels's tan press, 508 Danish glove leather, 668, 669 Dark blue, 734 brown, 733 gray, 735 green^ 733 rose pink for skivers, 750 Davy on the tannin in beech bark, 121 Davy's examination of the epidermis of the bamboo and sugar cane, 175 experiments on the tannin in oak bark in the spring and fall, 177 method of determining tannic acid, 139 Decaying animal and vegetable sub- stances in liquors, 360 Deer-skins, 45 Defects of alumed varieties of leather, 673-679 Degras obtained from the waters of wool factories, 418, 419 the residue obtained from the tanning of buck, goat, and sheep-skins, 419 Delane's method of salting hides, 49, 50 De Montoison's depilatory process, 270 Denmark, origin of horse leather in, 572 Depilating, action of lime and sulphur in," 28 3 and removing grease with a com- pound of water, lime, soda ash, saltpetre, and flowers of sul- phur, 281 and swelling hides with sulphu- retted hydrogen gas, with lime, soda, etc., 273, 274 by caustic soda, 290 by stacking in heaps, 301 by sulphuret of calcium and soda, 287 by sweating, 291-300 by the use of soda-ash, caustic lime, monosulphuret of potas- sium, hard soap, and soft water, 271, 272 composition of nitrate of potassa, chloride of sodium, sulphuric acid, and tartaric acid, 272, 273 compound of potash, lime, salt, sulphur, and charcoal, 274, 275 INDEX. 787 Depilating — hides and skins, patents for com- jDOunds for, 302, 303 processes and compounds for, 2 G 1-303 softening and plumping, hides and skins with sulphide of barium, 282, 283 use of "refuse gas lime" in, 275 with acid liquors, 2G5 with charcoal, 277 with double sulphate of sodium and calcium, 276, 277 with lime, 261-269 with slacked lime and ashes, 265 with water, burnt oolite, and muriatic acid, 284 with water In an open vessel, 286, 287 lime, and blood, 284-286 with sulphide and sulphuret of calcium, 283 Depilation and frizzing for chamois leather, 680, 681 and liming for glove leather, 648 by maceration among barbarous tribes, 37 by the hydrosulphate of lime, 288 Depilatory methods now nearly obso- lete, 300-302 of lye from wood ashes or potash, lime, etc., 278-281 of potash, lime, and orpiment, 288 process, Carter and Keith's, 270 De Montoison's, 270 Head's, 270 Robinson's, 269 Ward's, 269 Wilson's, 270 Desmond, 58 Determining the constituents of water, metirod for, 169-173 the tannic acid in tanning mate- rials, 139-164 Dewees and Green's stuffing com- pound of "B, S. oil," 419, 420 Dextrine for tawing, 656 use of in bating, 346 Dicing machines, patents for, 465-467 Digallic acid, 108 Dinitro-naphthalene, 747 Dirty chamois leather to clean, 688, 68"'9 Diseases of lambs and sheep, effects of, on leather, 674, 675 Disinfecting tanneries, importance of, 48 Distaff" and the loom, early use of, 36 Distillation of birch oil, 579-581 of sour tan liquors, 360, 361 Divi-divi, 117 leather tanned with, qualities of, 117 Dog-skin, 44 Dog-skins, Watts' s method of working into glove leather, 666 Domine's method of exhausting gall- nuts, 105 Donath on quebracho, 122 Donath's test of aluminium sulphate, 131 Dressing and finishing chamois leather, 685-689 blacking and coloring machine, 441-446 furs, Carter and Keith's process for, 621, 622 setting out and scouring machine, Burdon, 401-405 sheep-skin fleshers for glove bind- ings, etc., Hart's process, 557, 55"8 sheep-skins, Hesthal's process for, 560, 561 Drum, revolving, for handling hides, 357 Dryers for patent leather, 590 Dry flint hides, 54 sweating, 291 hides, soaking, 237, 241 in running water, 243 sunburned, weather-beaten, or moth-eaten, 55 treatment of in France, 242 working and softening in the hide mill, 242 salted hides, 54 Drying and striking out skins for "Morocco, 530 loft of a Morocco factory, showing the skins hung up, 530 loft of a sheep-skin tannery, 586 the skins after softening, 732 yard, with the sides of leather hung over the poles, 496 Dubbing, water- proofing, and whiten- ing upper leather, 504-507 Dudley and Brooks's process for hand- ling goat-skins, 529 Dung bating, the theory of, 336 use for bating, 335, 336 INDEX. Djar's process for preparing, coloi-ing, and polishing light skin for car seats, trunk covers, etc., 770 Dye, applying, 730 for Russia leather, 576, 578 liquor, brushing on the skin, 730, 731 liquors, mother, preparing for glazed leather, 729 Dyeing alumed leather, 721-732 by dipping, 723, 724 by paintin'g, 724-732 chamois or royal leather, 736- 740 glazed leather, 724 glove leather, 721 Grenoble method of, 724, 725 leather, 698-758 by means of a Vanadic com- pound, 764, 765 general remarks on, 698-705 Russia and Morocco leathers with aniline colors, 754-758 skins on the grain side, 723 on the flesh side, 721-723 sumach-tanned skivers with ani- line colors, 748-754 with aniline colors, and the methods of their preparation, 740-748 wool on sheep-skins, Jack's method and machine for, 624- 626 Dyer's art, importance of, 700 EAST INDIA kino, 114 Indies, goat-skins of, 42, 43 Eaton's process of depilating hides, 271, 272 Eddlemon and Walker's polish for leather, used for bags, satchels, etc., 772, 773 Edwards, Wm., the inventor of the hide mill and of the rolling contri- vance now employed for rolling sole leather, 252 Egg, white of, for glazing glove leather, 663, 664 yelk of, for tawing, 654-657 Eitner's directions for the use of ani- line colors, 754-758 experiments on the eifect of differ- ent inorganic consituents of water upon the depilated skin. 167 Elephant hides, 44 Ellagic acid, 107 Elm bark, 319 Ely's process for plumping before de- jpilating, 246-250 Emeraldine, 743 Enamelled, japanned, and patent leather, patents for, 595, 596 leather, 69, 70 first manufactured for car riage tojDs in the United States, by David Crockett, of Newark, N. J., 70 England's apparatus for handling hides, 353-356 paddle wheels for handling hides, 337, 355, 356 England wheel, use of, 512, 518 wheel, advantages of, 356 English method of dyeing, advantages of, 725 by painting, 725, 726 patents for mineral substitutes for vegetable tanning, early, 626 Enos and Clements' s leather whitener, 424 Enos's attachment to splitting machine to prevent injury to the arms of workmen, 371-375 tanning process, 599 Epidermis, composition of, 93 of bark, 174 of the bamboo and the sugar cane, Davy's experiments on, 175 useless to the tanner, 94 Erlanger leather, branning, 652, 661 finishing, 661-668 liming and depilating for, 649 method of soaking and rinsing for, 647 tawing pastes for, 653-661 treatment in bate of dogs ex- ci-ements for, 649-652 or French method of tawing, 642- 668 Ether, 698 extracting resinous substances from leather with, 127 use of, for exhausting gall-nuts, 104 Ethyl rosaniline gi-een, 743 Eucalyptus, bark of, 122 Eureka bark mill company, rolling machine of, 485, 486 Eurojie, hilly regions of, the coat-skins of, 43 INDEX. European galls, 115 Evans's artificial leather company, the leather produced by, 73 Evans's imitation sheep-skins, pi'epara- tion of, 561-563 Evaporator, McKenzie's, 230 Evening or making leather of uniform thickness, patents for, 557 Examination of leathers, 81-92 of vegetable tanning materials, chemical, 138-164 Extract, horse-chestnut, 120 of hemlock bark, American, 119 Extracthig tannin, the best method, 203 Extractive matter removing from tanned leather, 503, 504 substances, influence of, on the value of a tannic acid, 113 Extracts from tan- bark, patents for, 235, 236 of bark, purifying, 227-231 Ezekiel's description of the dresses and harness of the Babylonians, etc., 57 FACTS and principles in the sciences and arts, 56 Fagus silvatica, 121 Fair finished leather, 41 leather, 70 Farnham's composition of glycerine, resins, etc., as a base for a high polish to leather, 771 Fast brown for skivers, 752 red R for skivers, 752 Fat and resin in leather, determination of, 81, 82 jjercentage of, in leather, detei'- mination of, 83, 84 Fats used for tawing, 64 Feed i-olls for unhairing machines, McDonald's improvement in, 325- 327 Fehberg's volumetric denomination of tannic acid, 140 Fehling, Prof., method of determining tannic acid, satisfactory re- sults obtained by, 143 on Klemm's process, 695 Fehling' s method, modified by Miiller, 142, 143 Fennessy's bronze dressing for leather, 765, 766 Fermentation of tannic acid in unclean tanneries, 112 Ferric acetate, 715 in tanning, 629 aluminium in tanning, 629 chloride, 98, 714 citrate, 142 nitrate, 714 salts, 135 " blue-black," tannins which precipitate, 101 " green," tannins which pre- cipitate, 1 01 Knapp's processes of tanning with, 628-633 tanning with, 626, 627 sulphate for tanning, 627 in tanning, 628 advantages claimed for, 630 Pfanhauser's process for pre- paring and tanning with, 628 Ferrous sulphate, 131, 711, 712 Fibroin, 99 of silk, 99 of skin, 99 Filling and running the leaches, 219- 226 cup for Morocco manufttcturers, Walters' s, 539-541 Filtering tanning liquor for purposes of determining tannic acid, 140 water through exhausted tan, 112 Fine grades of leather, laying away, 366, 367 Finishing and dressino- chamois leather, 685-689 and pebbling machine, Knox's, 464, 465 butr leather, 516, 517 brushed kid, 532 glove leather, 661-668 grain leather, 515, 516 imitation French kid, 531, 532 machines, patents for, 465-46 7 oil goat, 535 pebble- grain goat, 535 polishing, glassing, pebbling, roll- ing leather, etc., machines for, 453-468 split leather, compound for, 451 straight grain goat, 532, 533 the side of heavy upper leather, details of, 497-500 the split, 500 upper leather, compound for, 450 ^90 INDEX. Fiorillo's method for applying aniline bronze color to leather, 766, 76 7 Fir bark, 118 Fischerstroern's method of distilling birch oil, 579 Fish oil, 70 Fitting the colored split, 500 Fitzhenry's leather dressing machine, 398-401 Flanders and Marden's splitting ma- chine, 369 Flaying skins and hides, important points to be considered in, 46 Fleck and Wolff's method of deter- mining tannic acid, 141 Flesh blacking, Hayward's, 449, 450 color, 735 Flesher, saw-tooth for dry hides, 309 the, 308 Fleshing and iinhairing, 304,' 335 by machinery, 313-333 hides and skins simultaneous- ly, Janson's machine for, 330-332 the most laborious ope- rations in tanning, 313 machines, patents tor, 333- 335. a sure hand required in, 311 by the hand process, 308-311 knife, German, 308 macliines not generally in use, 313 objection to, 311 slating, and striking out machines, Eoberts and Lenox's, 332, 333 the hide, the details of, 309-311 working, and unhairing hides and skins, Taylor's machine for, 327-329 Flinting machines, patents for, 465- 4G7 ^ Fluffing and grinding machines, pa- tents for, 556 Fluids for leaching, apparatus for the automatic distribution of, 204-208 France and Italy, lamb-skins of, 42 arrangement of the beam house in, 307 attention paid to the beam work on calf-skins in, 306 unliairing and flesliing as jjrac- tised in, 306, 307 Fraude, aspidospcrma found .by, in the baric of quebracho, 122 Fraudulently increasino- the weight ot hides by employment of sulphuric acid, 49 Fraser's experiments with tanned leather and chrome leather, 639 Freely's method of manufacturing ar- tificial Russia leather, 582 French beams, 307 "boarding" contrivance, 732 kid, imitation, finishing, 531, 532 ■ method of dyeing glazed leather, 726-729 or Erlanger leather, precautions to be taken in making, 642 method of tawing, 642-668 division of processes, 647 in Germany and Austria, 642 sumach, 116 whitening slicker, 423 Fresh liides, sweating, 299, 300 salted hides not generally sweated, 299 Friend and Annable's improvement in hide-mill, 253-255 Friend's glassing machine, 468-460 " Frieze," cause of during the process of sweating, 291 Frizzing and depilation for chamois leather, 680, 681 Fuchsine, 743, 744 Fuel of spent tan, 507 Fulling chamois leather in the oil, 682- 685 drum, Knapp's, for tanning, 630- 632 glove leather, 650 in of insoluble soaps of ferric oxide, etc., in tanning, 628 iron soap into the skin by Knapp's process, 630, 631 machine, the resemblance of the hide-mill to, 252 ' process, the, represented on tomb of Beni Hassan in Egypt, 252 Fulton's tanning process, 599 Fur and hair, tanning and coloring hides and skins with the, on, 620- 626 Furs, dressing, Carter and Keith's process for, 621, 622 to color, 624 Fustic, 118 INDEX. Wl GALLIC ACID, 108 formation of, 102 Gall-nut, tannin of the, 103 Gall-nuts, 114, 1.15 Chinese, 115 the best imported, 115 to exhaust, 104, 105 Gallotannate of potash, 109 Gallotannic acid, 101, 103 constitution of, 108, 109 experiments of Sehriff in re- gard to, 108 extraction of, 103 Galls, 115 green, 115 Gambler, 114 cutch and bark, imports and ex- ports of, 79 its use in tanning in Great Britain, 125 liquor, treatment of hides for patent leather with, 587 Garge's tanning process, 602 Gas lime refuse as a depilatory, 275 what composed of, 275 works, waste water from, for soft- ening dry hides, skins, and pel- tries, 243-245 Gassincourt on the tannin In tormentil root, 122 on the tannin in alder bark, 121 Gelatine, precipitation of with tannin, 139 Generator for preparing hydrosulphate of lime, 288-290 Gerber on quercus bitter. 111 on the substances contained in an aqueous solution of the inside layer of oak bark, 139 Gerland's method of determining tan- nic acid, 144 German calf-skins, 41 fleshing knife, 308 harness leather, 518 tribes, reindeer clothing of, 37 Germans, leather ships of the ancient, 57 German's tanning process, 598 Germany and Austria, French or Er- langer leather, tawing in, 642 steeping cisterns In, 312 Geum urbanum, 122 Gilding and ornamenting leather for suspender ends, 765 leather, 765 Glac6 leather, 664 Glassing and rolling brushed kid, 532 leather by hand with a glass slicker, 453 by machinery, 453, 459 machine. Friend's, 458-460 Hildreth's, 460, 461 machines, patents for, 465-46 7 or polishing, pebbling, finishing, rolling leather, etc., machines for, 453-468 Glauber salt for salting hides, 50 Glazing inferior qualities of glove leather, 663, 664 machine. Baker's improved, 462, 463 overhead for Morocco, 464 machines, patents for, 465-467 pony machine. Baker's, 463, 464 Glove binding, etc., sheep-skin fleshers for, 557, 558 Glove calf, 525 how long it remains in the limes, 526 leather, Aikens's method of work- ing lamb-skins Into, 664, 6 6' 6 Danish, 668, 669 dyeing, 721 . Norwegian, elm bark used for tanning, 119 skin for working, 647 Watts' s method of making, 666, 667 willow bark used for tanning Swedish, 121 sheep, 525 how long It remains in the limes, 526 Glucose and dried sour cheese, bating with, 346 Glueoside, pyrogalllc, 109 Strecker on tannin as a, 106, 108 tannin not a, 107 Glue factories, phosphoric acid of, for bating, 349 percentage of, in leather, 128 stock, hides which are classed as, 55 what made of, 39 white, use of, in determining tan- nic acid, 143 Glycerine, 53 and carbolic aeid, mixtures of, preserving hides, 50 resins, etc., as a base for a high polish to leather, 771 792 INDEX. "Glycerole" of egg, 417, 418 Goat and chamois skins, Aikens's method of working into glove leather, 665 and sheep-skins, tanning apparatus for, 536-545 oil, finishing. 535 pebble-grain finishing, 535 straight graining and finishing, 532-535 skin bags, filling with the sumach liquor, 527-529 skins for Morocco leather, classifi- cation of, 524 how long they remain in the limes, 526 placing in the tanning liquor, 527" whence generally obtained, and uses, 42, 43 Watts' s method of working into glove leather, 666 Gorsline's apparatus lor handling hides and skins, 387 Gouget on the origin of the art of tan- ning, 37 Gould's tanning process, 599, 600 ' Graduated line of color, 701 Grahowsky and Oser on the formula of quercotannic acid, 110 Grain, artificial, Patterson's process for forming on the hide, 593, 594 leather, finishing, 515, 516 or Morocco leather, imitation of, compounds for producing, 551- 556 split and buff" leathers, 511, 517 where manufactured. 511 Graining and boarding by machinerj', 431-440 machine, Coogan's, 432-434 •Hovey's, 434-438 for Morocco, 438, 439 machines for, 440 board for graining Morocco by hand, 534 machine for Russia leather, 578 Grape sugar, its use for increasing the weight of leather, 86 Grassi's method of determining tannic acid, 150, 151 Grauhe on determining tannic acid, 142 Gray, 723 Gray — brown catechu, 733 dark, 735 iron, 735 Grease, machine for removing, from leather, 421, 422 patents for machines for removing grease from leather, 422 ' removing with a compound of water, lime, soda ash, saltpetre, and flowers of sulphur, 281 Green, aniline, 742, 743 brilliant, for skivers, 753 dark, 733 hides, 54 soaking, 23 7 on Morocco with aniline, 756 on oil leather, 738, 739 picric, 733 Russia, for skivers, 753 salted hides, 55 sap, 734 shade, 724 shaving hides for upjier leather, 312 stock, laying, 366 "Green" tannins, 101 Green, Victoria, for skivers, 750 vitriol, 711, 712 Greens, olive, 733 Grenoble method of dyeing, 724, 725 Grinding, cutting, crushing, and con- veying tan-bark, 184-202 of bark, importance of, 184 Grounding and fluffing machines, pat- ents for, 550 Grouvelle and Duval- Duval's process of distilling birch oil, 580, 581 Gum arable in tawing, 655 H.5:MAT0X YLON Campeachia- num, 118 Hair and fur, tanning and coloring hides and skins with the, on, 620-626 and wool fabrics, early felted, not woven, 36 industries, 36 bulb, 95 follicle, 95 of the ox, how utilized, 39 papilla, 95 primitive manner of removing 263 sacks or roots, 95 INDEX. 793 Hallwaelis on Mittenzweis's method of determining tannic acid, 150 on determination of tannic acid, 143, 144 Halsey's combined vat and wheel, 529 wheel and vat for tanning Morocco, 542-545 Hamburgh, manufacture of horse leather in, 572, 573 Hammer's method of determining tan- nic acid, 144-146 Hammond's process of soaking hides and skins with the use of saltpetre, 239, 240 Handler rocker, 353 Handling and plumping, 352-3fi3 apparatus, Gorsline's, 357 appliances, patents for, 358, 359 heavy stock before laying away, 368 hides and skins, 352-359 England's apparatus for, 353—356 improvements in. 352 in the lime pits, Steinmann's apparatus for, 266-269 methods of, 352, 353 Steinmann's apparatus for, 357 in the interior of a large revolving drum, 357 processes still in use in Europe, 356, 357 sides for pebble and grain leather, 357 Hardness of water, process of determin- ing by a soap solution, 170 total, determination of, 171- 173 permanent, of water, determina- tion of, 173 Harness leather, dyeing with aniline colors, 757, 758 Hart's process for dressing sheep- skin fleshers, glove bindings, etc., 557, 558 Hatcher's tanning process, 600 Havana brown, 744 Hay ward's flesh blacking, 449, 450 Hazel color, 724 H B crown leather, Preller's, 691-693 Head's depilatory process, 470 process for soaking, liming, tan- ning, blacking, and gumming hides for upper leather, 500- 603 Heavy leathers sold by weight, 468 stock, handling before laying away, 368 upper leather, 492-503 details of the tanning of, 495-507 finishing the side of, de- tails of, 497-500 Heinzerling's leather, experiments "with, 636-640 working into shoes, 636 method of determining the tan- ning constituents in leather, 82 " _ of tanning with chromates, 633-641 mineral tanned leather, ability of, to resist water, 87-89 process, mineral constituents in leather tanned by, 85 of tanning, or tawing with chromium compounds, 61- 63 Hemlock and oak barks, astringent principle of, the sanie, 481, 482 general use of, in the United States, 598 bark, 118, 119 American extract of, 119 consumed in tanning in the United States, 75 qualities of, 118 the liquor yielded by a cord of, 221 use of, in the United States, 125 sole leather, varieties of, 482 tanned and union tanned leather, bleaching, 488, 489 leather, 481 grading of, 482 the coloring matter and resin m, 481 Henry's depilating compound, 274, 275 Hermstadt, 58 Herodotus on the clothing of the tribes of the Caspian Sea, 37 on the early use of sheep-skin for writing on, 57 Hesiod on leather shoes lined with fur, 57 Hesthal's process for dressing sheep- skins, 560, 561 Hibbard's process for preparing and tanning sheep-skins, 559, 560 794 INDEX. Hibbard's — tannino- pi'ocess, 598, 599 Hide mill, improvement in, by Friend and Annable, described, 253-255 invented by Wra. Edwards, Northampton, Mass., in 1812, 252 Middleton's, 258-260 the idea of, due to fulling machine, 252 mills, 250-2C0 differ greatly for the various branches of leather, 250 for Morocco leather, 250, 251 in common use, 252, 253 patents for, 260 Hides and skins, 33-55 coloring, partially tanned, 773 composition for preserving, 50 consumed in the United States, 75 criteria to 2;uide the purchaser of, 47, 48 depilating, 261-303 historical notes on their early uses by man, 33-38 importance of removing from slaughtered animals imme- diately, 45 important points in flaying, 46 injuries to, in soaking, 238 Napier's process for preserv- ing, 53 of animals which have died of contagious diseases, dan- gers in handling, 48 origin of their use by man, 33, 34 removing from animals, 45- 47 Sabath6 and Jourdan's pro- cess for preserving, 53 Slice's process of preserving, 53 selecting, 47, 48 unhairing them by the same composition with which they are impregnated for preserving, 50-52 varieties of, used for leather, 38-45 washing and soaking, 237- 243 Hides and skins — AVickersheimer's process of preserving, 53, 54 with the hair and fur on, tan- ning and colorinnf, 620-626 with the hair on. Carter and Keith's process for tanning, 621, 622 breaking, list of patents for, 261 classified as dry flint, dry salted, green, green salted, and part cured, 54 commercial classification of, 54 dry, are damaged when sun- burned, weather-beaten, or moth-eaten, 55 soaking in running water, 243 for buff" leather, preparation of, 511 for German harness leather, 518 for grain, split, and buff" leathers, 511 for leather, whence the American supply is, and in the future will be, drawn, 40 for upper leather, Head's process for soaking, liming, tanning, blacking, and gumming, 500-503 whence obtained, 494 fraudulently increasing the weight of, 49 from Buenos Ayres and Monte- video, difference in, 40 from Rio Grande, 41 Glauber salts for salting, 50 importance of preparing in the beam house, 263 indications of their readiness for scouring after soaking, 312 influence of hard water on, 98 known by the port from which they are shipped, 40 Lampert's apparatus for working, 338-341 liming of, too long continued, gives poor weight, 98 MacBride's discovery of the use of sulphuric acid for swelling, 58 number of, consumed in Russia, 66 of cattle, how affected by sudden changes of temperature, 40 of the improved breeds of cattle less thick and less useful for leather, 39, 40 INDEX. 795 Hides — or skins, with the wool, hair, or fur on, 621 parts of, how classed, 38 preparation of, for heavy upper leather, 494, 495 preparing for Klemm's oil leather, 693 preserving, 49-55 list of patents for, 54 Rock's process for preserving, 52 salting, 49, 50 skins, and bark, exports and im- ports of, 79 and peltries, processes for softening, 243-246 soaking after ileshiiig, the length of time for, 312 South American, how classified, wlience received, and their qual- ities, 40, 41 swelling or plumping, 167 tests for detecting sulphuinc acid when fraudulently used for in- creasing the weight of, 49 the skins of the larger animals, 38 the uses to which different kinds are put in making leather, 41 those that are stag, or tainted, and badly scored, grubby, or murrain, rank as damaged, 55 which are classed as glue stock, 55 with the hair on, Pingree's process for tanning, 620 Hide-workino- machine, the Holmes, 392-398 Hildreth's glassing machine, 460, 461 Hippopotamus hides, 44 tanned witli chromium com- pounds, 62 Historv of tanning, svnopsis of, 56- 63 Hoev's compound for renewing the surface of japanned leather, 592 Hoffman's putting out machine, 545- 550 violet, 741 Hog-skins, 44 Holbrook's process for preparing tan bark for use, 197-200 Holmes's improved scouring machine parts, 396, 397 scouring, setting, and hide-work- ing machine, 392-398 tan press, 507, 508 Holtz's apparatus for obtaining a pure and readily soluble tannin, 232-234 Homer has perpetuated the name of a tanner who showed kindness to him, 57 on the boots of Agamemnon, 57 Horse-chestnut bark, 120 extract, 120 Horse-hides, whence obtained, and their uses, 43 Horse leather for foot wear, 572-574 manufacture of, by Preller's method, 693 origin and manufacture of, in Denmark, 572 Hovey's boarding and graining ma- chine, 434-438 Howell & Co. the only exhibitors of Russia leather at the Centennial, 575 Humphrey's compound for imparting an intense black to leather, 761, 762 Hungarian leather, history of, 68 Hungarians celebrated at an early date for their white leather, -64 Hvdrates of potassium and sodium, '709, 710 Hydrochloric acid, 105, 107, 707, 708 bating with, 336 its employment in determin- ing lime in leathei-, 82, 83 its use in determining the percentage of fat in leather, 83 property of dissolving lime possessed by, 336 use of, in separating coriin, 97, 99 Hydrometer, the, 221, 226 Hydrosulphate of lime as a depilatory, 288 preparation of, 288-290 Hydrosulphuret of calcium as a depi- latory, 275 preparation of, 288-290 ILLINOIS, tanning interest in, 75, 76 Imitation alligator skin, 594, 595 French kid, American, 525 finishing, 531, 532 of grain or Morocco leather, com- pounds for producing, 551-555 Improved methods for tawing and dressing sheep-skins, 558-561 ^96 IKDEX. Improvement of an art, the means for, 5G Improvements in tan presses, 507— 511 Increasing the weight of hides by the employment of sulphuric acid, 49 Indigo solution, preparation of, for determination of tannic acid, 154 Injuries to hides and skins in soaking, 238 Injury to skins in branning, 676 Inorganic acids, action of, on skin fibre, 100 Inside sole leather tanning, 486, 487 Intercellular substance in skin, 97 Iodic acid, 106 Iodine, 106 use of, in determining tannic acid, 144 Iron, 53 alum, 132 in tanning, 629 basic igulphate of, for tanning, 629 gray, ^73 5 soap fulling into the skin by Knapp's process, 630, 631 Knapp's, in tanning, 630 of Prof. Kntipp, 135 sulphate of, 52 Irons, flat, polishing glove leather with, 663 Ii'ons's tanning process, 598 Isinglass, use in determining tannic acid, 143 Italian sumach, 116 Italy and France, lamb-skins of, 42 the tanning industry in, 7 7, 78 JACK'S method and machine for dyeing wool on sheep-skins, 624- 626 Jacob and Laban, early transactions between, 34 a shrewd cattle trader, 34 Jager's process of producing colors on leather with oxalic acid, salt of tin, etc., 767, 768 Janson's machine for simultaneously unhairing and fleshing hides and skins, 330-332 Japanned, enamelled, and patent leathers, patents for, 595, 596 leather, in imitation of alligator skin, 594, 595 mixtures for, 590, 591 Japanned leather — renewing the surface of, 592 or enamelled leather, preparing the cut surface of split leather for manufacturing, 592-594 patent and varnished leathers, 70 Japonica and other highly concen- trated tanning agents, effect of, on the leather, 482 Jeans' s method of determining tannic acid, 144 Jenkins's tanning process, 606, 607 Jenninos's artificial tanning material, 136, 137 method of tawing, 669-673 tawing process, theory of, 672, 673 Johnson's apparatus for the automatic distribution of fluids for leach- ing, 204-208 process for tanning light skins with the hair on, "620,'" 621 sprinkler for leaching, 205-208 Juglands regia, 119 Juncten, 70 Junior's method for manufacturing lace leather, 565-56 7 KANGAROO leather, 583 skins, leathers from, uses and where made, 45 Kathreiner on Jeanes's method of de- termining tannic acid, 144 on Lowenthal's method of deter- mining tannic acid, 157 on the tannic acid in tanning ma- terials, 158 Kathreiner's conclusions as to Lowen- thal's method of determining tannic acid, 159 directions for obtaining a correct sample of oak bark for ana- lysis, 160 Keeler's tanning process, 599 Kennedy's tanning process, 600, 601 Kester's experiments on the quantities of tannin of various kinds absorbed by skins, 126 Kid- and lamb-skins, assorting, 6 44 prices and qualities of, 644 brushed finishing, 532 Kid-skins for glove leather, 643 putrefaction of, 644, 645 Kidder's tanning process, 606 INDEX. 797 Kino, 114 Kips and skins, handling with Gor- sline's apparatus, 357 the skins of small or yearling cat- tle, 38 Kirkaldy, David, experiments of, with chrome leather, 62 Kirkaldy's experiments with chrome leather and tanned leather, 639 Klemni, tawing process invented by, 689 Klemm's leather, tests of, with boiling water, 695 oil leather, coloring, 694 preparation of, 693-697 strength of, 694 process for making oil leather, character of, 693 for oil leather, advantages of, 694 Prof. Fehling on, 695 tanning process for oil leather, 693-697 Knapp on the complete saturation of the skin tissue by alum, 132 on the experiments of Ludwig Kester on the quantities of tan- nin of various kinds absorbed by skins, 126 Knapp's attempts to reintroduce tan- ning with ferric salts, 135 experiments in obtaining leather solely with fatty substances, 364, 365 in I'egard to "I'otten," or "burned" leather, 677, 678 in regard to tanning and taw- ing, 660 fulling drum for tanning, 630-632 iron soap, 135 in tanning, 630 latest process of mineral tanning, 633 mineral tanned leather, charac- teristics of, 632, 633 process for tanning with ferric salts and other metallic ox- ides, 628 mineral constituents in leather tanned by, 8t of tanning 1877, new and peculiar features and ad- vantages claimed for, 632 of tanning with ferric salts, 1877, 629-633 Knapp's process — of tanning with salt solutions and soap baths, 695- 697 with stearine in spirit of wine, 697 processesfor mineral tanning, 1861 and 1877, 628, 629-633 Knife, unhairing, 304-306 Knives, curriers', 423, 424 patents for, 430 Knox's finishing and pebbling machine lor glassing and rolling brushed kid, 532 for Morocco, 464, 465 Kohler on determination of tannic acid, 144 Koppitz and Mayer's process of color- ing leather on starch surface, with an appearance similar to marble paper, 768, 769 Krameria triandra, 121 LAB AN AND JACOB, early herds- men, 34 Lace and whip leather, quick tanning process for, 567 leather, 563, 572 Junior's method of manufac- turing, 565-567 Loescher's method for manu- facturing, 567', 568 Lactantius on the reindeer clothing of the German tribes, 37 Lactic acid, 112 Lamb- and kid-skins, assorting, 644 prices and (qualities of, 644 and sheep, diseases of, effects of, on leather, 674, 675 Lamb-skins, Aikens's method of work- ing into glove leather, 664- 667 for glove .leather, 643, 644 of Asia Minor, France, and Italy, 42 treatment of, and uses, 41, 42 Watts' s method of makins into glove leather, 666 Lampblack, 69 Lampert's machine for workin<>" hides, 338-341 Larch bark, 118 798 INDEX. Larix Eurojicea, 118 Larrabee's unhairing machine, 314- 318 Laure's process of depilating with water in an open vessel, 286, 287 Lay-away vats for sole leather, 365 the liquor in, 367 Layers, number of, and period for each in laying-away, 366 Laying-away, 363-368 for finer grades of leather, 366, 367 green stock, 366 practical details, 365-368 Leach, regulating the volume of water or liquor run to the, 220 round, to find the capacity of, 212 the sprinkler, 203, 204 Leaches, conductors to the, 218, 219 false bottoms for, 211 filling ami running the, 219-226 flooring about the, 212 form of a supply tank for, 214 round, building,' 209-219 steady pressure for, to secure, 213 table showing the capacity of, 213 the kinds of, employed, 203-209 the size and capacity of, 224 Leaching and making extracts from tan-bark, patents for, 235, 236 apparatus, Johnson's, 204-208 finishing, 221 fluid, a liquor denser than water, inferior, 221 distribution of the, 220 old or weak liquors as a, 222 water as a, 221 of bark, importance of, 184 tan-bark, 203-236 the best method of, 203 the use of heat in, 221, 222 with little or no heat, 223 Lead chromate, 718, 719 nitrate, 714 sugar of, 716 Leather, a la garouille, 127, 129 alligator, "582-585 alum, 69 alumed, defects of, 673, 679 aluminium chloride used for in- creasing the weight of, 86 American, high rank of, 78 artificial, 72 tannins used for tanning, 137 ash in determination of the per- centage of, 82 Leather — average consumption of, among the populations of Europe much less than In the United States, 73 barium chloride used for increas- ing the weight of, 86 bark-tanned, effect of steeping in water, 62 behavior of, towards boiling water when not thoroughly tanned, 85 brought from Asia into Euro])e at an early day, 65 brown, for skivers, 749 light, 729 buff, 69 calf, ability of, to resist water, 88 carpets used in the time of Moses, 56, 57 chamois, 64 change in volume and ability of resisting water, 87-89 chemically considered, 63, 64 chestnut bark tanned, 127-129 chrome, effect of boiling in water, 62 effect of steejsing in cold water, 62 the effect of stuffing with fat or paraffine, 62 colored, antiquity of, 65 spoken of by Ezekiel, 56, 57 various places in which it has been manufactured, 66 coloring matter in a tannic acid may injure the appearance of, 113 with mineral pigments, 735, 736 commercial varieties of, 63, 64 Cordovan, 65, 66 currying establishments in tiie United States, 79 determination of means used to increase the weight of, 86 determination of the value and quality of, 81 dressing machine, Fitzhenry's, 398-401 dyeing, 698-758 enamelled, 69 evening or making of uniform thickness, patents for, 551 exjx'riments of Miintz and Schcin on the real value of, 127-129 INDEX. 799 Leather — exports and imports of, 7 7 extractive substances to the ex tent of 23 per cent, removed from hemlock-tanned, 127 fat and resin in, determination of, 81, 82 _ in determination of, 83 French or Erlanger, 642 fir-bark tanned, 12 7-129 Huffing and grounding machines, patents for, 550 for carriage tops, 70 for glovers and harness-makers' use, 64 foreign, the most famous, 65 free from resin, pounds of, ob- tained from 220 pounds of dry skin with different tanning ma- terials, 129 from alligator skins, qualities, uses, and where made, 44 from dog-skins, 43 from elephant-hides, 43 from hippopotamus-hides, 43 from hog-skins, 43 from horse-hides, 43 grape sugar used for increasing the weight of, 86 percentage of glue in, 128 hemlock, 127-129 hemlock and fir-bark give the best weight in tanning, 127 hemlock-bark tans two-thirds of American productions of, 118 horse-chestnut and oak-barks mixed for tanning, 120 Hungarian, 64 increase in the weight of skins by conversion into, 126, 127 increasing the weight of, determi- nation of the means used, 86 industry of the United States, ex- tent and importance of, 73 influence on, of tannic acid yield- ing pyrogallic acid, 113 its characteristic properties, 63 Japanned, 70 Kangaroo, 583 Knapp's method of employing ferric salts for tanning, 135 mineral tanned, characteris- tics of, 632, 633 lace, 563, 572 lime in, determination of, 82 Leather — liming too long gives poor weight and impairs the strength of, _ 98 list of the names applied to, in commerce, 71, 72 measuring machine of Williams, Moore, and Hurlburt, 469-473 Sawyer, 473-479 mineral constituents in, determi- nation of, 85 of, when tanned by Heinzerling's method, 85 of, when tanned by Knapp's method, 85 tanned, ability of, to resist water, 87-89 Mittenzweig's method of deter- mining the tannic acid in, 85 Mogador, 70 Morocco, 65, 66 produced at Mogador, 70 nitrogen in, determination of, 84 in, percentage of, 128 Norwegian glove, 119 not a chemical compound, 63 oak-bark tanned, 127, 128, 129 obtained by Knapp without tan- nin elements, 364, 365 oil, 70 parchment, 68 pathological and physiological tannic acids, influence exerted in the production of, 102 prepared with sumach, qualities of, 117 probably not a chemical combi- nation, 364 produced by the aid of picric acid, 138 quality of dependent upon the thickness, flexibility, and strength of the corium, 94 of, not improved by remain- ing a long time in the vats, 129 quebracho, 127, 128, 129 and chestnut bark used for tanning, 125 claimed to produce good, 122 raw materials employed in the production of, 93 resin and fat in, determination of, 81, 82 800 INDEX. Leather — resins may injure the (juality of, 113 resistance of, to breaking, 89 of, to tearing, 89 roan, 70 rock chestnut oak a valuable material in the United States for tanning, 119 russet, 70 Russia, 574-582 decadence of the use of, for bookbinding. 67 - saffian, 70 scourer and setting machine, Lockwood, S86-;>92 scouring machines, Deheney table for, 405-407 scraps and waste, process for making artificial leather im- pervious to moistui'e, 489, 490 shagreen, G5, 67 sides of, shown hung over poles in the drying-yards, 496 skin or corium, 93, 94 skiver, 70 soft for gloves, 642 sole, 481-491 ability of, to resist water. 88, 89 split, 70 splitting, 368-384 machine, McDonald and Beggs, 375-378 strength of, decreased by long liming, 98 of, in various parts of the skin, 91, 92 sumach-tanned, 64, 128 ^ generally used for tanning Morocco, 125 tan, ability of, to resist water, 88, 89 tanned, classed as hides, kips, and skins, 38 with chestnut bark and que- bracho, advantages claimed for, 129 with divi-divi, qualities of, 1 1 7 with oak bark after being- washed with ether and alcohol, 129 tannic acid in, determination of, 85 yielding pyrocatechin, influence of on, 113 Leather — tannin absorbed by each one pound of skin in the pro- duction of, 125-129 in, percentage of, 128 tanning substances in, determi- nation, 85 testing the strength of, 89-92 the art of varnishing, 59 "to draw from" the significa- tion of the old expressions, 58 to render the fibre more absorbent of chemical compounds and dyes, 552, 553 twisted, 689 used at an early date bj' the Israelites to write upon, 56 used by the Greeks in the con- struction of ships, 57 varieties of, tanned with sumach, 116 vegetable, 72 walnut bark produces a soft variety of, 119 wash, 71 water in, determination of, 82 weight of, decreased by long lim- ing, 98 Weiner's device for testing the strength of, 89 whang, 71 white, 71 whitening and buffing machine, 428, 429 machine, Clements's, 424- 428 willow bark used for tanning Russia, 121 used for tanning Swed- ish glove, 121 Leatherette, 581 Leathers, assorting for dyeing, 726- 728 examination of, 81-92 tanned with tan-bark and with the gall-nut, comparative behavior, 365 Lee's patent, artificial tannino; material of, 137 Lemon color, 733 Liebig on the action of potash on tan- nin, 107 on the transformation of tannin into gallic acid, 106 Light brown, 733 INDEX. 801 Light brown — and darker colors on leather with oxalic acid, salt of tin, etc., 767, 768 leather-brown, 729 leathers sold by measure, 468 not a simple body, 698 olive-green, 733 what it results from, 698 Lilac, 724 Lime and orpiment as a depilatory, 275 and sulphur action of in depilat- ing, 283 blood, and water for depilating, 284-286 gas as a depilatorj'-, 27,') hydrosulphate of, depilation with, 288 of, preparation of, 288-290 inconveniences of using for depi- lating, 2G 1-263 in leather, determination of, 82 liquor and sulphuric acid for bat- ing, 344 necessary for a vat, 265 orpiment and potash as a depila- tory, 288 pits, 264 use of, with upper leather, 492 vats, construction of, 265 in Morocco factory, 525 "live" and "dead," 266 series of, 266 water, 710 and suljihurous acid as a de- pilatory, 278 Limes, 710, 711 how long the goat-skins, glove calf, and glove sheep, remain in, 526 the practice of the use of old, hazardous, 266 treating the hides in the, 2G4-266 Liming and depilating for glove leather, 648, 649 duration of, 266 for chamois leather, 681 hides. Study's contrivance for, 357 too long gives poor weight, 98 process, 261-269 Linings, artificial sheep-skins for, 561, 563 Linseed oil, boiled, 69 51 Lippowitz on precipitation in deter- mining tannic acid, 143 Liquid for curing hides, composed of pyroligneous acid, aloes, and alum, 52, 53 Liquors, concentrating, 222 going into the leaches to be strained, 213, 214 in the lay-away vat, 367 List of compounds and materials for tanning and for tawing leather and for preparing raw hides, especially claimed or mentioned in any patent, 616-619 of patents for apparatuses for blacking leather, 449 for apparatus for stretching leathers, 596 for bark mills, 195-197 for bark-rossing machines, 182 for blacking compounds for leather, 451-453 for breaking hides, 261 for compounds for bating hides and skins, 351 for cm-rying leather, 420 for depilating hides and skins, 302, 303 for polishing and color- ing leather, 775 for stuffing leather, 420 for curriers' knives, 430 slickers, 430 for employing mineral sub- stances for tawing hides and skins, 641 for hide mills, 260 for leather splitting machines, 383, 384 for machines for boarding and graining leather, 439, 440 for evening or making leather of uniform thickness, 551 for measuring the areas of hides, skins, and leather, 480 for pebbling leather, 467 for removing grease from leather, 422 for rolling leather, 467, 468 for sharpening curriers' knives, 430 802 INDEX. List of patents for machines — for stoning, polishing, finishing, glassing, glazing, tlinting, creasing, and dicing leather, 465-467 for whitening, buffing, and shaving leather, 430 for methods and machines for packing tan-bark for transportation, 183 for manufacturing enam- elled, japanned, and patent leathers, 595, 596 for preserving hides, 54 for processes and apparatuses for leaching and mak- ing extracts from tan- bark, 235, 236 employing apparatus for tanning leather, 614- 616 for tanning leather, 609- 614 for putting out machines and leather tiuffing and ground- ing machines, 550 for scouring and setting machines, 407, 408 for softening hides, 246 for tanners' vats, agitators, and handling appliances, 358, 359 for unhairing and fleshing machine, 333-335 Litmus paper, its use for detecting fraudulent increase in the weight of hides, 49 Live oak, 122 Lixiviation, how commonly conducted, 203 Lockwood, automatic leather scourer and setting machine, 386-392 designs of, in his later scourer and setting machine, 391, 392 Loescher's metliod for manufacturing lace leather, 567, 568 Loft of a Morocco i'actory, showing the skins spread on the floor, 532 Logwood, 118 solution, saturation of leather with, 553 Lombardy poplar bark, 119 Loom and the distaff, early use of, 36 Lot and Abraham, rich in cattle, sil- ver, and gold, 34 Lowenthal's method of determining tannic acid, modified by Neu- bauer, 154-163 mode of determining the tannic acids in bark, 163 Lucas aniline black, 745 Luray, Virginia, details of the process of manufacturing oak slaughter leather at, 483-486 Lustre, giving leather, after dyeing, 725 on dyed oil leather, 738 on harness leather dyed with ani- line colors, 758 Lye from wood ashes or potash and lime, which has been treated by the gas generated by sulphuric acid, sulphuret of iron and water for unhairing hides and skins and jell- ing wool, 278-281 J^ynds's depilatory, 276 Lynn, Mass., large quantities of Mo- rocco produced in, 66 MAcBRIDE, DR., 58 discovery of 1774 in regard to hydrochloric acid, 336 the discovery of the use of sul- phuric acid for plumping, b}', 597 MacBride's discovery of plumping by means of sulphuric acid, 361-363 of the process of raising with diluted sulphuric acid, 5S McDonald and Begg's leather sj^litting machine, 375-378 McDonald's improvement in feed rolls for unhairing machines, 325-327 unhairing machines, 322-327 McKenzie's evaporator, 230 McMurtrie's compound, 346 Machine belt leather greased with tal- low, 522, 523 belts, crown leather for, 692 for removing grease from leather, 421, 422 for smutting leather, Bryant's, 447-449 Machinery in tanning processes, the general introduction of, 493 Machines ibr boarding and graining leather, patents for, 439, 440 INDEX, 803 Machines — for evening or making leather of uniform thickness, patents for, 551 for glassing or polishing, peb- bling, finishing, rolling leather, etc., 453-468" for measuring leather, 468-480 the area of hides, skins, and leather, patents for, 480 for rolling leather, patents for, 467, 468 for stoning, polishing, finishing, glassing, glazing, Hinting, creas- ing, and dicing leather, 465-467 for wliitening, bufhng, and shav- ing leather, patents for, 430 Madder red upon oil leathers, 737, 738 Magenta, 743, 744 Maine, tanning interest in, 75, 76 the bark obtained from, 494 Main's process of finisliing alumed leather, 667, 668 Malabar or East Indian kino, 114 Malpighi's net, 94, 95 Mammalia, skins of the, 36 Mammiferous animals, uses of, to man, 39 Mamre, the plain of, 35 Manasse's method for tawing sheep- skins, 558, 559 Manganese, 53 alum, 132 dioxide in tanning, 627 peroxide of, 107 Manganous sulphate, 131 Marine salt, 108 Maroon, black, and purple colors, im- parting to raw hides, 759, 760 Manjuis's method of examination of leather, 81 Martin's machine for glassing and finishincf leather, 454-458 Martin's yellow, 747 yellow on Morocco, 757 Martyn's black compound for leather, 758 composition for polishing, water- proofing, and coloring leather, 771, 77^2 Mason's building for sweating hides and skins, 293-295 Massachusetts, bark bought by the cord in, 494 currying business in, 79 tanning interest in, 75, 76 Materials and compounds for tanning and tawing leather, and lor prepar- ing raw hides, especially claimed or mentioned in any patent, 616-619 Mats made from sheep-skins tanned with the wool on, 42 Mauve, 743 Maynard's bating process, 346-349 depilatory of lime-water and sul- phurous acid, 278 May's compound for changing the color of leather, 773, 774 Means used to increase the weight of leather, determination of, 86 Measure, the, for a leather dyer what scales and weights are for the chemist, 702 Measuring leather, machines for, 468- 480 machine for leather. Winter's, 468, 469 of Williams, Moore, and Hurlburt, 469-473 Sawyer, 475-479 Winter's, 468, 469 machines invented in the United States, 468 the areas of hides, skins, and leather, 480 Mechanical work of dyeing alumed leather, and directions for preparing and applying vegetable dyes, 72]- 732 Merrill & Hoitt's process for prepar- ing raw hides, and imparting black, maroon, and purple, colors to them, 759-761 Merrill's process for boarding jDatent leather, 592 Merritt's process for producing japanned leather in imitation of alligator skin, 594, 595 Mesquite oak, 122 Metagallic acid, 1|)5, 106 Metallic oxides in tanning, 627 salts for preparing leather for mar- ket, 552 soap, 53 Knapp's process of tanning with, 628 Methods for determining the constitu- ents of water, 169-173 Methyl, alcohol, 53 green on Morocco, 756 violets on Morocco, 757 Methylene blue O, for skivers, 748 804 INDEX. Mexico, goat-skins of, 42, 43 Middleton's hide-mill, 258-260 Mi-fonce brown, 730 Mill for softening hides and for fulling cloth, described and illustrated, 256-258 Mills, hide, 250-260 Mimosa, 122 ■where used for tanning, 125 Mineral acids, depilating with, 265 and artificially prepared tanning substances, 130-138 constituents of leather, determi- nation of, 85, 86 kingdom, 35 pigment, 735, 736 substances for tawing hides and skins, patents for, 641 tan, Lee's, 137 tanned leather by Knapp's pro- cess, characteristics of, 632, 633 Heinzerling's, ability for resisting -water, 87- 89 tanning, 626-641 chromium alum the most important salt used in, 134 materials, 130-136 processes which have been abandoned, 629 •what is understood by, 626 Mittenzwei and Terriel's method of determining tannic acid, 147-150 Mixed brown, 734 Modified color, 701 Mogador leather, 70 Mohr's process for exhausting gall- nuts, 104 Molac and Triedel's process for tan- ning with ferric salts, 627 Monier, use of potassium ferrocyanide solution for precipitating tannic acid, 154 Montevideo, quality of the hides from, 40 Mordant for glazed leather, 726 used in Russia in dyeing Russia leather, 576, 578 Mordanting leathers for aniline colors, 740, 741 Russia leather, 577, 578 Mordants, 705-721 what they are, 705 when necessary with aniline colors, 740 Moret's composition for impregnating hides and skins, and preserving them in condition to be unhaired by im- mersion in water, 50-52 Morintannic acid, 101 Morocco and Russia leathers, dyeing with aniline colors, 754-758 boarding and graining, machine for, 4'38, 439 factory, drying loft of a, showing the skins hung up, 530 lime vats in a, 525 loft of a, showing the skins spread on the iioor, 532 view in a, 525 view of the tan tubs in a, 527 finishing and pebbling machine, Knox's, 464, 465 glazing machines,* 462-465 hand method of tanning, 541, 542 leather, 65, 66 classification of, 524 compounds for producing, 551-555 produced at Mogador, 70 sumach genei'ally used for tanning, 1 25 superseding Russia leather for bookbinding in j)ublic libraries, 67, 68 uses of, 524 what is understood by, 524 leathers, 524-555 the skins from which they are produced, 524 manufacture, decline of, in Russia, 66 in the United States, 66 manufacturers, AValters's fulling cup for, 539-541 process for finishing lower grades similar to, 552-555 putting-out machines for, 545-551 tannery, skins removed from the lime vats, 525 tanning in a combined wheel and "vat, 542-545 preparing the skins for, 525- 527 ware, water- proof, 535 ]\loru!> tinctoria, 118 Mosser's safety coupling for bark mill, 186-188 Mother liquors for glazed leather, 729 Moths, destruction of, 645, 646 injury of skins by, 645-647, 675 INDEX. 805 Mower's depilatory process, 278-281 Mullen's bating process, 349 Munfez and Rampercher's apparatus for filtering tanning licjuor foi- the purpose of determining tan- nic acid, 140 and Sclion, experiments of, re- garding the absorption of different tannins by the skin, 127, 128 on leather tanned with oak bark after being washed with ether and alcohol, 129 on tanning with quebracho, 122 and Schon's opinion that leather is a solid combination, 127 that the percentage of tannin in pure leather is a test of the quality of the leather, 127 on the determination of nitrogen in leather, 84 Muriate of ammonia, 336 bating with, 341, 343 of soda, super-tartrate of potassa, and tartaric acid as a bating compound, 342, 343 Muriatic acid and burnt oolite, 284 Myrobalan used in Europe as an addition to oak bark in tanning, 118 Myrobalans, 117, 118 NAMES applied to leather in com- merce, list of, 71, 7 2 Nankeen browns for skivers, 754 Nankin color, 724 yellow, 734 Naphthaline colors, 747 Naphtharazine, 747 Naphthol yellow L for skivers, 749 Naphtyl blue, 747 Naphthylamine red, 747 violet, 744 Napier's process for preserving hides and skins, 53 Nature, empire of, divided into three kingdoms, 35 Neubauer on Wagner's method of de- termining tannic acid, 53 Neubauer's modification of Lowen- thal's method of determining tannic acid, 154-1G3 Neubauer's — treatment of a sample of oak bark, 160, 161 Neutral alkaline chromates, 134 Newark, N. J., manufacture of enam- elled leather in, 70 Morocco industry in, 66 production of Russia leather in, 6 7 New Jersey, tanning interest in, 75, 76 New York, tanning interest in, 75, 76 Nitrate, 714 of potassa in soaking hides and skins, 239 of silver as a test for chloride, 86 Nitric acid, 107, 707 decomposition of, 707 its use for acidulating in test- ing for barium salt, 86 its use in determining the percentage of lime In leather, 83 use of, in preparing artificial tannin, 136, 137 Nltroo-en in leather, determination of, "84, 85 percentage of, in leather, 1 28 Noble's tanning process, 601, 602 Norwegian glove leather, elm bark in the manufacture of, 119 AK AND HEMLOCK BARKS, general use of, in the United States, 598 the astringent principle of, the same, 481, 482 bark and myrobalan used together in Europe for tanning, 118 chemical examination of, 1 59- 163 consumed in tanning in the United States, 75 substances In the inside layer of, 139 to obtain a correct sample of, for analysis, 160 where used for tanning, 125 barks, 119 slaughter leather, made at Luray, Virginia, 483-486 varieties of, 482 sole leather tanning and finish- ing, 483-486 tanned leather generally of the choice hides, 481 806 index: Oak— taiuied sole leather, reasons for commanding a higher price, 481 Texas hide leather, varieties of, 4S2 wood, tannin obtainedfrom, 122 Oaks of different ages, tannic acid yielded by, 112, 113 Obsolete depilatory methods, 300- 302 Ochre, 69 Oil, fiiUing chamois leather in, 682- 68 S"" goat finishing, 535 leather, 70 colored black for shoemaker's purposes, 689 Klemm's preparation of, 693- 697 to restore softness to dyed, 739 of vitriol, 706 of vitriol, salt, and bran, bating with, 344, 340 ' or chamois leather, dyed by dip- ping, 736 dyeing with aniline co- lors, 741 manufacture of, 679-689 uses of, 679 Olive, 730 brown, 733 green, 724 greens, 733 oil for tanning, 655 Oliver and Howell's machine for stretching leather, 588, 589 Oolite and muriatic acid for depilating, 284 Orange, 734 B R for skivers, 751 fat color on straps, 758 on Morocco, 756 tones or the redder shade on Mo- rocco, 757 Orceine B for skivers, 750, 751 Organic acid for bating, 336 Oriental ancient tanning, 65 Ornamenting and gilding leather for suspender ends, 765 Orpiment, lime, and potash, as a de- pilatory, 288 Osmic acid, 107 Osmium, oxide of, 107 Overhead ijlazing machine for Mo- rocco, 4 64 Ox, the uses of, to man, 39 Oxalic acid, 82, 107, 708 preparation of solution of, 155 Oxides in tanning, metallic, 627 Oxychloride of phosphorus, 108 PACKING tan-bark for transporta- tion, methods and machines for, 183 Page's tanning process, 602 Painting, dyeing by, 724-732 Pallas, the traveller on the production of shagreen leather, 67 Pangue, 122 Parchment, artificial, 68, 69 dyeing with aniline colors, 741 history, uses, and principal places of production, 68, 69 the purposes for which it is used, 69 vii-gin, 68 whence the name is derived, 68 Parenchjma in bark, 175 Parisian violet, 741 Parkins' s bating compound, 343, 344 Part cured hides, 55 Pastes, tawing for olove leather, 653- 661 " " Patent enamelledand japanned leather, patents for, 595, 596 japanned or enamelled leather, 585-596 leather, boarding, 592 degrees of heat for drying, 590 drying, 590 ground laying mixture for, 590 hides used for, 583 pumicing the surface of, 591 substitute for, 595 tanning material used for hides, intended for, 585, 586 treatment of the hides for, 580-592 varnish for, 592 A^arnishing, 592 system of the United States, 54 Patents, compounds, and materials for tanning and tawing leather, and for preparing raw hides, especially claimed or aientioned in any, 616- 619 INDEX. 807 Patents — for apparatuses for blacking leather, 449 for stretching leather, 596 for bark-rossing machines, 182 for bark mills,^195-197 for blacking compounds for lea- ther, 451-453 for compounds for bating hides and skins, 357 for coloring and polishing leather, 7 75 for currying leather, 420 for depilating hides and skins, 302, 303 for stuffing leather, 420 for curi-iers' knives, 430 slickers, 430 for employing mineral substances for tawing hides and skins, 641 for leather splitting machines, 383, 384 for machines for boarding and graining leather, 439, 440 for evening or making leather of uniform thickness, 557 for measuring the areas of hides, skins, and leather, 480 for pebbling leather, 467 for rolling leather, 467, 468 for sharpening curriers' knives, 430 for stoning, polishing, finishing, glassing, glaz- ing, flinting, creasing, and dicing leather, 465- 467 for whitening, buffing, and shaving leather, 430 for methods and machines for packing tan bark for trans- portation, 183 for manufacturing enamelled, japanned, and patent leathers, 595, 596 for preserving hides, list of, 54 for processes and apparatuses for leaching and making ex- tracts from tan-bark, 235, 236 employing apparatuses for tanning leather, 614-616 for tanning leather, 609-614 Patents — for putting out machines and leather fluffing and grounding machines, 550 for scouring and setting machines, 407, 408' for tanners' vats, agitators, and handling appliances, 358, 359 for unhairing and fleshing ma- chines, 333-335 I Pathological tannic acids, 102 Patterson's process for forming an artificial grain on the hide after it has been buffed or split by a machine, 593, 594 Payen's experiments in the distillation of birch oil, 580 Peabody, Mass., the upper leather pi-oduced in, 493 Peach color, 724 Pearl ash, 718 Peat, tannin from, 138 Pebble and grain leathers, handling the sides for, 357 grain goat finishing, 535 Pebbling and finishing machine, Knox's, 464, 465 leather, patents for machines for, 467 polishing, glassing, finishing, roll- ing leather, etc., machines for, 453-468 Pectic acid, 113 exerts no influence upon a so- lution of potassium manga- nate, 162 Pectine, 113 Peeling the bark, and the most con- venient time for doing it, 176, 1 77 Pelouze's process for the extraction of gallotannic acid, 103 Peltries, processes for softening, 243- 246 Pennsylvania, bark from, 494 taiming interest in, 75, 7 6 Perkins's machine for removing grease from leather, 420, 421 violet, 741 Permanganate of potash solutions, re- duced by tannin, 107 Persoz's method of analyzing tanning materials, 141, 142 process for coloring black with aniline, 745 Peschir, on the tannin of ratanhy root, 121 808 INDEX. Pfanhanser's process for tanning with a basic ferric sulphate, 628 Phenol brown, 747, 748 colors, 746 red, 746 Philadelphia, Pa., importiance of the raoroeco industry in, 66 production of Russia leather in, 67 Phillips's process of bleaching hemlock tanned and union tanned leather, 488, 489 Phloroglucin, 112 Phoenicians, leather ships of, 57 Phosphine-orange on morocco, 755, 757 Phosphoric acid, 105 for bating, 336 of glue factories, for bating, 349 Phosphorus, oxychloride of, 108 Phyllocitannic acid, 120 Physical means to test leather, 86-92 Physics, 714 Physiological tannic acids, 102 Pickard's tanning process, 605 Pickhardt & Kuttroff, aniline colors of, 748 Picnometer, 144 Picric acid, formula of, and mode of production, 138 skin conA'erted into leather, by, 138 green, 733 Pimicia granatum, 122 Pingree's process for tanning hides with the hair on, 620 " Pin mill" for Morocco tanning, 525 Pinu.t abies, 118 halepensis, 12,1 Platinum chlorine, 84 Platoso-ammonium chloride, 84 Plumbic acetate, 7 1 6 Plumer and Kernan's process for re- moving extractive matter from tanned leather, 503, 504 Plumping and depilating hides and skins, 282, 283 applied only to the heavier classes of hides, 360 by means of sulphuric acid, 361- 363 hides, MacBride's discovery of the use of sulphuric acid for, 58 or swelling, 359-363 the essential action of, 359 Plumping — two processes of, 360 with sulphuric acid, precautions to be taken in, 362 Polish for leather, used for bags, satchels, etc., 772, 773 to leather, a base for, 771 Polishing and coloring leather, com- pounds for, 755- 775 patents for, 775 glassing, pebbling, finishing, roll- ino; leather, etc., machines for, 4.53-468 glove leather, 661-663 with tlat-irons, 663 machines, patents for, 465-467 water-prooiing, and coloring leather, composition for, 7 71, 7 72 Pollock's process of making artificial sole leather, 489-491 Porpoise skin, 44 Potash, 717, 718 acetate of, 105 alum, 131, 713 principally used in tawing and in mineral tanning, 132 American, 51 bichromate of, 107 lye, its use in determining the per- centage of fat in leather, 83 lime and orpiment as a depilatory, 288 Potassa, 70 Potassium bichromate, 133, 718 characteristics and qualities of, 133, 134 for tanning, 628, 629 withdrawn from different samples of chrome-tanned leather by the action of water, 636-640 bi tartrate, 717 carbonate, 717, 718 chloride of, 61, 62 ferriccyanide, 719, 720 ferrocyanide, 719 hydrate, 709, 710 manganate, solution of, prepara- tion of, 155 Preller's H B crown leather, 691- 693 leathej', weight of, 691 method, manufacture of horse leather by, 693 INDEX. 809 Prellev's method — of tawino;, 689-693 time required for, 692 process, why it hns not been more generally adopted, 693 Preparation of the hides for heavy iippei- leather, 494, 495 Preparing, coloring, and polishing light skins for car seats, trunk covers, etc., 770 tan-bark for use, 197-200 the cut surface of split leather for manufacturing japanned or enamelled leather, 592-594 Preserving hides, 49-55 hides and skins, Moret's compo- sition for, 50-52 Napier's -process for, 53 Sabathe and Jourdan's process for preserving, 53 Wickersheimer's pro- cess, 53, 54 list of patents for, 54 Rock's process, 52 Primary colors, modifications which these colors are capable of under- going, 700 Primicive colors, 699 Prism, the, 698, 699 Principles and facts in the sciences and arts, 56 Process for finishing lower grades of leather, similar to Morocco, 552-555 for plumping before depilating, and the treatment of hides or skins, with an acid solution before liming for the removal of salt or other matter, 246-250 for preparing tan-bark for use, 197-200 for preserving hides and skins, Sacc's, 53 and compounds for depilating hides and skins, 261-303 Processes employing apparatus for tanning leather, patents for, 614-616 for softening hides, skins, and peltries, 243-246 for tanning leather, patents for, 609-614 for water- proofing, dubbing, and whitening upper leather, 504- 507 Proctor's upper leather tannery, a view of the cellar of, 368, 369 Proprionic acid, 112 Protacete barks, 121 the tannins of, 121 Protea conocarpa, 121 Protocatechuc acid, 112, 120 Proust, 58 Prussiate of potash, yellow, 719 Fterocai'pus, erinaceus, and mar- snpium, 114 Pultz's process of aluminium tannino-, 641 Pumicing the surface of patent leather, 591 Purifying extracts of bark, 227-231 Purple, black, and maroon colors im- parting to raw hides, 759, 760 Putnam's composition for finishing split leather, 451 Putrid soaking, 312 Putting out goat- and sheep-skins, 545 machine, 545, 546 machine, Hoffman, 545-550 machines for Morocco, 545- 551 machines, patents for, 550 Pyrocatechi n ,113 Pyrogallic acid, 105, 113 glucoside, 109 Pyroligneous acid, 52, 708 QUALITATIVE examinations of water, 169 Quebracho, 122 and chestnut bark, tanning with, 129 used for tanning in England, etc., 125 where used in tanning, 125 Qu ere i tannic acid, 101 Quercitron yellow, 734 Quercotannic acid, cpuilities, compo- sition, and formula of, 110, 111 Quercus ac/ilops, 117 bitter or quercin, 111 infectoria, 115 vioniicnUi, 119 pedunculta, 115 red. 111, 112 tinctoria, 119 tirens, 122 Querphlobaphene, 112 Quick tanning process for lace and whip leather, 567 810 INDEX. Quick tanning — Seguin's system of, 58 Q.uinland's compound for imparting a lustrous black gloss to leather, 764 Quinotannic acid, 101 RABE on the formula of the tannin in ratanhy root, 121,122 Rady's process for water-proofing, dubbing, and whitening upper leather, and giving the leather a " satin finish," 504, 505 Raising by sour tan-liquor, 301, 302 by yeast, 302 the hides, 2G3 with barley, 300 with sulphuric acid, MacBride's discovery of, 58 Ratanhy red, 122 root, 121 Raw materials of the tanner, 93 Raw skins for Erlanger leather, the kind required, and the modes of buying and preserving, 643-647 Realgar, 51 Receipts for various vegetable colors and for coloring leather with mine- ral pigments, 732-736 Red ulazarine, 735 aniline, 743, 744 for skivers, 752 madder, on oil leather, 737, 738 oak bark, 119 prussiate of potash, 719, 720 Reddish shades with, aniline, 756 Reds, 734, 735 Reel for handling in the lime vats, 266 hand for handling hides, 352, 353 Reimer and RoUet on the intercellular substance in skin, 97 on the formula of coriin, 84, 85 on the matter extracted from skin, 99 Reinsch on the tannin in tormentil root, 122 Removing extractive matter from tanned leather, 503, 504 Renewing the surface of japanned leather, 592 Reseda luleola, 118 Resin and fat in leather, determina- tion of, 81, 82 Resinous gums and floating particles, removing from bark extract, 227 substances in tannin, effect of, 127 Resins and camphor tannins from, 138 pectine substances but little studied by chemists, 113 Rete Malpighianum, 94, 95 Reusch in regard to the strength of Klemra's oil leather, 694 Rhinoceros, 45 Rhus species, 116 Richardson, Alpha, first splitting ma- chine patented by, 1831, 369 Richardson's union splitting machine, " 369-371 Richter's process for forming a solu- tion for tawed leather, 769, 770 Rinsing and soaking for glove leather, 648 Rio Grande, quality of hides from, 41 Roan, 70 Roberts and Lenox's fleshing, slat- ing, and striking-out machine, 332, 333 Robinson's depilatory process, 269 tanning process, 603, 604 Robiquet and Boutron's apparatus, use of, in extracting gallotannic acid, 103, 104 Rochleder and Kawalier on tannopinic acid, 109, 110 on the action of alkalies on tannin, 107 on the treatment of tannin Avith hydrochloric acid, 107 on the tannic; acid in the horse chestnut, 120 Rock oak bark, 1 1 9 Rocker handles for handling hides, 353 Rock's liquid for curing hides, com- posed of pyroligneous acid, aloes, and alum, 52, 53 Rollers for polishing glove leather, 661-668 Rollet and Reimer on the intercellular substance in skin. 97 Rolling leather, machines for, 453-468 patents for machines for, 467, 468 machine for rolling sole leather, 485, 486 Roots, tannin of, 121, 122 Rosaniline, 743 blue, 742 green, 742 . violet, 741, 742 Rose, Bengal, for skivers, 753 color, 724 pink for skivers, 750 INDEX. 811 Roseine, 743 Rossing bark, 181, 182 machines, patents for, 182 of bark before and after shipping, 181, 182 "Rotten" or "burned" leather, 677 Rove, 115, 116 Rubine, 743 Riiemelin's tan vat, 607, 608 Rufitannic or tannoxylic acid produc- tion, composition and formula of, 110 Running water, soaking dry hides in, 243 Russet, 70 Russia and Morocco leathers, dyeing with aniline colors, 754-758 consumption of hides and skins in, 66 decline of Morocco manufacture in, 66 exports calf-skins to Germany and France, 41 leather, 574-582 artificial, 581, 582 at the centennial exhibition, 575 black, coloring, 578 coating with gum tragacanth solution, 578 dye for, 576 dyeing, 576-578 hides used in the manufac- ture, 575 imparting the odor of, to arti- ficial leather, 582 its (]ualities and places of pro- duction, 67, 68 mordant used in Russia in dyeing, 576-578 name and origin, 574 not now much used in public libraries in the United States for bookbinding, 67 odor of, produced by birch bark, 755 similar to, imparted by Lombardy poplar bark , 119 period of tanning, shortening the, 576 process of manufacture as practised in the United States, 575-578 red G light aniline dye, 755 R dark aniline dye, 755 Russia leather, red — G R medium aniline dye, 755 uses of, 574 willow bark used for tan- ning, 121 oil, manufacture of, 578-581 tanning in, 66 wealth of, in fur-bearing animals, G6, 67 Rust yellow, 734 Rutea, 114 formosa, 114 SABATHE and Jourdan's process for preserving hides and skins, 53 Saccharine substances, use of, in bat- ing, 346 Sacc's process for preserving hides and skins, 53 Safhan leather, 70 St. Crispin, who stole leather to make shoes for the poor, 58 St. Real, 58 Sal ammoniac, 714 its use in determining the percentage of lime in leather, 83 Salem, Mass., the upper leather pro- duced in, 493 "Salem tan press," 508-511 Weston's, 508-511 Salicylic acid for preserving hides, 50 Saiix alba, 1 20 arenaria, 120 fragilis, 120 purpura, 120 Salt, common, 135, 136 for tawing, 654 the most simple and cheapest means of preserving hides, 50 use of, in separating coriin, 97, 99 use of, in sweating fresh hides, 299 used for tawing, 64 Salted calf-skins, liming, 264, 265 hides, softening, 241 treatment of, 242 Salting hides, 49, 50 Delane's method of, 49, 50 Saltpetre, 53 in tanning, 239 use of, in soaking hides and skins, 239, 240 Salts, 711 chromium, 133, 134 812 INDEX. Salts- ferric, 135 Salzburg vitriol, 712 Salzer's test of Schulze's .method of determinino; tannic acid, 14G Sap green, 734 Sassafras root, 122 Satin finish on leather, 504 Saturation of skin, moment of, accord- ing to Muntz and Schon, 129 Saw-tooth flesher for dry hides, 309 Sawyer's leather measuring machine, 473-479 Scarlet, 735 No, 2, for skivers, 754 Schlosser's composition for depilating green and dry hides, 272, 273 Schmidt's description of Aikens's method of working lamb- skins into glove leather, (i64-<]6G of Watts' s method<)f working the skins of lambs, goats, and dogs into glove leather, 6G6, 667 Schrilf's investigation in regard to gallotannic acid, 1 08 Schulze's Investigations in regard to the tannic acid yielded by oaks of different ages, 112, 113 Schulze's method of determining tan- nic acid, 145-147 Science and the art of tanning, 59, 60 S(!orza rosa, 121 Scourer and setting machine, Lock- wood, 386-392 use of. In Massachusetts, 388 Scouring, 385-407 after bating, 337 and setting machines, patents for, 407, 408 brush, 385 by hand, 385, 386 dressing, setting -out machines, Burd'on, 401-405 machine parts. Holmes, 396, 397 setting, and hide-working ma- chine, the Holmes, 392-398 slicker, 337, 338 table, 386 upper leather, 337 Scraping and stretching upon the grain side for cliomois leather, 681 Sea green, 723 Seal-skins, 43, 44 Seasoning straight grain goat, 533 Seasons and place at the time of bark- ing. Influence of, on the richness in tannin, 177 Sebaceous glands, 95 Sebacic acids, how determined In de- termining the percentage of fat In leather, 84 Seguin, 58 Seguin's system of quick tanning, 58 Selecting hides and skins, 47, 48 Setting and scouring machines, pa- "tents for, 407,^408 scouring, and hide-working ma- chine, the Holmes, 392-398 machine and scourer, Lockwood, 386-392 out, scouring, and dressing ma- chine, Burdon's, 401-405 Sewlno- goat- skins for tanning, 527 machine for sewing goat-skins, 527 " Shades," 703, 704 "Shading" a defect In leather, 676, 677 Shagreen leather, 65 qualities and places of jwoductlon of, 67 Shark-skins, 45 Shaving, whitening, and buffing leather, patents for machines for, 430 Shaw's compound for finishing upper leather, 450 Sheep, Importance of, as sources of leather, 42 skin fleshers' dressing. Hart's pro- cess, 557, 558 for linings, binders, and skivers, 555-558 treatment of, 556 tannery, drying loft of, show- ing the skins hung up to dry, 556 exterior perspective view of, showing the slat openings Into the dry- ing loft, 556 finishing department of, 557 skins, artificial, for linings, 561, 563 dressing, Hestal's process for, 550,'561 dyeing the wool on, 624-626 Heshers, splitting, 556 for linings, binders, and ski- vers, where the American supply is obtained, 555 INDEX. 813 Sheep-skins — Hibbard's process for pre- paring and tanning, 559, 560 improved method for tanning and dressing, 558-561 in boots and shoes, large con- sumption of, in Massachu- setts, 555 in chrome tanning do not re- quire to be ireed from olea- ginous constituents, 62 manufacture of, into linings, bindings, and skivers, im- portance of, 555 removal of, from the vats and draining, 556 rolling, glassing, and pebbling by machinery, 557 sometimes employed for man- ufacturing Morocco leather, 41 tanned and finished by the employment of chromium compounds are not porous, 62 tanned and oiled, 41 with chromium com- pounds, 61, 62 with the wool on, 42 tanning and finishing, 655- 563 materials and processes for, 556 tawing, Manasses's method for, 558, 559 their mode of treatment and uses, 42 used by the ancient lonians and Persians to write upon, 57 uses of, 41 worked up as skiver, roan, and Morocco, 42 the home supply, 42 valuable for the purposes of the tanner, in inverse proportion to their value as a source of wool, 42 Ships of leather, use by the Phoeni- cians, 57 "Side" and "split," tanning and finishing the, 492-503 Sicilian sumach, 116 Siebel's use of refuse gas lime, 295 Silica in gramineous plants, 175 . Silica — in the epidermis of the bamboo, sugar-cane, and the bog-weed, 175 Skin, a transverse section of, 94, 95 animal, 93-100 animal, construction of, 93 connective-tissue fibres of, 96 difference in the c[uantity of tan- nins absorbed by the, 125 " Skin dressed," descriptive of the savage in early times, 37 Skin fibre, important properties of, 100 fibroin, 99 flesh side of, 94 for Morocco tanning, preparation of, 525-527 "grain side" of, 94 influence of, on the quality of leather, 94 intercellular substance in, 97 moment of saturation of, for tan- ning, 129 structure of, and its behavior with reagents, 93 table of the strength of, in differ- ent places, 91 tables showing the quantity of tannin absorbed by, 125-129 the chemical and morphological constitution of, 96, 97 use of, in determining tannic acid, 140 Skins and hides, 33-55 coloring partially tanned, 773 consumed in the United States, 75 important points in flaying, 46 preserving them, 50-52 removing from animals, 45- 47 selection, 47, 48 washing and soaking, 237- 243 Wickersheimer's process for preserving, 53, 54 with the hair on. Carter and Keith's process for tanning, 621, 622 and peltries, processes for soften- ing, 243-246 artificial tannins used for tannine, 137 ^ class of, to which tawing is ap- plied, 64 814 INDEX. Skins — cleaning before dyeing, 721 decompose if moist, 96 do not absorb an unlimited amount of tannin, 129 for glove calf, and glove sheep, whence obtained, 525 for glcve leather, manner of work- ing, 647 influence of hard water on, 98 light, for car seats, etc., prepar- ing, coloring, and polishing, 770 tanning with the hair on, Johnson's process, 620, 621 numbers of, consumed in Russia, 66 obtained by crossing of he goats and ewes, 644 of animals, used as apparel of the people, 36, 3 7 of interest in connection with the leather manufacture, 36 of the mammalia class of animals, 36 of young animals, necessity of handling carefully, 675 or hides with the wool, hair, or fur on, Coe's process for tan- ning, 621 those of calves, sheep, goats, deer, pigs, seals, etc., 39 with hair and fur on, tanning and coloring, 620-626 Skirtings, 41 Skiver, 70 Skivers, sumach tanned, dyeing with aniline color, 748-754 Sky blue, with mineral pigments, 736 Sky's artificial tanning material, 137 Slating goat-skins, 527 Slicker, French whitening, 423 glass, for glassingleather by hand, 453 scouring, 337, 338 Slickers, curriers', patents for, 430 Sliming lamb-skins, 664 Smith's compounds for producing imi- tation of grain and Morocco leather, 551, 552 leather whitening and buffing machine, 428, 429 preparation of tan-bark for trans- portation, 182, 183 Smutting and blacking appliances, 440-449 Smutting — leather, 447 machine for, Bryant's, 447- 449 Snouba bark, 121 Snyder's tanning process, 598 Soaking after fleshing, the length of time for, 312, 313 and rinsing for glove-leather, 647, 648 and washing hides and skins, 237- 243 dry hides in running water, 243 final, before placing the hides in the ooze, 338 hides after fleshing, 311-313 after fleshing, importance of, 311 and kips in foul, bloody water, 241 and skins, injuries which arise in, 238 in a steeping cistern after fleshing, 312 in France and Germany, 312 putrid, 312 Soaks, for dyeing, 720, 721 for hides for upper leather, 495 for skins for Morocco tanning, 525 period which the hides should re- main in the, 241 Soap and oil blackings, 449 iron, Knapp's, in tanning, 630 metallic, 53 solution, for determining the hard- ness of water, 170 Soda, 718 alum, 713 and sulphuret of calcium for de- pilating, 287 as a substitute for potash, in the manufacture of chamois leather, 686 caustic, depilation by, 290 lime, its use in determining nitro- gen in leather, 84 lye, its use in determining the per- centage of fat in leather, 83 muriate of, super-tartrate of po- tassa and tartaric acid, as a bating compound, 342, 343 Soderberg's bating process, 349 Sodium and calcium, as a depilatory, 276, 277 bicromate, 134 .carbonate, 718 INDEX, 815 Sodium — (.•Hvbonate, use of, in determinirg tannic acid, 144 chloride in tanning, 633 chloride of, Gl, 62, 715 hydrate, 709, 710 Sodom and Gomorrah, 35 Soerensen's process for dyeing leather, by subjecting it to the action of A'anadic compound, 764 Soft leather for gloves, 642 Softening dry hides, skins and peltries, by soaking them in the waste water from gas works, 243, 245 hides, mill for, 256-258 skins, and peltries, processes for, 243-246 machine, Tidd's, 570-572 plumping and depilating hides and skins with sulphide of barium, 282 salted hides, 241 the skin after dyeing, 731, 732 Softness, to restore, to dyed oil leather, 739 Sole leather, 481-491 artificial, 489-491 inside tanning, 486, 487 tanned with (.-hestnut oak bark, 119 tanning and finishing oak slaughter, 483-486 varieties of, in the United States, 482 what is sought to be com- bined in, 481 what is understood by, 481 leathers, classification of in the United States, 482 Soles of boots and shoes, compound for changing the color of, 7 73, 7 74 Solferino, 743 Soluble blue for skivers, 752 Solutions for staining tawed leather, 769, 770 Sorting kid and lamb-skins, 644 Sour liquor, plumping with, 360, 361 liquors, Botchford's process of distilling, in order to get rid of decaying animal and vegetable substances, 360, 361 tan-liquor, raising by, 301, 302 South America, goat-skins of, 42 American climate, effect of, on the hides of the cattle, 40 South American hides, how classified, whence received, and their qualities, 40, 41 Spanish sumach, 116 Spectrum, 698, 699 colors contained in the, 701 Spent tan, utilization of, 507 Spill & Co 's vegetable leather, 72, 73 Split calf-skins, sometimes used for Morocco, 41 finishing of the, 500 grain and bufi' leathers, 511, 517 leather, 71 compound for finishing, 451 prejjaring the surface of japanned or enamelled leather, 592-594 Splitting hides for patent leather, 587 when done, 493 leather, 368-384 machine, belt knife, 378, 379 Enos's attachment to prevent injury to the arms of work- men, 371-375 Flanders and Marden's belt knife, 369 McDonald and Beggs', 375- 378 Richardson's Union, 369-371 machines, 36 9-384 belt knife, Cummings's im- provement in, 380-383 facilities afibrded by, 369, 370 patents for, 383, 384 Sponhouse's method of manufacturing water-proof leather, 505-507 Spring and fall, tannin in oak-bark in the, 177 the propel' time for j)eeling bark, 176 Sprinklei', hanging, 208 leach, the, 203, 204 should be run slowly in the leach, 221 Stack's bating process, 345, 346 Staining tawed leather, solution for, 769, 770 Stannic chloride, 714 Stannous chloride, 141, 714 Statistics of the tanning industries of the United States, 74-80 Steam, boxes for exhaust and direct, 216, 217 depilating with, 270, 271 exhaust, regulating the supply of, 218 816 INDEX. Stearine in spirit of wine for produc- ing white glazed leather, 697 Steeping cistern for soaking hides after tleshing, 312 cisterns in France and Germany, 312 Steinmann's apparatus for handling hides in the lime pits, 26G-269, 357 Stenhouse on myrobalans, 117, 118 on quercotannic acid, 110 on the tannic acid contained in Sicilian sumach, 117 Stoning machines, patents for, 465-467 out, 431 Strabo on the early clothing of the people, 37 Straight grain goat finishing, 532—535 Straining cloth of the supply tank of leaches, 214 the liqnors going into the leaches, 213, 214 Strecker on tannin as a glucoside, 106, 108 Strength of chrome leather and tanned ^leather, 638-6^0 of leather, testing, 89-92 of skin in different places, table of, 91 Stretching and scraping upon the flesh and grain sides for chamois leathe'r, 681 capacity of chrome leather and tanned leather, 638-640 iron, 687 leather, ajjparatus for, patents for, 596 Oliver and Howell's machine for, 588, 589 machine. Coupe's, 568, 569 the hides for patent leather, 588 Striker applying to the skin, 730, 731 Strikers, 729 Striking out and drying skins for Morocco, 530 fleshing, and slating machine, Roberts and Lenox's, 332, 333 Strontium, 134 Study's conti-ivance for liming hides, 357 Stufhng and stuffing wheels, 408, 409 compound, Thayer's, 418, 419 Williams's, 417-420 "B. S." oil for, 419, 420 leather, patents for, compounds for, 420 Stuffing — the split, 500 Substitute for patent leather, 595 Sugar cane, silica in, 175 Sugar of lead, 98, 716 used by TurnbuU in bating, 336 use of, in bating, 346 Sulphate, ferrous, 711, 712 of alumina, 61, 62 of copper, 52 of iron, 52 tanning, 629 of sodium and calcium as a depila- tory, 276, 277 Sulphates, 711-714 Sulphide of barium for softening, plumping, and depilating hides and skins, 282, 283 of calcium for depilating hides and skins, 283 Sulphur and lime, action of, in depila- ting, 283 dioxide and water for bating, 346- 349 Sulphuret of calcium and soda, depila- ting with, 287 for depilating hides and skins, 283" Sulphuretted hydrogen gas for depila- ting and swelling hides, 273, 274 Sulphuric acid, 105, 706 and lime liquor for bating, 344 as a test for barium salt, 86 composition, formula, action, and specific gravity of, 363 concentrated, 130 used in preparing arti- ficial tannins, 137 early use of, by tanners, 362 for bating, 336 fraudulently increasing the weight of hides by, 49 in plumping, proportions of, 362 Nordhausen, or fuming. 706 jdumping with, 361-363 precautions to be taken with in plumping, 362 pure dilute for analysis, 156 raising with, MacBride's dis- covery- of, 58 use of in plumping, 359. 360 Sulphurous acid and lime-water as a dejjilatory, 278 INDEX. 817 Sumach for gi-ain, split, and buff' leathers, 511 its use in tanning, 125 Kathreinev's determination of tan- nic acid in, 158 leather prepared with, qualities of, 117 native use of in the United States, 598 varieties and qualities of, 116, 117 Sumach-tanned leather, 64 skivers dyeing with aniline colors, 748-754 Supei'-tartrate of potassa, muriate of soda and tartaric acid as a bating compound, 342, 343 Supply tank for leaches, 213 of leaches, heating while leaching is not going on, 215 Surface of split leather, preparing for manufacturing japanned or enam- elled leather, 592-594 Swan's bating process, 350 Sweat-box for warm sweating, 298 Sweat glands, 95 Sweating, care to be observed in, 296- 298 depilating by, 291-300 fresh hides, "299, 800 hides, 241 and skins, building for, 293- 295 large hides, 296, 297 process, cold, 291-293 employed in Germany and other parts of Europe, 298 how it acts on the hides, 296 warm, 298, 299 small hides and kips, precautions to be taken in, 296 Swedish glove-leather, willow-bark used for tanning, ] 21 leather, imitation of dyeing, 723 sumach, 117 Swelling and depilating hides with sulphuretted hvdrogen gas, 273, 274 hides, MacBride's discovery of the use of sulphuric acid for, 58 or plumping, 359-363 the essential action of, 359 Swiss goat-skins, 43 52 TABLE for leather scouring ma- chines, Daheney's, 405-407 of Schwarz & Co., showing the strength of skins in different places, 91 of specific gravity and pei'centage of tannic acid, 145 of the quantity of tannin required for the conversion of one pound of skin into leather, 125, 126 showing the capacity of leaches of different sizes, 213 with bed of zinc for dyeing skins, 721, 722 Tables of the percentage of tannin in various tanning materials, 123, 124 Tallowed leather currying, 523 Tan-bark, chestnut oak, 483 grinding, cutting, and crush- ing, 184-200" preparing for transportation, 182, 183 leather, behavior of, in water, 89 of, toward boiling water, as a test of tanning, 85, 86 liquor, sour, raising by, 301, 302 tannic, gallic, and acetic acids in, 360 meter, the, 139 press, Daniels's, 508 Holmes's, 507, 508 presses, economy in the use of, 607 improvements in, 507-511 spent, as a fuel, 507 tubs in a Morocco factory, view of, 527 vat, Rueraelin's, 607, 608 Tanned leather, classed as hides, kips, and skins, 38 effect of water on, 637-640 Tanner, a, named by Homer, 57, 58 Tanneries and other places where skins are stored, disinfecting, 48 in the United States, products of, 75 Tanners, the Tui'ks, Russians, and Hungarians the most celebrated in the first centuries of the Christian era, 65 Tanners' vats, agitators, and handling appliances, 358, 359 Tannic acid a primary product of ve- getable life, 113 Carpene- Bai'bieri's method of determinintr, 143 818 INDEX. Tannic acid — colorimetric method of deter- mining, 142 contained in Sicilian sumach, accoi'ding to Stenhouse, identical with tannic acid, 117 Davy's volumetric method of determinino-, 139 estimation of, by means of its specific gravity, 139 extractive substances exert a material influence upon the value of a, 113 Fehbei'g's volumetric denom- ination of, 140 Fehling's method modified by Muller of determining, 143 fermentation of, by fungi and ferments, 112 Fleck and Wolf's method of determining, 141 gallotannic acid and that de- rived from East India kino are the same, 114 Gerland's method of deter- mining, 144 Hammer's method of deter- mining, 144 in acicular form, obtaining, 232-234 in bark decoction, to deter- mine with solution of po- tassium manganate, 162, 163 in tanning materials, deter- mination of, 139-164 in the presence of indigo solu- ; tion, 154 Jeans's method of determin- ing, 144 loss of, by the use of hard water, 112 Mlintz and Rampercher's ap- paratus for determining, 140 j of the aqueous solutions, sepa- > ration of, 105 1 or tannin, 100-113 Persoz's method of determin- ' ing, 141 I physiological and pathologi- cal, 102 precipitation of, with cupric acetate when testing for grape-sugar in leather, 86 I Tannic acid — propertj^ of, of forming in- soluble combinations with earthy alkaline salts, 112 use of, in preparing connec- tive-tissue substance, 97, 99 I various kinds of sumach pro- bably contain different va- rieties, 11 7 which, when heated, forms pyrogallic acid, the leather produced by, 113 Wildenstein's method of de- termining, 142 yielded by different plants at different stages of growth, and by different parts of the same plant, 112, 113 acids of the horse chestnut, 120 our knowledge of, very in- complete, 102, 103 varying action of different kinds on skin, 113 which have not been thor- oughly examined, 110 yielded by oaks of different ages, 112, 113 Tannin, 107 action of, on hides, 363, 364 behavior of, towards various sub- stances, 106-108 chromic acid in aqueous solution, while hot, decomposes, 107 decomposes at about 410° to 419° F., 105 free from sugar synthetically pre- pared by Schriff', 108 from gall-nuts, form and charac- teristics of, 105 from wood of the live oak, 122 gall-nuts yield the richest, 114 Holtz's apparatus for obtaining a pure and soluble, 232-234 importance of, to the tanner, 100 in alder bark, 121 in chrome leather, experiment of Dr. Clark in regard to, 636-640 in oak bark in the spring and fall, 177 in oak-tanned leather, two and three years respectively in th(^ pit, 129 in ratanhy root, 121, 122 in tanning materials, comparison of results obtained by several described methods, 163, 164 INDEX. 819 Tannin — in various tanninj^ materials, tables of, 123, 124 in willow barks, 120, 121 it is yet a question whether it can- not be produced by artificial means, 60 melting and decomposition of, 105 new formula of confirmed, 109 not a glucoside, 107 not absorbed in unlimited quanti- ties by the skin, 1 29 of hemlock bark, 119 of horse-chestnut bark, 120 of oak barks, 119 of protaceaj barks, 121 of ratanhy root, 121 of the gall-nut, 103 of the scorza rosa, 121 of various kinds absorbed by skins, 12G-128 of willow bark, 121 or tannic acid, 100-113 percentage of, in leather, 1 28 reduces permanganate of potash solutions, 107 should be digallic acid, according to Schritf.'^lOB solution, preparation of, for de- termining tannic acid, 155 solutions, impure, modify them- selves in contact with the air, 1 08 the number of plant substances containing, 100, 101 transformation of, into gallic acid, 106 under the form of a polygallic glucoside, 109 Tanning, ancient, oriental, 65 aluminium, 641 , and coloring beaver, otter, and other skins with hair or fur on, 622-624 and coloring hides and skins with hair and fur on, 620-626 and finishing grain, split, and buff leather, 511-517 imitation French kid, brushed kid, straight grain goat, pebble goat, and oil goat, 524-535 oak slaughter sole leather, 483-486 sheep-skin fieshers for linings, binders, and skivers, 555- -558 Tanning and finishing — sheep-skins, 555-563 the "side" and "split," 492- 503 apparatuses for goat- and sheep- skins, 536-545 based rather on physical action than on chemical reaction, 364 by Klemm's process for oil leather, 693-697 constituents of leather, 82 establishments in tlie United States, 75 improvements in, largely mechani- cal, 59, 60 in the United States, capital in, 75 rank of different States in, 76 influence of increase in popula- tion and wealth on, 65 inside sole leather, 486, 487 interests in the United States, statistics of, 74-80 knowledge of the structure of the skin, and its behavior with re- agents, importance of, 93 known in the time of Moses, 56 liquor of Triedel and Molac, for- mula of, 627 material for Morocco, 525 materials for sheep-skins, 556 generally used in this country, 481 generally used in various countries, 124, 125 mineral, 130-136 the most important, 1 1 3 various, table of tannin in, 123, 124 vegetable, 100-129 chemical examination of, 138-164 mineral, 626-641 Morocco by the hand method, 541, 542 in combined wheel and vats, 542-545 origin of the art of, 37 or tawing, Heinzerling's process of, 61-63 process, Daniel's, 600 Enos's, 599 Garge's, 602 German's, 598 Gould's, 599, 600 820 INDEX. Tunning process — Hatch's, 600 Hibbard's, 598, 599 Irving's, 598 Jenkins's, 60G, 607 Keeler's, 599 Kennedy's, 600, 601 Kidder's, 606 Noble's, 601, 602 Page's, 602 Pickard's, 605 Robinson's, 603, 604 Snyder's, 598 the theory of, 363-365 Wattles' s, 599 what it consists in, 598 Wheelock's, 605, 606 Wyeth's, 604, 605 processes, 597-609 generally followed in the United States, 597 large numbers which have been invented, 597 patent, precautions to be taken in using, 597 patents for, 609-614 science has not done its duty in regard to, 59, 60 sheep-skins, Hibbard's process for, 559, 560 substance in leather, determina- tion of, 85 substances artificially prepared, 136-138 mineral and artificially pre- pared, 130-138 synopsis of the history of, 56-63 the most widely spread, and best developed industry of Russia, 66 the oldest method of. Go upper heavy leather, details of, 495-507 what it consists of, 63 with chromates, Henzerling's method of, 633-641 ferric salts, 626, 627 Knapp's processes, 628- 633 Tannins, absorbed by the skin, varia- tion in the f[uantity of the dif- ferent, 125 former classification of, 101 obtained by treating peat, brown coal, coal, etc., with nitric acid, 138 Tannins — profluced by the action of sul- phuric acid on I'esins and cam- phor, 138 quantities of, required for the con- version 1 lb. of skin into leather, 125, 126 variation in the chemical and physical behavior of, 101 which precipitate the ferric salts blue, 101 ferric salt green, 101 Tannomelanic acid, 109 composition and formula of, 109 how obtained, 109 Tannopinic acid, 109, 110 formula of, 110 Tannoxylic, or rufitannic acid, pro- duction, composition, and formula of, 110 Tapley's unhairing machine, 318-322 Tartar, chemical action of, 717 crude, 717 emetic, use of in determining tannic acid, 144 Tartaric acid, 709 Tartrates, 717 Tawed leather, Richter's solution for staining, 769, 770 Tawing, 642-697 aluminium acetate preferable to aluminium sulphate or alum for, 132 aluminium alum less desirable than chromates for, 1 34 and dressing sheep-skins, im- proved methods for, 558-561 chromium alum the most import- ant salt used for mineral tan- ning and, 134 class of skins to which it is ap- plied, 64 difference between Aikens's and other methods, 665, 666 fluids, Jennings's, 669-671 French or Erlanger method of, 642-668 hides and skins, patents for, em- ploying mineral substances for, 641 introduced into Hungary before the 12th century, 64 Jennings's method of, 669-673 material used for hides for patent leather, 585, 586 INDEX. 821 Tawing — 01' tanning, Heinzerling's pi'ocess of, Gl-63 paste, object of using, G57— 061 pastes for glove leather, 653-661 jiotash alum used in, 132 practised by the Romans who derived it from Africa, 64 Preller's method of, 689-693 sheep-skins, Manasse's method for, 558, 559 what it is, 64 Taylor's machine for unhairing, desh- ing, and working hides and skins, 32'7-329 yerniinalin cliehula, 117 Terra ja})onica, 1 1 4 adulterations in, detection of, 114 discovery of, the tanning jiro- perty of, 58, 59 Terreil's modification of Mittenzwei's method of determining tannic acid, 149 Tesera sumach, 116 Testing leather, physical methods of, 86-92 the strength of leather, 89-92 Tests for detecting the fraudulent in- creasing of the weight of hides, 49 Thayer's stuffing compound, 418, 419 Thompson and Johnson's bark mill, 190-195 Thymol, 54 Tice and O'Connell's process for finish- ing lower grades of leather similar to Morocco, 552-555 Tidd's softening machine, 570-572 Tigris and Euphrates, valley of, hair and wool industries in, 36 Tin bath for coloring partially tanned hides and skins, 773 composition, 714 salt, 714 Tinnerholm's compound for whitening leather, 774 depilatory process, 281-284 Titre, making the, 156 Tools used in barking, 177, 178 Tormentll root, 122 Towein's graining machine for Russia leather, 578 Tragacanth solution for giving a bril- liant appearance to Russia leather, 578 Train oil, 64 Trajan's Forum, marble bust of a skin dressed savage found in, 37 Transportation of tan-bark, 182, 183 Troy or Starbuck bark-mill, arrange- ment of, 185 Tucker's bating process, 350 Turly's bating process, 351 TurnbuU's plan for submerging goat- skins, 629 Turning steels, 309, 310 Tui'pentine, 69 use of, in determining the percent- age of fat in leather, 84 Twisted leather, 689 Tyralline, 743, 744 Tvrol sumach, 116 ULMIC MATTP:R, 107 Ulinus campestrifi, 119 Uncara gainhir, 114 Unhairing and fleshing, 304-330 as practised in France, 306, 307 by machinery, 313-333 hides and skins simultane- ously, Janson's machine for, 330-332 nnu.'hines, patents for, 333- 335 of hides, the most laborious operations in tanning, 313 by the hand process, 304-308 fieshing, and working hides and skins, Taylor's machine for, 327-329 goat, calf, and sheep-skins, 526 laides and pulling wool. Mower's process for, 278-281 and skins, composition for preserving and, 50-52 how usually effected, 304, 305 by machinery an accom- plished fact, 313 knife, 304-306 handling the, 305, 306 machine, Larrabee, 314-318 McDonald, 322-329 Tapley, 318-322 machines, McDonald's improve- ment in feed-rolls for, 325-327 Union tannage, 119, 481 light liquors used in, 489 slaughter leather, varieties of, 482 822 INDEX. United States, cattle ranches in, 35 statistical facts relating to currying in, 79 statistical facts relating to tanning in, 75 Upper leather, compound for finish- ing, 450 Head's process for soaking, liming, tanning, blacking, and gumming hides for, 500-503 hides for, green shaving and placing in the bate, 312, 313 tannery, cellar of a, 368, 369 what comprised under this head, 492 leathers, the hides from which they are produced, 492 use of lime with, 492 VAC HE-LEATHER, preparation of, 519, 522 Valonia, 117 where used for tanning, 125 Various machines for putting out skins, 545, 546 Varnish for patent leather, 592 Varnishing leatlier, the art of, 59 patent leather, 592 Vat and wheel combined for tanning Morocco, 542-545 or tank with feeding pipe for Morocco tanning. Baker's, 527, 528 tan, Ruemelin's, 607, 608 Vats, agitators, and handling appli- ances, patents for, 358, 359 for hides for patent leathei-, 586, 587 in which the England wheels revolve, 355, 356 of sumach leather for goat-skins, 527 Vauquelin, 58 Vegetable colors, 732-735 kingdom, 35 leather, 72, 73 tanning materials, 100-129 chemical examination of, 138-164 Verdegris, 716, 717 Vickers and Holmes's bating composi- tion, 344 Victoria green for skivers, 750 Vinegar wood, use of, with sour tan liquor in plumping, 359 Violet, 724, 734 aniline, 741, 742 color on Morocco, 757 Hofmann's, 741 Parisian, 741 Perkins's, 741 rosaniline, 741, 742 Vision, 698 Vitriol, blue, 712 green, 711, 712 or sulphuric acid for plumping, 361 Salzburg, 712 white, 712 Von Hildebrant, 59 Meidinger, 58 WAGNER on the use and value of tannin, 102 Wagner's classification of tannic acids, 102 method of determining tannic acid, 151-153 Walker's process for gilding and orna- menting leather for susj^ender ends, 765 Wallaby skins, 45 Walnut bark, 119 Walrus hides, 45 tanned with chromium com- pounds, 61, 62 Walters' s filling cup for Morocco manu- facturers, 529, 539-541 Ward's depilatory' process, 269 Warm sweating process, 291, 298, 299 Warner's apparatus for tanning goat- and sheep-skins, 536-539 Warrington, carbonate of ammonia employed by, for accomplishing the purposes of the bate, 336 Wash leather, 71, 6 79 wheel in a Morocco factoiy, 525 Washing and soaking hides and skins, 23 7-243 goat-skins, 526 wheel for glove leather, used in Germany and France, 650-652 Water, 165-173 analysis, AVanklyn and Frankland on, 169 as a leaching fluid, 221 change in volume, and ability of leather for resisting, 87-89 INDEX. 823 Wjiter— determination of pei'raanent hard- ness of, 173 of total hardness of, 171-173 eflfect of different inorganic con- stituents of, upon the depilated skin, 167 filtering through exhausted tan, 112 for cold sweating process, 292 from gas works for softening dry hides, skins, and peltries, 243- 245 general remarks concerning, 165- 169 hard, loss of tanni(! acid by the use of, 112 importance of a uniform tempe- rature of, in the manufac- ture of waxed-calf, 168 of, in tanning, 165 in an open vessel, depilating with, 286, 287 in leather, determination of, 82 methods for determining the con- stituents of, 169-173 process of determining the hard- ness of, by a soap solution, 170 soft preferred for the manufacture of uj^per leather, 167 supply of a tannery, 168 the effect of soaking chrome tan- ned leather in, 637 the temperature of, importance of, in tanning, 167, 168 to the dyer, wliat white color is to the painter, 700, 701 Waters, determining the cjualities for tanning purposes, 166, 167 hard and soft, in tanning, 165, 166 spring and well, constituents of, 166 Water-proof leather, the art of ])repar- ing, 59 Morocco ware, 535 Water-proofing, dubbing, and whiten- ing upper leather, 504-507 polishing, and coloring leath- er, composition for, 771, 772 Watteau's depilatory compound, 276, 277 Wattles's tanning process, 599 Watts's method of working the skins of lambs, goats, and dogs into glove leather, 666, 667 Waxed-calf, temperature of the water in which the skins are soaked, 168 Weight of hides, fraudulently increas- ing, 49 Wells's bating jirocess, 350 Weston's horizontal cylinder breaker bark mill, 1 85 " Salem tan press," 508, 511 Whang, 71 Wheel and vat for tanning Morocco, 542-545 for agitating the tanning liquor in the vats, "586, 587 Wheelock's tanning process, 605, 606 AVheels, England's, time and rate of running, 356 paddle, for handling hides, Eng- land's, 337, 355, 356 Whip and lace leather, quick tanning process for, 569 White glazed leather, by Knapp's pro- cess, 697 leather, or tawed leather, 71 vitriol, 712 Whitening and buffing machines, 428, 429 buffing, and shaving leather, pa- tents for machines for, 430 leather, 423-431 compound for, 774 the three ways of, 423 machine leather, 424-428 slicker, French, 423 upper leather, processes for, 504- 507 AVickersheimer's process of preserving hides and skins, 53, 54 Wiener's apparatus for testing the strength of leather, 89, 90 Wildenstein's colorometric method of determining tannic acid, 142 Williams, Moore, and Hurlburt's measuring machine, 469-473 Willow bark, 120, 121 barks, tannin in, 120, 121 Wilmington, Del., large quantities of Morocco produced in, 66 Wilson's bating process, 350 depilatory process, 270 Winter's leather measuring machine, 468, 469 Woburn, Mass., grain, split, and bufi" leather manufactured in, 511 Wolff's black staining compound for concealing defects in leather and for applying to pocket-books, 762, 763 82-4: INDEX. Wood, tannin obtained from, 122 vinegai' for preserving hides, 50 use of, with sour tan liquor, in plumping; 359 Woodbury's process for coloring par- tially tanned hides and skins, 7 73 Wool on sheep-skins, dyeing. Jack's method and machine for, 624- 626 pulling and unhairing hides, Mow- rer's process for, 278-281 Working hides, Lampert's apparatus for, 338-341 W^yeth's tanning 2:)rocess, 604, 605 YEAST, raising by, 302 • Yelk of egg, action of, in tan- ning,'"657-661 constituents of, 657 for tawing, 651-654 Yellow, 723 aniline, 743 for skivers, 749 barberry, 734 Yellow — barked oak, bark of, 119 Martin's, 757 on Morocco, 759 nankin, 734 on Morocco with aniline, 755 on oil leather, 739 "Philadelphia," on Morocco, 756 prussiate of potash, 719 quercitron, 734 ust, 734 shade in Morocco, 757 Yellowish-brown shades on Morocco, 755, 756 ZANE'S improved bark conveyer, 200-202 Zinaliiie, 743 Zinc, 53 acetate, ammoniacal solution of, 143 sulphate, 131, 712 Zollickoffer's bating compounds, 341- 343 F. STAMM. JOHN BEST The Eureka Bark Mill Co. Build four sizes SOLID MILLS, SEGMENT MILLS, STEAM JACKET MILLS, for high or low speeds, strong or light powers, for steam, water or horse powers. Will dust less on dry or brittle bark ; gum less on wet or tough bark ; will grind bark that other mills cannot ; will grind more uniform, and do more work with less power than any mill now made. LEATHER ROLLER m^ MACHINERY. (See cut, page 486.) We make the most powerful PRES- SURE IRONS, ROLLERS and CONCAVES or BEDS, of best material and workmanship. Roller Beds planed to any radius or length of vibrator. HORIZONTAL CENTRIFUGAL PUMPS, "With Steam Charging- Attachment expressly for Tanners, May be located where most convenient, with suction pipe from cistern to pump : can be quickly charged with steam, and discharged through pipe or hose to any point desired. Horizontal Centrifugal Pump. Castings for Wet Tan-Burning Ovens. Cast-Iron Screw Conveyors. Tan-Packing Machines, for packing ground bark or quercitron in bags. Jl^^Send for Descriptive Circular. Prompt attention given to all inquiries, and orders filled at short notice. Address, EUREKA BARK MILL CO., Lancaster, Pa., U.S.A. Founded by Mathew Carey, 1785. CATALOGUE OF PUBLISHED BY HENRY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS, BOOKSELLERS, AND IMPORTERS, 810 WALNUT STREET, PHILADELPHIA. g^^Any of the Books comprised in this Catalogue will be sent free of postage at the printed prices to any address in the World. Jg^^'A Descriptive Catalogue, 96 pages, 8vo., and our other Catalogues, the whole covering all of the branches of Science Applied to the Arts, sent free and free of postage to any one in any part of the world, who will furnish us with his address. J^^ Where not otherwise stated, all of the Books in this Catalogue are bound in muslin. OJk.TJLLOC3-TJE OF pfactieal and ^ciEntific Boo^^ PUBLISHED BY Henry Carey Baird & Co. 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To which is added A Comparison of the Resisting Properties of Iron and Steel. By A. Brull. Translated from the French by A. A. Fes- QUET, Chemist and Engineer. 8vo. . ' . ... ^i.oo VAILE.— Galvanized-Iron Cornice-Worker's Manual: Containing Instructions in Laying out the Different Mitres, and Making Patterns for all kinds of Plain and Circular Work. Also, Tables of Weights, Areas and Circumferences of Circles, and olher Matter calculated to Benefit the Trade. By Charles A. Vaile. Illustrated by twenty-one plates. 4to ^S-OO VILLE. — On Artificial Manures : Their Chemical Selection and Scientific Application to Agriculture. A series of Lectures given at the Experimental Farm at Vincennes. during 1867 and 1874-75. By M. Georges Ville. Translated and Edited by WiLLlAM Crookes, F. R. S. Illustrated by thirty-one engravinos. 8vo., 450 pages ^6.00 VILLE.— The School of Chemir,al Manures : Or, Elementary Principles in the Use of Fertilizing Agents. From the French of M. Geo. Ville, by A. A. 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