A TECHNICAL TREATISE ON SOAP AND CANDLES; WITH A GLANCE AT THE INDUSTRY OF FATS AND OILS. BY K. S. CRISTIANI, Chemist, AUTHOR OF "PERFUMERY AND KINDRED ARTS." ILLUSTRATED BY ONE HUNDRED AND SEVENTY-SIX ENGRAVINGS. PHILADELPHIA: HENRY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 810 WALNUT STREET. LONDON: SAMPSON LOW, MARSTON, SEARLE & RIVINGTON, CKOWN BUILDINGS, 188 FLEET STREET. 1881. Copyright by HENRY CAREY BAIRD & CO. 1881. COLLINS, PRINTER. rHEFACE. At this advanced age it is quite unnecessary to speak of the irpportance of the arts of manufacturing soap and candles, as they have become necessary to all civilized nations, and it has been well said that we may judge of the degree of civilization of a people by knowing the amount of soap they consume; and the chemists who by their research discovered the methods of making artificial soda, and the true constit- uents of the fats and oils and their utilization may be con- sidered among the greatest benefactors of their race, giving to the world cheap cleatiliness, as well as cheap light. To remove these arts from the darkness of empirical rules to the light of modern science is one of the principal desires in the construction of this work, for the author has had an experience of nearly forty years in these and kindred arts, in pharmacy, chemistry, soaps, perfumery, etc., and he well knows how little science has been consulted in making these useful articles, and how much guesswork with the usual un- certain results, depending upon the experience which the operator may have had, and the more or less secret his pyo- cesses. These experiences and processes may have served a useful purpose when the arts were confined to making domes- tic soaps and tallow candles, but they cannot avail at the present time, when they have become a thoroughly scientific manufacture. To render this work as complete as possible, and bring all the processes and formulas up to the present time, the author has given much time and care to its compilation ; aided by his long experience, and having access to all that has been discovered and written in France, Germany, England, and this country, he issues it with confidence that it will be found a useful guide, and by its simplicity and correctness well adapted for the use of the soap and candle manufacturer of the present age. iv PREFACE. Americans, true to their renown, have made the 2;reatest advance in the mechanical part of these arts by their nume- rous improved machines and apparatus for the saving of labor and improvement in the products, and the author has illustrated some of the most recent, most admirable, and most durable. From such causes they are making rapid strides towards the highest excellence, aided by these improvements, so that our products will compete favorably with any now made, although we must still yield to France the palm for superiority in toilet soaps. In the department of candles there may be considered quite a revival in the manufacture at this time, particularly for the better class of goods, and he has therefore given it careful consideration. The use of gas in the large cities and petroleum everywhere, the latter particularly affording a good and cheap light for the million, has caused this manu- facture to suffer neglect for some years; yet gas has its disad- vantages and petroleum its dangers, so that candles are be- coming much more used at feasts and festivals and in the homes of the wealthy, aiding much in the decorations of modern homes by their attractive designs and giving a softer and more pleasant light. Knowing the importance of the arts of w^hich he treats, the author has sought to make his book as complete as possi- ble, and he believes he has left out nothing that would be useful or important. How well he has performed his task experience in its use must show. In conclusion the author takes pleasure in acknowledging his oblio^ations to the writings on the same subject of Pro- fessors Morfit and Dussauce, both published by the pub- lishers of the present work, and of those of Messrs. Lich ten- berg, Steinheil, and Malepeyre, and very many others of later dates, indeed too many to enumerate in this place. Philadelphia, March 4, 1881. Note. — Owing to the difference that obtains in the several countries as to the weights and measures and thermometer scales, the author has ren- dered all the French or decimal weights into that most used in this country — the avoirdupois; when fluids are called for, into that of the apothecary, and when the centigrade scale of the thermometer is given, which is gene- rally the case in most scientific books, into that of Fahrenheit, thus simplif)-- ing the subject to the reader. CONTENTS. SECTION I. Introduction. SECTION II. History of the Soap and Alkali Trades. SECTION III. Materials used in the Manufacture of Soaps. PAGE Alkalies 26 Potash 27 Comparative Table of the Quantities of Ashes and Potash contained in different Vegetables . . . . . . . . .30 Quantity of Ashes yielded by different parts of Plants ... 30 Berthier's Table of the Quantities per cent, of Soluble and Insoluble Matters 31 Table of the Composition of the Mixture of Soluble Salts extracted from the Ashes of some Vegetables . . . . . .31 Extraction of Potash 32 Combustion of the Plants in Furnaces ... . . 33 Leaching or Washing of the Ashes ....... 34 Red American Potash . . . . . . . . .35 Ashes made from Tartar . . . . . . . . .37 Potash made from Beet-root Molasses ...... 38 Composition of Commercial Potashes ; Table of the Composition of the Principal Commercial Potashes . . . . . . .39 Purification of Potash ......... 40 Soda 41 Natural Sodas ; Soda of Narbonne ....... 42 Soda of Aigues-Mortes ; Soda from Sea- weeds ; Spanish Sodas . . 43 Mixed Barilla ; Salted Barilla ; Natron . . . • .44 History of the Fabrication of Artificial Soda ..... 45 Fabrication of Crude Soda ; Sulphate of Soda ..... 48 Mixture 49 Calcination ........... 50 Expense of Manufacturing Artificial Soda in France ; Production ; Artificial Salted Soda 52 vi CONTENTS. PAGE Analysis of Crude Artificial Soda ; Refined Carbonate of Soda . . 54 Crystallized Carbonate of Soda, or Crystals of Soda .... 55 Caustic Salts of Soda . . . . . . . . .57 Analysis of an English Caustic Soda ....... 58 Table of Specific Gravity of Sodas and amount of Caustic Soda . , . 59 Caustic Soda from Cryolite; Ammonia; Rubinium and Caesium . 60 Lime ............ 61 Water 64 Table of Hardness of Waters and of Soap Decomposed by . .66 Salt 67 Fats and Oils ........... 68 Fats of Animal Origin ; Tallows . ..... 75 Vohl's Apparatus for Rendering Tallow ...... 84 Lard 86 Rendering by Steam ; Wilson's Process ...... 88 Butter 90 Composition of Butter . . . . . . , . .91 Bone Fat 92 Horse Fat ; Glue Fat 93 Neat's Foot Oil ; Kitchen Fat 94 Fish Oils; Cod liver Oil 95 Oils and Fats of Vegetable Origin ....... 97 Physical Properties of Oils; Olive Oil . . ' . . • .98 Palm Oil 99 Palm-kernel Oil 104 Cocoa-nut Oil ........... 105 Gallipoli Oil . . 107 Almond Oil; Sesame Oil ......... 108 Rapeseed Oil and Coleseed Oil ; Groundnut Oil . . ... 109 Ben Oil 110 Avocado Oil ; Sunflower Oil ; Cotton-seed Oil . . . . .111 Castor Oil; Poppy-seed Oil 113 Hempseed Oil ; Analyses of Hempseed Oils . . . . .114 Nut Oil ; Beach-nut Oil 115 CamelineOil; Mustard-seed Oil ; Colza Oil . . . . .116 Hazel-nut Oil; Linseed Oil; Oleic Acid, Olein, Commercial Red Oil 117 Vegetable Tallow ; Shea Butter or Galam Butter . . . .121 Butter of Nutmeg or Oil of Mace; Composition of Butter of Nutmeg . 122 Tallow of Virola ; Oil of Laurel ; Cocoa Butter . . . .123 Carapa Oil ; Malibar Tallow ; Goa Butter ; Grape-seed Oil ; Oil of Tobacco Seeds; Oil of Belladonna Seeds ..... 124 Waxes; Beeswax; Palm-tree wax • . . . . . .125 Carnauba Wax ; Myrtle Wax ; Ocuba Wax ; The Wax of Bicuyda ; Rosin or Colophony . . . . . . . . .126 CONTENTS. vii SECTION IV. The Recovery op Offal and other Kefuse, Fats, and Greases. PAGE The Yield of Offal Fats hy means of Sulphuret {BIsnlphidel of Carbon 131 Wool Fat and Fuller's Fat 132 Composition of the Residuum . . . . . . . .136 SECTION V. The Adulteration of Fatty Bodies. Olive Oil ; Oil of Sweet Almonds . . . . . . .140 RapeseedOil; Sesame Oil 5 Linseed Oil; Black Poppy Oil; Hemp- seed Oil 141 Castor Oil; Neat's Foot Oil; Oleic Acid; Palm Oil ; Cocoa-nut Oil 142 Assays of Oils ........... 143 Qualitative Assays . . . . . . . . . .144 Table of the Colorations taken by different Oils . . . . .146 Falsification of Lard ; Alterations; Falsifications . . . .148 Falsifications of Tallows . . . . . . . . .149 Falsifications of Waxes ; Yellow AVax and Sulphur ; Yellow Wax and Yellow Ochre; Yellow and Whitf Wax and Calcined Bones; Wax and Resins ; Pitch, etc 150 Wax and Starch or other Amylaceous Substances ; Wax and T.dlow . 151 SECTION VI. The Chemical Equivalents Applicable to Soap. SECTION VII. Saponification — Theoretical, Chemical, and Practical. SECTION VIII. , Alkalimetry. Analysis by Measure, or Volumetric Analysis 167 The Burette ........... 168 The Pippette 172 Flasks . . . . . . . . . . . .175 Cylinders for Mixing . . . . . . . . . .176 Scales and AVeights ; Tincture of Litmus ; Cochineal Tincture . .177 The Preparation of the Tincture of Litmus 178 Tincture of Cochineal ; the basis of Alkalimetry . . . .179 Table of the Quantities of Bases Neutralized by Normal Nitric Acid . 182 viii CONTENTS. PAGE Normal Alkali . 184 Estimation of the amount of Soda in Lyes of Potash . . . .185 Analysis of Lime . . . . . . . . . . 194 SECTION IX. The Application of Soaps. SECTION X. The Establishment of a Soap Factory with the Necessary Plant. Description of the Soap Manufactory for Marseilles Soap of Gontard in St. Quen, near Paris . . . . . . . ,199 Description of a French Soap Factory for making Mottled Marseilles Soap ; Factory Building 203 Kettles ; Fireplace ; Grate ; General Chimney ..... 204 Ash-pan ; Cisterns in Masonry ; Large Masonry Vats ; Cellars ; Basins ; Frames ; Store-rooms . . . . . . . . .205 Description of a General Plan for Manufactory of Soap heated by Steam ; Boiler ; Fireplace ; Chimney ; Dome ...... 206 Kettles ; Pipes ; Cisterns ; Cellars ; Foundation of the Kettles ; Sheet- iron Vats; Frames . . . . . . . .207 Drying-Room 208 Kettles ; Masonry Kettles 211 Cast-iron Kettles 212 Sheet- iron Kettles ; Heating of Kettles by Fire 213 Heating of Kettles by Steam . . . . . . . .215 Steam Series . . . . . . . . . . .217 Hubert's Apparatus for Boiling Soap by means of surcharged Steam . 219 St. John's Steam Jacket 221 Morfit's Steam Jacket 222 Caldrons or Boiling Pans ......... 224 Lye Vats 225 Siphon ♦ • . . .228 Bogardus's Eccentric Mill for Grinding ; Drum Sieve . . . 229 Soap Frames ; Frames of Masonry 230 Frames of Iron 231 Whittaker's Patent Soap Frames 232 Frames of Wood 233 Hersey's Patent Rotary Soap Pump . . . . . . .236 Cutting Operation 238 Slabbing and Barring Machine ........ 239 Caking Machine 242 CONTENTS. ix PAGE Champion Slabber; Ralston's Patent Cutter, with Stamping and Spreading Attachments ; Crutching Machines ; Steplien Strunz's Soap Crutching Machine ........ 243 Strunz's Jacket Crutching Machine 245 Minor Implements .......... 246 SECTION XI. The Fabrication of Soaps. Soaps by Boiling ......... 248 Tables of Lime to be applied in proportion to contents of Potash and Soda to pure Carbonate of Alkali ....... 250 Preparing Potash Lye from Wood Ashes ...... 253 JPreservation of the Lyes . . . . . . . . .254 Tables of Experiments with Sodas of 86° and 72° Baum6 . . .258 Table of the Contents of Anhydrous Potash, with the corresponding Specific Gravities and degrees of Hydrometer according to Baume . 259 Dalton's Table of Potash, contents of Lyes according to their Specific Gravities ........... 259 Table of the Contents of Anhydrous Soda, with the corresponding Specific Gravity and Hydrometric degree of Baume with the quanti- ties of Fats Saponified by Lyes of various strengths . . .261 Dalton's Table of the various specific gravities of Sod:is contained in the Lyes 262 Hard Soaps (Soda Soaps) ; to make a good Marble or Marseilles Soap 266 Clear Boiling . . 269 The Grinding or Filling of the Soap . . . . . . .271 The Marbling of the Soap 272 Formulas for Marseilles Soaps ; AVhite Marseilles (Castile Soap) . 274 Pasting 276 Separation; Clear boiling, or Coction . . . . . .277 Fitting 279 White Soap from Olive Oil 280 White Castile (Marseilles) Soap as made in England, Germany, and the United States ; Tallow Soap (Curd Soap) . . . .281 Palm Soap 284 Combinations in vogue for Palm Soap ; Rosin Soap (Yellow Soap) . 285 Rosin Soap with Cocoa-nut Oil ........ 286 Resinous Grain Soap and Turpentine Soap . . . . .287 Olein Soap, Oleic Acid Soap, Elaidin Soap 288 First and second services of Lye . . . . . . .291 Fitting 292 Stirring the Soap in the Frames ....... 294 Castile Soap from Cotton-seed Oil 296 Mottled Castile Soap from Cotton-seed Oil 298 X CONTENTS. SECTION XII. The Fabrication of Soaps (continued). Extempore and other Soaps. PAGE Little Pan Soaps ; Half-boiled Soaps 301 Tallow Soap by the Cold Process ; Cocoa-nut Oil Soap by the Cold Process 303 Kosin Soap by the Cold Process ....... 304 Transparent Rosin Soap ; Borax Soap ...... 305 Swiss or Half-boiled Soaps ; Swiss Palm Soap ..... 306 Swiss White Wax Soap ; Swiss Yellow Soap 307 Swiss Rosin Soap ; Swiss Olein Soap ...... 308 Hard Soap from Potash Lye ; Tallow curd (grained) Soap . . 309 SECTION XIII. The Fabrication of Soaps (continued). Soft Soaps. Gentele's Formula . . .315 Calculating the Proportion . . . . . . . .316 Boiling of Soft Soap 317 Particular Remarks . . . . . . . . . .318 Grained Soft Soap (Fig Soap) ; Artificial Grain Soap . . .320 Elaidin Soft Soaps 321 White Soft Soaps 322 English Crown Soap (First Quality) ; Crown Soap (Second Quality) ; Green Soft Soap . .323 SECTION XIV. The Fabrication of Soaps (concluded). SiLICATED AND OTHER FiLLED SOAPS. Common Cocoa-nut Oil Soaps ; Common Filled Rosin Soaps . . 326 Soluble Glass Soap (Silicated Soap) ; Gossage's Process . . . 327 Dunn's Silicic Soap . . . . . . . . . .331 Guppy's Process 332 Davis's Alkalumino Silicic Soap ....... 333 Sand Soap ; Quartz Soap ; Ponceln Soap ; Greaves or Crackling Soap ; Bone Soap 334 Other Filled Soaps, with Fornuila; . 335 / CONTENTS. xi SECTION XV. Nkw Soaps by New Methods. PAGE Saponification of Fats by means of Carbonated Alkalies . . .337 Saponification of Fats by Sulphuretted Alkalies 338 The Process of Mege Mouries ........ 339 Methods of M. D'Arcet 341 Soaps by Steam Pressure ; Bennett & Gibbs's Apparatus . . . 346 ^ SECTION XVI. Soap Analysis. Determination of the amount of Alkali ...... 352 Determination of Sebacic Acids and of the Rosin . . . .357 Congealing Points of Sebacic Acid according to Stockhardt . . 358 Bruckner's Table of the amount of Soap and Glycerine furnished by Fats ; Determination of the amount of Rosin . . . . .359 Determination of Soap as to Admixtures ...... 362 Table of the Analyses of Soaps 363 Valuation of Soaps .......... 364 Cailletet's Process; Characteristics of the Aqueous Solutions of Soaps, Normal Acid, and Alkaline Liquor . . . . . . . 365 Preparation of the Normal Acid Liquor ...... 368 Preparation of the Normal Alkaline Liquor . . . . .369 Saponimetry ; Soaps composed of Solid and Liquid Fatty Acids . 370 Soap of Oleic Acid and Rosin . . . . . . . .375 Mixtures of Potash and Soda . . *. . . . . .3 76 SECTION XVII. Remelting of Soaps. The Whittaker Remelter 381 SECTION XVIII. Miscellaneous Useful Soaps. Altenburge's Rosin Soap ; Dresden Palm Soap ; Oflf'enbach Palm Soap 383 Wax or Bleaching Soap ; Bran Soap ; Ox-gall Soap for Scouring Woollens ; Scouring Balls 384 French Scouring Soap ; Scouring Tablets ; Erasive Soap ; Labor- saving Soap ; Country Soap ........ 385 Domestic Soft Soap ; Shaker's Soft Soap; Borax Soft Soap; Lubri- cating Soap ........... 386 xii CONTENTS. PAGE Agricultural Soap (Whale Oil Soap) ; Fig Soap; Pearl Soap Powder; Borax Soap Powder; London Soap Powder . . . . .387 Belgian Soft Soap; Ammoniated Soap; Medicated Soft Soap; Marine Soap ............ 388 SECTION XIX. Toilet Soaps. To Render and Purify the Grease 390 Toilet Soaps by Boiling . . • . . . . . . , 392 Half- Palm Soap 393 Pasting; Separation; Coction ........ 394 Fitting ; First Liquefaction . . . . . . . .395 Second Liquefaction . . . . . . . . . .396 White Soap from Cocoa-nut Oil 398 SECTION XX. Toilet Soaps by the Cold Process. Extempore Soaps. White Soap by the Cold Process 402 Rose Soap ........... 403 Windsor Soap ; Yellow Soap ; White Windsor Soap . . . . 404 Honey Soap ; Glycerine Soap ; Marsh-mallow Soap .... 405 Old Brown Windsor Soap ; Half-boiled Soap — Swiss Soaps . . 406 Kurtin's Table showing the composition and product of Soap by the Cold Process, from Concentrated Lye and Mixture of Cocoa Oil, with Palm Oil, Lard, and Tallow 408 SECTION XXI. Miscellaneous Toilet and Medicated Soaps, with Fokmulas. Cold Cream Soap .......... 409 Bouquet Soap; Lemon Soap . . . . . . . . 410 Orange Soap ; Elder- flower Soap ; Heliotrope Soap ; Frangipanni Soap 41 1 Superfine Soaps ; Ambergris Soap (Ambrosial Soap) ; Benzoin Soap 412 Jonquille Soap (Superfine) ; Millefleur Soap . . . . .413 Savon a la Marechale (Surfin) ; Savon Hygienique (Extra fine) ; Savon a la Violette de Parme . . . . . . . . . 414 Lettuce Soap ; Cucumber Soap ; Mousseline Soap ; Savon de Muguet (Lilly Soap) ; Rose-leaf Soap (extra fine) 415 Violet Soap (yellow) ; Vanilla Soap (superfine) ; Rose Windsor Soap 416 Violet Windsor Soap ; Musk Windsor Soap ; Names for French Toilet Soaps .417 CONTENTS. xiii PAGE Medicated Soaps ; Carbplic Soap ; Medicated Tar Soaj) ; SulpViur Soap ; Tooth Soap ......... 418 Tannin, Salicylic, Disinfectant, Thymol, Croton Oil, Benzoic Acid, Castor Oil, Petroleum, Paraffin, Creasote, Bromine, Idonine, Tur- pentine, Alum, Borax Toilet, Mercurial, Irish Moss, Bran, Corn Meal, Oat Meal, Camphor Ice, and Wax Soaps; Eggj-yolk Soap . 419 Bordhardt's Herb Soap; Beef-marrow Soap; Spermaceti Soap; Shaving S^ps in Tablets . . . . . . . .420 Shaving Compounds ; Floating Soaps ; Nymph Floating Soap ; Rose Floating Soap ; Powdered Soaps . . . . . . .421 Soap Essences ; Transparent Toilet Soaps ; Transparent Soap by the Cold Process ........... 422 Transparent Glycerine Soap ........ 423 Transparent Soft Soaps ; Liquid Glycerine Soap ; Soft Toilet Soaps of Potash ; Shaving Creams ; White Soft Soap ..... 424 Almond Shaving Cream ; Rose Shaving Cream ; Ambrosial Shaving Cream ; Shaving Cream by Boiling ; Naples Soap or Shaving Cream 42G Soap Balls or Savonettes; Glycerine Cocoa-nut Oil Soap . . . 427 SECTION XXII. Manipulation of Soaps; Machinery and Appliancks, Pkrfuming, Coloring, Finishing, etc. Soap Caking Machine 428 Cutting Table ; Hand Press 431 King's Foot-power Soap Press ; Hersey's Patent Steam Soap Press . 432 Stripping of Soaps ; Rntschman's Stripping Machine . . . 434 Soap Mills; Rutschman's Power Soap Mill 435 Plotting 437 Rutschman's Vertical Plotting Machine ; Hydraulic Plotting JNIachine ; Finishing and Polishing Soap Cakes 438 Coloring Toilet Soaps . . . . . . . . .439 Perfuming of Toilet Soaps ; Perfumes for Honey Soap . . . 440 Perfumes for Glycerine Soaps; Perfumes for White Windsor Soap; Perfumes for Rose Soaps . . . . . . . .441 Perfumes for Elder-flower Soap ; Perfume for Cashmere Soap . .442 SECTION XXIII. Volatile (Essential) Oils, and some other Materials used for THE Perfuming of Soaps. Oil of Valerian ; Oil of Bergamot ....... 443 Oil of Bitter Almonds ......... 444 xiv CONTENTS. PAGE Oil of Lemon ; Oil of Fennel ; Gaultheria or Wintergreen Oil . . 446 Geranium Oil ; Caraway-seed Oil ; Oil of Jasmin .... 447 Limette Oil ; Oil of Lavender ; Oil of Cloves 448 Neroli or Orange-tlower Oil ; Oil of Patchouly ; Oil of Portugal ; Attar of Roses, Oil of Roses 449 Oil of Sassafras ; Oil of Marjoram ; Oil of Thyme .... 451 Oil of Vitivert ; Cassia Oil; Oil of Rosemary ; Oil of Canada Snake- root; Oil of Pimento ; Oil of Nutmegs ; Oil of Cinnamon . . 452 Ambergris ; Musk or Bisam ........ 453 Peruvian Balsam ; Civet ; Tincture of Civet ..... 454 Tincture of Ambergris ; Tincture of Musk . . . . . .455 PAET II. MANUFACTURE OF CANDLES. SECTION I. LXTRODUCTION, INCLUDING THE ThEORY OF FlAME. SECTION II. The Materials for Candles, with their Preparation. Preparation of Tallow ; Chopping Board ...... 463 Power Machine for Cutting Tallow; Kettles for Rendering in small Factories 464 Hood for Kettle 465 Presses ............ 466 Centrifugal Mill 470 Saponification by Lime . . . . . . . . .472 Wood Frame- work . . . . . . . . . .474 Hydraulic Press . . . . . . . . . .475 De Milly's Process 477 Saponification by Sulphuric Acid . . . . . . .478 Saponification by Sulphuric Acid without Distillation ; Saponification of Fats by Water combined with Distillation . . . . .479 Saponification by Water under High Pressure; Prof. Kraft's Report on Sebacic or Fatty Acids ........ 480 Distilling Apparatus . . . . . . . . . .481 CONTENTS- XV SECTION III. Materials for Candles (continued). PAGE Paraffine 482 Spermaceti ........... 483 Machine for Reducin^Crytallized Cakes to Shreds ; Wax . . . 484 Sebacylic Acid ; Elaidic Acid ; Glycerine ...... 486 SECTION IV. The Manufacture of Candles. Wicks, AND their Preparation. Wick Cutters 490 Apparatus to combine the Soaking of the AVicks with the Cutting . 492 SECTION Y. The Manufacture of Candles (continued). Dipped Candles. The Necessary Apparatus ...... ... 494 SECTION VI. The Manufacture of Candles (continued). Moulded Candles. The Moulds 502 Moulding by Hand 503 Moulding by Machinery ......... 504 Leubel's Moulding Machine ........ 506 Morgan's Moulding Machine 508 Improved Continuous Wick Machine . . . . . . .512 Ashley's Moulding Machine ; Camp's Moulding AVhecl . . . 513 Stearine Candles . . . . . . . . . .515 Moulding Stearic Acid Candles . . . . . . . .517 The Moulds for Stearic Acid Candles; Bleaching the Stearic Acid; Moulding Stearic Acid Candles by Hand . . . . .518 Moulding by Steam 520 Paraffine Candles ; Moulding Paraffine Candles ..... 522 Spermaceti Candles ; Moulding Spermaceti Candles . . . .523 Wax Candles 524 Moulding Wax Candles ...... . . 525 Large Bougies or Cierges for Churches ...... 526 XVI CONTENTS SECTION VII. The Manufacture of Candles (continued). Polishing and Finishing. PAGE Apparatus for Polishing and Finishing ...... 528 SECTION VIII. The Manufacture of Candles (continued). Composite and Patent Candles. Belmont Sperm Candles; Belmont Wax Candles; Star Candles; Cerophane Bougies ; AdamanVme Candles; Artificial Wax Candles 532 Diaphanous Candles ; Composition Candles ; Various Patent Candles 533 SECTION IX. The Manufacture of Candles (concluded). Decorated and Colored Candles, Tapers, Night Lights, etc. Colored Candles .537 Toy Candles, Decorated Candles ....... 538 Wax Tapers 540 Night Lights or Tapers . . . . , . . . .542 APPENDIX. The Metric System of Weights and Measures. Weights and Measures . . . . . . . . .545 Tables showing the Relative Value of English and French Measures . 547 Hydrometers and Thermometers . . . . . . .555 Thermometers . . . . . . . . . . .557 Centigrade and Fahrenheit ........ 558 Note. — Soda Ash by the Ammoniacal Soda Process . . .561 Index 563 A TECHNICAL TREATISE ON SOAP AND CANDLES, WITH A GLANCE AT THE INDUSTRY OF FATS AND OILS. SECTION I. INTRODUCTION. The term soap is now applied to all those compounds of oils or greases or sebacic acids with the salifiable bases or alkalies, which by their detergent properties aid in the re- moval of dirt or grease in washing, scouring, and scrubbing. The term detergent means the power of rendering soluble in water the adhering grease or dirt on the skin or clothes ; for which purpose soap is now universal Ij^ applied by all nations. Indeed we can almost form a true estimate of the degree of civilization to which a country has attained, by knowing the amount of soap used by its inhabitants. It is perhaps unnecessary here to mention the great im- portance and usefulness of the art of manufacturing soap, as an article so universally used has attracted the attention of chemists from the most remote period ; yet, although soap has been made and used for so long a time, it is only in modern times that its manufacture has reached a scientific character, for it is less than sixty years since 'Chevreul first advanced the proper theory of saponification, and made known the elements of the fats and oils and their chemical reactions with the bases or alkalies. 2 18 TECHNICAL TREATISE ON SOAP AND CANDLES. To the magnitude of its agriculture, manufactures, and commerce we turn to discover the wealth of a nation, and in applying the light of science to all of the most important manufactures, and thereby improving the quality and cheap- ening the cost, we increase the demand, give importance and character to an art, enlarge and extend the product, and bring w^ealth to a country and its people. While as Americans we are proud to know that we excel in the many new machines and apparatus intended to facili- tate the manufacture of soaps, and are constantly improving the quality of our products, yet we still procure from Europe many of their superior productions ; but as we realize that there is still something to learn, and we seek to excel, we are quite likely ere long to equal any soaps made in any country. The arts of manufacturing soaps and candles rest upon ex- act principles and fixed rules, and are true chemical industries. So it is important that the manufacturer should endeavor by steady experiment and practice to learn these arts scientifi- cally, that he may fully understand their true foundations. Being chemical arts, it has been necessary to use many scientific terms, but the author has sought to give the sim- plest explanations while yet retaining accuracy, that the worker, who may be without experience, may fully under- stand the meaning of all he reads, and it is his object here to make all processes as simple as possible, compatible with their accuracy and importance. In conclusion, he desires to give a word of advice founded on experience, to all who wish to enter into the important manufacture of soaps, as well as to those already in it ; to seek the most approved means of making good honest soaps, soaps that will bear all tests, and bring him reputation, respectability, and fortune, for though by sophistication and adulteration a larger quantity may be marketed by the at- traction of low prices, yet quality is the only true test, and superiority should be the aim, as it is the only road to respectability in the trade. • HISTORY OF THE SOAP AKD ALKALI TRADES. 19 SECTION II. HISTORY OF THE SOAP AND ALKALI TRADES. If we could go back sufficiently far in the history of nations, we should find that commerce meant the barter of the commonest natural products. Just as people progressed in civilization so did their wants increase, and to meet their requirements it became necessary to apply to natural pro- ducts much study, to shape them to suit the desired uses. So we see the beginning of manufactures which now repre- sent the most important factor in the commerce of nations. While in early times everything was accomplished through agriculture and the increase of the earth, it is still the most important, but guided by the intervention of science. In considering the history of manufactures, we will see that they have been chiefly developed through chemical re- search, and few, if any, have been more interesting or im- portant to the progress of a country than the branches known as the soap and alkali manufactures and trade. So we must consider chemistrj^ as a science built on a framework which has been raised by the labors of such men as Berzelius, La- voisier, Scheele, Gay-Lussac, Leleivre, and others, and see the application of derived knowledge to the arts and manufac- tures, and appreciate the natural consequences of cheap soap and cheap oils, ''cheap cleanliness and cheap light." While we find that soap has been used for some centuries and by many nations, it is not so well established that tlie ancients were acquainted with it, as it is known that they used ashes and alkaline earths; which, though they had a detersive power, yet as found in nature were very corrosive and destructive to fibrous material and to the human skin. These natural substances are still used in some countries as substitutes for soap. 20 TECHNICAL TREATISE ON SOAP AND CANDLES. It is difficult correctly to ascertain at what time or by what nation soap was first made and used.. It is claimed hy some that the Greeks first invented it, yet it is first distinctly spoken of as an invention of the Gauls, whence the Germans obtained the art and were distinguished for their superior goods, whicli was at least a century before Italy established its manufacture in the eighth century, and in the beginning of tbe tenth century it was introduced into France, where large factories were established in Marseilles hy a colony of Phoceans, decendants of the Greeks. Marseilles was particu- larly adapted to this industry, as all the needed materials were there abundant. Olive oil w^as common, and the neigh- boring sea-coast provided the vegetable sodas, and the sea- port on the Mediterranean had a large commerce with all Europe and the Levant. So France became the great market for this useful product, and was celebrated for the superior quality of its soaps, and very deservedly, as the processes then in use have been fixithfully adhered to, and all these combinations are to this day wisely continued with the ad- dition of improved applications natural to the adv^ance in everything else. These manufacturers have with prudence added to their materials onl}^ such as have proved after careful experiment to be of decided advantage. In tlie war with Spain in the beginning of this century the sources of much of their material both alkali and oil were cut oft', very much to their disadvantage, and the government with great wisdom ottered a large reward for the discovery of the means of substitution. This was ac- complislied by Leblanc w^ho discovered a process for making caustic soda from culinary salt; a discovery that has been of great importance, and may be said to have revolutionized the soap and alkali trades; for artificial soda as it is called is now universally used. So with their olive oil which became scarce and dear, for it was also largely supplied by Spain ; the manufacturers Avere compelled to try other oils, and poppy oil, hempseed oil, sesame oil, and groundnut oil, were used in combination. The latter oil especially proved a suc- cess, in fact an improvement to the soa[». So at the present HISTORY OF THE SOAP AND ALKALI TRADES. 21 time no Marseilles (Castile) soap is made with olive oil alone, as the addition of any of these oils in certain proportions has been proven beneficial ; pi-eventing the soap from acquiring too solid a consistency when dry, which that made from olive oil alone was sure to have, except when made with lye from barilla, which contains a large percentage of potash, and the hygroscopic character of this alkali had a like effect in keeping the soap plastic and more soluble. In turning from France to England we see that but little progress was made in this art; soap was indeed made, but only in the crudest form and gener.illy in the household or for fulling. The first mention of its manufacture was in 1524, in London; in 1641 a factory for its production is de- scribed in some records in the British Museum. The trade was retarded, like many others, by the special privileges granted to a subject by the sovereign, and again by the heavy excise duties. These obstructions prevented progress so that but little improvement can be found from the time of Queen Anne till the present century, when in 1804 Muspratt made artificial soda by Leblanc's process, which immensely cheap- ened and increased the manufacture of the article. Yet to the date of the first International Exhibition of 1851, England had made so little progress that she was surprised that the manufacturers of other countries carried off nearly all the prizes given for that branch. This surprise caused an agita- tion for the repeal of the excise, which was finally accom- plished in 1853. The result of this repeal was so beneficial that we find in 1870 the amount manufactured had increased fully fifty per cent. Yet England has not kept pace with some other countries in the progress of the art, though some important discoveries in cheapening the cost of soap have there been made, par- ticularly the addition of rosin, palm oil, and silicate of soda. The former article may be considered an ameliorater, making it more soluble ; the latter while cheapening does not mate- rially injure its quality, the silicate of soda, having an alkaline reaction and a detersive quality, being less objectionable than 22 TECHNICAL TREATISE ON SOAP AND CANDLES. the many articles now in use as sophistications of soap, some of which are pernicious and should be abandoned. In 1870 England manufactured about 250,000,000 pounds of hard and soft soap, but since then we cannot trace any material increase, for countries that then w^ere principally dependent for soaps on England now make most of their own. But of alkali England has steadily increased its sup- ply until it now in quantity excels all other nations. The Germans, who in early times made the best soap and exported it to other countries, have made but moderate progress in modern times. At the present day, however, the practice of the art being open to all the people, who have established many small factories and applied to the trade its true chemical character, they are producing superior goods, though this superiority is not sufficiently maintained to claim particular notice in comparison with the products of other countries. The soft soap of Germany is still much used for household purposes as well as for manufacturing, and it has acquired a reputation for excelling in quality that of other countries. Why, we cannot say, for there have been neither many improvements nor much science given to its manufacture. Of the manufacture of alkali in Germany there had been but a limited improvement for many years, until it was found that England was extending her alkali trade to an enormous extent, when the Germans saw the necessity of improving their goods and economizing their processes, which latter had heretofore been conducted in a very wasteful manner. This compelled them to establish large works and to employ experts at liberal wages. The result has been not only a better product, but a large increase in the quantity manufac- tured and in a single decade. Eor a period of time past recollection Germany had made both soft and hard soaps with potash lyes, the latter by using salt in turning the soft soap into hard, the culinary salt or chloride of soda producing a decomposition by parting with its chlorine, forming chloride of potash, which w^as precipi- tated in the spent lye along with the glycerine, leaving a HISTORY OF THE SOAP AND ALKALI TRADES. 23 sebacic acid soda soap. This process is still in vogue in countries where wood is bujnt as fuel, and potash and wood " ashes are abundant ; notably Russia and the newly settled portions of the United States. Germany now employs the artificial soda in almost all its soaps, and is making much of its alkali from cryolite for the use of the glass manufac- turers as well as the soap boilers. In our own country there has been a steady progress in the improvements constantly making in this useful and important art, until now we are producing goods which for quality compare favorably with any made elsewhere ; more- over we have invented much new and improved machinery and apparatus that greatly facilitate the processes, saving labor and time and improving the quality. Thus the United States is at this time but little behind any other country, either in the amount made or in the quality of the article ; while in the economy and facility of their manufacture this industry is in advance of that of nearly all other coun- tries, and is steadily progressing, so that it cannot be long before we shall equal in quality and excel in quantity, for already we are making soap in larger quantities than Great Britain, and are but little behind France. We are also making so much of our own alkali that we shall soon be inde- pendent of other countries. We have hitherto been supplied from England, which is still largely in advance in the pro- duction of soda and its adjuncts, having in operation over fifty large alkali works and making goods valued at $20,000,000 per annum. At the present time the United States has several of these works and many more are pro- jected. When Chevreul described the exact constituents of the fatty bodies, and made known the processes for their separa- tion, a great impetus was given to both the arts of soap and candle manufacture. The stearine or solid part was made into candles while the olein or liquid part was converted into soap, the glycerine which had previously been thrown away was extracted from the sublye and utilized and has since become of great importance in many arts. 24 TECHNICAL TREATISE ON SOAP AND CANDLES. The importation of palm and cocoa-nut oils added an im- portant variety to the list of soaps, particularly of toilet- soaps, the former being a useful and pleasant material, im- })roving all soaps into which it enters, which cannot, hc^wever, be said of cocoa-nut oil, as it retains a rancid odor wdiich it seems impossible to remove, and wdiich is to most people objectionable, so that it should be used with caution. On the other hand, it has many good qualities, making soap handsome in appearance and in use giving a copious lather. It has also properties peculiar to itself; thus it saponifies only in strong lyes, and will dissolve in salt water and is often called marine soap. It will also retain a large percentage of water without impairing its solidity or appearance. These properties it in some degree imparts to other soaps to which it may be added, and it has been the means of much sophis- tication and adulteration, which has given to purchasers an idea of inferior quality, yet to some it is a favorite because of the richness of its lather. In giving statistics of soaps, w^e can only give approxi- mate figures, as we find nothing later than 1870 and 1876. Great Britain has over 350 soap manufactories making over 250 million pounds of soap per annum, of which 50 million w^ere exported. France has fewer factories but makes quite as much, including toilet-soaps, while the value is much greater. Of Germany, we have only Berlin, which makes about 30 million pounds per annum. The United States m 1870 made nearly 200 million pounds, while at this date the increase, judging from our own researches, must be fully thirty per cent., as that has been nearly the amount of in- crease of export. We ship much to South America and elsewhere. Thus in reviewing the history of the soap and alkali trades we see that neither has attracted much attention till modern times, for even looking back so short a period as fifty years we find that they received but little notice, except in France, where at that time in Marseilles alone there were made about 120 million pounds per annum. About this period Paris founded soap establishments similar to those in Southern HISTORY OF THE SOAP AND ALKALI TRADES. 25 France, and made goods that rivalled those of the older manufacturers, hesides numerous and superior toilet-soaps as well as family and industrial soaps. The former were better than the world had ever known; and this superiority has been maintained against all competition. So we reach our own times and find large soap, candle, and alkali works in nearly all countries, whose products are consumed in vast quantities, and are a staple of commerce of the first importance, requiring large capital, employing many hands, and giving wealth to the nations. Although many of these productions are still of inferior quality, the arts are of the most progressive character, and there is a steady improve- ment accompanied by a constant effort towards superiority — healthy elements which ere long must lead almost to perfec- tion. We must now leave this fascinating subject with a notice of some natural products that are used as substitutes for soap, though they have not yet been found of importance enough to supplant it in utility — such as the berries of the soap-tree {Sapindus saponaria) of South America and the West Indies; aquilla bark {Qiiillaza saponaria) used for washing silk and woollens; the juice of the soapwort {Sap- onaria officinalis) or "bouncing-bet," all of which form a lather with water. In California the Phalangium pomari- dianum is used as a substitute for soap and has its odor; there are also many natural earths and clays that have an alkaline reaction and can be used as substitutes for soaps, though with caution as they usually contain other chemicals which might prove injurious to the skin or clothes. Many of these natural products have been utilized in pharmacy and the arts. 26 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIOIT III. MATERIALS USED IN THE MANUFACTURE OF SOAPS. ALKALIES. Besides the two indispensable ingredients that constitute the materials of which all soap is made, viz., alkali and fats or oils, there are several others scarcely less important in the art, as lime, salt, water, etc., all of which wnll be properly described. The two important alkalies potash and soda, which are the oxides of the metallic bases potassium and sodium, in the new chemical nomenclature are termed potassium hydrate and sodium hydrate, meaning the caustic alkalies in solu- tion, and are described by the formulae iTaHO caustic soda, KHO caustic potash. From these oxides the bases can be formed, which have for the chemist many peculiar and inter- esting properties, but for the soap maker are of but little interest, having no practical use in his art. But as regards the oxides or what we call potash and soda, he cannot be too intimately acquainted with all their properties, in fact an accurate knowledge of them is necessary to facilitate his manufactures, for by this means he can intelligently account for all success as well as all mistakes that may occur in his processes. While each of the alkalies mentioned will form soaps, the soaps so formed will have different characters, though each may have equal detergent power in dissolving grease and dirt, yet they have different uses in the arts and for domestic purposes, and are quite different in their physical properties, the soaps from potash being soft, those from soda hard. This property is often utilized to modify the quality of soaps, to make one harder or the other softer. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 27 The other ingredients of soap, namely the fatty acids, have many and distinct properties, the study of which is scarcely less important than that of the bases or alkalies, for as a fatty or sebacic acid may be more or less solid, so will it impart this jDroperty to the soaps into which it enters; thus stearine or the hard principle of fats will form a much more solid soap than oleine or the liquid part. This rule may have some exceptions under certain conditions. In the working of these fatty acids, or their behavior when combined with the alkaline bases, they may each have some peculiarity either in saponification or in the resulting soap, so we see the importance of a close studj^ of the character- istics of each. For those in common use we can take for our guide the experience of others, but there are constantly arising new oils, greases, waxes, etc , witli whose properties we must experiment to discover their peculiarities and their usefulness in forming soaps. We shall describe in the proper places the secondary sub- stances indispensable in this manufacture, giving their pro- perties and mode of use, but it will be unnecessary to detail all their chemical properties, as such descriptions would take unnecessary space, so we will confine ourselves to the properties they possess when applied to the arts of making soap and candles. Yet if the soap maker has the inclination and the time to study all the chemical properties of materials he may use, in fact to study chemistry generally, it would be of great ad- vantage and add much interest to his work and no doubt result in a great improvement to his w^ares. With these few preliminary remarks we will proceed to the description of all known ingredients and materials in use for making soap. Potash. Potasse, Fr. Kali, Ger. Potash was at first called fixed vegetable alkali, because it is generally obtained from the ashes of many plants. It is known in the market by diftereut names, derived from the 28 TECHNICAL TREATISE ON SOAP AND CANDLES. vegetables which furnish it, or from the countries it comes from. However, vegetables are not the only source from which potash is extracted. A great part of the minerals which compose the crystalline rocks contain it in variable quantities, in combination with different acids, principally silicic acid. Pure potash is not met with in nature. However, the principal source of potash is the combustion of vegetables. The presence of potash in vegetables was an enigma for a long time, for vegetables, properly so called, do not create potash ; but they liave the valuable faculty of borrowing from the soil and manures the soluble salts they contain, among which are potash and soda, combined with various acids, and especially organic acids. During the combustion the organic acids are decomposed, and the car- bonic acid resulting from this decomposition combines with potash and soda to form subcarbonates of these bases. Of late years potash has been procured in great abundance from the salt-rocks in Stasst'urt, in Prussia, and Kalucz, in Hungary, principally from carnalite, a chloride of potassium and magnesium. The magnesia is precipitated from the solution with hydrochloric acid, leaving the potassium salt; the chloride of potash is then submitted to the process de- scribed for the production of caustic soda from chloride of soda (Leblanc's process), and caustic potash is thus produced in quantities that have almost superseded, on the continent, all potashes from other sources. Independently of the carbonates of potash and soda, the ashes of vegetables contain also several other salts, particu- larly the chlorides of potassium and sodium, sulphates of potash and soda, carbonates and phosphates of lime and mag- nesia, silicate of alumina, and a certain quantity of organic matters not decomposed, which color the saline residuum obtained by the lixiviation of the ashes. By calcining this residuum to redness in a reverberatory furnace, white potash is obtained. We must here make an important observation. Vegetables which grow on the sea-shore, or in the neighborhood of salt mines, give by their incineration very small quantities of MATERIALS USED IN THE MANUFACTURE OF SOAPS. 29 potash ; they principally contain soda. Those, on the con- trary, which grow inland and in soils free from chloride of sodium, yield, by their combustion, ashes which contain principally carbonate of potash, mixed with very small pro- portions of soda. These vegetables are the only ones em- ployed in the preparation of the carbonate of potash. Independently of the culture, it is easily demonstrated that the quantity of ashes furnished by different vegetables i^ not identical. It varies considerably according to the different species, the influence of climate, and particularly the nature of the soil in which they have grown. Experience also proves that the young parts of the i)lants, in which cir- culates a rich and abundant sap, are those which contain the greater percentage of salts of potash. It is thus that the leaves of a tree yield more potash than the branches, and these more than the body of the tree. D'Arcet, who has experimented much on the manufacture of alkalies, has published an interesting paper on the extrac- tion of potash from the ashes of the horsechestnut. He as- certained that one hundred parts of dried chestnuts yielded nearly half their weight of ashes at 65 alkalimetric degrees. The following table gives the quantity of potash contained in certain veoretables : — 30 TECHNICAL TREATISE ON SOAP AND CANDLES. Comparative Table of the Quantities of Ashes and Potash contained in different Vegetables. Jfames of (he vegetables. Quantity of Quantity of Chemist who made the ashes. alkali. analysis. 100 parts of — Willow 2.80000 A CiO A AA 0.28400 Kirwan. Elm .... 2.36727 A OAAAA 0.39000 Oak .... 1.35185 0.15343 Pertuis. Poplar •i A Tit* 1.23476 A City A a 't 0.07481 Yoke-elm . 1.12830 A 1 o cr /I A 0.12540 Beech .... 0.58432 0.14572 Pitch-pine tree . 0.31740 A 1 OA 0.73180 de Fontenelle. Vine .... 3.37900 A PrrirAAA O.SoOOO Kirwan. Stalks of corn 8.86000 1 . 75000 Wormwood y. 74400 tV OAAAA 7.30000 Fumitory . 21.90000 AAAAA 7.90000 Fumitory . o2. 10000 O A 1 er AA 8. U 1500 de Fontenelle. Vines of hops 1 A ATkAAA 10,00000 O A 1 cr AA 3. U 1500 Thillaye. Vines of Windsor beans 1 A AAAAA A 1 OAAA 4. i/iyuu Common nettle . 10.()71bo 2.5U33U Pertuis. Common thistle . 4.U42D0 A K0~0 i O.Oo and loss . . . i 1.20 2.28 2.64 3.73 3.86 1.249 100.00 100.00 100.00 100.00 100.00 100.000 Alkalimetric degrees 56.0 53.1 55.0 54.4 31.6 69.3 We see, by the above table, that independently of the sul- phates and chlorides, all potashes contain soda in variable proportions; the American potash is that which contains the least, and that of molasses contains the most. The in- soluble residuum is partly composed of carbonates and phosphates of lime and magnesia, silicate of alumina, and the oxides of manganese and iron. The first of these oxides colors them blue, the second communicates to them a red shade. Purification of Potash. — It is easy to separate from potash the greater part of the sulphate it contains. It is sufficient to dissolve it in the least possible quantity of water. The sulphate, much less soluble than the carbonate, remains un- dissolved ; it is stirred several times with water, w^hich dis- solves the alkali. This solution is used to dissolve a new quantity of potash. The sulphate washed and dried is sold for about half the price of the potash itself, and as that sul- phate has no useful effect when mixed with potash, it is better to extract it and sell it separately. The chloride of potassium, very slightly soluble in a liquid saturated with carbonate of potash, is partly separated by the same process. The solutions obtained at 45°, by this process, are evapo- rated in kettles of gradually decreasing depth. It is into the deepest kettle, directly heated, that the liquid is introduced : as fast as the evaporation reduces the volume, fill the kettle with the solution, and the other MATERIALS USED IN THE MANUFACTURE OF SOAPS. 41 kettles with the solutions already concentrated in each preceding kettle. In this way, as fast as the solution con- centrates and retains the water with more tenacity, it is placed in a flatter vessel, in which the stirring is more easily eftected, and the column of liquid being of less height above the bottom, the saline incrustations, which w^ould be an obstacle to the passage of heat, do not form so easily. The desiccation is achieved in the latter kettle, w^iich is flatter. The carbonate of potash, economically purifled by this process, is used in the arts requiring a purer product than commercial potash. Wherever wood-ashes can be bought at reasonable prices for the manufacture of soft soaps, a large saving is attained and they deserve far more consideration than has hitherto been given them. Under favorable condi- tions the lye produced from wood-ashes will cost but one- half, often but one-third of the price of that made of potash. The reason for this is partly found in this, that by the home manufacture of potash in the form of lye, both the cost of boiling and calcination as well as the expense of transportation will be saved. The supply from this source is constantly diminishing, and recently commerce has been supplied from new sources. The rock-salt mines and the beet-sugar fac- tories have become the most reliable. Their potashes are richer in alkali and freer from impurities, and are from this fact more desirable, requiring much less labor in the prepa- ration of the lyes. For the proper tests for potash the reader must turn to Alkaliraetry, Soda. Sonde, Fr. Natron, Ger. Soda, the base of all hard soaps, exists in nature in the waters of various lakes and springs in many parts of the world, and the ashes of marine plants, w^hich were formerly the source of all commercial soda. But since the discovery and manufacture of artificial soda from culinary salt, that is in general use for making soaps, and being furnished comparatively pure, and in a caustic and concentrated form, 42 TECHNICAL TREATISE ON SOAP AND CANDLES. there is a saving of much labor and cost for plant outlay. The caustic sodas of commerce are generally sufficiently pure for all ordinary soaps of commerce, though for superior toilet soaps the lye should be perfectly pure. The soap maker will find it necessary to make his own lye, and that from the crystallized carbonate of soda made caustic with the hydrate of lime is the most reliable. Chemically pure soda is composed of sodium and oxygen, but is never found in this state in nature; it is always in combination either with chlorine, with which it forms chlo- ride of sodium (common salt), or with acids, principally carbonic acid. With this latter it forms the carbonate of soda. This salt is met with abundantly in several countries of the world, and particularly in the East, where it has been known for a long time by the name of natron. Natural sodas are the carbonates of soda, obtained by the incineration of several species of plants growing on .the sea- shore. These plants furnish very variable proportions of carbonate of soda mixed with different salts. Those which give the most are : the Salsola soda^ and the Salicornia ^iiropoea. During their vegetation, the plants draw from the soil the salt it contains, and assimilate the soda, which they trans- form, at least partially, into organic salts, principally in acetates and oxalates, decomposable by heat. Gay-Lussac ascertained by analysis, that the salsola soda contained a considerable proportion of oxalate of soda. When these plants are burned, the organic acids are destroyed, and the carbonic acid resulting from the combustion combines with the soda to form a carbonate. Sodas take their names from the countries which produce them. Soda of Narbonne. — This soda, more generally known by the name of salim\ is the best manufactured in France. It is the richest in pure or carbonated soda, which is the only useful alkali for the preparation of solid soaps. The plant which produces it is designated by the name of salicorna annua. The plant is cultivated in several parts of the south of France. The plant is cut before its complete maturity ; MATERIALS USED IN THE MANUFACTURE OF SOAPS. 43 is spread in the sun to dry, and then incinerated. Good salicors give from 20 to 25 per cent, of carbonate of soda. Soda of Aigues-Mortes. — This soda is prepared in the neigh- borhood of Aigues-Mortes. It is obtained by the incinera- tion of very different plants growing naturally and without cultivation, on the shores of the Mediterranean. These plants are collected, dried, and burned on the ground, or in proper furnaces. This soda is found as a black and compact half-melted mass. It contains a large proportion of common salt. Its richness in carbonate of soda is about 8 to 10 per cent. Soda from, Sea-weeds. — This soda, prepared for a very long time on the coasts of l^ormandy and Brittany, varies greatly in its composition. It is furnished either by sea- weeds, or by plants designated by botanists under the names of fucus marilimus^ vesicidos habejis, and commonly called goemon. These plants are collected at low tide, dried in the sun, and calcined. The residuum is a black mass, often porous, and is called kelp-soda. This soda is not very rich in carbonate, for its proportion is never above 5 per cent. ; it generally contains only from 2 to 3. It is most valuable on* account of the bromine and iodine it contains. Spanish Sodas. — Prior to the present century, Spain fur- nished, under the names of sodas of Alicante, Malaga, and Carthagena, the greater part of the carbonate of soda used in Europe. Among the numerous varieties of Spanish sodas, three kinds are principally distinguished in the market ; they are known by the names of barilla, mixed, and salted barilla. The first, which is the richest in pure alkali, and conse- quently the most valuable, is furnished by the plant known by the name of salsola soda. When the plant has attained its full growth, it is cut and dried in the sun, and incine- rated in cylindrical pits dug in the ground, about five feet deep. To begin the operation, a few armfuls of dry material are thrown into the pit, and ignited. The combustion is kept up by adding little by little new dry plants and is 44: TECHNICAL TREATISE ON SOAP AND CANDLES. accelerated by stirring the mass from time to time with an iron rod. This operation lasts about four days, and is finished when the pit is filled to two-thirds or three-fourths of its depth with the products of the combustion. A few days after, the residuum is taken out, then broken into large pieces and put into barrels. The soda thus obtained is called soft barilla ; it is a hard and compact mass, of a gray-ash color. Eecently prepared, its fracture is smooth. Mixed Barilla. — Mixed barilla is obtained in the same manner as the above, by the combustion of certain marine plants growing on the shores of the Mediterranean. The only difference between these two kinds is that the first is manufactured only from choice plants, carefully cultivated and free from weeds ; on the contrary, the mixed barilla is prepared with plants not so well cultivated, which grow in grounds nearer the sea — it is used to manufacture solid soaps. Salted Barilla, — This kind differs from the two above named by the strong proportion of neutral salts it contains, and by being less alkaline. The plants which produce it grow without cultivation on the sea-shore in soils strongly impreg- nated with salt. During their growth, these plants absorb a large quantity of salt, which is found in the ashes after the incineration. Although less pure, less alkaline, and less esteemed than the two last described, the salted barilla is still of great use in the manufacture of Marseilles soap. Its blackish color, and its being more highly sulphuretted than the others, together with the large proportion of salt it contains, cause it to play, in the fabrication of marbled soap, the same part as salted soda. The blue of the marbling is brighter and more intense, it progressively contracts the molecules of the soap, and during the operation keeps it constantly separated from the lyes. But since the discovery of artificial soda its use is limited. Natron. — Is a natural sesqui-carbonate of soda, abundantly found in several parts of the world, and particularly in Egypt. Egyptian natron is now extracted from two lakes, one MATERIALS USED IN THE MANUFACTURE OF SOAPS. 45 near Cairo, and the other a short distance from Alexandria. During winter these lakes are filled with a water of a violet- red color, which passes by infiltration through the soil of the surrounding hills. During its course it runs through a soil in which salt and carbonate of lime are abundant. By the contact of the water, a spontaneous reaction takes place between these two salts, wdiich are reciprocally decomposed. Deliquescent chloride of calcium is formed, wdiich infiltrates into the lower part of the soil, and the sesqui-carbonate of soda efiloresces at the surface. This double decomposition is considerably favored by the dampness of the soil and the heat of the climate. Rain water or w^aters which exude from the soil dissolve the efflorescence of carbonate of soda, and flow into the lakes in which they reach a height of about six feet. These lakes are from thirteen and a half to fifteen miles in length, and about three-quarters of a mile in width. The bottom is stony and solid. During the great heat of the summer, these waters concentrate and evaporate, and the natron deposits on the soil, from which it is extracted in gray crystalline plates, which are purified and bleached by successive solutions and crystallizations. Commercial natron is in mass or in plates, with a grayish- white color. Its fracture is granular or crystalline, and it contains from 20 to 30 per cent, of pure soda. In very dry years these lakes furnish about 450,000 lbs. of natron. In Hungary, and certain parts of South America, there are siniilar lakes furnishing, during the summer, an abun- dant efflorescence of sesqui-carbonate of soda. Matron is also collected in some of the lakes around Tripoli, but it is not so abundant as in the lakes of Egypt, although the product is purer. History of the Fabrication of Artificial Soda. — The discovery of the process for the manufacture of soda from chloride of sodium has exercised on the progress of modern industry so powerful an influence, that it is necessary here to dwell upon the circumstances under which it was produced. The pri- ority of this discovery has never been successfully contested, and the name of Leblanc, to whom it is due, is now known 46 TECHNICAL TREATISE ON SOAP AND CANDLES. all over the world; however, on many points of detail, some doubts existed, which have only recently been explained. In 1856, M. Dumas presented to the Academie des Sciences^ a paper which definitely established the true history of this important question. Long since, the old Academy of Sciences had offered a prize of 2400 francs ($480) for the conversion of chloride of sodium into carbonate of soda. Father Malherbe, in 1777, was the first who thought that he had attained the indus- trial solution of the problem ; he proposed to convert first the salt into sulphate of soda, and then to heat this salt with charcoal and iron. Macquer and Montigny, in 1778, made a favorable report on this work. Guyton de Morveau, as- sociated with Carny, had, a few years before, erected an establishment at Croisie, in which the salt, being mixed with lime, was afterwards allowed to rest in contact with the air. Very soon the carbonate of soda effloresced on the sur- face of the mixture, but the results were not economical. In 1789, De La Metherie proposed to calcine sulphate of soda with charcoal ; he thought that he should thus obtain sulphurous acid and carbonate of soda, while in reality he obtained only sulphuret of sodium. This incorrect hypo- thesis, as we shall see, became the basis of the discovery of Leblanc. As early as 1787, he had begun the study of this interesting question ; when he knew of the experiments recommended by De La Metherie, he tried them, and ascer- taining their worthlessness, attempted to modify them. He then conceived the idea of associating the carbonate of lime with the sulphate of soda and charcoal, when its success was certain and the magnificent discovery of the fabrication of soda was accomplished. Ten months after the publication of De La Metherie, the problem was solved by Leblanc. It was then that, associated with the Duke of Orleans, Diz^ and Shee, he thought of rendering his discovery an indus- trial one. In the act of association, and in a sealed package opened in 1855, he described the process as he then under- stood it. It consisted in heating in closed crucibles 100 parts of sulphate of soda, 50 of chalk, and 25 of charcoal. It MATERIALS USED IN THE MANUFACTURE OF SOAPS. 47 was not yet the industrial process as we know it at the present day. However, the trials in the laboratory were continued ; a manufactory was established at St. Denis, and soon (Sep- tember 23, 1791), on the report of D'Arcet, Desmarets, and de Servi^res, Leblanc obtained a patent for fifteen years. In his description, the crucibles had disappeared; they were superseded by a reverberatory furnace; the proportion of sul- phate of soda w^as diminished one-half; in a word, the real industrial process was exposed with such precision that since that time very few changes have been made. Unhappily, fortune was not to reward Leblanc. The manufactory of St. Denis was just beginning to work when the revolution put an end to all business; the property of the Duke of Orleans was seized, and, the manufactory being included, the fabrication was stopped. Soon, the Continental war preventing t?ie importation of Spanish sodas, the French industry felt the loss of this important element so essential to its work. Then, on the proposition of Carny, the com- mittee of public safety obliged the inventors of the process to manufacture soda from chloride of sodium, and to sacrifice to the country the fruit of their discoveries. Le- blanc first offered his processes to the committee; soon a report from Lelievre, Pelletier, D'Arcet, and Giroux, ren- dered them public, but it was not Leblanc who put them into practice. The property of the Duke of Orleans was sold, and the manufactory with them. However, that same manufactory was given back to Leblanc as an indemnity for the publication of his process ; but he could not find the capital necessary for conducting it, and, notwithstanding all his exertions, he utterly failed to accomplish anything, and was at the time of his death, in 1806, in a state of abject poverty. However, if the author of this discovery was dead, it was not so with the discovery itself ; notwithstanding the diffi- . culty of obtaining saltpetre to manufacture sulphuric acid, and then the sulphate of soda, the process of Leblanc was soon put in practice by several manufacturers. It was first Payen, then Carny, who applied it : the first near Paris, the 48 TECHNICAL TREATISE ON SOAP AND CANDLES.- second at Dieuze. The fabrication of soda was rapidly grow- ing, and in 1806 glasses were seen at the exposition of in- dustry, sent by the manufactory of Saint-Gobain, prepared with artificial soda. However, the new product had one defect which often caused it to be rejected by the trade; this defect consisted in its sulphuretted nature. D'Arcet found the cause of that imperfection. Leblanc's furnace was rec- tangular, and the flame was not active enough in the angles, and there resulted a partial transformation of the sulphate of soda into sulphuret of sodium. D'Arcet rounded off the angles, and transformed the rectangular furnace into an elliptic one. With this improvement, the fabrication of artificial soda rapidly increased, and in 1812, notwithstand- ing the absolute prohibition of foreign sodas, the price of that substance had diminished fully two-thirds. Fabrication of Crude Soda. — This fabrication comprises three distinct operations, which are : 1. The transformation of the chloride of sodium (common salt) into sulphate of soda, by sulphuric acid; 2. The mixture of the sulphate of soda with the chalk and charcoal ; 3. The calcination of the soda, or the conversion of the sulphate of soda into carbonate, in a reverberatory furnace. Sulphate of Soda. — The sulphate of soda manufactured in France and England is destined for the preparation of crude soda. The processes followed in its manufacture vary accord- ing to the localities. When hydrochloric acid has to be col- lected, common salt is decomposed b}" sulphuric acid in cast- iron cylinders, heated in various ways. But at Marseilles, where the fabrication of artificial soda constitutes one of the most important trades, the greater part of the hydrochloric acid produced during the operation is lost. The sulphate of soda is directly prepared in reverbera- tory furnaces by decomposing salt by sulphuric acid. These furnaces are generally divided into tw^o compartments. The part placed near the hearth is destined for the fabrication of the crude soda (carbonate of soda); the second part is sepa- rated from the first by a low brick wall ; the side of this part is formed of hard stone, in which a cavity is cut; it is in MATERIALS USED IN THE MANUFACTURE OF SOAPS. 49 this cavit}^ that the sulphate of soda is prepared, by the re- action of sulphuric acid ou salt. The proportions of acid and salt generall3^ used are : — Salt 2000 lbs. Sulphuric acid at 50o 3200 " The salt is first introduced into the cavity, then the sul- phuric acid at 50° is poured upon it. Under the influence of heat the decomposition takes place ; the hydrochloric acid resulting from the reaction is disengaged, and the sul- phuric acid combines with the soda to form sulphate of soda. The operation lasts from three to four hours. It is ascer- tained that it is finished, when the mixture has acquired a pasty consistency, and when no more hydrochloric acid is disengaged. To bleach the sulphate and disengage the last portions of hydrochloric acid it contai)is, the temperature of the furnace is raised. When the salt is sufiiciently dried, it is taken out. If the operation has been well conducted, a nearly white sulphate is obtained. Thus prepared, the salt constitutes an acid sulphate. It is specially employed to prepare soft, or purely alkaline soda. The above quantities give from 2200 to 2260 lbs. of sul- phate of soda well prepared, or from 110 to 113 lbs. of sul- phate for 100 of salt. By a later process the hydrochloric gas forming hydrochrotic acid is saved, thus preventing the escape of the gas which contaminates the air of the neigh- borhood. Mixture. — This operation consists in mixing the sulphate of soda, previously calcined, with the proper proportions of carbonate of lime and charcoal. To obtain an alkali of a high degree, it is essential that the quantities should be in such proportions, that the sulphate of soda will be entirely transformed into carbonate. Theory indicates the respective proportions of the substances to be employed ; but in prac- tice, the doses of carbonate of lime and charcoal have to be increased. E'ot only is a more complete decomposition of the sulphate of soda attained, but the insolubility of the sul- 4 50 TECHNICAL TREATISE ON SOAPS AND CANDLES. phuret of calcium is also determined by the formation of an oxy-sulphuret of that base, nearly insoluble in cold water; then by lixiviating the crude soda with cold water, the solution contains only the alkali nearly free from sulphuret. The best proportions to use are: — Calcined sulphate of soda .... 2000 lbs. Dry carbonate of lime 2100 " Charcoal 1100 " To render the reaction more easy, the substances are pre- viously ground in vertical mills, then passed through a metallic sieve. The carbonate of lime must be perfectly dry ; generally it is desiccated by exposing it for a few days on top of the arch of the furnace. The mixture of the sub- stances being intimately effected, the calcination is proceeded with. Calcination. — As we have already said, the furnaces are generally made in two compartments. The first, where the temperature is the highest, is used to calcine the soda; in the second, the waste heat is utilized to prepare the sulphate of soda. When an operation is begun, the furnace must be brought up to a strong red heat before introducing the mixture. That condition being complied with, introduce the mixture into the furnace, and after spreading it as evenly as possible, leave it exposed for some time to the action of the heat. In order to have an equal and regular heat, the fire requires great attention, especially at the beginning of the operation. When the reaction begins, the mixture softens and agglu- tinates, and the parts exposed to the highest temperature begin to melt. At that moment, stir the mixture with an iron rod so as to hasten the decomposition of the sulphate. From this time, feed the furnace with* fresh fuel so as to obtain a bright and continued fire. Continue to stir the mixture from time to time. It is ascertained that the opera- tion is almost finished when the fusion is nearly complete, and when the incandescent substance throws out luminous jets, which burn with a white or bluish flame. These jets, MATERIALS USED IN THE MANUFACTURE OF SOAPS. 51 are due to the combastion of the oxide of carbon ; when they become more rare and less intense, it is a characteristic sign of the conversion of the sulphate of soda into carbonate. Then slacken the action of the fire, for a higher elevation of temperature would cause the volatilization of an appreci- able quantity of soda. Thus, when the luminous jets have diminished in intensity, draw^ off from the furnace the melted mass, which is received in square sheet-iron boxes five or six inches deep and three feet in diameter. These boxes are phiced on rails and then put under sheds. After the soda is solidified and cooled, it is broken into large pieces and put into barrels. This soda is generally in a melted and compact mass, par- ticularly if the calcination has been pushed too far ; but when the operation has been well conducted, its texture is not so compact, and sometimes is porous. It is preferred in this state, because by lixiviation it is more easy to deprive it of its soluble salts. When well prepared it resembles good Spanish soda ; it has a gray-ash color, and is without smell. Its richness in pure alkali is generally constant, and depends essentially on the purity of the sulphate. If the sulphate contains only a few hundreths of undecomposed salt, and is completely converted into carbonate by proper proportions of chalk and charcoal, a soda is obtained which generally contains thirty-six per cent, of alkali. This soda, designated by the name of soft soda, or alkaline soda, is specially used for the saponification of oils in the fabrication of marbled and white soaps. As soon as the furnace is empty, load it again as at first w\th a mixture of sulphate of soda, chalk, and charcoal, and operate as we have indicated. The complicated reactions are thus explained : Under the influence of the charcoal, the sul[)hate of soda is transformed into sulphuret, and at the same time, oxide of carbon is dis- engaged. Afterwards, the sulphuret of sodium and the car- bonate of lime are mutually decomposed, and from that decomposition result sulphuret of calcium and carbonate of soda ; but as this reaction takes place at a temperature at 52 TECHNICAL TREATISE ON SOAPS AND CANDLES. which the carbonate of lime is decomposed, a part of the soda is obtained in a caustic state. The proportion of caustic soda contained in the carbonate of soda, is as much more considerable as the dose of charcoal has been increased, and that the mixture has been carried to a higher temperature. In a subsequent chapter we shall give the process for analyz- ing caustic alkalies. We think it Avill interest the reader to know the real cost of the substances used and produced, and we give below a detailed table of the expense of manufacturing 20,000 lbs. of artificial soda in France. These numbers are very exact, and deserve full confidence. Baw Materials. Sulphate of soda, 14,000 lbs. at $1.60 the 100 lbs. . . . $224 00 Carbonate of hme in powder, 14,700 lbs. at 6 cents the 100 lbs. . 8 82 Powdered coal to transform the sulphate into carbonate, 7000 lbs. at 22 cents the 100 lbs 15 40 Coal used as a combustible about 3 tons 16 00 Other Expenses. Labor about 6 days 5 00 General expenses 6 00 Total 1375 23 Production. — 20,000 lbs. of crude soda marking 36 alkali- metric degrees. We see by the above table that the expense of manufactur- ing 20,000 lbs. of crude soda is $275.22, which puts the price of 100 lbs. at $1.38. Artificial Salted aS'oc?^.— Artificial salted soda is a mixture of soft soda and common salt. The proportion of salt varies from 25 to 40 per cent, of the weight of the soda. The use of this soda is necessary for the coction of marbled soaps. On account of the large proportion of salt it contains, it has the property of contracting the paste of the soap, and preventing its dissolution in the lye. Like soft artificial soda, it is prepared by the decomposition of the sulphate of MATERIALS USED IN THE MANUFACTURE OF SOAPS. 53 soda by chalk and charcoal, only in the preparation of the sulphate, the quantity of sulphuric acid necessary to decom- pose the salt is diminished, so that the sulphate obtained contains from 30 to 40 per cent, of undecomposed salt. The proportions generally employed are : — Salt 2000 lbs. Sulphuric acid 50°, from . . . 1200 to 1400 lbs. The decomposition is conducted in the same manner as for the soft soda. The sulphate obtained is calcined and mixed with the carbonate of lime and coal in the following propor- tions: — Sulphate of soda Carbonate of lime Coal in powder The substances are reduced to powder, and intimately mixed together. The decomposition takes place in the same manner as for the soft soda. Salted artificial soda has a less constant composition than soft soda. Independently of the strong proportion of salt it contains, it is also more sulphuretted than the latter. This inconvenience is due to a more or less considerable portion of sulphuret of sodium, which has not been decomposed dur- ing the reaction, and is left mixed with th« soda. This inconvenience may easily be remedied by completely trans- forming all the sulphuret into carbonate, by introducing an excess of chalk into the mixture. Thus, an oxi-sulphuret of calcium, very slightly soluble in cold water, is obtained, and by lixiviating the soda with cold water, a solution is ob- tained, which only contains traces of the sulphuret. It is evident, that under many circumstances the sulphuret might be troublesome, and such would be the case, if this soda were used in the fabrication and purification of fine soaps. But we must remark, that artificial salted soda is particularly employed in the fabrication of marbled soaps, and besides its advantage of contracting the paste of the , soap, the sulphuret it contains contributes to develop the beauty and intensity of the marbling. 2000 lbs. 1300 " 9000 " 54 TECHNICAL TREATISE ON SOAPS AND CANDLES. Chemical analysis demonstrates that 100 parts of crude artificial soda contain on an average : — The insoluble residuum is composed of oxysulphuret of lime, and coal. Bejined Carbonate of Soda. — Purified carbonate of soda is designated ih the trade by the name of soda ash. This salt is very important on account of its numerous applications in industry. It is specially used in the preparation of toilet soaps. For their fabrication the richest in alkali is preferred, and principally the one which is entirely free from sulphuret. For a long time this salt was obtained by the lixiviation of the ashes of sea-weeds, but now it is extracted from arti- ficial crude soda. To prepare this salt, select the soda which is richest in alkali, and containing the least sulphuret. The lixiviation may be ettected by various processes. In the manufacture of crude soda, where sal soda is also prepared, the pro- cess is rational, simple, and economical. Baskets made of metallic cloth are filled with coarsely powdered soda, and then successively passed through solutions of soda growing weaker and weaker. The last passage is through pure water. By this operation a solution at 25° or 28° B. is obtained. To have it perfectly limpid, it is left to settle for several days, and is then concentrated. This operation is generally conducted in four cast-iron kettles arranged in steps, and heated by the same hearth. The first receives the heat directly all over its surface ; the flame afterwards heats the others, and then is lost in the chimney. The top kettle is employed to boil the solutions, the middle ones to evaporate them, and the lower one to concentrate them to dryness. During the operation, add new solutions to take the place of the evaporated water, in such a manner that the level of the liquors is always the same. To prevent the salt from attaching itself to the bottom and the Pure soda Salt . 20 to 25 30 to 35 2 to 5 1 to 2 Undecomposed sulphate of soda Foreign salts . . . MATERIALS USED IN THE MANUFACTURE OP SOAPS 55 sides of the first kettle, take it out with a skimmer as fast as it deposits, and let it drain on an inclined plane, or on shelves lined with lead. Continue this until all the solutions are evaporated to dryness. To obtain a very pure and very rich carbonate of soda, some manufacturers evaporate the solution until a pellicle is formed on the surface, and in this state pour it into sheet- iron vats, where it crystallizes. A few days after, the mother-liquor is decanted, and the salt is left to drain. The crj^stals contain only a few hundreths of foreign salts; the mother-liquor contains uncrystallizable caustic soda, sulphate of soda, and chloride of sodium. Whatever be the method of operating, the salt of soda obtained always contains a large amount of water, interposed between its crystals. Be- sides, it is colored by organic substances, which give it a brownish shade. To obtain this salt very dry and very white, calcine it in a reverberatory furnace, strongly heated. Furnaces in which the calcination takes place have their beds entirely covered w^ith a thick and half-melted coat of salt itself ; the bricks or stones being rapidl}^ destroyed under the influence of a high temperature. The carbonate of soda thus obtained is very white, and is much richer in pure soda when the crude soda, from which it is exhausted, is itself pure. The sal soda is obtained nearly chemically pure, as we have said, by concentrating the solutions of crude soda and causing them to crystallize. The crystals being drained and calcined in a reverberatory furnace, yield a carbonate of soda of 90 or 92 alkalimetric degrees. The amount of refi.ned soda ash from crude soda, varies according to the quality of the soda used. Generally, 1000 pounds of good crude soda, at 36°, yield from 380 to 400 pounds of a very white refi.ned soda ash, and marking from 80 to 85 alkalimetric degrees. Crystallized Carbonate of Soda or Crystals of Soda. — Crj^stals of soda constitute the pure subcarbonate of soda. Although less used than the dry carbonate of soda, this salt finds nu- 56 TECHNICAL TREATISE ON SOAPS AND CANDLES. merous applications in the arts. In soap factories it is used to prepare the pure Ije of soda. !N"early all the crystallized sal soda found in commerce is obtained by the lixiviation of artificial soda. To prepare it use the purest and richest soda. The crude soda is lixivi- ated in the same manner as we have indicated above. All the solutions which mark from 20° to 25° B., are mixed in large sheet-iron vats and allowed to rest ; a few days after, when all the liquors are clear, they are decanted and sub- mitted to a gentle ebullition in a cast-iron kettle. When the boiling solutions mark from 28° to 30°, they are poured back into the vats, which are surrounded with coarse cloths, so as to retard the cooling. By resting, a sedi- ment is deposited at the bottom of the kettles, and the liquor becomes perfectly limpid. When the temperature is at 70° to 75° C. (158° to 167° F.), the liquors are decanted and then set to crystallize, either in earthen jars, or in small sheet- iron vats of a capacity of 6 or 8 gallons. In winter, the crystallization takes place in the space of a few days. When the concentration of the lyes has been carried to 34° or 35° B., the crystallization is so complete that very little mother-liquor is left. The concentrated lyes at 28° to 30°, give less crystals, but the product is richer. The caustic soda and the foreign salts remain in solution in the mother-liquor, while in the first case, they crystallize with the carbonate of soda. Another process is also used to prepare the crystals of soda. It consists in dissolving retined soda ash, of a high degree, in boiling water. The operation is effected in a cast-iron kettle. When the liquor marks 30° B., yg^'oxF quicklime, diluted with water, is added to it. After an ebullition of a few minutes the fire is removed, and the liquor is allowed to rest, so as to become limpid. This result being obtained, the clear liquid is drawn off and left to crystallize. The crystallization takes place in a few days ; the salt is then separated from the mother-liquor and allowed to drain. This process yields whiter, finer, and purer crystals than those obtained by the direct treatment of the crude soda. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 57 The first process, however, is generally used because the crystallized carbonate of soda can be extracted from the crude lyes, while, by the second, it is necessary to employ the refined salt of soda. The mother-liquor from the first crystallization yields after a strong concentration at 34° B. a new quantity of crystals of soda, which can be purified by dissolving it in half its weight of boiling water. The uncrystallizable mother-liquor is used to prepare a caustic salt of soda of a weak degree. This salt contains only from 40 to 50 per cent, of pure soda. Crystallized carbonate of soda contains 62.80 per cent, of water, so that 100 pounds represent only 37.20 of dry carbon- ate. This salt is very soluble in water. Boiling water dis- solves almost its own weight, and cold water almost half. In the arts, the great solubility of this salt is utilized to purify it ; for this purpose it is dissolved in the least possible quan- tity of boiling water. The liquor is left to crystallize, and it deposits, by cooling, fine crystals of pure carbonate of soda. This salt is thus formed : — Carbonic acid 15.42 Soda 21.78 Water 62.80 100.00 Caustic Salts of Soda. — The caustic salts of soda represent for the same weight, a larger quantity of pure soda than the same salts when carbonated. Starting from this principle, there is an advantage in using salts of soda, the carbonic acid of which has been partly or totally eliminated, for the ponderal quantity of the missing acid is substituted by an equivalent weight of pure soda. It is thus that in their dif- erent applications of industry, caustic alkalies produce, at equal weights, more considerable results than when in the state of carbonates. The fabrication of the caustic salts of soda is very simple. For this purpose it is sufiicient to mix the crude soda with 30 per cent, of powdered lime (hydrated lime), and proceed 58 TECHNICAL TREATISE ON SOAPS AND CANDLES. with the lixiviation in the same manner as in the prepara- tion of the salt of soda. The result of the washing gives lyes marking about 25° B. These lyes, being clarified by settling, are rapidly evaporated to dryness in cast-iron kettles. The salt is drained and carried into a reverheratory furnace, where it is spread in a layer from three to four inches thick. The furnace is at first heated moderately to dry the salt slowly without melting it, then the temperature is raised until it becomes red. This is an essential condition to expel the water, and destroy the organic matters, which color it. During the operation the mass is stirred, so as to multiply the points of contact of the substance with the caloric. The product thus obtained is white, and excessively caustic. Ex- posed to the air it absorbs carbonic acid, and passes to the state of carbonate. Salts of soda, more or less caustic, are also found in the trade. They are prepared with the mother-liquors from the fabrication of the crystals of soda. These liquors contain in solution, large proportions of caustic soda mixed with dif- ferent salts principally with sulphates and chlorides. By concentrating them to dryness, and incinerating the residu- um, a kind of caustic salt of soda is obtained. From these remarks it may be seen that owing to the facility of obtaining the artificial caustic soda which is now made ready for use and in a very nearly pure state, and that almost all manufacturers of soap are at present using it in their works, most of the caustic soda of commerce will bear analysis for its percentage of sodium hydrate. We give the analysis of an English caustic soda, branded 70°, which we have tested. Sodium hydrate 83.840 Alumiaum chlorate chloride sulphite sulphate silicate 4.686 6.522 4.503 0.039 0.470 trace MATERIALS USED IN THE MANUFACTURE OF SOAPS. 59 This shows at a glance that the caustic soda made for the manufacture of soap is reasonably pure — this sample show- ing no trace of carbonate of soda, the other salts not being in sufficient quantity to impair the soap, which if boiled would almost entirely precipitate with the waste lye. The healthy rivalry of the manufacturers of soda is such that an impure article could scarcely find a market. These sodas possess many advantages to the soap-maker in these days over those formerly in use, and a saving of much time and labor that had to be spent in making caustic the sodas of commerce, which were of such varying qualities and strengths, and filled with so many foreign salts, that it required an expert chemist to anally ze them. At present, when we know the relative purity or strength of a certain make of soda, and by test ascertain the amount of caustic soda it contains, the hydro- meter of Baume will give us the specific gravity, and we can easily judge of the quantity necessary to use. The following table may prove useful in this connection. Specific gravity. Per cent. Specific gravity. Per ceut. 2.00 77.8 1.40 29.0 1.85 63.6 1.36 26.0 1.72 53.8 1.32 23.0 1.63 46.6 1.29 19.0 1.56 41.2 1.23 16.0 1.50 36.8 1.18 13.0 1.47 34.0 1.12 9.0 1.44 31.0 1.06 4.7 It is almost needless to explain that the specific gravity of the solution increases with the amount of caustic soda dis- solved in it. In another section we w^ill give the necessary working tables for manipulation. On the score of economy in the cost of soap-maker's lye, there might be conditions where the barilla, kemp, and other soda ashes could be economically used, but they can hardly apply to this country, unless it be in the far West, where many natural sources of soda are found, and where there are several soda works already established, and whose products rival the English. 60 TECHNICAL TREATISE ON SOAPS AND CANDLES. Caustic Soda from Cryolite. From cryolite, a mineral found in Greenland, a caustic soda is now made in this country, Germany, and Denmark, which is nearly free from impurities. Cryolite is the fluoride of aluminum and soda, and in preparing the soda, the sodium aluminate is dissolved out with water, and decomposed with carbonic acid, the hydrate of alumina being separated, and formed into an alum useful in the arts. The remaining car- bonate of soda is dissolved and condensed to form crystal- lized carbonate of soda, or it is decomposed with lime to form caustic soda, in the manner already described. The sodas from this source are so nearly pure that they claim a preference in the manufacture of most soaps, particularly those made by the cold or extempore process when all the impurities the alkalies may contain remain in the soap. Cryolite is also the most convenient source of aluminum, a valuable silver-like metal. Ammonia. Amynoniaque, Fr. Ammoniak, Ger. Volatile alkali. This important alkali deserves mention here, but has few properties applicable to our art, unless in an analytical test in some experiments, when it can be recommended as a normal alkali free from impurities. For soap it has no practical use, though we find several patents have been given for its addi- tion to other soap where it is claimed to improve its detersive action. It has many uses in pharmacy and the arts, but they are foreign to the subject of our work. RUBINIUM AND CaESIUM are alkalies recently discovered which are analogous to potash in their character, but have no application in the art of making soap, as they are scarce and expensive. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 61 Lime. Chaux, Fr. Kalk^ Ger. Lime, called quicklime and caustic lime, is, chemically, cal- cium oxide, and does not occur naturally, but always with an acid oxide, as carbonate, sulphate, silicate, etc. The use of lime to the soap-maker is important, for by its power of ex- tracting the carbonic acid from alkalies, they are thereby made caustic and suitable for combining with the fatty acids and forming soap, though it does not form a component part of it. A soap can be made of lime and a sebasic acid, but it is insoluble. Lime used for technical purposes is prepared by calcining natural carbonate of lime in kihis. During the burning the carbonic acid is disengaged, and quicklime is the product of the calcination. The qualities of lime essentially depend on the purity of the carbonate used to prepare it. When the calcareous stone (carbonate of lime) is mixed with large proportions of quartz, magnesia, or alumina, a lime of an inferior quality is ob- tained, which slacks with difficulty, and forms, with water, a paste without homogeneity. It is then called poor, and is rarely used in soap-making. Lime prepared with a carbon- ate sensibly pure, that is, which contains only traces of foreign matters, is of a superior quality, and is called /a^. It rapidly combines with water, and grows very warm. If very little water is added, it slacks and forms a white and light powder, with a burning and caustic taste, and turning the blue vegetable colors green. Lime thus prepared is known by two difterent names. For the chemist it is hydrated lime, for the manufacturer it is slacked lime. If a sufficient quantity of water is poured on slacked lime, it combines with that liquid. The elevation of temperature, which takes place during the combination, often reaches 350° C. (662^^ F.). If the quantity of water is large enough, a more or less thin paste is obtained, which is called milk of lime. It is always in this form that lime is used to prepare caustic lyes of potash or soda. 62 TECHNICAL TREATISE ON SOAPS AND CANDLES. Lime recently burned is white, or slightly colored, if the limestone used to prepare it contains oxide of iron. To as- certain if it is completely caustic, treat a few drachms by nitric acid. If the lime is entirely caustic, it ought to dissolve in the acid without disengaging carbonic acid. If there is any effervescence during the solution, it is a proof that it still contains carbonate of lime, which has not been trans- formed into caustic lime. Entirely caustic lime is more de- sirable, as it decomposes the carbonates of potash and soda better. Its density is not constant, it varies according to the nature and purity of the carbonates which have produced it. Its mean specific gravity is 2.4. Quicklime exposed for some time in the air, attracts its water and carbonic acid : it is transformed into carbonate of lime. In this state it has lost all its causticity, and does not possess the property of depriving the carbonates of potash and soda of their carbonic acid. Water will dissolve a certain proportion of lime. Very exact and recent experiments have shown that one thousand parts of water dissolve one of quicklime. That small quan- tity is, however, sufficient to communicate to water a strong alkaline reaction, and restore the blue of litmus paper, red- dened by an acid. Lime-water is a valuable reagent for ascertaining the causti- city of lyes of potash and soda. Pour a small quantity of the lye to be tested into a glass, and add to it perfectly lim- pid lime-water ; if the lye is completely caustic, the two liquors remain limpid ; if, on the contrary, there is in the lye a portion of undecomposed alkaline carbonate, a white pre- cipitate of carbonate of lime is produced. Lime plays an important part in the preparation of lyes. It is the essential and indispensable agent of their causticity. When we examine the preparation of lyes, we shall indicate the special conditions of this operation, one of the most im- portant in its manufacture; We may here state that lime is not an integral part of soap — its action being chemical. It 'jombines with the carbonic acid of the alkaline carbonate MATERIALS USED IN THE MA*NUFACTURE OF SOAPS. 63 with which it is in contact, and forms an insoluble carbonate of lime. The pure alkali, or hydrated alkali, remains in solu- tion in the water, and constitutes the caustic lye used in the fabrication of soaps. We may add, that lime used to prepare lyes must always be of good quality, and, if possible, recently burned. It ought to mix easily with Avater, and should not effervesce with acids. In places where it is difficult to obtain it readily, it ought to be kept in barrels perfectly closed, and in a dry place, because by being exposed to the air it attracts moist- ure and carbonic acid. But when lime-kilns are near a manufactory of soap, it is better to use lime recently burned. When the lime is supposed to contain impurities it would be advisable to submit it to the alkalimetric test, for this pur- pose. Besides titered nitric acid a solution of sal-ammonia is needed, which in one hundred parts, contains about twenty- five parts of sal-ammonia. For this test weigh off exactly 2.8 grammes (43.20 grains) of burned lime, place it in the 100 cubic centimetre (3.38 flu. ozs.) trial glass, add at first some water, so that the lime be slacked and reduced to powder ; then again 40 cubic centimetres of water (1.35 fiu. ozs.), 25 cubic centimetres (0.845 flu. oz.) of the sal-ammonia solution, and finally fill up to the mark with water, until in all 100 cubic centimetres (3.38 flu. ozs ) are obtained, l^ow place a tightly fitting cork in it, shake repeatedly, and allow the whole to clear oft', by settling. Then take 10 cubic centimetres (0.338 flu. oz.) of the liquid into a beaker, which contains already 10 or 20 cubic centimetres (0.338 or 0.676 flu. oz.) distilled water, color with tincture of litmus blue, and admit by means of a grad- uated pipette the normal nitric acid, until the blue color changes into that of a red onion. The cubic centimetres of nitric acid used, multiplied by ten, give the percentage of caustic lime which the tested lime contains. A very good mode for keeping lime for use is to slack it into a stirt' paste and put it into water-tight vats or barrels where it will keep a long time, while only the upper surface having absorbed carbonic acid can be removed before using for causticizing the lye. 64 TECHNICAL TREATISE ON SOAPS AND CANDLES. Water. Eau^ Fr. Wasser^ Ger. Water in the manufacture of soap performs a prominent and indispensable part, and may well be called a raw material. It is particularly important to have it pure, both for the soap and as an ingredient for the lye. There are often dissolved in the water of wells and springs various earthy salts, lime, dolomite, etc. These salts often decompose a portion of the soap, and when used in making or melting they also cause a loss in the causticity of the lye, which in a large factory re- sults in a great pecuniary loss. Thus it is exceedingly important to see that the water used is entirely pure, and if that is not possible, to ascertain the extent and kind of impurities, and to iind a suitable remedy to make the water fit for use. To give exact instruc- tions for the analysis of all waters would require much space which is not possible here. Yet, as it is important we will give the test recommended by Fleck, which not only offers the most reliable but furnishes the most ample and accurate results for the technic, and besides all this, is very feasible. It rests upon the decomposition of the earthy salts which are present in the water, by means of a soap solution of a certain degree. To ascertain the final reaction of the water to be tested, it is only necessary to color the same with an always equal amount of reddish litmus tincture until it be- comes light red. As soon as all the earthy salts are decom- posed by the soap, the liquid takes with a new addition of soap solution, a drop at a time, its former bluish color. The soap solution is so normal, that 20 cubic centimetres (0.676 flu. oz.) of it in 100 cubic centimetres (3.38 flu. ozs.) of a saturated solution of gypsum, become decomposed. By this the degree of hardness of a water is determined ; as also in the case of a water, of which 100 cubic centimetres (3.38 flu. ozs.) require 20 cubic centimetres (0.676 flu. oz.) soap-solu- tion, and is noted as 20; in other words, the cubic centi- metre of soap solution used, expresses the immediate degree of hardness of the water tested. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 65 The main requisite for these tests is an entirely neutral soap ; which must contain neither free nor carbonated alkali. The common soaps being for this purpose seldom applicable, Marseilles soap, therefore, as a rule, is used for this purpose. In the absence of this soap, a neutral soap can easily be made, by dissolving a common oil or tallow-soap in dis- tilled water, and settling it with warm culinary salt, and by washing out the grainy soap with a gradually diluted culinary salt solution upon a filter, till the liquid indicates but a weak alkaline reaction. Finally, the yet moist soap is pressed in linen, in order to remove the still adhering parts of the solution of culinary salt. After drying it somewhat in the air, it is dissolved by warming with about ten times its volume of 70° or 80° alcohol, allowing it to cool off, settle, and then filter. Stronger alcohol must not be used, because the solution would congeal. To cause this soap solution to decompose 20 cubic centimetres (0.676 fiu. oz.), put 100 cubic centimetres (3.38 flu. ozs.) of a satu- rated solution of gypsum into a beaker, color the liquid with some reddened litmus tincture, and add from a 0.10 cubic centimetre (0.027 flu. dr.) graduated pipette or burette, so much of the soap solution as will cause the red color again to become blue. To reach this point with more accuracy, there is next to the first beaker a second beaker, also tilled with gypsum water, which by means of litmus tincture has been colored blue. If on the appearance of the desired blue shade of color, 20 cubic centimetres (0.676 flu. oz.) have been used of the soap solution, it will have the correct titer; but if less have been used, it must in the same proportion be diluted with so much weak alcohol, that 20 cubic centimetres (0.676 flu. oz.) are reached. Supposing cubic centi- metres (0.422 flu. oz.) had been required, then to every 12.5 cubic centimetres of soap solution 7.5 cubic centimetres (U.248 flu. oz.) alcohol would be needed ; if of the first 11 (0.371 flu. oz.) was had, so would need 12.5 : 1000 = 7.5 : X = 600 cubic centimetres (20.28 flu. ozs.) alcohol 5 66 TECHNICAL TREATISE ON SOAP AND CANDLES. to be added, so that 1600 cubic centimetres (1.689 quarts) soap solution are formed, which accordingly is ready for use. Since the waters which are to be tested as to their degrees of hardness, almost without exception, contain larger or smaller quantities of bicarbonate of lime, which reddens the tincfure of litmus, only by boiling can the carbonic acid as an insoluble carbonate of lime separate. The waters must be boiled about five minutes before commencing to add the soap solution, and then be mixed with so much nitric acid that the liquid obtains a light red color. If a nitric acid of a certain strength is applied — for instance of one-tenth equiva- lent to the liter (1.05 quart) (54 : 10,000) — then the quantity of the nitric acid used will also prove the hardness of the water, since 1 cubic centimetre (0.27 flu. dr.) of such an acid corresponds to about 2 cubic centimetres (0.54 flu. dr.) of the normal soap solution. If, therefore, in the testing of a well- water 8 cubic centimetres (0.270 flu. oz.) of the latter acid have been used, while, on the other hand, for the solution of the carbonate of lime 4 cubic centimetres (0.135 flu. oz.) of the ^'(5 standard nitric acid had been applied, it follows, there- fore, that 2 cubic centimetres (0.54 flu. dr.) of the soap solu- tion have to be brouo-ht into account for the carbonate and nitrate of lime, and 6 cubic centimetres (0.203 flu. oz.), hence 6° for the permanent degree of hardness. Every degree of hardness corresponds to 100. cubic centi- metres (3.38 flu. ozs.) 12 milligrammes (0.18 grains) gyp- sum, or 5 milligrammes (0.077 grain) of pure lime, so that for the single degrees of hardness the following values are proved, which permit an approximate conclusion as to the soap which is decomposed by the water. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 67 Degree In ICOO kg. water. 101)0 Kg. 01 Degree In 1000 kg. water. lOUK Kg. 01 of water decom- of water decom- hard- pose soap hard- pose soap ness. with 28 p.c. ness. with 28 p.c. Lime. Gypsum. water. Lime water. 20 1.01 kg. 0.96 " 2.45 kg. 14.75 kg. 10 0.50 kg. 0.45 1.23 kg. 7.31kg. 19 2.33 '* 14.02 9 1.10 6.58 " 0.91 " 2.21 " 13.30 " 8 0.40 " 0.98 " 5.85 17 0.86 " 2.08 " 12.57 " 7 35 " 0.86 " 5.12 " 16 0.81 " 1.96 " 11.85 " 6 0.30 " 0.74 4.89 " 15 0.76 1.84 " 11.12 " 5 0.25 " 0.61 " 3.66 " 14 71 " 1.72 " 10.39 " 4 0.20 " 0.49 " 2.93 " 13 0.66 " 1.59 " 9.67 " 3 0.15 " 0.37 " 2.19 " 12 0.61 " 1.47 8.94 " 2 0.10 " 0.25 " 1.46 11 0.56 " 1.35 " 8.21 " 1 0.05 " 0.12 " 0.73 " But there are some waters the hardness of which ex- ceeds 20°, i. e., such, as besides a large amount of gypsum contain also chloride of calcium and dolomite salts, which decompose a larger amount of soap. The purest waters are rain and snow waters. River water is generally sufficiently pure for making soap and lye. A simple remedy for waters containing lime, is a solution of silicate of soda of 20° B., 5 per cent, of which added to the water will cause the lime to precipitate and leave the clear water sufficiently pure for use. Salt. Culinary salt or sodium chloride playing an important part in the manipulation of soap it is necessary to give some of its characteristics and the impurities that impair its use- fulness and cause a loss of soap. Most of the salt of commerce contains forei2:n salts such as chloride of magnesium, sulphate of soda, gypsum, etc. These impurities decompose a large proportion of soap, forming metallic and insoluble soaps that are either precipitated or if held in the soap impair its detersive qualities and injure its appearance. The salt furnished by the evaporation of sea water is so very impure that it should be entirely avoided. That from mineral springs is very much better though often contaminated with organic matter, while that made from the salt mines or rock salt has, as a rule, the fewest impurities, although it is never entirely pure. 68 TECHNICAL TREATISE ON SOAP AND CANDLfiS. In boiling soap, salt is so important a material for refining that the soap-maker should pay proper attention to procur- ing it reasonably pure, otherwise he may fail in obtaining a good color, or he may lose by the decomposed soap and alkali carried off with the waste lye. Should he suspect that his salt has many impurities he can refine it in the manner indicated for hard water, viz., with silicate of soda. This process is quite simple, it being only necessary to dissolve the salt in a suitable quantity of warm water and to add the solution of silicate of soda in the proportion of say 5 per cent., when after stirring for a time and being left to rest, it will carry down with the precipitate almost all of the lime and other salts, and the soap-maker may use the upper clear portion with confidence.* By means of the crystal carbonate of soda a solution of culinary salt can also be somewhat purified, as the contaminating salts are thereby changed into insoluble carbonates which precipitate and can easily be separated. Fats and Oils. Both fats and oils occur as the constituents of animals as well as plants; in animals these substances are deposited in particular tissues in larger quantities, and are found in all parts of plants, principally in the seeds and fruit; and are characterized by their physical and chemical properties. Such as are liquid at ordinary temperatures are termed fat oils, those that have a soft consistency are called lard or butter, while those that have a higher melting point and are solid at the normal temperature, are classified with tallow and suet. In a pure state they are generally colorless and but of faint odor and are of an average specific gravity of 0.9. They are insoluble in water and but slightly soluble in alcohol, but freely in ether and carbon bisulphide and in volatile oils. Some fat oils absorb oxygen and dry up and are called drying oils, others only assume a rancid state when exposed to the air. When heated to 250° or 300° C. (482° or 572^ F.) they MATERIALS USED IN THE MANUFACTURE OF SOAPS. 69 are decomposed', forming volatile acids of a disagreeable and irritating odor. At a still greater heat they form a com- bustible gas which has three times the illuminating power of coal gas and is very much purer. The fatty bodies are of very great importance in numerous industries, in domestic economy and for lubricating ma- chinery, but perhaps their greatest and most important use is in the fabrication of soap and candies, so indispensable in all civilized countries. We have already mentioned that the true properties and constituents of oils and fats were unknown until Chevreul, Scheele, and others published the results of their researches, their nature and elementary composition, and gave a scientific character to all manufactures into which they entered and particularly to the making of soap and candles. These re- searches have been fully confirmed by all later experiments, and possess so much interest and importance that we shall endeavor to give this branch of the subject thorough and complete treatment. The fats and oils finding application in the manufacture of soap are either of vegetable or animal origin, and either liquid, as linseed oil, hemp oil, olive oil, poppy oil, fish oil, etc., or they are more or less solid, as tallow, lard, palm oil, cocoa-nut oil, etc. Under the influence of alkalies, and the bases of metallic oxides generally, they are all decomposed into various sebacic acids and glycerine. Liquid fats, i. e. oils, assume at a low temperature a firm consistency (linseed oil only at 27° below C, 16.6^ F.), while the solid fats, i. g., tallow, etc., at an increased tem- perature become oily (some even below 100° C, 212° F.). All fats and fatty oils are according to their chemical composition called glycerides, i. g., glycerine combinations in w4iich are comprised according to the theoretical view, of 3 atoms of water or 3 atoms of hydrogen of the glycerine, w^hich is according to the general chemical formula CgHgOg, and 3 atoms or equivalents of sebacic acids. According to the first or older view glycerine is considered = CgH^O, -t- 3H0, and contains, according to this view, a sub- stance, the so-called glyceryl-oxide or lipyloxide, = CgH503, which occurs in glycerine with 3 equivalents of water, but ap- 70 TECHNICAL TREATISE ON SOAP AND CANDLES. pears in the fats combined with 3 equivalents of sebacic acids. In the fats we find especially pal mitic acid of gl jceryl-oxide or so-called palmitin =0^11503 -f 3(C32H3j03), furthermore stearic acid glyceryl-oxide, so-called stearine = CgHjOg + 8(035113303), and finally oleic aid of glyceryl-oxide or so-called oleine = C^H^O, + 3(C,,H3303). According to a more modern view, glycerine is con- sidered as a so-called triple acid alcohol = Og^^ | Og, in which the three separately written hydrogen equivalents (H3) are represented in the fats by 3 equivalents of the above- mentioned sebacic acids. The palmitin of the fats is accord- Pi ) ing to this tripalmitin =0g ^TT^ s [Og*, the stearine is tristearine = Og /p"^TT [ Og ; the oleine is trioleine = The pure fats of the vegetable as well as of the animal kingdom, the tallows no less than the lards and oils, are not combinations of merely one sebacic acid with the above men- tioned glyceryl-oxide, but contain altogether at least one liquid fat, i. e., the combination of one solid and one liquid acid, with glycol-oxide. These combinations have a con- sistency similar to the sebacic acids contained in them, but are somewhat more fusible. Many fats of the most varied origin differ in the pure state only by the relative quantities of the same solid and liquid combinations, which they obtain one from the other ; for instance, olive oil and human fat ; others, howeverj contain the same solid fat as these, but as to their combinations and their properties are an essentially different liquid acid in combination with the glyceryl-oxide. In others again, for instance palm oil and cocoa-nut oil, the solid acid certainly, and perhaps also the liquid acid, is a pecu- liar acid. In general, we have at the ordinary temperature the firm combinations called stearines, and the liquid combinations called oleines. However, we mean by stearine, stearic gly- ceryl-oxide, the combination of a specific accurately known solid acid, which is contained in many animal fats, especially in that of oxen, sheep, etc. By the term oleine or elaine, oleic MATERIALS USED IN THE MANUFACTURE OF SOAPS. 71 or elaic acid glyceryl-oxide, we mean the liquid combination which occurs in a great many animal fats, as well as in many vegetable fats, and in both the same chemical combination exists. A number of vegetable oils, however, contain another oleic acid, which is sometimes called oleine acid. It possesses the property of drying to a tough solid body when exposed to the air, while common oleic acid only thickens to a smeary fatty substance. For this reason the oils which contain the former are called drying oils, and the others fat oils. The second combination of a solid sebacic acid with glyceryl-oxide, which is sometimes mixed with stearine and again with oleine, is called palmitin (margarine), and the acid palmitic acid (margaric acid) is next to the oleic acid the most extensively distributed sebasic acid. It is found as a solid ingredient along with stearic acid in ox-tallow, and in fat as well as drying oils, and palm oil. The pure combina- tions of the above-mentioned substances are odorless ; but the most of the raw fats, those of the vegetable kingdom as well as of the animal kingdom, possess a specific odor, by which they may be distinguished from one another. In some, it orignates from an admixture of volatile oils, for instance, in the oil of mace ; in others from glyceryl-oxide combinations with volatile acids, for instance, lactic acid, valerianic acid, capronic and hircinic acids, as in mutton tallow; in others, as in linseed oil, the odor depends upon unknown admixtures. To the touch the fats are known by their specific lubricity, in water they are all insoluble, most of them also in alcohol, excepting castor oil. Heated alcohol takes up a goodly amount of the fats, which after cooling ofif again almost entirely separate, but they are freely soluble in ether, volatile oils, sulphuret of carbon, chloroform, acetone, and pyrolig- neous acid (wood spirit). They are rich in hydrogen and oxygen, of the latter they contain 70 to 80 per cent, but nitro- gen (azote) is not contained therein. Their specific gravity is always less than that of water, and changes according to the kind of fat between 0.910, and 0.930 at 15° C. (59° F.). The fats in fluid condition expand at every increase of tem- 72 TECHNICAL TREATISE ON SOAP AND CANDLES. perature over 1° C. (33.8° F.) by ysV^ joVu of their volume, so that at 120° C. (248° F.) they have j'^ more volume than at 0° C. (32° F.). In the dark they become phosphorescent, by a slight increase of temperature ; the real fat oils and fats boil only at 170 to 250° C. (338 to 482° F.),the drying oils, however, beween 100 and 115° 0. (212 and 239° F.). No fat can be distilled without decomposition ; while it boils at the high temperature of 800° C. (572° F.), the escap- ing vapors are not those of the undecomposed oils, but those of the formed products of decomposition, which, according to the applied temperature, as well as to the amount or kind of the divers sebacic acids contained therein, vary very much. The glyceryl-oxide is first decomposed, a very volatile body is formed, which is violently irritating to the eyes, at the ordinary temperature is liquid, soluble in water, and is called acrolein. By this property, it is easily ascertained whether a fat-like substance is really fat, a combination of glyceryl- oxide, or not; for the least amount of glyceryl-oxide makes itself noticeable by the intensely sharp smell of acrolein. The oleic acid, too, will be in a great measure decomposed, and but little distils over unchanged. From it is formed the so-called sebacic acid, with a series of substances such as carburetted hydrogen gas, the so-called oil-forming gas (chiefly illuminating gas) and like carburetted substances. If stearic acid be present, it separates in palmitic acid and also in several carburetted substances^ and even the palmitic acid does not distil entirely over unmixed, although a large pait thereof is found among the products of the distillation. If the pressed or rendered fats are exposed to the air, they absorb oxygen, at first slowly but afterwards more rapidly. During the process the so-called drying oils cover themselves with a skin, and thereby withstand the influence of the air much longer. The other oils or fats become somewhat tough and thick, and gain a disagreeable odor, show an acid reaction, and taste sharp and are gritty. This is especially the case when the oils have absorbed much albumen and similar matter from the organs of plants or animals from which they have been obtained. By the shaking up of such oils in hot water MATERIALS USED IN THE MANUFACTURE OF SOAPS. 73 and a small quantity of hydrate of dolomite, this condition, which is called rancid^ may he changed. Many acids ahsorb the glyceryl-oxide entirely or partly from the sebacic acids. If a little hydrate of sulphuric acid for instance is carefully mixed with olive oil, so that no heat- ing ensues, glj^cerine will be separated, which with the sul- phuric acid combines and forms a compound of glycerine and sulphuric acid, while the sebacic acid is free. But if the oil is carefully mixed with half its volume of hydrate of sul- phuric acid, then the sebacic acids combine also with the sulphuric acid and form bodies which by the addition of water are decomposed, transferring all the sulphuric acid thereto, in cold air gradually, by boiling at once, into several other acids, among which, however, neither palmitic nor oleic acid is found. Upon the influence of sulphuric acid on fats, rests in part its application in purifying the same. The oils obtained from seeds by pressure are never free from albumen and other impurities ; a moderate addition of sulphuric acid causes these substances to coagulate and produce in water soluble glycerine sul[»huric acid. If, on the other hand, too much sulphuric acid is used, there will be formed monomargaric, hjdromargaritic, hydromargaric, monoleic, and hydroleic acids, which are very limpid and contain less carbonic acid than oleic and margaric acid. In the melting of tallows and animal membranes, we must be careful in the application of sulphuric acid. A large quantity of this acid makes the melting easier, but we obtain, as experience teaches, tallow which is very fusible, which for the manufacture of candles is not desirable, and obviously originates from the formation of hydromargaric acid, etc. In order to obtain the hardest possible tallow for chandlers, such as even in warm weather may be moulded and may be easily taken from the moulds, the melted tallow should be permitted to cool off very slowly. Stearine and palmitin will then separate in noticeable crystals, and in a tempera- ture of 20° to 25° C. (68^ to 77^ F.), a large part of the olein 74 TECHNICAL TREATISE ON SOAP AND CANDLES. can be removed by pressing. Thus a tallow is obtained which at all seasons of the year may be manufactured into candles. These are harder, less fusible, and whiter, since the olein is generally of a yellowish hue. Such candles are in the market under the name of stearine candles, which must not be confounded with stearic acid candles, which are some- times also called stearine candles. This will be more fully explained in the section on candles. Diluted nitric acid at first acts on the oils similarly to sul- phuric acid. It sets one part of the glycerine free. Con- centrated acid, however, reacts very strongly with it ; they froth violently, and at times even ignition ensues. A great number of products of oxidation are thus formed — volatile and less volatile acids. Nitric acid causes a very singular change in the olein, the sebacic acid, and the fats. The olein of the drying oils does not undergo this change. Without withdrawing from the olein its glyceryl oxide, the nitric acid will change it at the ordinary temperature into a white body, called elaidin, and the acid produced therefrom, the elaiodic acid, is not liquid like the oleic acid, but solid. Both these acids have the same chemical composition. The salifiable bases decompose, as has already been ob- served, the combination of the sebacic acid with the glj^ceryl oxide, and unite with the stearic, palmitic, and oleic acids, and all other sebacic acids, into salts, which are called soaps when the base is an alkali, and plasters when the base is protoxide of lead (litharge). The glyceryl oxide separates, by the combining of 1 eq. of the same with 3 eq. of water, into glycerine. Caustic ammonia produces the same decomposi- tion, but only after a very long time ; or it unites with the oils into a thick and milky fluid, which is known under the name of volatile liniment. Carbonated fixed alkalies form also creamy liquids, from w^hich, however, diluted acids sepa- rate the fat unchanged. Culinary salt and sulphate of copper are dissolved by the fats without changing them. The number of the various fats found in the animal and vegetable kingdoms is infinitely large; almost every kind MATERIALS USED IN THE MANUFACTURE OF SOAPS. 75 possesses a fat or oil which, either on account of its smell, color, etc., differs from the other. In a great part these dif- ferences exist only in the various quantitative mixtures of the liquid and solid parts, and are caused by small, unessen- tial admixtures, a small amount of volatile substances which are to be considered as unessential to the fat. There have been very many different kinds of solid and liquid fats found which have not yet been thoroughly examined. Fats of Animal Origin. Tallows are those fats or greases obtained from the ox, the sheep, the goat, and the deer, and are the hardest, having the highest melting point. The first two named find the most prominent application in the manufacture of soaps, and are mixtures of oleine, margarine, and stearine, in varying proportions, according to the age, the season, and the nature of the food. Animals fed upon dry food furnish the most solid tallow^, that of those that are pastured is less so, while those fed upon swiil furnish a very soft grade. It is also noticed that fat produced in summer is softer than winter fat. The fat occurs enveloped in very thin cellular tissues which are moist in fresh tallow and are easily decomposed and soon undergo a change in the air. It is necessary therefore, especially in summer, to keep it in a cool place or at once to separate it from the membranes by rendering. Besides the three constituents above mentioned, tallow contains the glycerides of some volatile sebacic acids, as lactic, capric, capronic, and valerianic acids, besides some peculiar matters not yet fully tested and explained. To obtain the tallow from the membranes which surround it, the fatty tissues are cut into small cubes, placed in a suitable vessel and exposed to a heat which exceeds that of boiling water. In the beat the membranes are destroyed, the melted tallow runs out and can be separated from the mem- brane by straining. This process has been in practice a long time and is so still. Sometimes a still higher temperature is applied in order to cause the residium to undergo a 76 TECHNICAL TREATISE ON SOAP AND CANDLES. roasting, thereby trying to obtain a greater yield of pure tallow. In general though, this method remains imperfect and a larger or smaller loss of tallow is sustained, much remaining in the tissues, which are but imperfectly opened by this operation and become so hard that they yield the tallow under the press with difficulty. Furthermore it is an impos- sibility to obtain an even temperature with which to operate through the entire melting process. On the bottom it be- comes too high, to the detriment of the color and quality of the tallow. Finally during the melting process are devel- oped from the animal substances gaseous and other vapors of a disgusting odor. The application of steam in lieu of a free fire is but a slight improvement, because the temperature remains too low and besides by the immediate contact of steam with the fat, the substance of the membrane is changed into glue, which can be separated from the tallow only with great diffi- culty. In hermetically sealed vessels by an increased pressure and a direct stream of steam the raw tallow may be melted, the fat finally separating from the glue solution which settles on the bottom. That in the process of mere melting the membrane yields the fat with so much difficulty, is demonstrated especially in the fact that the tissues are not completely destroyed and opened. To manipulate to a more complete opening, various means have been proposed and applied, which answer the purpose equally well so that one or the other is brought into use. Most convenient is the method of allowing the lumps of fat, instead of cutting them into small pieces, to pass through narrow rollers whereby all tissues are opened, and after this the tallow may be rendered in the heat. Another process (by Evrard) consists in the mixing and warming of 300 parts of cut tallow with caustic natron lye (made of 1 part calcined soda dissolved in 200 }.>arts water). The odorous substances, partly volatile acids, combine with the natron and remain in the lye dissolved, while the pure fat is separated. By this mode Faiszt obtained from 100 parts of raw, 88 parts of pure tallow, and from the lye by the addition of acid 8 parts more, MATERIALS USED IN THE MANUFACTURE OF SOAPS. 77 hence together 96 parts. In this manner all the fat may be obtained, and yet no special advantage is found in this pro- cess, especially if we consider the labor, and also the circum- stance that in this case no greaves or cracklings are yielded which find a good and profitable use in feeding swine and dogs. In the same manner D'Arcet, according to his acknowl- edged excellent method, brings diluted sulphuric acid to operate on the raw tallow whereby the important advantage is had, that, by the cbemical destruction and opening of the tissues, the development of the fetid vapors is lessened and they become more bearable. According to D'Arcet the raw tallow is melted with half its volume of water, to which has previously been added 3.3 per cent, of sulphuric acid, keeping the entire mass boiling until the separation of fat and tissues is finished. Although this operation was origi- nally calculated for an open fire, it may nevertheless be per- formed over steam, since by the acid the separation of fat is furthered in a high degree. In the apparatus of Taulet the heating of steam is performed from the outside, in that of Chamby by a direct introduction of steam, whereby the greaves or cracklings are so loosened that they are pressed out with ease, or by mere reboiling render the tallow com- pletely. Experiments with the first apparatus yielded 2 to 4 per cent, more than the operation over an open fire. With regard to the direct introduction of steam, experience has taught to apply less water by an increase of acid, i. 6., to apply about one-fifth water with 6 per cent, acid, since by means of the condensed water the proper proportion is estab- lished. On the same principle as that of D'Arcet, the method of Lefevere is founded. He prescribes the maceration of the cut- up tallow for three or four days in the diluted acid, and then the remelting of it in fresh water. As long as fresh tallow, or at least some which is not too old, is worked, the methods before mentioned are ample, even the simple rendering, espe- cially if the raw tallow has been pressed through rollers. It matters not whether by the one or the other method a few per cent, of fat more or less are gained, if the remaining greaves 78 TECHNICAL TREATISE ON SOAP AND CANDLES. can be used for feeding cattle and swine. Experiments of comparison whether the yield by the one or the other method of melting tallow is more profitable are still wanting. The statement that so much pure tallow was obtained from 50 kilogrammes means nothing, since the raw tallow is un- equal in fat, and yields at one time more, at others less, so that a superabundance of membranes is on hand. The real drawback that presents itself in the rendering out by melt- ing is the unbearable smell, which becomes, not only for the immediate neighborhood but for a wide circle, a source of the greatest nuisance, so that especially in larger cities fre- quent complaints are entered against this evil. Many pro- positions have therefore been made, to have the rendering of tallow performed in such a manner that the bad smell may not appear. The most thorough investigations have been made by Stein, and later by Grodhaus and Fink, in Darmstadt. It is known that the smell of the bad tallow is caused by the decaying of the membranous parts, which thereby taint the fat which in a pure state is less changeable. The chemi- cal change must have great similarity with that which en- sues in the formation of cheese, wherein fat and azotic substances by mutual contact succumb to corruption. In this case at least so much is known — that the smell emanates chiefly from acids which develop their smell not only while free but even while latent in bases. Resting on this, Stein deemed it possible to remove the fetid smell of the tallows melting by a double principle, by either suppressing the corruption or by making their bad smelling product odorless. The experiments which Stein made in- the lirst direction were whereby he applied either antiseptics, as for instance sulphuric acid or tannin, or such substances as destroy putrids, as neutral chromate of potassa, hypermanganesic aeid with sulphuric acid and also nitric acid ; all these however have not had a satisfactory result, and the required operations were more- over too complicated. Stein therefore searched for the other principle by disin- fecting the odorous products and thus removing the trouble caused in rendering tallow. He then started with the belief MATERIALS USED IN THE MANUFACTURE OF SOAPS. 79 that they are predominant volatile oils, so that it was neces- sary to change them into salts, which on their part would be without smell or of a lesser odor. In this case too the purpose could obviously be reached in a dual manner. The salts mentioned could be formed in the liquid itself, or, since the odoriferous acids must needs be volatile, could be formed outside. For the first case lime-water was tried, which mani- festly must needs work similarly to Evrard's method (lye of soda), but in preference to this possessed the undeniable advantage of an always even and very great degree of dilution, so that the free acids in all probability became neutralized, but no fat was saponified, and possibly the lime combinations of the acid were of a less fetid smell than the natron combinations. In fact the smell decreased in a noticeable manner when it was placed in lime-water; but when it was melted therewith, the smell increased, so that the application of lime-water must be avoided. In a very ingenious manner Stein now tried the conversion of the bad smelling acids into ethyl-oxide salts, which have even an agreeable smell. Although a very successful result was hereby reached because the smell vanished and did not re- appear even in the process of melting, however another circumstance happened which retarded the process. The sulphuric acid which separates from the sulphuric ether acid (necessary in the forming of the ethyl-oxide) furthers the solution of the glue producing formation, in consequence whereof the formation of an emulsion ensues from which the fat can be separated only with difficulty. Hence this pro- cess of melting had also to be abandoned. It now only remained to cause the escaping odors, after coming forth, to be made harmless. This process too is based on the idea that these substances are acids, which might be bound by an acidifiable base, and for such Stein applied hy- drate of lime in combination with coarse-grained charcoal— the lime to retain the bad smelling acids, the coal the other bad smelling combinations. For this purpose a 5 to 7 J centi- metre (1.96 to 2.94 inch) wide sieve-crown, which could be placed steam-tight upon the steamboiler, which in place of 80 TECHNICAL TREATISE ON SOAP AND CANDLES. the sieve bottom was covered with canvas, filled with slack- ened lime and fresh-burned charcoal of hazelnut size, and thus placed upon the melting vessel. All vapors which escaped from the latter had to pass through the lime-coal mixture, and proved on their exit perfectly odorless. Although the melting of tallow under application of the described apparatus, which Stein calls the " charcoal cover," is sufficient for the strictest requirements in regard to the objectionable smell, this process will not meet with general use, since it requires a steam-tight sealing of the charcoal cover upon the melting vessel, which in operations in larger quantities is only fulHlled with difficulty. To this must be added, that for every renewed melting a new filling of the cover with lime and charcoal will be necessary. This pro- cess can only be called practical if applied in the melting by steam; but if — as is still the practice inmost soap-boiling establishments — the melting is performed over an open fire, where in the cover a paddle has to be applied, in order to stir the tallow, then the products escape through the opening for the paddle and enter the work-room. To avoid this, the cover and paddle ought to be connected air-tight by means of an India-rubber hose. There is therefore no doubt, after the above stated ex- periments of Stein, that the smell, which is caused by the melting of old tallow, may be removed by chemicals, in one way or another; the carrying out on a larger scale, how- ever, is obstructed by so many difficulties, that it appears quite justifiable to reach the purpose by a more simple and secure remedy. In fact Grodhaus and Fink, of Darmstadt, have abstained from applying any chemical preparation, and endeavored to remove the evil in a philosophical way. Their experiments, which have resulted satisfactorily, are in their totalit}^ so instructive, that ^ve deem it entirely justifiable to report them here in full. The melting of the tallow is performed either in the boiler over an open fire, or by meams of steam melting in large re- servoirs made of sandstone or in wooden vats. It has already been mentioned, that the rendering over an open fire gives MATERIALS USED TN THE MANUFACTURE OF SOAPS. 81 particular cause for developing the bad smell, because, near the end of the melting process, the fleshy and sinewy parts in the fat, the greaves, are constantly burnt, which must be avoided by constant stirring. By this stirring which can- not be dispensed with, the tallow upon the higher sides of the boiler decomposes, and the products which originate thereby are volatilized. For these reasons Grodhaus and Fink believed that their experiments should be extended as w^ell to the dry melting of tallow as to the wet process. The wet method of melt- ing over an open fire could be employed, since by it the same process for diverting the smell may be followed as by tbe method of dry melting. Since the endeavors of Professor Stein to avoid the formation of odors had from the beo-innino; no favorable result, and the method proposed by him to disin- fect the odoriferous gases by meansof the " coal cover" requires much attention and expenditure of time, and for technical as well as economical reasons will hardly ever find application, Grodhaus and Fink, therefore, limited their experiments to the search for easier means of destroying the developing fetid vapors. For these experiments two melting vats were |»laced in juxtaposition, and in them the raw tallow was melted with diluted sulphuric acid and by means of steam ; furthermore, two boilers were placed contiguous to each other over an open fire with their joints — a so-called Russian chimney, which reached about 90 centimetres (35 inches) above the roof of the one-story melting house. In the following experiments, which were made for the purpose of carrying the vapors through the chimney, through one of the already mentioned boiler-fires, a warmed chimney was used, because, if the experiments with such a low chimney would furnish favorable results, a higher chimney would undoubtedly, wherever it existed, promise still greater success. The first experiment was to decide whether the developed vapors by a steam melting process could be burned by means of a common boiler fire. Hence one of the above-mentioned melting coops was provided with a well fitting cover. In this cover was a hole 7J centimetres (2.92 inches) wide, over 6 82 TECHNICAL TREATISE ON SOAP AND CANDLES. which a tin pipe was fixed and carried under the grate of one of the boilers over an open fire. The contents of one of the melting coops consisted of raw tallow, of first and second qualities, mixed Avith the required amount of diluted sulphuric acid. The fire under the boiler close by burnt briskly when the steam was admitted into the melting vat. As the vapors developed therein, it was found that they were drawn off completely through the tin pipe which had been placed upon the cover, and streamed towards the fire ; they passed freely through the grate, the fireplace, and the chimney. But it very soon became manifest that they extinguished the fire, which before the commencement of the steam de- velopment burned very brightly. The admission of steam into the melting vat was now interrupted, the fire was again started afresh and the steam readmitted, and the same obser- • vation made for a second and a third time, viz., that the fire was extinguished. The experiment of drawing the vapors under the grate of a fireplace, and there to burn them, gave according to this trial no favorable result. A second experiment was made in this manner: the tin pipe which was intended to carry the vapors from the melting vat was made to discharge itself into the fireplace. The vapors were easily drawn from the melting vat into the flames, did not extinguish the fire, and did not have the least smell at the opening of the chimne^^ and thus the fetid smelling pro- ducts had been destroyed. This mode of wet melting, where the melting vessel can be supplied with a well fitting cover and the stirring of the contents does not become necessary, can be highly recommended. For a permanent apparatus of this kind a cast-iron inlet pipe would answer the purpose best, and should be immured in the side wall of the fireplace about 6 centimetres (2.36 inches) above the grate, right into the flame where this iron pipe might be placed, while out- side the wall a tin pipe might serve. By a third experiment the tin pipe for carrying off the Tapors was brought into immediate connection with the chimney of the boiler fire. Here too the success was com- plete; the vapors passed off entirely, and no particular smell MATERIALS USED IN THE MANUFACTURE OF SOAPS. 83 could be noticed from the chimney opening. That this manner of carryinjo; off the vapors operates in a high chimney better than in a low chimney is self-evident. Even if it should happen that in foul weather the smoke of the chimney with tlie impregnated vapors should be pressed down into the streets, the spreading of a bad smell would not be so great as if the vapors were dispersed from the melting-room. A further experiment was made by which tallow was melted over an open fire, and where otherwise the well fitting wooden cover of the melting kettle was supplied with an opening for the stirring paddle ; in order immediately to draw the vapors off and admit them into the fireplace and there to burn them up, but this operation led to no practical result. The vapors drew ofi:* but slowly into the fire, and escaped when the open- ing for stirring was not closed, or rather through it and the cracks between the rim of the cover and the kettle, instead of making their escape through the pipe. This arrangement would only be applicable when the cover closes perfectly and an opetiing for the paddle either could be entirely dispensed with, or a steam-tight paddle could be used. This experiment, changed in such a manner that the vapors which develop during the melting over an open fire were carried ofi* by means of a pipe through the chimney, furnished a satisfac- tory result. The vapors vanished so readily that the opening for the paddle might be left open during the entire period of melting without the least escape of vapors or fetid gases. According to the above-described experiments we would recommend, as the most suitable and convenient of all the means thus far known, the carrying off of the vapors and odoriferous matters which form and develop in the operation of either wet or dry melting, by steam or over an open fire, by the application of a pipe to the chimney of a fire after it 18 started. Where the dry melting is preferred, the cover must be made of strong plate-iron and be provided with a slit for the paddle. For the purpose of scooping out the melted tallow, the cover must furthermore consist of two parts which are joined by hinges. Only in rare cases, by reason of inclement weather, may it happen that the vapors 81 TECHNICAL TREATISE ON SOAP AND CANDLES. ■which thus stream tlirough the chimney opening descend into the street and become noticeable. The facts re[K)rted by Grodhaus and Fink we can confirm by our own experience; we will not fail, liowever, to draw attention to the fact, that the chimney used for the carrying off of vapors must be built of well burned bricks, otherwise in its higher parts where a condensation of water takes place it will gradually become soft and be destroyed. According to tiie same method and based on the same principle the melting of tallow is performed in England, with this exception, that the vapors are not, as in the process of Grodhaus and Fink, carried immediately into the cliimney, but are admitted into a wide pipe which is carried into the fire. The absorption here is so strong that not only all vapors out of the melting kettle, but also a certain quantity of air is drawn in with it, and the admission of the vapors will be noticed at the opening of every developing pipe. The com- bustion occurs in the mouth of the pipe, and the gases reach the chimney almost entirely disinfected. In other establishments at Manchester, the vapors are led through a coke oven. In the large soap manufactories of Cowan & Son, twenty square kettles for the preparation of the fat are placed along the wall; every kettle has two openings, of which one opens outside and admits air, while the other is in connection wuth the ash-pit in which the draught may be regulated accord- ing to desire. All kettles communicate with a horizontal pipe which carries the vapors under a particular fireplace. Among the many new inventions for rendering tallow, etc., in a manner to avoid the offensive odors arising from the operation, that invented by Yohl is perhaps the most success- ful. The kettles are provided with covers through which the gases are conducted and consumed. Figure 1 represents this apparatus. A is the cast-iron cauldron, lined with sheet lead, and has a riddled bottom dd; a is sl tap to draw off the waste water; b is the tap through which the fat is drawn ; p is the fire-grate ; B is the door for filling ; c the cover, with a mica plate S S ; in the door is also a mica plate T for viewing the interior. MATERIALS USED IN THE MANUFACTURE OP SOAPS. 85 D is the vessel into which the gases pass by the tube lo ; y is a cover with sand joints r r ; powdered lime is placed in D on oblique shutes to absorb the offensive gases. Any liquids condensed flow off through the pipe A, and the gases and Fig. 1. steam pass into the condenser E, which contains coke moist- ened with sulphuric acid. The liquids pass through the pipe K, while the gases pass through the tube F into the ash-pit G under the furnace. G has a door through which a power- ful draft can be sent, carrying all the gases into the tire to be there consumed. In the rooms in which the raw materials are stored, there generally prevails such an unbearable smell, which the de- composing and putrefying substances diffuse, that it has been suggested to preserve the raw material in closed spaces, these to be connected by means of a pipe with a fireplace or with a high chimney into which all exhalations and the air that enters from the outside through the door cracks may be carried. But this evil might be met in a more efiicacious way ; for instance, by working up the hides and bones, and treating them with phenyl acid, which is furnished to the industries by Dr. Calvert. These hides come from South 86 TECHNICAL TREATISE ON SOAP AND CANDLES. America and Australia. Before they are shipped they are placed in water which contains 2 to 3 per cent, of phenyl (carbolic) acid. Hides treated in this manner showed not a trace of bad smell. A similar contrivance, especially for the melting of tallow for candles and soap manufactories, is used in the estab- lishment of Price of Battersea, England. The raw fats are melted in large vessels which are covered with flat hermeti- cally fitting covers of lead and riveted to the wall. In the centre of the cover is a square opening of 80 centimetres' (81 inches) width, which is supplied with a water trap, and makes the attention to the vessel convenient. Upon the cover is placed the short end of an inverted [\_ forming pipe of 15 centimetres' (5.89 inches) diameter, the other end of which being 4J metres (14.76 feet) long runs under the floor- ing of the work-room and opens into a canjil. In the lower part of the pipe enters another pipe which is in connection with a force-pump which squirts water through a ro.se from above. The vapors in the vessel condense as soon as they come in contact with that stream of water, and the descend- ing liquid matter impregnated with all the miasms flows into the Thames. There are yet a number of other ways for rendering tallow, which, however, are mostly but modifications of the one or the other of the above-stated methods. Thus, the tallow in many establishments is rendered over an open fire or by steam, pressing the greaves and treating them again sepa- rately with diluted sulphuric acid and heat. By this means the cellular tissues are destroyed, the tallow flows out com- pletely, and is washed out at first with a sub-lye and lastly with water. In more modern times in many of the larger soap manufactories, rendering modes have been introduced which are described in our article on lard. Lard. In the United States hog's lard has numerous applications in the arts, and occupies an important place in commerce on MATERIALS USED IN THE MANUFACTURE OF SOAPS. 87 account of the large quantities produced and the many useful purposes for which it is used. Not the least important are Fig. 2. 88 TECHNICAL TREATISE ON SOAP AND CANDLES. those of soap and candles. Lard consists of about 63 parts of oleine with 37 parts of stearine, the oleine or oil having many uses while the stearine is used in the fabrication of soap and candles. In making candles it is treated chemically, produc- ing stearic acid and glycerine, being rich in this latter useful article; while the oleine or red oil is made into soap. This process will be detailed in our section on candles. Lard is much used in cooking and is generally pure, yet it is sometimes sophisticated with the stearine from cotton- seed oil. It is rendered or melted in several ways, chiefly by the open fire, for it is made in nearly every farm-house. In cities and in large operations steam is found to i)resent the most economical mode. Many inventions are in use for rendering lard, and among them few are more appropriate than the one here illustrated for rendering tallow and lard by steam and pressure, Fig. 2. Bendering by Steam. Wilson^s Process. The apparatus consists of a series of steam-tight digesters, each of 1200 to 1500 gallons capacity. These digesters are composed of boiler-iron plates tightly riveted together in the form of an inclosed cylinder, in length about two and one-half times greater than the diameter, and are furnished with dia- phragms or false bottoms. The drawing. Fig. 2, is very ex- plicit, and the mode of working these machines, and the use and application of their various appointments will be men- tioned in reciting the process as practically carried through in the laboratory of the inventor. It is as follows : The false bottom being arranged in its place, and the discharging hole closed up, the steam-tight iron tank or cylinder is filled through the man-hole with the rough lard material, to with- in about two and a half feet of the top. This d(me, the man- l)late K is securely fitted into the man-hole H, and steam let on from an ordinary steam boiler, through the foot valve, into the perforated pipe C within the tank. Set the w^eight on the valve at the requisite [)ressure, and during the steam- ing, frequently and carefully assay as to the state of the con- tents of the tank by opening the try-cock R. If the quantity MATERIALS USED IN THE JVIANUFACTURE OF SOAPS. 89 of condensed steam in the tank is too great, it will be indi- cated by the ejection of the fatty contents in a spurt. In such a case it is then requisite immediately to open the regu- lating cock X and draw off the condensed steam, through it, into the receiving tub T, until the fatty matter ceases to run from the try-cock aforesaid. After ten or fifteen hours' continued ebullition, the steam is stopped oft", and that excess already in and uncondensed, allowed to escape through the try-cock and safety-valve. After sufficient repose, the fatty matter separates entirely from water and foreign admixture, and forms the upper stratum. It is drawn off through the cocks jpp in the side of the tank, into coolers of ordinary construction. The tank being emptied of its lard contents, the cover F is raised by means of the rod G, from the dis- charging hole E, and the residual matters at the bottom let out into the tub T. If, on inspection, the contents of this tub have retained any fat, it must be again returned to the tanks, when they are being filled for a fresh operation. Experience has determined that, to produce the best result, the steam pressure should be not less than fifty pounds to the square inch, though that often used is seventy-five pounds, and may be augmented to one hundred pounds when it is desired to expedite the operation. We should, however, advise against so high a pressure in the preparation of tallow; it may do well enough for lard ; but if these closed tanks are made to operate as digesters, the efiect produced by the decomposition of bones and other matters, which, in the wholesale way of preparing fats at the West, are generally thrown in indiscriminately with the rough suet, would be to deteriorate its quality. The better way is to take a little more time, and thus insure a better result. The process is sufiiciently economical as it is, for, wiiilst by a pres- sure of between fifty and seventy pounds, the bones, etc., are made to yield all their oleaginous or fatty matter, there is no action occasioned whicli will convert them into an offensive constituent. In making lard from the w^hole carcass of the hog, excepting the hams and shoulders, a yield is always obtained, by the use of this apparatus, full twelve per cent. 90 TECHNICAL TREATISE ON SOAP AND CANDLES. greater than by any other methods ; whilst in rendering tal- low, the gain exceeds the product furnished by the ordinary plans at least six per cent. To say nothing of the economy both of time and labor (fifty per cent, of each), the material obtained is so much superior, that it always commands, if not the preference, at least a slight advance of price, in the market. The marc or residuum, thrown out into the tub T, being rich in nitrogenous and phosphated matter, when dried and mixed with bog or street earth, and gypsum, makes manure equalling the best guano. Proper management of the apparatus will generally pre- vent any escape of the offensive vapors incident to the ope- ration ; but occasionally leaks will occur at the valve. The condensed steam carries down all the impurities of the fat, and leaves it clean and white. Moreover, it is firm if rapidly cooled in vessels of small capacitj^, for the temperatures of large volumes fall so slowly, that partial granulation ensues and softens its consistency. With all these advantages, however, this process is not wholly faultless ; for the difficulty of separating all the water slightly endangers the purity of the fat, as the former intro- duces, in solution, a portion of animal matter, which, in time, becomes putrescent, and imparts an offensive smell to the latter. Repeated washing of the fat with fresh water, and careful remelting and settling, would remedy this defect in a great measure. Butter finds but little application in the manufacture of soap, on account of its cost, though if it were less costly it would prove a very advantageous material particularly for toilet soaps, as soap made wnth it is of beautiful consistency and appearance, and it is subject to less loss in saponification than most other fatty bodies. Butter is the fatty substance with which the globules of milk are formed. These globules do not freely float in this liquid ; they are surrounded by a very thin membrane, which MATERIALS USED IN THE MANUFACTURE OF SOAPS. 91 prevents them from joininoj together. When, by any pro- cess, they can be united, butter is formed. A butter well prepared must be of a fine yellow color, of a middling con- sistency, with a peculiar and slightly aromatic odor, and an agreeable taste. It must be easy to cut into slices. The composition of butter seems to be very complex. M. Chevreul has demonstrated that this body contains five neu- tral substances, which are, olein^ margarin^ butyrin^ caprin^ and caproin. These fatty bodies, treated by alkalies, are saponified and transformed into oleic, margaric, butyric, cap- ric, and caproic acids ; the last three are volatile, and can be separated from the two others by distillation. According to Heintz, butter contains ordinarily olein, much palmitin, a little stearin, and small quantities of neu- tral bodies giving by saponification myristic and butyric acids. Butter dissolves in 28 parts of boiling alcohol at 35° C. (95° F.); it melts at 36° C. (96.8° F.). It becomes rancid very easily; this alteration can be prevented by salting or melting it. Butter washed with warm water, cooled and pressed yields, by successive crystallizations in a mixture of alcohol and ether, a substance melting at 48° C. (118.4° F.), which presents the characteristics of margarin. The liquid fatty body ex- tracted from butter by pressure is almost entirely formed of a substance different from olein, and is transformed by saponi- fication into glyceryl oxide and a new acid, oleo-huiyric acid. The relative proportions of the immediate principles of butter vary under different circumstances; however, the fol- lowing composition has been assigned to it : — Margarin . 68 Butyrolein 30 Butyri 3 92 TECHNICAL TREATISE ON SOAP AND CANDLES. Bone Fat The grease contained in the bones of the sheep and the ox is a very useful material for soap, saponifying in the same manner as tallow, though making a softer soap, its melting- point being much lower. It usually contains many impuri- ties ; that extracted from fresh bones finds application as a very fine lubricator for machinery. To produce this fat, the bones are broken, as much as pos- sible in a lengthwise direction. Where large quantities are worked up — as in bone-kilns — they are crushed by passing them through iron rollers. The crushed bones are then put into a kettle, partly tilled with water, and heated to the boil- ing point, which causes the fat to float on the surface, where it is skimmed off with a flat iron-spoon and passed through a sieve, which retains the solid particles. When it is noticed that no more fat separates, the bones are taken out, by means of a large perforated shovel, and replaced by fresh ones, so that the water may be used several times. The fat thus obtained is generally of a brownish color and of an unpleasant odor, and when cooled oft', congeals to a grainy, smeary consistency, and retains some water, which may be separated by remelting and settling. The soda soap made with bone fat is not very solid, but with a suitable quantity of linseed or hempseed oil and potash lye a soft soap is made, which after some little time shows a very fine so-called natural grain derived from the crystallized stearic and palmitic acid potash soap. In several places still another kind of bone fat is yielded, in the process of making glue. This fat is at the ordinary temperature liquid like oil, and has a dark brown color, which, however, does not pass over into the soaps boiled therein, but by salting passes down into the sub-lyes, so that a nearly white soap is yielded, which is not very hard. Hence it is customary to mix it with other fats, palm oil, tallow, etc. This fat often contains from two to three per cent, of lime, most likely lactic acid lime, which is soluble in fat oils. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 93 This lime causes the fats boiled in the soda lyes to become spongy, and can only be separated by adding culinary salt, and then with difficulty. To avoid these troubles, the lime should be separated, which can very easily be done if the fat is worked with a sufficient quantity of water containing sul- phuric or muriatic acid. Whether or not such a fat contains lime, can be ascertained, if a sample thereof is mixed with a solution of oxalic acid and well stirred. If lime be pre- sent there appears after a little while a liquid, which be- comes muddy by the formation of oxalate of lime ; in the other case the water which is under the oil appears, after separating from the oil, entirely clear. Horse Fat. This fatty body, though repulsive on account of the care- less manner in which it is prepared from the carcass, is yet, when extracted from the recently slaughtered animal, a very suitable and good material for the manufacture of com- mon soap, the product with soda lye being white and of good consistency. The appearance of this fat varies according to the organs from which it is taken, and the care given to its production. It is either solid, forming a real tallow, or it is more or less of the consistency of lard, and is generally of a dirty-white color. The horse fat which appears in commerce, and which comes from slaughtered horses, and appears to be produced with more care, of course deserves in many respects the pre- ference. It is almost odorless, of a yellowish tinge, of the consistency of butter, and yields just as white and solid soap as pure tallow or bleached palm oil, and does not impart to the clothes washed therewith that disagreeable smell which they acquire from the common horse fat soap. Glue Fat. In making glue from hides, tendons, etc., much fat is col- lected which if well prepared can be usefully employed in 94 TECHNICAL TREATISE ON SOAP AND CANDLES. making soap. As found in commerce glue fat contains a large amount of lime and other impurities, which can, how- ever, be extracted with dilute sulphuric acid. When the fat is boiled in a live per cent, solution of sulphuric acid for about an hour, the lime and other impurities are carried down with the water, the clear grease floating on the surface whence it can be ladled off. This sebacic acid will then make with soda Ije with or without rosin a good and firm soap, useful for all domestic purposes. It should be boiled, for in the Swiss or cold soaps it would not answer so well. Neat's Foot Oil. If this product were abundant it could be usefully applied in making soaps of good quality, but it is generally used for dressing leather, for which it is admirably adapted. It is prepared by boiling in water the feet of cattle deprived of flesh and sinews, and removing the grease which floats upon the surface. It is of a greenish-yellow color, and if fresh has no odor, is limpid at ordinary temperatures, becoming solid in the cold. It forms w^ith soda lye a very fine white soap partaking of the nature of the fat, being somewhat soft, olein being the largest constituent of the oil. Kitchen Fat. The refuse fat of families, hotels, restaurants, etc., finds a very useful purpose in soap manufacture, and when it is sys- tematically collected and properly purified becomes of much value. It is, however, often of inferior quality, being soft, green, and limpid, and in this state is termed weak stock. In this condition it may be much improved by boiling with salt and alum, but a much better mode would be the purifi- cation with dilute sulphuric acid, a process often mentioned in this treatise. We deem the utilization of this and other refuse greases and fats of so much importance that w^e shall give a special section more fully explaining it. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 95 Fish Oils. In this category are classed the oils from a very numerous variety of animals many of which are not, strictly speaking, fishes. The oils of commerce are extracted from whales, seals, porpoises, and many kinds of fishes, and are almost always designated by the name of the source, as whale, seal, cod-liver oil, etc. Many called train oils are extracted from the seal, herring, etc. Train oil has a specific gravity of 0.925 to 0.930, and is principally composed of common olein with palmitin. Its peculiar smell originates from valerianic acid, glyceryl oxide, and a substance which is considered to be a combina- tion of a special acid, viz., dolphic or phocenic acid, with glyceryl oxide. Various means are applied in purifying the bad smelling and dark colored train oils. Shaking with milk of lime, with diluted potash or soda lye, culinary salt, and copperas is common, as well as filtering with wood ashes. According to Davidson, train oil should be shaken with a decoction made of oak bark, then have mixed with it 4 parts of chloride of lime (bleaching powder) stirred into 12 parts of water, permitting it to clear ofi', when a thick whitish mass will be separated, and add diluted sulphuric acid to settle the lime which be- comes free. We are convinced, by experiments which we have made on a large scale, that this means is by far the best of all those used for disinfecting, since train oil loses by this treatment the greater part of its disgusting smell, so that such train oil unsaponified appears almost odorless. But nevertheless the smell reappears when the train oil is changed into soap. Hence train oil can only be used in manufacturing very common soaps, or by mixing small quantities of it with other fats. Cod-liver Oil is obtained from three species of fish, viz., from the torsk {Gadus callarias)^ the say {Gadus carbonarius), and the shark 96 TECHNICAL TREATISE ON SOAP AND CANDLES. {Gadus poUackhis) ; in France, according to Gobeley, from the livers of Baja batis and Raja cavata. It has been proposed .to term the first sorts Morrhua oil, and the latter Raja oil. The shark livers furnish the oil but slowly ; they must there- fore be cut up into pieces and boiled down. The say livers, as well as the torsk livers, w^hen thrown into water have a great portion of their oil to flow out spontaneously ; that of the latter is a thinner liquid but somewhat darker, while that of the former is lighter but of a thicker consistency. All livers are finally boiled down, and furnish ordinarily the - common cod-liver oil, which, however, never possesses the disao-reeable smell of common train oil. The main bulk of cod-liver oil is likewise composed of palmitic acid (11 to 16 per cent.), oleic acid (70 to 74 per cent.), and glycerine (9 per cent.) ; furthermore of a peculiar sub- stance, called gadidn, a body of the nature of a weak acid, small portions of lactic acetic acid, valerianic acid, gall substances, iodine, phosphorus, sulphur, traces of bromine and inorganic salts. By shaking up with water the dark cod- liver oil becomes somewhat lighter, since a part of the pig- ment substances are dissolved. Diluted sulphuric acid causes the separation of brownish flakes ; concentrated sul[)huric acid causes the train oil to become of a brown color. Train oil has the property of dissolving large quantities of colophony, without thereby changing its consistency, i, e., not becoming a thicker liquid. Rosin being usually much cheaper than train oil, this peculiarity has been utilized for the pur- pose of adulterating it. Such an adulteration is, however, ^ easily detected by placing the suspected train oil in a flask with an equal volume of alcohol, and shaking it, when the rosin will be completely dissolved. When left to settle, both liquids separate into two layers, of which the lower is the train oil. By kee[»ing a record of its original volume we may conclude how^ large a quantity of rosin had been added, making an allowance for a small portion which had been dissolved in the alcohol. Sometimes the fat of sahno-phymallus^ known under the name of ash-fat^ is brought into commerce in place of train MATERIALS USED IN THE MANUFACTURE OF SOAPS. 97 oil. It is a mild yellow oil, which has a weak fishy smell, and is for making soap no less applicable than train oil. The vegetable oils applied to the manufacture of soaps are very numerous and valuable, and are found in the fruits, seeds, etc., of plants. They are usually termed fixed oils, and are generally limpid at ordinary temperatures; some, however, have more or less consistency, containing palmitin, stearin, etc., combined with the olein. All have a specific gravity less than water, or about 0.920. We append tables of the usual vegetable fatty bodies em- ployed in making soa}>, with their sources of production and their j\e\d from the seeds, etc. : — Oils and Fats of Yegetablk Origin. Fixed oils. Olive oil . Groundnut oil . Hempseed oil . Almond oil Coleseed oil Rapeseed oil Cocoanut oil Cotton-seed oil. Beechnut oil Cocoa butter Hazel-nut oil Poppy oil . Ben oil Laurel oil . Linseed oil Castor oil . Camelina oil Nut oil Sunflower-seed oil Sesamum oil Pitch-tree oil . Pine oil egetables which produce them. Olea Europaea. Arachis hypogaea. Cannabis sativa. , Amygdalus communis. , Brassica oleracea. Brassica napus. Cocos nucifera. Gossypium hcrbaceum. Fagus sylvatica. . Theobroma cacao. Corylus avellana. Papaver somniferum. Guilandina morinffa. Laurus nobilis. Linum usltatissimum. Kicinus communis. Myagrum sativum. Juglans regia. Helianthus annuus. Sesamum orientale. Pinus abies. Pinus sylvestris. Etc. etc. The following table gives the quantities of oils which may be extracted from the vegetables: — 7 98 TECHNICAL TREATISE ON SOAP AND CANDLES. 100 parts in weight. Oil extracted. 10) parts in weight. Oil extracted. Nut ... . 40 to 70 Euphorbium 30 Castor . . . . 62 Wild mustard 30 Hazel-nut 60 Camelina 28 Cress . . . . 56 to 58 Woad . . . . 29 to 36 Sweet almonds . 40 to 54 Gourd . . . . 25 Bitter " 28 to 46 Lemon -tree . 25 Black garden poppy . 56 to 63 Onoporde acanthe 25 Radishes 50 Epicea seeds 24 Sesamum 50 Hempseed . 14 to 25 Linden 48 Linseed 20 to 30 Earth-nut 43 Black mustard 1.5 Cabbage 30 to 39 Beech . . . . 15 to 20 White mustard 36 to 38 Sunflower seed 25 Turnip .... 33.5 Apples . . . . 15 Plum . . . . 33.5 Grapestone . 14 to 22 Coleseed 36 to 40 Horsechestnut 8 Rapeseed 35 to 40 Olive . . . . 12 to 20 Cotton-seed . 20 Physical Pro'pprties of Oils.- -Fixed oils, at the ordinary tem[ierature, are nearly always liquid ; some however, such as palm oil, cocoanut oil, etc., are more or less consistent. They are also more or less mucilaginous, with a feeble taste, sometimes disagreeable. Some are colorless, but generally they have a sight yellow tint; some are of a greenish-yellow color, and this color is due to a peculiar principle they hold in solution. Their sjiecific gravity is le>s than that of water, all floating on this liquid, but it varies. Olive Oil is perhaps the oldest known and used for the purpose of making fine soaps, and possesses all the best characteristics for the purpose, making a firm white soap having an agree- able odor. At ordinary temperatures it is fluid, but at a low degree of heat it congeals, the stearin crystallizing. It consists of about seventy-five per cent, of olein with twenty- five per cent, of stearin. Olive oil being consumed as food in large quantities, there is much care taken to produce a fine quality for this purpose, and the best of the first and second pressing is usually re- served for table use. It is obtained from the ripe olives by MATERIALS USED IN THE MANUFACTURE OF SOAPS. 99 submitting the crushed fruit to a pressure either between warmed iron phites, or heating the mass slightly, before put- tino; it into the bao^s. The first oil is called viro^in oil. The marc, being again steamed or heated, is submitted to the press a second time; this product is still a very good oil. At the third pressing the marc is often mixed with hot water, and when it is pressed the oil runs out combined with the water and some albumen and floats upon the surface, whence it is skimmed off. For an inferior oil the marc is thrown into vatsand allowed to ferment ; the remaining oil being liberated floats on the surface. This last oil i;* usually mu(;h colored and of unpleasant odor, but it is the oil usually applied in making soap. The resulting soap does not retain either color or odor, but is white and sweet. The oil of manufacture, or huile (Vir^fer^ as the common oil is termed, is consumed in large quantities at Marseilles and elsewhere, to the amount of nearly four million gallons per annum, principally in manufacturing the Marseilles or castile soap, and, owing to its great value, it is the subject of much adulteration with other bland or sweet oils, princi- ply nut oil, sesame oil, j>opjty oil, aiid cotton-seed oil. The detection of these sophistications is quite a difficult matter, although we give elsewhere some directions for that pur|)Ose. Olive oil, though making some of the best soaps known to commerce, is now seldom used alone, the soap becoming when dry too hard for general purposes. It is now customary to add to it a certain quantity of hemp-seed, rape-seed, poppy-seed, or ground-nut oil, these oils being slightly dry- ing oils and producing a softer soap, qualify the olive-oil soap in its consistency. Palm Oil may be considered next in importance to olive oil in the fabrication of soap, for which purpose it is consumed in vast quantities, in England especially, where it was first used. It enters into nearly all their best rosin soaps, and this admix- ture has given both character and popularity to English 100 TECHNICAL TREATISE ON SOAP AND CANDLES. yellow soaps. It is also used advantageously in many soaps for toilet purposes. It is obtained from the fruit of a species of palm, the Avoira Mais or JElais guianensis ; according to others, however, from Cocus biitf/raeea, as well as from an areca species. It is, how- ever, not improbable, that all these plants produce similar vegetable oils. Palm oil is a [)roduct of the soil of tropical Africa and South America (Guiana); the Canary Islands, and also of some other regions. Owing to its general ap- ].)lication in manufacturing soMp it has become a very im- portant article of commerce, a place to which it was as- signed by dint of a renmrkable connection of circumstances, and by the endeavors of the English government in the suppression of the slave trade. Since this traffic, by the measures taken against it by Etigland — if not yet entirely suppressed — is much limited, the natives of those coast dis- tricts are compelled, in lieu of as heretofore trading in human beings, to pay for their necessary commodities, at this day, with some of the useful products of the African soil, includ- ing palm oil. The largest consumption of palm oil is in England, which country, in 1879, imported 147,993,216 lbs., but the consumption of it is also very great in Germany, France, and the United States. The ditJerent kinds in the market have various names; the prima logos and secunda lagos being the most excellent ; the former can be more easily bleached than the latter. The fruits of these palms are of the s^ze and dimension of a pigeon's egg, and contain a solid kernel under a fleshy cover. The pain] oil is extracted from this latter, not from the kernel. For this purpose the pared flesh is boiled out in water, when the oil collects on the surface in a fluid state, and can easily be skimmed oflf. After cooling off it forms a reddish-yellowy fat of the consistency of butter, which melts at 29° C. (84.2° F.). Since the word oil is applied to desig- nate the liquid fiUs, the name of i)alm oil is an improper one ; palm butter would be more correct. Its smell is strong, but agreeably aromatic, and reminds one of orris root. As it ap- pears in commerce, the palm oil is always more or less rancid, MATERIALS USED IN THE MANUFACTURE OF SOAPS. 101 e. I., it contains free sebacic acids, instead of being in the fresh state neutral with glyceryl oxide. The quantity of these free acids increases with age, and at the same time the melting-point rises: the dark orange-red color changing into lemon-yellow. Pelouze and Bendot found in fresh palm oil one-third, in that which melted at 31° C. (87.8° F.) (me-half, in another sample, which melted at 36° C. (96.8° F.), four-fifths of its weight in free acid. In very old palm oil, Stenhouse found the melting-point 37° C. (98.6° F.). From the tests made by Fremy and the above-mentioned chemists it was o^leaned that this veiretable fat contains free oleic acid, a specific sebacic acid, palmitic acid, and some palmitin, e.i., palmitic acid oxide of glyceryl. The latter can be obtained by pressing the palm oil at 10° to 12° C. (50° to 53.6° F.), and a second time at about 20° C. (68° F.) in large quantities, as a wax-like white mass, of which a sort of stearin candles can be njade, while the yellow oil that flows oft* may be made into soap. Since the reddish-yellow color of the palm oil is not de- stroyed during saponification, but remains in the soap, the oil must, if w4iite soaps are to be manufactured, first be bleached. This is done, either by means of oxides, as muriatic acid, nitric acid, sulphuric acid, etc., alone or with permanganate or chromate of potassa, or by heating the palm oil to a certain degree. In all these cases the color will be more or less com- pletely destroyed, without reappearing in the soap. It must, however, be observed, that the bleaching by means of oxida- tion generally, especially with sulphuric acid and chromate of potash, furnishes a better and a whiter oil, and is more easily accomplished, although more expensive, than the bleaching bj^ heat. The latter requires, moreover, more at- tention in the managing of the process, and a greater loss (from three to four and a half per cent.) is entailed, than by the first method. For the bleaching of palm oil by means of bichromate of potassa, a quantit}^ of palm oil is melted at 60° C. (140° F.), and left standing over-night, so that all impurities may 102 TECHNICAL TREATISE ON SOAP AND CANDLES. settle upon the bottom. On the day following, the clear oil is placed in a clean barrel and allowed to cool off to 40° to 38° C. (104° to 100.4° F.). At the same time a portion of water is heated to the boiling-point, and in this is dissolved a suitable quatitity of bichromate of potnssa. If for instance 1000 kilogrammes (2200 lbs.) of palm oil are to be worked, 45 kilogrammes (99 lbs.) of water are taken, and 15 kilo- grammes (33 ll>s.) of the bichromate of potassa are dissolved therein. After the solution has cooled oft' somewhat, pour in 60 kilogrammes (132 lbs.) commercial muriatic acid. This mixture of chromic acid salt solution and muriatic acid is now poured into the palm oil, which during this process is being well stirred. After a period of tive minutes, the oil becomes dark-green, by separation of chromate or by for- mation of chrom-chloride, which by a continuation of the stirring entirely separates, or is retained by the water in solution. Should the oil not yet be sufticiently bleached, the operation should be repeated by using I kilogramme (8.8 ozs.) bichromate of potassa and 1 kilogramme (2.2 lbs) muriatic acid, as before. The bleaching of palm oil by the application of heat is more simple, but does not readily furnish such a clear oil as is required for some soaps. Here two things have to be ob- served : first, that the heat is not too much increased, be- cause the oil might assume a disagreeable brownish color, which appears in the soap; secondly, that the oil is previ- ously melted upon water, or at least melted at a moderate heat, and left to rest for a short time, and poured oft* as clear of all sediment as possible. If the latter, consisting espe- cially of small pieces of fruit and of small imperfect fruits, is heated with the oils which are to be bleached, a good oil is never obtained. The temperature which is applied in this case varies, and some operators go as high as 160° C. (320° F.); but it is found that [)alm oil can be bleached thoroughly at 120° C. (248° F.), or as much as is possible by the process of heating. The contact of the air accelerates the process of bleaching; and palm oil is bleached the fastest and best in a kettle which is covered with a well-fitting lid, in which MATERIALS USED IN THE MANUFACTURE OF SOAPS. 103 an iron pipe of 7| to 10 centimetres (2.9 to 3.93 inches) thick- ness is inserted, which opens in the chimney of the fire space, of the kettle similar to the apparatus used hy Grodhaus and Fink or Yohl, elsewhere illustrated, for the removal of the fetid vapors in the pn^cess of rendering old tallow. This has at the same time the advantage, that the sharp poignant smelling vapors are removed without any danger whatever, since it is performed at the lowest possible temperature with- out the oil becoming in the least brown, and the process is finished in from three to ten hours, according to the quantity. It is generally i)referable not to bleach too large quantities at once, indeed there is rarely a saving of time; since a portion of 400 kilogrammes (880 lbs.) bleaches in four separate por- tions, /. 6'., each time 100 kilogrammes (220 lbs.) easier and better than when all is taken at once. The finishing of the bleaching process is best ascertained by placing from time to time a few drops of the oil upon a porcelain plate, and thus comparing their color. As soon as it is observed that the succeeding drops are no longer of a difierent shade of color than those preceding, the operation is considered finished. In cooling ofi' the bleached oil, great care must be taken in adding water to it, for if it is not performed with the greatest care, an explosion may ensue. It is niore judicious to add a portion of formerly bleached cold oil, until the tem- perature has sunk below 100° C. (212° F.), when, without the least danger, water may be added to hasten the cooling ofi", so that the oil may be drawn oft* into wooden vessels. If carefully conducted the palm oil thus bleached possesses either a light yellowish color, or it is of a greenish hue probably emanating from a small quantity of copper from the kettle. The soap boiled from it is not entirely white when fresh, but assumes whiteness after being a short time ex- posed to the light. By the bleaching of palm oil, not only the color of the oil and the glyceryl oxide are decomposed, but the palmitin also while losing 1 equivalent of carbon and 1 equivalent of hydrogen is changed into palmitic acid which causes a loss 104 TECHNICAL TREATISE ON SOAP AND CANDLES. of about 2.75 per cent, in oil, which by the bleaching with chromate of potassa and muriatic acid is avoided. Palm oil is sometimes confounded with galam butter, shea butter, or bambuk butter, which has much similarity with it, possesses a dirty-white or reddish color, and melts at 80° 0. (86° F.), readily becoming nincid, and in this acting similar to palm oil. The galam butter is the product of bassia par/diy a tree belonging to the saponaes species, growing in the in- terior of Africa. The others are, we believe, derived from the same source. Palm Kernel Oil has recently made its appearance in the market, and it is but a short time since it found application in the manufacture of soap. It is obtained by crushing and pressing the stony kernels which are contained in the fruit of the avoira elais. In the raw state it has an almost coffee-brown color and a peculiar cocoa-like fragrance. Before its ap[)lication to the niaking of soap it must be bleached. To do this, the follow- ing recipe will answer: 50 kilogrammes (110 lbs.) of fat are well stirred with a rake in a sub-lye or in a solution of culi- nary salt of 26° B., at a temperature of 100° C. (212° F.). After this it is left to settle awhile, during which time the fat which has already lost considerable of its color, rises to the surface. It is then scooped oft', warmed to 35° C. (95° F.) mixed with 1 kilogramme (2.2 lbs.) of crude muriatic acid and a solution of | kilogramme (8.8 ozs.) chromate of potash in water, and well stirred. On the following day the oil is reheated to 35° C. (95° F.), and again \ kilogramme bichro- mate of potassa and 1 kilogramme muriatic acid are added. The oil thus bleached, called in commerce palmitin oil, has a faint reddish tint and an agreeable smell similar to that of a mixture of palm oil and cocoa-nut oil, and in consequence thereof it may be used with good results for making the so- called Swiss soaps, also for colored toilet soap, whicli in this case is not subject to that disagreeable odor which cocoa-nut oil soda soap possesses. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 105 CocoA-i^uT Oil. Of tins valuable oil three kinds are at present known in commerce, Ceylon, Sidne}', and Cochin China oils, the latter beino^ considered mnch the best — whether from a different species of palm or the care in its preparation is not known. These oils are obtained by boiling the ground or crushed kernels of the nuts of the cocos nueifera^ the cocos butyracea and perhaps other species. Cocoa-nut oil is a white usually rancid fat of the consistency of lard with an unpleasant taste and smell; it melts at 20 to 22° C. (68 to 71.6° F.) and con- geals at 18° C. (b4.40° F.). Tyndall made some experiments, and obtained by the opera- tion, from 210 kilogrammes (462 lbs.), dividing the cocoa-nut kernels into portions of 3J kilogrammes (7.33 lbs.) in pressing bags made of bast mats, various sorts of oil of steadily in- creasing melting points, after having five times increased the temp)erature of the masses which were prepared for pressing, viz., 1 portion of 42| kilogrammes pressed at 14-1 50 C. (57.2-590 F.) 2 " 6| " " 18-190 C. (fi4.4-66.20 F.) 3 " 10| " " 240C. (7o.20 F.) 4 " 13| " " 29-300 c. (84.2-S60 F.) 5 " 4-| " 40-410 C. (104-105.80 F.) Together 119^ kilogrammes (262 lbs.) The remaining cakes which were pressed out weighed 77J kilogrammes (170.5 lbs,), the rest of 13| kilogrammes (29.4 lbs.) was mostly oil which runs down from the press into a sejjarate vessel. From this it is manifest that the kernels contain 60 per cent, or somewhat more, and probably two different fats, one fluid and one solid, which in the seed are separately present, but during tiie process of pressing become mixed with each other the higher the tem]:)erature becomes. So that, according as may be desired, the oil may be pressed out at first fluid, then firm or even of a medium consistency. In fact, by the above stated experiment the first and second portions were entirely liquid and translucent, the third half 103 TECHNICAL Tl^EATISE ON SOAP AND CANDLES. liquid and milky, the fourth firm and of a dirty-white color, the fifth pure white and very solid. The solid fat which has received the name kocin was for- merl}^ deemed to be the combination of a specific acid, viz., kocin, cocoa-nut tallow, or cocoa-nut stearic acid, wnth oxide of glyceryl. Heintz, moreover, has shown that the latent acid which is contained in kocin combined with oxide of glyceryl is a mixture of two difierent acids, lauric and my- ristic, which is in the proportion of 14 parts of lauric with 3 parts of myristic acid, with 6 to 6J parts of palmitic acid, and it has the same melting point as the hitherto presumed acid of kocin = 35° C. (95° F.). Myristic acid melts at 34° C. • (93.2° F.), lauric acid at 44° C. (111.2° F.). The mixture has therefore a lower melting point than the average of the two acids. A similar action Heintz proved to exist in the case of palmitic and stearic acids. In cocoa stearine we hence have lauric and myristic acids of oxide of glyceryl. The action of cocoa-nut oil in the process of saponification is peculiar, and quite difterent from that of tallow and other fats. The cocoa-nut oil soaj) can only be separated by con- centrated solutions of culinary salt, and then becomes so ex- traordinarily hard that it cannot be cut. For this reason a clear boiling to the solid would in case of the cocoa-nut oil soap be entirely contrary to the end in view, and very difficult. While furthermore, tallow for instance treated with very strong lye floats above and then can hardly or not at all be saponified; in the case of cocoa-nut oil just the contrar}^ happens. It does not form that milk-like mixture with weak lyes by which the process of saponification is usually preceded, but floats as a clear fat above, only when by a continued boiling and evaporation the lye has reached a certain strength, the 6a[)onification suddenly ensues. For saponifying cocoa-nut oil, In'cs of sucli strength are used that the soap with the lye receives the intended contents of water, and a separation thereof becomes unnecessary. Of course the amount of the alkali must be so accurately calculated that the soap receives no excess of alkali, or at least but very little. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 107 The higlily disagreeable odor which is natural to cocoa- nut oil is retained by the soaps made from it, and thus far no remedy has been made known that is capable of remov- ing it. Since the odorous matter is volatile, it seems feasible to remove it by heating. By an experiment made for this purpose this was accomplished only to a certain degree, but it is not impossible that by a still further continued and also increased heating, this pur[tose may yet be accomplished. The gradual addition of a little water to the heated oil seems also to operate efficaciously in the removal of the smell. If cocoa-nut oil is slow^ly heated until it reaches 165° C. (329° F.) it develops a poignant rancid smell not unlike that of lacteal acid; the oil remains thereby colorless and obtains a high degree of limpidity. By continued heating to 240° C. (464° F.) and if this temi>erature is kejtt constant for a while, the fat loses the capability of immediately congeal- ing after it cools oH'. Only after 24 hours a part of such oil becomes tirm, which can be easily pressed out from the liquid mass, and it is very solid and entirely colorless. Per- haps this solid matter might in many cases be used to advantage in the manufacture of candles. After remaining for 40 hours exposed to the cold, the other part of the oil also congeals. The properties of this article, as given above, are posse?^sed in common by the Cochin China, Ceylon, and Sidney cocoa- nut oils; only the latter are, as a rule, of a somewhat softer consistency, and also less white in color, than that from Cochin China; nor does the saponification occur with each oil in the same manner, which probably is caused by the fact that by the pressing of the kernels the liquid at»d the solid fats are not always kept mixed in the same proportions. Gallipoli Oil, also called Illipe oil, or Bassia oil, is obtained from the seeds of Bassia latifoUa and Bassia lo-ngifolia. It melts at 26° to 28° C. (78.8° to 82.4° F.) ; is, in its solid state, greenish-white, when melted yellow, and has a weak, not disagreeable smell. 108 TECHNICAL TREATISE ON SOAP AND CANDLES. Of late it has been much used in Eiio-land and France for the purposes of soap manufacture. Almond Oil. This well-known oil, though making a very superior soap of a beautiful wax-like iippearance, is too costly for any except the finest toilet soaps, and then it is generally mixed with equal parts of refined hog's lard. It is found in com- merce of a clear yellowish-white color, and, if fresh, has no odor, and is of a pleasant, sweet, nutty taste. It is made by expressing the almond kernels, which are ground and steamed and placed under heavy pressure. The oil obtained is sub- mitted to the action of steam-heat, the impurities subsiding with the condensed water; tlie marc is dried and powdered to make a useful toilet powder. Both the sweet and the bitter almonds are used for making the oil, the former con- taining nearly fifty per cent, of oil, while the latter have less than thirty per cent. Sesame Oil. This valuable oil, from the seeds of the Scsamum orieiUale^ has many good properties for forming a superior soap espe- cially adapted for the toilet, but generally in combination with other oils or fats. The plant, originally indigenous to India, however gene- rally thrives in warm climates, and is frequently cultivated as an oil plant. In India three varieties are said to be known, viz., with white seed, with partly colored, and with brownish-black seed grains; the latter furnishing the oil of commerce, and containing 40 to 50 per cent. The sesame seed comes in great quantities from India and Africa to Europe, to France, Germany, and England, where by press- ing the oil is obtained. It is yellowish, in a pure state odorless and tasteless. When first pressed it tnstes some- what sharp, but this taste is soon entirely lost. If exposed to the air for some time it attains a hemp-like smell. The MATERIALS USED IN THE xMANUFACTURE OF SOAPS. 109 oil has a specific gravity of 0.923 at 15*^ C. (59° F.) ; at 8.° C. (46.4° F.) it coiiireals and assumes a consistency like palm oil; heated to 150° to 200° C. (302° to 392° F.) it becomes somewhat lighter in color. Sesame oil finds a very extensive application as table oil, illuminating oil, and especially for soap-making. It is used in asimihir manner to olive oil, and serves frequently for adul- terating it. According to Pohl sesame oil, mixed Avith sul- phuric acid, turns quickly to a brownish-red color, while olive oil attains a green-yellow or brownish-yellow hue; ac- cording to others the presence of sesame oil in another oil is perceivable by a stronger foaming, which becomes visible when the oil is left to descend in a tliin stream from a height of 1.2 to 1.5 metres (47 to 59 inches). What influence the state of the seed, the age of the seed, and the manner of pressing have on the projierties of the oil, has not yet been ascertained. Soda soap made from sesame oil always re- mains somewhat soft, and hence it is best applied for mak- ing soft soap, or added to fats making a hard soap. Rapkseed Oil and Coleseed Oil. This last named oil is acquired from Brassica campesMs. The seeds give 40 per cent of their weight of a light, thin- nish, limpid oil, whose si)ecific gravity is 0.913. Br.issici nifus furnishes the so-called rapeseed oil, which has a pecu- liar smell. In all other respects these oils show congruous action, and are adapted for making soft soap. The soda soaps remain always somewhat soft. Groundnut Oil. This oil is obtained from the fruit of the Arachis hypogma^ a legumine plant. Tiiis small, creeping plant is indigenous to South America and the coasts of southern Africa and Asia. Since the later part of the last century it has been cultivated in our Southern States, and in Italy, Spain, and the southern parts of France. 110 TECHNICAL TREATISE ON SOAP AND CANDLES. The plant is small and has, like many plants of the same species, an inclination to twine around other objects. As soon as the fruit commences to form, the blossom-bearing stem has a particular inclination to creep into the soil. Blossoms which do not reach under the soil, remain either not bearing or the fruit does not ripen. In the cultivation of the [)lant, the main thing consists in taking care that all stems which haveiinished blossoming are covered with earth. In the wild state, the plant produces five or six pods or shells; but their number increases greatly in the cultivated state. The pods are 2J to 3J centimetres (0.97 to 1.36 inches) long, have one to three seeds in each, and have dirty-yellow- ish, leather}', rugged, lengthwise-raised shells. The fruit itself is longitudinally round, outside covered by a very thin, curly, brown skin; it is white similar to white beans, which it in taste also resembles, if the oily taste be not considered. When roasted it does not taste unlike tlie roasted almond, for which it is often a substitute. In Spain, its flour is mixed with the roasted fruit of cocoa, or it is used as a sub- stitute for the latter. Its oil has a light green color, and does not seem to become easily rancid. It furnishes an ex- cellent soap, which is firm, white, and odorless. Within the last few years, it has for this purpose been applied in Ger- many, France, and elsewhere with profit. Ben Oil is obtained from the seeds of tlie Galaridira moriiiga and is very applicable in perfumery, it having the property of re- sisting rancidity better than almost all known oils. For this reason it is used in oiling clocks. The more solid parts are extracted by congealing the oil and thelim[)ie-seed oil or olive oil. The better grades of cotton-seed oil are frequently mixed with exi)ensive oils, and there are many firms in England and the United States who refine cotton-seed oil, of which enormous quantities are sent to Italy, to serve in the adul- teration of olive oil. The loss caused by the process of re- fining is between twelve and fifteen per cent. The modus operandi of this refining is at present not gene- rally known. Although Pohl had the following process for refining patented, yet it seems to us, that it cannot be rational. According to this process the seeds are crushed between iron rollers, and pressed in iron presses, whereby a dark crude oil and an excellent oil cake are obtained, which latter is very useful for feeding cattle. 100 parts of the crude oil are mixed with 12 parts of a mixture which consists of a solution of potash of 42° B., a solution of tartaric salts of 42° B., and milk of lime of 10° B. This solution is to be mixed with the heated, almost boiling oil, the entire mass stirred for a period of two hours, and then allowed to rest for twenty-four liours, when the oil will have lost its dark color and may be filtered. After filtration, and after the oil has MATERIALS USED IN THE MANUFACTURE OF SOAPS. 113 been nearly drawn ott", there still remains a residue with some oil, which is boiled for two hours with ten per cent, of strong salt water. The oil rises to the surface, and can, when the residue has become firm, after a little while be poured out, and tlien applied in the usual way to make a good soap. (See formulas for these soaps.) Castor Oil. This oil is extracted from the seed of the shrub Rlcinus conununis, either by pressing in the cohl way, or, as is fre- quently done in this country, by a slight roasting and crushing of the seeds and boiling in water, whereby the oil gathers on the surface, when it is skimmed off, and by heating is freed from water and afterwards filtered. If the seeds are at first pressed while cold, and afterwards moistened with alcohol, and pressed out a second time, about 30 per cent, more oil is obtained. This is a pale yellow, nearly odorless, and a very thick liquid ; its specific gravity is 0.951. In the cold it con- geals slowly. While fresh it is odorless and of mild taste ; exposed to the air it soon becomes rancid ; by shaking it with water and calcined magnesia this rancidity can be removed. In small portions it slowly dries when left exposed to the air. In the saponification ricinus oil furnishes three acids: 1st, the stearic ricinic acid, which melts at 74° G. (165.2° F.); 2d, ricinic acid, at 22° C. (71.6° F.); and 3d, the acid of oil of ricinus, which melts somewhat below 0° C. (32 ^ F.). Ricinus oil has the property, when saponified with soda, of furnish- ing transparent soaps; but for this purpose the lye has to be entirely free from other salts or carbonic acid. It is particu- larly suitable for toilet soaps. Poppy-seed Oil. Extracted by expression from the seeds of the Papaver som- niferum. When pure it resembles olive oil in its appearance and taste. It is nearly colorless, or of a yellow color. Its specific gravity is 0.9249 at 15° C. (59° F.). It solidifies 8 114 TECHNICAL TREATISE ON SOAP AND CANDLES. at — 17.7° 0. (0° F.). The concrete oil sometimes retains this state at —2.2° C. (i8° F.). It becomes rancid with difficulty; It is soluble in 25 parts of cold, and 6 of boiling alcohol ; it mixes in all proportions with ether. It is very siccative. It has nothing of the narcotic properties of the poppy. To effect its extraction, break the capsules as soon as they have experienced a certain degree of desiccation. Separate the seeds, and sift them so as to get rid of the dirt; reduce them to a kind of flour, which is put into coarse cloth bags, and submitted to the action of the press. The oil is col- lected in earthen jars and allowed to rest ; then decanted and put into barrels. Before the introduction of sesame and earthnut oils into the fabrication of Marseilles soap, this oil was used in a cer- tain proportion for the fabrication of marbled soap. The reason for such an addition was that olive oil alone gave too hard a soaj* ; an addition of from 10 to £0 per cent, of black poppy oil attenuated the strong consistency of the soap and rendered it more unctuous and soft, and it retained its water much lono;er. Hempseed Oil. Extracted from the seeds of the cultivated hemp, Cannabis sativa. The composition of hempseed varies a little according to the specimen, as may be seen by the following analyses: — Oil 33.6 35.65 Organic matter . . . . . 23.6 Nitrogenized malter .... 16.3 V 51.31 Lignin 12,1 * Mineral substances .... 2.2 7.39 Water 12.2 5.65 100.0 100.00 When fresh, hempseed oil is of a greenish-yellow color; it becomes yellow with time; its odor is disagreeable, and its taste sickly; its density equals 0.9252 at 15.5° C. (60° F.). It thickens at — 15°C.(5°F.) and concretes at — 27.5° C. (17.5° below 0° F.). It is soluble in all proportions in boiling alco- hol, but requires SO per cent, of cold alcohol to dissolve it. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 115 The process for obtaining it consists, the same as with all the other oils, in reducing the seeds to flour, submitting the latter to the action of the press, and purifying the oil ob- tained with sulphuric acid, or with caustic alkali. It is used in the fabrication of soft soaps, of green soaps, especially when this fabrication is carried on in winter, because it can be submitted to a very intense cold without solidifying. It is also added to castile soaps to keep them softer. Nut Oil. Extracted from the walnut, fruit of the royal nut tree Juglnns regia. The oil recently extracted is fluid, nearly colorless, with a faint odor, and a taste which is not disagree- able. The oil of the second pressure is greenish, caustic, and siccative. The oil extracted from the unpeeled kernel has generally a greenish-yellow color. Its specific gravity at . . 120 C. (53.60 F.) = 0.9283 . . 250 C. (770 F.) = 0.9194 " ' . . 940 C. (201.20 F.) = 0.8710 At —15° C. (5° F.) it thickens, and at —26.1° C. (15° below 0^ F.) it takes the consistency of a white mass. The extraction of the oil must be made only two or three months after the fruit has been gathered. After separat- ing the kernels and peeling them, they are crushed, so as to form a paste, which is put into bags and submitted to the action of the press. The oil which runs first is called virgiii oil, and is used as an aliment ; the residium is moistened with boiling water, and is pressed anew ; this second oil is reserved for manufacturing purposes. ITuts give about 50 to 60 per cent, of oil. This oil enters into the composition of green soaps ; it is employed also for lighting. Beech-nut Oil. Extracted from the fruit of the beech {Fagus sylvatica). This oil is of a light-yellow color, with a peculiar odor, a sickly taste, thick and muddy when first extracted ; it is 116 TECHNICAL TREATISE ON SOAP AND CANDLES. limpid, although a little viscous, after a sufficient rest. Its specific gravity is 0.9225 at 15.5° C. (60° F.) ; at —17° C. (1.4° F.) it congeals into a yellowish-white mass. It may be kept a long time without alteration, and, unlike other oils, it improves by age. It forms with soda a soap firm enough, but which remains plastic. The kernels are reduced to a pulp, which is put into coarse cotton bags, and submitted to the action of the press ; the resulting oil is stored in large jars, to allow it to deposit the mucous parts, and the oil thus refined is ready for the market. This process generally gives from 15 to 20 per cent, of oil. Cameline Oil. A drying oil of a light-yellow color extrncted from the seeds of the Myagrum sativum. It has a peculiar taste and odor, and is much employed on the continent of Europe in combinations for fabricating soft soaps, for which it is well adapted, as it tends to make them clearer. Its specific gravity is 0.926; it congeals at 0° C. (32° F.). Mustard-seed Oil. This oil, abundantly produced in making table mustard, is extracted from the seeds of the Slnapis nigra and Sinapis alba^ is a valuable oil for many purposes besides soaps. The -white mustard yields about 36 per cent, of oil, the black about halt' that quantity. The soap from this oil is of a superior quality. Colza Oil, obtained from the seed of the Bmssica campestris to the amount of nearly 40 per cent, of its weight, is a very fine oil much used on 'the continent of Europe as a lamp oil. It makes an excellent soap with soda lye. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 117 Hazel-nut Oil, made from the nuts of the corylus avellana, which are very rich in oil, yielding nearly 60 per cent., is a very fine oil of a pale-j'Cllow color, analosjous to almond oil, for which it is often substituted in perfumery and pharmacy. It also makes a beautiful soap, though too costly for general use. Linseed Oil is obtained, as is well known, from the seeds of the flax l>lant, TAnum. usitatissimum^ by pressure and the aid of heat. These seeds furnish in their dry state from 25 to 30 per cent, of oil, which possesses a beautiful yellow color and a peculiar smell. It is rather limpid, and even at a very low temperature does not congeal. Beside the liquid gly- ceryl-oxide combination, it contains a small portion of pal- niitin. Exposed to the air, the oil dries to a tough mass, which when entirely dry is insoluble in ether or alcohol. The olein of linseed oil is the combination of oxide of glyceryl with a peculiar acid, which in many of its properties varies from the oleic acid of other fat substances. This oil when exposed to the air very easily changes, and absorbs oxygen rapidly.^ Oxidized oleic acid, if treated with alkalies, fur- nishes dark colored soap. Fresh linseed oil saponified with soda makes a soft soap of a light-^^ellow color, of which, by adding culinary salt, solid soda soap may be obtained. If this is exposed in thin layers to the open air, it will become dry and yellow. After a few weeks it may be dissolved in water mixed with soda and salt. If this process be repeated, the liquid receives an almost black hue, a yellow soap will be the result, which in a great measure contains only palmitic acid, while the oleic acid has been destroyed ; by decomposing with muriatic acid, a brown substance separates. Oleic Acid, Olein, Commercial Red Oil. The oleic acid which is found in commerce is obtained as an auxiliary product in the fabrication of stearic and palmitic 118 TECHNICAL TREATISE ON SOAP AND CANDLES. acids for making stearin acid candles. As by this process the solid acids are never completely separated from the oleic acid, it contains more or less stearic acid or palmitic acid. Pure oleic acid is a liquid as clear as water, scentless, and tasteless, of an oily consistency, and does not redden litmus paper, either by itself or in alcoholic solution. It is not soluble in water, but with alcohol and ether is easily mixed. At 4° C. (3fc).2° F.) it congeals into a white crystalline mass. B}^ dry distillation it passes over but little altered into the receiver, and it may be distilled by the steam bath without any decomposition. By mixing with hydrate of potassa, oleic acid is divided into palmitic and acetic acids; at the common temperature it absorbs a large amount of oxygen, but a much more rapid absorption takes place at 100'^ C. (212° F.), when the oleic acid assumes a yellow or brownish color, becomes rancid with acid reaction, and loses the power to congeal at a lower temperature. E'itric acid changes the oleic acid in a short time into elaidic acid. The common oleic acid of commerce, which has suffered more or less from the changes caused by the influence of the air, is brownish-yellow or brown, rancid with acid reaction. It makes a difference, whether the oleic acid was obtained by saponification of the fat with lime and separation with sulphuric acid, or by the process of the so-called acfdy sapo- nification and distillation. The latter is generally rejected by soap manufacturers for the production of soda soaps, and is, therefore, much cheaper than that obtained by the pro- cess of saponification with lime in the fabrication of stearic acid. According to Stas, the natron soap, produced from distilled oleic acid, does not retain as much water as soap made with the oleic acid made by the saponification of lime. According to Buff, the former possesses a sharp disagreeable smell, and its potash soap has not the property of becom- ing soluble in potash lye. This is the case, only when oleic acid has been distilled at too high a temperature. It is to be questioned, whether a stream of steam and a tempe- rature of 250° C. (482° F.) are suflicient to volatilize the sebacic acids, which have already been separated by sulphuric MATERIALS USED IN THE MANUFACTURE OF SOAPS. 119 acid, viz. : whether stearic and palmitic acids do not require a higher degree of temperature, for their separation from the oleic acid and their volatilization, and furthermore, whether the oleic acid, separated by sulphuric acid from glycerine, has not been already so changed that it will act differently from that which has been obtained by the saponification of lime. The soap manufacturer has, therefore, always cause to ob- serve the difference in the two kinds of oleic acid, which are in commerce, and to direct his attention to a possible adulteration of the oleic acid with the cheaper kind. The small quantities of sulphate, which will be formed, cannot be injurious to the* soap, since the api>lied alkalies, as potash or soda, already contain large quantities of sulphate. In the fabrication of soap oleic acid serves principally in producing soft or potash soaps, especially the so-called elain soaps, for which equal equivalents of potash and soda with the necessary amount of oleic acid are boiled. But there is also a solid olein soap made, as will be described hereafter. Accurately speaking, caustic alkalies would not be required in order to change oleic acid into soap, since it combines easily with the carbonated alkalies. But in fact there would be very little gained by it, for by the mixing of oleic acid with the solutions of carbonic acid alkalies there ensues such a strong ebullition of the mass, owing to the escape of the carbonic acid, that the lye can only be added in small portions. This is troublesome, and takes much more time than if the alkalies are ap[)lied in the caustic state. Besides this, soaps which are made with carbonate of soda always re- tain a spongy quality, which is not desirable to consumers. We have seen above, that oleic acid, when melted with hydrate of potash and moreover with an overplus of it, will be dissolved into palmitic and acetic acids. According to theory there are thereby originated, from 100 parts of oleic acid, about 90 or 91 parts palmitic acid. Since the latter has almost the threefold value of oleic acid, while this by its change into palmitic acid loses only 10 per cent, of its weight, it would be of great advantage, if it could be changed in a cheap and easy manner into palmitic acid. Such an operation 120 TECHNICAL TREATISE ON SOAP AND CANDLES. is proposed by Juenneman, who describes it in the following way : In the cover of a modern vat, several vessels of stone are so applied, that not only the cover upon the vat, but also the vessels of stoneware fit tightl}^ ; on the bottom a ser- pentine pipe is fixed which conveys the steam. The oleic acid is now poured into the stoneware vessels and 10 per cent, of common nitric acid is added, then steam is admitted through the pipe into the vat (it is best to apply surcharged steam) and the mixture is thereby heated to 100^ C. (212*^ F.),then one per cent, finely powdered starch flour is gradu- ally added ; an operation by which in the first place the forma- tion of palmitic acid is intended, which, as we have already stated above, changes the oleic acid into the solid elaidic acid, being isomeric to it. A strong ebullition insues, the mass being stirred for about one hour, is kept at an equal temperature, then ladled over into another vat, and with sufiicient w^ater by means of steam, boiled out. Thus the oleic acid has become a light yellow mass, which melts at 45^ C. (118° F.), i. e., elaidic acid. It is then placed in a copper kettle, with an equal weight of hydrate of lime added thereto. This kettle of copper is inserted in an iron kettle, from the sides of which it must have a space of 5 centimetres (1.95 inches), the space between is to be filled with melted paraffine ; into one of the kettles a thermometer is in- serted, which for the security of its scale, is surrounded by a pipe made of copper. The hydrate of lime is made by sprink- ling caustic lime with boiling lye of potash, whereby the lime is reduced to a fine powder, which must be used at once. Now, the outer kettle is to be heated, until the elaidic acid contained in the inner kettle has reached a temperature of 220° to 230^ C. (428^ to 446^ F.), wiiich heat is to be re- tained, while constantly stirring with an iron ladle, for seven or eight hours. Then a sample is taken out, in order to as- certain, by analysis with diluted sulphuric acid, whether all the fat has been changed into palmitic acid. As soon as this is the case, the fat is transferred into a suitable appara, tus for distilling, and distilled after adding the requisite quantity of sulphuric acid and a stream of surcharged steam. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 121 That which passes over is pure palmitic acid, a firm, white mass, which melts at 62° C. (143.6° F.), and can be applied to manufacture the so-called stearic acid candles of priinequality. Tliis product, however, has not yet found practical appli- cation. Although soap manufacturers do not require the pure pal- mitic acid, they can make use of it, to mix it with a suitable proportion of oleic acid (3 parts oleic ncid, 2 parts of palmitic acid), thus reestablishing the original projjortion of the liquid to the solid acid, and for obtaining a mixture of sebacic acids, from whicli fine and solid soaps may be produced. Vegetable Tallow. By this name a fat, which is pressed out of the seeds of Brindonia indica^ is known. The seeds give 75 per cent, of their weight in fat of a grayish-wdiite color, and of the consist- ency of common tallow, with which it has much similarity. This product can be purified and bleached by treating it with about one-half per cent, of concentrated sulphuric acid, pre- viously diluted with water. After sufficient influence of the acid is had, it is removed by washing it out. With soda vegetable tallow^ makes a hard, wiiite, and odorless soap. It is thought that this article might be profitably used for manu- facturing soap. Shea Butter or Galam Butter. A vegetable fat which has only recently been introduced into commerce. It is of the consistency of butter, and of a gray or greenish-white color, and is obtained from the dried and bruised seeds of Bassia parkii^ by boiling them in w^ater, and by skimming oft' the rising fat. Its melting point varies from 23°, 24°, 29° to 35° C. (73.4°, 75.2°, 84.2° to 95° F.). Shea-butter furnishes a very hard and w^hite soap, which lathers but little, but for its first mentioned peculiarity miglit be used with good results, to make solid soaps from weaker sorts of fat. 122 TECHNICAL TREATISE ON SOAP AND CANDLES. Butter of Nutmeg or Oil of Mace. • Extracted from the kernel of the nutmeg, fruit of the nutmeg tree, Myristica aromatica, M. offi<-inalis., M. rnoschata. Pure butter of nutmegs has a pale yellow color; its odor and taste are strong and sweet ; it is composed of — Concrete oil, similar to tallow . . . .43.07 Yellow biUyrous oil 58.08 Volatile oil 4.85 106.00 By pressure, in filtering paper, and by repeated solutions, and crystallizations in ether, a solid matter is extracted from the butter of nutmeg, called myristin. Submitted to distil- lation it yields about one-eighth of its weight of volatile oil. The nutmeg contains two oils, one volatile, and the other fixed and concrete ; the first is a whitish-yellow, lighter than water, with an acrid and pungent taste, and an odor of nut- megs; the second is white without taste and odor. It gives by analysis : — • White insoluble substance (stearin) . . , 24.00 Butyrous insoluble colored substance . . .7.60 Volatile oil 6.00 Acid (by approximation) 0.80 Fecula 2.40 Gum 1.20 Ligneous residuum 54.00 Loss 4.00 100.00 The mace or outside envelop of the nutmeg contains also two difi^erent oils, one fixed and the other volatile. This butter is principally prepared in Holland in the following manner: Fresh nutmegs are crushed in a mortar and are slightly heated until reduced to a paste ; they are then intro- duced into cotton bags, and pressed between metallic plates previously heated. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 123 Tallow of Yirola. Extracted from the fruit of the Myristica sebifera. This kind of vegetable tallow is found in commerce in the form of square masses, similar to cakes of soap, but not so long nor so thick. They are often covered with a kind of efflorescence of a nacreous appearance, which exudes in the same manner as benzoic acid. This tallow melts at 43° C. (109.4° F.), and is soluble in alcohol and ether. The mode of extraction consists in crushing the kernels and boiling the paste in water ; the fatty substance separates and collects on the surface, where it solidities on cooling. Oil of Laurel. Extracted by expression from the berries of the laurel of Apollo, Laurus nobilis. The oil of laurel found in commerce is green, with a buty- rous consistency, and slightly granular, similar in appearance to half-solidified olive oil. It contains a volatile oil which gives it a disagreeable odor. It melts by the heat of the hand at about 40° C (104° F.). Alcohol extracts from it the green coloring substance and the volatile oils; it leaves a colorless, concrete oil, similar to tallow. This solid part has received the name of Laurine. The fruit of the laurel con- tains two kinds of oils — one volatile, which resides in the pericarp; the other fixed, which is furnished by the kernel. The first is obtained by distillation, and the other by decoction. To obtain the concrete oil, the fruit is crushed and reduced to a paste which is boiled with water ; the mixture is strained and pressed ; the grease formed of a fixed and a volatile oil solidifies on the surface, and is removed and melted anew over a water bath to expel the water. It is kept in closed vessels. Cocoa Butter. Extracted from the Cacao Theobroma in the form of a whitish semi-solid grease. The beans yield nearly forty per 124 TECHNICAL TREATISE ON SOAP AND CANDLES. cent, of oil, finding application in pharmacy as a vehicle for applying many drugs, and in perfumery for cosmetics. For soap it has not been largely used, though it would make a superior soap for toilet purposes. Carapa Oil, or vateria tallow, is the product of the kernel of a species of personia, a palm-tree, met with in Bengal and Coromandel. It is of a bright yellow color, and known as pine tallow. Malabar Tallow, obtained from the fruit of the Vateria indica^ is a white, wax- like tallow, melting at 85^ C. (95° F.) ; it is natural to Mozambique, and but little known in Europe or the United States. GoA Butter, a fat from the seed of Brindonica Indica^ is used by the natives as butter. It is white, of pleasant taste, and melts at 40^ 0. (104° F.) ; it is also used in medicine. Grape-seed Oil. The seeds from wine lees yield about 10 or 12 per cent, of a pale-yellow oil that might be utilized for soap. It is now used in the countries of production as a table oil. Oil of Tobacco Seeds has been used for various purposes. It is perfectly bland, and resembles poppy-seed oil. Oil of Belladonna Seeds is similar to that from the tobacco seeds, and is used in some parts of Germany as a lamp oil. MATERIALS USED IN THE MANUFACTURE OF SOAPS. 125 Waxes. Beeswax. — Wax is tlie siibatance secreted by the bee, an insect belonging to tbe family of the Mellifica^ order of tlie Hymenoptera. As it exists in the combs and after purifica- tion, wax is a solid fatty body, compact, of a yellow color, more or less dark, insoluble in water, soluble in fixed oils, in 20 per cent, of boiling alcohol and ether, and in spirit of tur- pentine ; it has no taste; its odor is aromatic and similar to that of honey. Wax is dry, not greasy, to the touch, tena- cious, yet brittle. Yellow wax melts at 62° C. (143.6° F.) to 63° C. (145.4° F.). Its sp. gr. is 0.9750. It burns without leaving any residuum. There are two kinds of wax, the yellow wax., the properties of which we have just described, and the white wax^ which is the bleached yellow wax. The white wax is obtained by melting the yellow wax and reducing it to thin plates, like ribbons, and exposing them to the sun and air for several days, until perfectly white. It is white, slightly diaphanous when thin, without taste, nearly without odor, hard and brittle at 0° 0. (32° F.), and very malleable at 30° C. (86° F.); it becomes softer when heated ; at 65° C. (149° F.) it is completely liquid, but it cannot be boiled without decompo- sition. Like yellow wax, it is insoluble in water, partly soluble in alcohol, but dissolves very well in ether and in fixed and essential oils. Its sp. gr. is from 0.960 to 0.966. Its frac- ture is slightly., granular ; it sticks to the fingers when kneaded ; it is inflammable, and burns with a white flame without leaving a residuum. Beeswax has but little appli- cation for soaps, though it is customary to add a little to the finest soap to improve its appearance and consistency. Palm-tree Wax. — Produced by the Ceroxylon andicola^ which is very abundant in Kew Granada. It is obtained by scraping the epidermis of the tree. The scrapings are then boiled in water, and the wax floats on the surface without melting. In a crude state it has the form of a gray-white powder. Purified by treatment with boiling w^ater and 126 TECHNICAL TREATISE ON SOAP AND CANDLES. alcohol, it is yellowish-wbite, but slightly soluble in boil- ing alcoliol, and precipitates by cooling. It melts at 72° C. (161.6° R). Carnauba Wax is produced by a palm tree which grows abundantly in the provinces of the north of Brazil. To ob- tain it, the leaves are cut and dried in the shade, and soon the wax is separated in the form of thin scales which are melted. This wax is soluble in boiling alcohol and in ether ; ])y cooling it crystallizes ; it melts at 88.5° C. (191.3° F.) ; it is very brittle, and is easily reduced to powder. Myrtle Wax is obtained by boiling in water the berries of sevenil si)ecies of Myrim^ especially the Myrica cerifera^ a tree very common in the Southern States. These berries give 25 per cent, of their weight of wax. The crude wax is green and may be saponified. Purified by treatment with boiling water and cold alcohol, this wax is greenish-yellow, and melts at 47.5° C. (117.5° F.). Ocuba Wax is obtained from a Myn'stica in the province of Para, and in French Guiana. This tree produces a fruit with a stone covered with a thick crimson pellicle, which colors water red. To extract the wax, the stones are crushed, reduced to a pulp, and boiled for some time with water ; the wax floats on the surface. This wax is yellowish-white, soluble in boiling alcohol, and fusible at 36.4° C. (97.7° F.). The wax of bicuycla, obtained from the Myristlca bicuyda^ is yellowish-white, soluble in boiling alcohol, and melts at 35° C. (95° F.). It is but little known to commerce. Rosin or Colophony. With the name rosin" we designate a group of bodies which appear in nature solid, brittle, and again in semi-solid substances; they are not soluble in water, but soluble in ether, alcohol, and sulphuret of carbon, they are rich in carbon, poor in oxygen, and free from nitrogen, and burn with a fuliginous flame. I^one of the rosins are a chemical elemen- tary body, but, like all immediate matters furnished by the plant, a complicated mixture of substances. The integral MATERIALS USED IN THE MANUFACTURE OF SOAPS. 127 coraponeiits of rosin are the resinous acids, carbonate con- taining substances, which eject from carbonate of alkalies the carbon, and combine with the alkalies. Besides the abietic acids there are in the natural rosins volatile oils, gums, often cinnamonic acid and benzoic acid. They are divided into three principal groups: 1st, common rosins ; 2d, balsams ; and 3d, gum resins. The latter are dis- tinguished from the common rosins by their contents of gum. The balsams are generally solutions of rosins in volatile oils, or mixtures of volatile oils and rosin. That the resins belong to the most extensive vegetable substances, is well known, and has been proved by numerous chemical experiments and investigations. These substances have been found in all classes of the vegetable kingdom, yea, even in the tissues of the fungi; also in all organs of plants, and in all known vegetable tissues their presence has been proved. All resinous matters are products of a so-called regressive metamorphosis of matter. Notwithstanding the extraordinary distribution of the resins in the vegetable kingdom, the number of the plants which furnish applicable resins is proportionately small, and the number of the families to which these plants belong is also relatively limited. For soap manufacturers only that rosin has interest which is furnished by most of the Fbrus species, and is presented in commerce under the name of common rosin or colophony. The balsams of the abies^ hence of the pines, firs, etc., are called turpentines. They originate partly in the bark, partly in the young wood of the trees. In the bark it seems to be prevalent in the pith, /. g., the starch grains which are in- closed in the pith of the resinous fibres; while in the wood substance it appears to be the parenchyma which furnishes the material for the formation of rosin. The rosin, or bal- sam, ducts of the abies^ wherein the turpentine often gathers in masses, and is conducted outside or to the wood substance, is found in all the trees of this family. They appear least in the bark, frequently though also in the wood substance, and 128 TECHNICAL TREATISE ON SOAP AND CANDLES. originate either by transformation of entire tissue-cords or by separation of the res^iiration tissues. Turpentine is the origin of the productions known as oil of turpentine, pine-tree rosin, black pitch, and colophony, and is especially produced in ]^orth America and Europe. The resin is either accidentally exuded, or the yield of rosin is the object of a planned operation of the rosin scraper or pitch maker, whereby the rosin is caused to flow from the trees by intentional incisions in the same. The turpentine, which flows spontaneously from the trees and is dried by the atmosphere, contains but little oil ; while the fresh exuded oil, on the other hand, contains almost all of its oil. If the turpentine is distilled with water, the oil passes over, and a rosin mass remains as a residue, the " boiled tur- pentine." If rosin is melted without w^ater, until it becomes clear, then the colophony or rosin remains. All rosins desti- tute of oil, originating from turpentine, either by sponta- neous exudation, or by distillation of the volatile oils, are as common rosins, despite their dift'erence of origin, brought into one category, namely, the pine-tree rosin. Up to the most recent period, it has been endeavored to prove the existence of several different abietic acids in rosin, i. e., an amorphous combination, pinic acid (C^pH^oOJ, and another crystallizing in rhombic prisms, thesylvinic acid (C^pH^oOJ. According to Streaker the first is . only the amor- phous modification of the latter. According to the investi- gations of Laurent, French turpentine is said to contain a combination of great afllinity with sylvinic acid, w^hich he called pimar acid ; and, according to Unverdorben, there is in colophony a specific abietic acid, which originates from the sylvinic acid by heating, viz., colopholic acid. But in opposition to this are the investigations of Maly, who in turpentine, in fir-tree rosin, and in colophony proves but one acid, to wit, the abietic acid (C^^H^^O^), which in the sub- stances named appears either as such, or is substituted by its anhydrite. The resinous trees form the anhydride. If this is exposed to the air, it is transformed by absorption of water into abietic acid. By melting the always crystallizing acid MATERIALS USED IN THE MANUFACTURE OF SOAPS. 129 changes into its amorphous anhydrid. Fir-tree rosin contains, therefore, according to Maly, abietic acid ; colophony, on the other hand, its anhydrid. The amorphous substance of the fir rosin is soluble in 72 per cent, of alcohol. It is an indif- ferent substance. It was formerly termed the gamma rosin or turpentine, in contradistinction to the two acidy combina- tions of the pine-tree rosin, which were formerly called alpha and beta rosins. Besides its application in the fabrication of soap, common rosin finds varied uses. The most important of these em- ployments are the manufacture of varnishes, lacquer, cements, brewers' and bottlers' pitch, and for lubricating wagons and machinery. For. the purposes of soap-making it is sometimes desirable to have a very light rosin. This may be attained by artifi- cial bleaching. The rosin is melted in a kettle and allowed to settle until all dross has gathered on the bottom, which is performed in about half an hour. The clear rosin is scooped over into another kettle, and to each 100 pounds of it 20 pounds of salt solution of 9° B. are added. This entire mass is left boiling for one hour, when the fire is diminished. As soon as the boiling ceases, the rosin settles upon the bottom, and the salt lye separates as a brownish fluid on the surface. This salt lye is ladled out, the salt water renewed, and again boiled. If the rosin is not yet sufficiently discolored, the operation is repeated for the third time. Rosin is employed as well in the fabrication of hard as of soft soaps; but never worked up alone, always in conjunc- tion with some fats. Soap of pure rosin never becomes solid, but even for a soft soap it cannot be applied alone, inasmuch as it never attains the peculiar consistency which is expected of a good soft soap. 9 130 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIOKIY. THE RECOVERY OF OFFAL AND OTHER REFUSE FATS AND GREASES. It is a peculiarity of raodern times, that science and in- dustry are constantly endeavoring to utilize otherwise useless and rejected ottal and refuse matters for various objects. This is a gain which should be all the more prominent, since it ad- vances the national welfare, and also aids in the removal of such matters which, having become putrefied, infect the air with poisons which are often the cause of disease and epi- demics. In the vicinity of large cities, establishments which attend in a rational manner to working up and utilizing the offal of organic nature, are a great blessing. Thus Paris has in its environs such manufactories on a grand scale. The largest and most important of them is the one of Soutfrice & Co., at St. Denis. It would be very interesting to state here what a variety of things are manufactured in that estab- lishment. In the year 1862 they began to utilize the rem- nants and the offal from the slaughter-houses, from which they drew a yearly yield of 120,000 francs ($24,000). The year following they gave their attention to the scum, dross, and dregs of the river Seine. In consideration of the vast advan- tages which this undertaking would have on the state of the public health, the Prefect of the Seine granted to this firm, for a nominal revenue, the sole yield accruing from the work of clearing the river of cadaverous and floating fats, as well as other stuffs injurious to health. In December, 1864, Souffrice & Co. undertook the removal of the putrid waters, the sweepings imd the vegetable remnants from tw^enty-flve public institutions of Paris. The vegetable refuse was puri- fied by steam, and used for feeding hogs. In this way the RECOVERY OF REFUSE FATS. 131 firm mentioned was enabled to fatten 3000 hogs per annum. In December, 1867, they constructed two distilling appara- tuses for the manipulation of the black residues of the refined rape-seed oil, and obtained thereby an annual production of 500,000 pounds of pure sebacic acids, w^hich are a suitable in- gredient for the manufacture of soaps. They furthermore purchased from the railway companies the old wheel grease, to obtain the fat contained therein, and paid for it annually 100,000 francs ($20,000). Besides the fats and' sebacic acids, the chief product of the establishment is an azotic fertilizer. Of this, thousands of tons are annually manufactured. The Yield of Offal Fats by means of Sulphuret of Carbon. For the recovery of fat from refuse matter the introduc- tion of sulphuret of carbon has wrought a great service, since by its aid it has become possible to extract fat from such substances as contain but small portions of it, and which by further pressing will no longer yield it. Some time ago Deiss had his aim directed to it, and applied the sulphuret of carbon in the manner indicated. Thus he extracted fat from the black tar-like residues, which are yielded by the distillation of fats in the stearine manufactories, from the sawdust which had served for the filtering of oil, from the dirty remnants, which were formed by refining the oils with sulphuric acid, from wagon grease, and from oily polishing rags. The residuum of the distillation of fat which, by a faulty saponification, often contains upwards of twenty per cent, of fat, must, before the treatment with sulphuret of carbon, be mixed with sawdust in order to enhance the filtration of the dissolved fat. The sediment from the treatment of oils with sulphuric acid often contains fifty per cent, of sebacic acid. In order to gain this the residuum is treated by washing out the sulphuric acid with hot water, then dried, mixed with sawdust and extracted. The sawdust, which is used for filtering oil, still 132 TECHNICAL TREATISE ON SOAP AND CANDLES. yields with sulphuret of carbon, even after being pressed as much as possible, a farther 15 to 18 per cent, of oil. The old wagon grease is first treated with sulphuric acid, then washed and dried and finally extracted. Fatty rags are, without any further manipulation, at once treated in sulphuret of carbon. This treatment has a threefold advan- tage: the gaining of the fat, cleansing of the rags, so that they may again be used, and averting great danger of fire, which originates frequently from spontaneous combustion in heaping up these oily rags in the work-rooms. For all the above mentioned purposes benzine might also be used in lieu of sulphuret of carbon, but the latter has the advantage of possessing a greater poAver to dissolve fats. Be- sides this, it should be noticed that oftals, which have been lying in dampness, and contain glutinous fat, cannot be worked up with benzine, while worked with sulphuret of carbon they furnish good results. Wool-fat and Fuller's-fat. Already in the second decade of this century, Kurrer, von Westrumb, and others, had drawn attention to the fact that immense quantities of fat were lost from the washing vats of the cloth manufactories, spinning establishments, dyeing fac- tories, etc., and they recommended that these losses be re- deemed. In the washing of the wool must also be estimated the sebacic acid, which the not unimportant quantity of soap furnishes, and is requisite for the process of scouring, as well as the comparatively high amount of the wool yolk or suint. The oldest method for the utilization of the fatty substances of the soap waters, consisted in leading the water running from the washing-tubs into especial cisterns, mixing it there with milk of lime, then letting it settle until it had cleared off. After removing the liquid above, the slimy sediment was taken out, strained through coarse canvas for removing the sand, hair, etc., and well dried. The slime having assumed a doughy consistency, it was straightened out into pieces of the size of half a brick, and dried in the air. The dry Hecovery of refuse fats 133 pieces, called " suinter," from the French word " suint" (wool-sweat) were then dried in retorts, for the fabrication of illuminating gas. This manufacture of sidnter, as simple as may appear its manipulations, requires great space and appointments. The drying of the limy fat masses, which can only be accomplished in thin layers, proceeds in damp weather but slowly, and is during the winter season only manageable in artificially warmed and ventilated localities. To this must yet be added, the slow settling of the fatty masses, but loosely combined with lime, and the difficulty, on account of the ever varying amount of fat of the soap- water, to guess the right proportion of the precipitation. Either too much or too little lime may be applied, and hence sufler in the first case disadvantage for the fabrication of illuminating gas, in the latter case great loss of the sebacic acid. For this reason this method of fabrication has been abolished, and the fat is at present gained from the rinsing waters by decomposing the same with sulphuric acid. A compact, creamy mass is separated, which is mainly composed of sebacic acids, and, according to its respective origin, is either called wool-fat or fuUer's-fat. By the first appellation is designated the fat obtained from the offal liquids of the wool-washing establishments, while the soap-waters of the cloth manufactories, dyers' establishments, etc., furnish the fuller's-fat. From the suint, potash is now obtained in France in paying quantities. For recovering these offal fats, the following process is pursued : The soap-water is put into reservoirs of pine wood. Such a reservoir, which is 2.70 metres (8.85 feet) long, 1.73 metres (5.57 feet) wide, and 1.57 metres (5.15 feet) deep, holds up to the filling level 7000 litres (1849 gallons). Sulphuric acid is added, and, in order to hasten the separation, steam is admitted for a period of from one to two hours. The use of sulphuric acid depends, as is self-evident, on the amount of alkali contained in the soap-water; but a little surplus is always allowed, since by it a quicker and more complete separation, and in consequence thereof a more solid refined mass is obtained. On an average 50 pounds of sul- 184 TECHNICAL TREATISE ON SOAP AND CANDLES. phuric acid of 66° B. are sufficient for a complete separation of 7000 litres of soap-water, and furnish 390 to 410 pounds, on an average ; hence 400 pounds of fat substance, accord- ing as this is allowed time to drop off into the filtering basins. The filtering vessels consist of baskets, which are filled with coarse hemp cloth. When now the caseous doughy mass is amply drained of water, by filtration, and has reached the requisite plastic consistency necessary for forming it into pressed cakes, it is wrapped up in hemp cloths, and in the usual way laid between plates in a hydraulic press, and, at first cold, somewhat later with admission of steam, pressed until the complete exhaustion of the liquid contents is reached. In the press cloths remains thereby a solid residuum about one-half of the mass w^hich had been taken, while an equal mass of watery fat runs into the reservoir. The latter quantity reduces itself likewise by the various opera- tions of the refining process to one-half of its weight, where- by a3neld of 25 per cent, of salable wool-fat from the pressed mass, ^. 7.1 grammes (0.25 oz.) per litre (2.1 pints) soap- water may be accepted as the mean value of fabrication. The crude aqueous fat contained in the press reservoirs yet needs the purifying and draining of water. For the purpose of purifying, the fat is placed in iron tanks of 3J feet diam- eter and 5 feet in height, which are inserted into iron hous- ings. According to the greater or lesser purity of the fat the fifth or fourth part of its volume of water and from 2 to 3 per cent, of its weight of sulphuric acid of 66° B. are added, and heated by a direct introduction of steam to a moderate boiling, and kept up for one hour. Thereupon the steam is cut ofi", the mass allowed to settle for a few hours, and then the lower dull and slimy stratum is drawn ofi'. The liquid drawn ofit' is replaced by a like quantity of pure water, and with it boiled up moderately in order to remove the sulphuric acid traces. i^Tow the whole is allowed to deposit, and, after removing the watery stratum, the clear mass of fat is then drawn ofi*. The fat thus gained is still very aqueous. For removing the water the fat is put into kettles in which pipes, either of iron or copper, and of a spiral shape, are RECOVERY OF REFUSE FATS. 135 placed, and through these serpentine pipes the steam vapors circulate and evaporate the water. Frequently the wool-fat is bleached before draining, be- cause it receives a better appearance, and thereby a corre- spondingly increased commercial value, and IS, moreover? freed from its disagreeable smell. The bleaching is performed in wooden vats, which are lined inside with lead, and pro- vided with a stirring apparatus as well as with a heating serpentine. The bleaching liquid is composed of a solution made acid by sulphuric acid and chromate of potash — 3 parts of sulphuric acid of 66° B. to one part of chromate of potash — of which, in most cases, a small quantity produces the desired result. In the first place the deoxidized fat is placed in the vat while it is yet warm, and heated while the diluted acid is added under constant stirring (in small por- tions) on account of the ensuing ebullitions of the chromate of potash, which is to be diluted in threefold its weight of water. The temperature must during the entire operation — which lasts one hour and a half — not exceed 56° C. (132.8° F.). After standing several hours the bleached fat mass settles on the surface. Thereupon the watery salt containing liquid is removed, w^ashing the fat afterwards with pure water, and after the removal of the wash-water the stratum of fat is taken ofiT, which, by heating with indirect steam, is then freed from water. If fuller's-fat is heated and permitted slowly to cool off in vessels, a separation of a solid and liquid mass takes place. In order to attain this the fat is heated to 75° C. (167° F.), placed in large vats of 2| to 3 feet diameter, and 6 to 10 feet high, and its temperature slowly decreased to 9 to 12° C. (48.2 to 53.5° F.). To attain the most perfect separation possible, the cooling off must be effected very gradually, otherwise the solid sebacic acids are only kept suspended in the liquid mass as a curd, w^iich is difficult to separate from the liquid mass. By a careful operation the sebacic acids separate on the sides and bottom of the vat in crystals. The liquid part may be drawn off by means of a spigot in the bottom of the vat. The solid masses are then pressed out in order com- 136 TECHNICAL TREATISE ON SOAP AND CANDLES. pletely to remove the oily part. Such a process of separation requires in the summer season — in case a cool cellar is not at disposal — from three to four weeks; during intense winter coldness it may become necessary to surround the vessels for crystallization with non-conductors of heat, thus to delay the cooling off. The liquid fat which is drawn off is called wool-fat train. The value of the pressed residuum, as noted above is equal to 50 per cent, of the weight of the mass, and it may be stated that carefully mixed samples of different pressings in the manufacturing business result in the following composition : Water 10.66 Fatty substances . 84.7^ Other organic matters 22.37 Fine sand 30.33 Soluble silicate 0.08 Sulphuric acid . . . . . . .0.28 Phosphoric acid .0.09 Oxide of iron and clay 0.99 Lime 0.25 Magnesia 0.10 Alkalies 0.12 100.00 According to this, this material is very well suited for manufacturing illuminating gas on account of its great value in fat and other organic matter, of which the former fur- nishes per pound 9, the latter 7, cubic feet of illuminating gas. Since 100 pounds of gas-coal give on an average 500 cubic feet of illuminating gas, and 8 cubic feet of wool-fat gas have a lighting capacity of at least 10 cubic feet of coal gas, there will be no error in considering the press cakes as of equal value with good gas coal, especially if all other accessory cir- cumstances are taken into consideration. Inasmuch as in the pressed residuum, which represents 50 per cent of the mass, 34.74 per cent, fat substances are con- tained, therefore 17.37 per cent, of the total fat value of the manufacturing material have only a secondary value; hence the method just described is yet a very faulty one and capa- ble of improvement. Vohl has therefore proposed to mix RECOVERY OF REFUSE FATS. 137 the soap-water with chloride of calcium, and to decompose the lime-soap thus produced by muriatic acid. He operates as follows : — The soap- water is mixed with an aqueous solution of chlo- ride of calcium as long as a caseous precipitate ensues. The lime-soap thus formed is separated by straining by means of large baskets, which are lined with hemp cloth (not too coarse), and then freed by letting drop off and pressing out the greater part of the water contained therein. The mass drained of its water is then placed in well-covered vats of 12 feet high and 4 J feet wide, and decomposed therein with a corresponding quantity of muriatic acid, which is as free as possible from sulphuric acid. By a direct introduction of steam the decomposition is accelerated, and the separated sebacic acid kept liquid. The gases which during the de- composition of the infused steam vapors are developed, pass through a cooling worm of cast iron, which empties into a tightly closed iron box. The latter contains slaked lime, and is, by means of a pipe conduit, connected with the heat- ing apparatus of the steam-boiler. By this apparatus all noxious gases and vapors are completely destroyed. After the decomposition of the lime-soap has been completely effected, the mixture is left for six hours to rest, and then, by means of a spigot in the bottom of the vat, the solution of chloride of calcium is drawn off, w^hich in turn is again applied for a new precipitation. The fat mass is now again mixed with one-half of the quantity of diluted muriatic acid of the proportion used for decomposition, and for one-half to three-quarters of an hour steam is again passed through. Thereupon the steam is cut off' and the entire mass is left at rest. Three strata have now formed, one lower aqueous sour liquid, one upper clear stratum of fat, and one middle emulsion-like stratum, consisting of fat and diluted acid. The clear diluted acid is now drawm off, without, however, allowing the emulsive stratum to pass off' with it. The emulsion causes great difficulty in the separation of the sebacic acids from the watery liquid. The sebacic acids are then either freed from water, and at 138 TECHNICAL TREATISE ON SOAP AND CANDLES. once brought into the trade, or they are previously bleached. For draining off the water the emulsified oil stratum is either heated by the addition of culinary salt over an open fire (in case of a common kind of fat), or (for better sorts of fat) with indirect steam. This latter mode of heating is applied espe- cially when the soap-waters originate from the scouring or boiling of silk, or from Turkey-red (Adrianople red) dyeing establishments; hence in greater part being the result of olive-oil soap. For bleaching purposes a solution of sulphuric acid mixed with chromate of potash is used. When separated and washed, the yet warm sebacic acids of the lime soap are placed in the vats (with the emulsion stratum), and while being diligently stirred the bleaching liquid is added, and the mixing kept up for half an hour longer. After resting six hours the bleached sebacic acids are, in a great measure, separated ; the green aqueous liquids being drawn off they are washed once or twice with warm water. After the wash water has been removed the oil emulsion is drawn ofiT. The clear fat mass is then at once drained of water. The emulsive stratum is mixed with 10 to lo per cent, of canadol (a kind of benzole), whereby an immediate separa- tion ensues, and the canadol is again separated by distillation. This treatment of the emulsified stratum with canadol takes place only after five or six bleaching operations, that is when sufficient material has accumulated to fill a distilling appa- ratus. The canadol regained can always be used again for renewed operations. In this manner the sebacic acids re- covered from the silk-scouring and Turkey-red dyeing estab- lishments are of a light yellowish color, and possess but a faint odor. Yohl has not, we are sorry to state, communicated the results of his experiments, so that a comparison between his and the usual method of operation is impossible. It is known, however, that chloride of alkalies cannot be completely re- moved from sebacic acids by washing with water. From this fact reason is found for objections to Vohl's method. Vohl attempts to remedy this difficulty by the partial appli- cation of canadol. RECOVERY OF REFUSE FATS. 139 The wool-fat, as usually brought into the market, is a solid, tough, dirty, yellow-brownish mass, which is difficult to remove with the spade from the casks in which it is packed for transportation. It finds application in the manufacture of soaps, and in the fabrication of lubricators. For soap- making it serves principally in the preparation of rosin soap ; but soap-boilers do not much like to work it on account of its inferior yield, which is explained by its chemi- cal composition. Fuller's-fat forms a thick oily mass, and is a much more valuable fat, as its price indicates, which is quoted at about double that of wool-fat. It likewise finds application chiefly in the fabrication of oils for lubricating and in the manufacturing of rosin soaps. These offal fats are never by themselves used for soaps; but always in combination with other fats, particularly palm oil or tallow, and especially with rosin, saponified. By using these refuse fats for lubricating materials, it is considered that they are not neutral, but contain free sebacic acids. It is therefore almost always more desirable to use them for soap. Yohl in 1867 attempted to calculate the amount of soap used in the city of Cologne, and the loss of fat caused thereby, and reached the result, that that city, which at that time con- tained 120,000 inhabitants, lost annually by the soap used 1,200,000 pounds of fat. This calculation extends only to the soap consumed for private purposes. Establishments of industry, hospitals, and other public establishments are not considered in his calculation, so that the total loss in fat is really still higher. In consideration of the large amounts which this loss represents, and considering that the products of decomposition of the soap- water, which finds its way into gutters, culverts, etc., develop unwholesome miasma, Yohl proposed to collect the soap- waters even in private residences, and to deliver the same to the respective manufactories for working them up. This proposition, however, will for a long time to come remain naught else but a well-meant desire, and we must regard it already as a great progress, when those who possess a great quantity of refuse and offals con- taining an amount of useful materials, begin gradually to utilize them. 140 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIO^s^ Y. THE ADULTERATION OF THE FATTY BODIES. Fats and oils are subject to adulteration and falsification, particularly those of great commercial value, and generally with fats and oils of lower prices. By exposure to the air they absorb oxygen and become rancid ; some oils dry into a kind of varnish, and are called drying oils ; the fats are adulterated with foreign substances to increase their weight. We cannot here go into a general analysis of all these im- portant materials, but will examine such as are in common use and most liable to sophistication. Olive Oil. Olive oil for the manufacture of soaps is ordinarily adul- terated with cole-seed oil, cotton-seed oil, and poppy oil. These mixtures are sometimes disguised by coloring them green with indigo, so as to create the impression that green olive oil is present. The adulteration with black poppy oil is the most frequent, not only on account of the cheapness of this oil, but also on account of its sweet taste, and its odor being but little pronounced. We shall see hereafter the pro- cess for detecting these falsifications. Oil of Sweet Almonds. The oil of sweet almonds is principally falsified with poppy oil and with sesame oil. Several processes have been pro- posed for detecting this falsification. Oil of sweet almonds becomes cloudy at — 20° C. (4° below ADULTERATION OF THE FATTY BODIES. Ill 0° F.), find solidifies at —25° C. (13° below 0° F.), while poppy oil begins to solidify between 3.9° C. (39° F.) and 6° C. (42.8° F.). One part of aqua ammonia mixed with 9 parts of oil of sweet almonds forms a white soft soap, very smooth and homogeneous, if the oil be pure ; on the contrary, it is clotted if it contains more than one-fifth of poppy oil. Rapeseed Oil. This oil is falsified with linseed, mustard, and whale oils, oleic acid, etc. Ammonia with pure oil gives a milk-white soap; and a yellowish- white soap, when the mustard and whale oils are present. Gaseous chlorine colors rapeseed oil brown, when it contains whale oil ; if pure, it remains color- less. Sesame Oil. This oil is ordinarily mixed with earth-nut oil. Linseed Oil. This oil is falsified with hempseed oil, and especially with fish oil. Pure linseed oil treated by hyponitric acid becomes pale pink ; by ammonia, dark yellow, and gives a thick and homogeneous soap. Black Poppy Oil. This oil is often mixed with sesame and beech-nut oils. The pure oil is colored a light yellow with hyponitric acid, while beech oil acquires a pink color. Ammonia colors it a light yellow ; the consistency is slightly thick, and the soap is a little granular. Hempseed Oil. The adulteration of this oil is always done with linseed oil. The pure oil treated by ammonia becomes yellow, thick, and granular. 142 TECHNICAL TREATISE OX SOAP AND CANDLES. Castor Oil is generall}^ mixed with black poppy oil. The adulteration is easy to detect with alcohol at 95° B. ; a certain quantity of oil agitated with this liquid is dissolved and leaves the foreign oil as a residuum. Neat's Foot Oil. This oil is without doubt the most adulterated oil found in commerce; it is mixed with whale, black poppy oil, and olein. Oleic Acid. This acid is often mixed with rosin oil. The pure acid, treated with an acid solution of nitrate of mercury, yields a pale straw-colored foam; the rosin oil yields a very dark orange foam. Palm Oil. This oil has been mixed with or manufactured entirely of yellow wax, lard, mutton suet, colored with turmeric, and aromatized with powdered orris root, without any genuine palm oil. By treating the suspected oil with ether, all the fatty bodies are dissolved ; the turmeric and orris root re- main insoluble. By saponification the mixed or artificial oil takes a reddish shade due to the action of the alkali on tur- meric. Sometimes powdered rosin has been mixed with it; this falsification is easily detected by treating the oil with alcohol : the rosin is dissolved while the oil remains insoluble Cocoa-nut Oil. The commercial oil is often adulterated with mutton suet, beef marrow, or other animal greases, sometimes also with the oil of sweet almonds and wax. The oil falsified by these substances does not completely dissolve in cold ether. The ethereal solution is muddy like that given by pure butter. ADULTERATION OF THE FATTY BODIES. 143 The oil thus falsified has a taste and an odor less agreeable, a color rather grayish than yellowish, and has less consist- ency. The melting point is the best method of ascertaining the purity. Adulterated with greases or tallows the oil melts at 26° to 28° C. (78.8° to 82.4° F.); with oil of sweet almonds it melts at 23° C. (73.4° F.). ASSAYS OF OILS. Fatty oils are characterized by certain special properties, by w^hich it is easy to determine their purity, or to know in what proportions they are mixed. All retain in solution substances, which become colored under the influence of certain chemical agents. These sub- stances may acquire a special coloration only by operating at a known temperature. The discoloration is about the same if we operate on oils of the same kind, obtained at the ordi- nary temperature, or at a higher temperature than that of the atmosphere. By old oils, we understand those which, though prepared for some time, have been placed in good conditions of con- servation. Olive oil, for example, placed for one or two years in a warm place, kept in a vessel half full, and exposed to the contact of the air, if tested in a certain manner, is colored like the oil of sesame. This discoloration indicates a decided alteration of the substance it holds in solution. This characteristic may be met with in the oil used in manu- factures, never in that employed for food. The latter is generally colorless, or very little colored. By some other modes of testing, this oil behaves like one which has been well preserved, or has been recently obtained. Several authors have spoken of coloration, but their pro- cesses to produce these colorations are diflScult ; besides, the colorations obtained are not characteristic enou2:h to enable us to determine the purity of a commercial oil. We must understand by this name, the oil as it is usually prepared in the arts. The following processes are easy of employment: 144 TECHNICAL TREATISE ON SOAP AND CANDLES. With the oil tried, a coloration ought to he produced similar to that assumed hy the same kind of oil placed in similar conditions. If there is a mixture, the coloration obtained will be proportional to the volume of each oil in the mixture. We know that fatty oils are formed of fatty acids, and glycerin ; that these combinations are more or less stable according to the conditions of conservation of the oils ; lastly, that by the nitrogenous substances they contain, sub- stances which play the part of a ferment, the glyceric com- binations are decomposed into glycerine and fatty acids. If an aqueous solution of potash is made to act at the ordi- nary temperature on a rancid non-siccative oil, the fatty acids set free unite first with the potash ; then the alkali has its action on the undecomposed compounds. If the same oil, but not rancid, is treated in the same man- ner with potash, the alkali reacts at first on the combinations which in rancid oil are decomposed by the ferment. If we treat a commercial oil at the ordinary temperature for thirty seconds, by a solution of potash, and afterwards if this mixture is acted upon by an alcoholic solution of bromine, this substance is absorbed by the fatty substance much quicker than if it had not been saponified. This ab- sorption is assisted by a more complete saponification, and it takes place with a production of heat which varies for every kind of oil. W^ shall now enter into some details in regard to the pro- cesses of assaying oils. Qualitative Assays. Mi^st Process. — It consists in allowing a mixture of warm aqueous sulphuric acid and concentrated nitric acid to react on oils for 30 seconds. The quantity of acid to be used varies according to the temperature at which the operation is conducted. At 7° C. (44.6° F.), 8° C. (46.4° F.), 9° C. (48.2° F.), the quantities to be taken are — ADULTERATION OF THE FATTY BODIES. 145 1st. Sulphuric acid sp. gr. 1.80 to 1.84 (650to 660 B.) . . . 7 cub. cent. (1.89 flu. dr.) 2d. Water 3 " (0.81 flu. dr ) 3d. Oil 4 " (1.08 flu. dr.) 4th. Nitric acid sp. gr. 1.35 to 140 (35© to40OB.) 3 " At 10° C. (50° r.). 11° C. (51.8° F.j, 12° C. (53.6° F.), 13° C. (55.4° F.), 14° C. (57.2° F.), take 1st. Sulphuric acid .... 6 cub. cent. (1.62 flu. dr.) 2d. Water 3 3d. Oil 4 " 4th. Nitric acid 3 " At 15° C. (59° F.), 16° C. (60.8° F.), 17° C. (62.6° F.), 18° C. (64.4° F.), 19° C. (66.2° F.), take 1st. Sulphuric acid . . . . 5 cub. cent. (1.35 flu. dr.) 2d. Water 3 " 3d. Oil 4 " 4th. Nitric acid 3 " At 20° C. (68° F.), 21° C. (69.8° F.), 22° C. (71.6° F.), 28° C. (73.4° F.), 24° C. (75.2°), take 1st. Sulphuric acid .... 4 cub. cent. 2d. Water 3 " 3d. Oil 4 " 4th. Nitric acid 3 " (0.81 flu. dr.) Measure in a graduated tube the sulphuric acid, which is introduced into a test-tube closed at one end, 20 centimetres (7.9 inches) in height, and 18 millimetres (0.70 inch) in diameter. Let the acid drain well, then, in the same tube, measure the water which is poured upon the acid, and mix quickly by shaking the tube. The produced heat ought to range from 44° C. (111.2° F.) to 48° C. (118.4° F.). Into this warm mixture pour the oil which has been measured in another graduated tube. Lastly, add the nitric acid care- fully measured. Apply a sheet of India rubber to the open- ing of the tube and shake it strongly for 30 seconds, then dip it immediately into cold water, where it is left for five minutes. The oil collects at the surface of the liquid and begins to be colored. After five minutes, remove the tube 10 146 TECHNICAL TREATISE ON SOAP AND CANDLES. and keep it in a vertical position where it is left to rest. Fifteen minutes after observe the coloration. When the acid mixture is not warm enough, the earth-nut oil blackens very little or not at all ; if the tube is not dipped into cold water, the brown coloration easily disappears and becomes dark-red. The reaction of the warm acid mixture on the coloring matter ought to be suspended by an immer- sion of five minutes in cold water."^ The following Table A gives the colorations taken by dif- ferent oils. ^ Note. — It is important that the sulphuric acid should always be very concentrated (sp. gr. 1.80° to 1.84°). ^ The temperature which succeeds the best is from 160 C. (60.80 F.) to 170 C. (62.60 F.), in using 5 cub. cent, of sulphuric acid. ADULTERATION OF THE FATTY BODIES. 147 Temperature. 67.4° ; 69.2° ; 71° ; 72.8° ; 74.6° F. Acid. Colorless, or slightly greenish Yellow, in- fusion of saffron Slightly or- ange color, which dis- appears Colorless Colorless Very little coloration o straw Straw Orange Soot, or in- fusion of cott'ee Red-orange, or red-cur- rant Red-currant Dark brown o CD O to • o 9 ^. 3 ^ tS .~ 1% B CO 8 (( t( (( 15.70 U. (I u 0.29 ( ( 15.75 u 0.30 ( ( n (( 15.79 A an U.bv) tk 31 t( n ( ( 15.83 0.68 ( ( u 0,32 t i ( ( 15.88 0.67 (( (( 0.33 (( (( ( ( 15.92 0.66 (( u 0.34 ti ( i 15.97 II V. 00 i( 0.35 (( il ki 16.01 fl fl4 V 04 ^^ (i 0.36 fl 16 05 0.63 it 0.37 ( < 16.10 " A O.o2 (( l( 0.38 n (( ( I 16.14 '1 A /J1 (( 39 (1 16.19 u. uu ( < yj. 4iu ( ( <( 0.59 (I i( 0.41 u 16.27 ( < 0.58 i( 0.42 u u a 16.32 0.57 0.43 <( 16.36 (( 0.56 (( u (( 0.44 (( u 16.41 0.55 l( (( 0.45 ii 16.45 54 it (( (( 0.46 u (; 16.49 u 0.53 u (( 0.47 u fi 16.54 0.52 ti 0.48 n 16 58 (( 0.51 0.49 16.63 u 0.50 u (( n 0.50 u n 16.67 a 0.49 (( n 0.51 u (t <( 16.71 (( 0.48 u 52 (( (( 16.76 (( 190 TECHNICAL TREATISE ON SOAP AND CANDLES. Mixture of carbonate of potash and carbonate of soda. Amount of nitric acid required for one gramme ot the mixed alkalies. 0.47 grm. KO, CO, + 0.53 grm. 0.54 " NaO, CO, (t 16.80 com. 0.46 16.85 0.45 (( 0.55 tt 1 1 16.89 0.44 0.56 1 1 tt 16.93 (( 0.43 0.57 1 1 tt 16.98 0.42 0. 58 1' " 17.02 (( 0.41 0.59 it 17.07 0.40 u 0.60 tt tt 17.11 " 0.39 ( < 0.61 17.15 it 0.38 (( 0.62 17.20 0.37 (( 0.63 (( tt 17.24 0.86 u ( ( 0.64 (( 1 1 17.28 (( 0.35 ( ( 0.65 tt it 17.33 it 34 ( ( 0.66 ( ( it it 17.37 it 33 ( ( 0.67 a 17.41 it 0.32 ( ( 0.68 tt 17.46 tt 0.31 (( 0.69 i ^ " tt 17.50 1/C 14.29 1 7 Art 4fi 40 54.77 fi7 5.9 U i . OO 80 95.26 1 o 15.48 1 Q rt7 47 4 / 55.96 fiQ 00 U57. UU SI O I 96.45 1 A 14 16.67 on 4S 40 57.15 70.47 82 y 4 .04 JO 17.86 00 HQ 4Q 4y 58.34 71 93 83 no uo yo.oo lb 19.05 OQ /I7 ^0 4< ou 59.53 79 40 84 1 (\(\ C\A luU U4 1 < 20.24 OA (»Q Oi 60.72 74 87 85 1 ni OQ lUl.*o 1 Q lo 21.43 Oft AH ,cO. 4U 61.91 76.33 86 1 AO /I O Jy 22.62 07 Q7 A l.O i 00 63.11 77.80 87 1 AO A- 1 lUo 01 on 23.82 OQ Qi. 64.30 79.27 88 ■if\A 1U4 oU 01 4il 25.01 tJv.OW OO 65.50 80.73 89 lUo.yy OO 26.20 QO 07 ou 66.69 82.20 90 1 n7 1 ft IU4 lo 27.39 Q9 79 OO. to o t 67.88 83.67 OA /C4 28.58 on uO 69.07 85. 13 OS 29.77 QA A7 oD. < OO 70.26 86.63 OA 30.96 OO lo fiO 71.45 88.14 Of? 32.15 OtJ. DU fil \) I 72.64 89.61 OQ 33.34 41 07 73.83 91.10 29 34.53 42.53 63 75.03 92^57 30 35.73 A A (\A 44. U4 04 76.22 Q 1 09 y-t. Uo 31 36.91 45.53 65 77.41 95.50 32 38.10 47.00 66 78.60 96.97 33 39.29 48.47 67 79.79 98.43 34 40.49 49.93 68 80.98 99.90 ALKALIMETRY. 193 We also append a table for soda : — o to soda .' eS CrystaHized car- bonate of soda NaO,CO2,10HO. a NaO. drate of i lO HO. " ID tc . § °o' la NaO. drate of i iO HO. xn m \ 1.29 1.71 4.61 51 65.81 87.19 285.29 2 2.58 3.41 9.22 52 67.10 88.90 239.87 3 3.87 5.13 13.83 53 68.89 90.61 244.48 4 5.16 6.82 18.44 54 69 68 92.82 249.10 5 6.45 8.55 23.05 55 70.97 94.08 253.71 7.74 10 26 27 66 56 72.26 95.74 258.32 7 < 9.03 11.97 32 29 57 73.55 97.45 262.94 g 10.32 13.64 36.88 58 74.84 99.16 267.55 9 11.61 15.39 41.49 59 76.18 100.87 272.16 10 12.90 17.10 46.13 60 77.42 102.58 279.77 11 14.91 18.81 50.74 61 78.71 104.29 281.40 12 15.48 20.52 55.35 63 80.00 106.00 286.01 13 16.77 22.53 59.87 68 81.29 107.71 290.62 14 18.06 23.93 64.58 64 82.58 109 42 295.28 15 19.35 25.64 66.19 65 88.87 111.18 299.85 16 20.64 27.35 73.80 66 85.16 112.84 804.46 17 21.93 29.16 78.42 67 86 45 114.55 809.08 18 23.22 30.77 88.03 68 87.74 116.26 818.69 19 24.52 32.84 87.64 69 89.08 117.97 818.80 20 25.81 34.19 92 26 70 90.82 119.68 322.90 21 27.10 35.90 96.87 71 91.61 121.89 327.52 22 28.34 37.63 101.48 72 92.90 123.10 382.18 23 29.68 39.32 106.10 78 94.19 124.81 336.74 24 30.97 41.03 110.71 74 95.48 126.52 841.86 25 32.26 42.74 115.32 75 96 77 128.28 345.97 26 33.85 44.45 119.94 76 98.06 129.94 350.58 27 34.84 46 16 124.55 77 1)9.85 181.64 855.20 28 36.13 47.87 1^9.16 78 100.64 188.85 359.81 29 37.42 49.58 133.78 70 101.93 185.07 364.41 80 38*71 51.29 188.39 80 108.25 186.77 369.03 31 40.00 53.00 148.00 81 104.51 188.48 878.64 32 41.29 54.71 147.61 82 105.80 140.19 878.26 33 42.58 56.92 152.28 83 107.09 141.90 882.87 34 43^87 58.13 156.84 84 108.88 148.61 887.48 35 45.16 59.84 161.45 85 109.67 145.82 892.09 86 46^45 61.55 166.07 86 110 96 147.08 896.71 37 47.74 63.26 170.68 87 112.25 148.71 401.32 38 49.03 64.97 175.29 88 118.55 150.45 405.43 39 50.32 66.68 179.90 89 114.84 152.16 410.55 40 51.61 68.39 184.51 90 116.18 158 87 415.16 41 52.90 70.10 189.18 91 117.41 155.88 419.77 42 54.19 71.81 198.74 92 118.70 157 29 424.34 43 55.48 73.42 198.35 98 120.00 159.00 429.00 44 56.77 75.23 202.97 94 121.29 160.71 438.61 45 58.06 76.94 207.58 95 122.58 162.42 438.22 46 59.35 78.65 212 19 96 128.86 164.18 442.84 47 60.64 80.35 216.81 97 125.15 165.84 447.45 48 61.93 82.06 221.42 98 126.74 167.55 452.06 49 63.22 83.77 226.08 99 127.08 169.26 456.67 50 64.52 85.48 280.64 100 129.44 170.79 461.28 13 194 TECHNICAL TREATISE ON SOAP AND CANDLES. Analysis of Lime, It might scarcely appear admissible to judge from the nature of a small piece of lime — such as is needed for its investigation — and to draw conclusions as to the value of the entire bulk from which this fragment was taken. An average sample should therefore be chosen. This is done by taking from a number of pieces small portions, and pulver- izing and mixing them well. From this mixture of lime are weighed oft' 2.8 grammes (43.21 grains) of lime, which are placed in a 100 cubic centimetre (3.88 fl. ozs.) measur- ing flask, slaked with water, mixed with 5 grammes (77.15 grains) muriate of ammonia, and then the flask filled up to the mark with water. After the ensuing decomposition, and when the liquid has cleared oft*, 10 cubic centimetres (0.388 fluid oz.) standard nitric acid are placed in a porcelain saucer, mixed with tincture of litmus, and by means of a pipette — graduated to yV cubic centimetre (0.027 fluidrachm) divisions — titrated with the normal ammonia liquid until the appearance of the blue color. Of this 12.7 cubic centi- metres (0.427 fluid oz.) are used. Inasmuch as the consump- tion is the larger the more diluted the liquid is, so becomes the proportion in this instance reversed. In order to find the percentage of caustic lime, we must divide by 12.7 in 10x100 = 1000; and thus obtain 78.74 per cent. In the case of another lime, treated in the same manner, there were used for 10 cubic centimetres (0.338 fluid oz.) of nitric acid 11.6 cubic centimetres (0.891 fluid oz.) of the am- 1000 monia liquid; the same contained therefore jy^^ 86.2 per cent, caustic lime. THE APPLICATION OF SOAPS. 195 SECTIO]^ IX. THE APPLICATION OF SOAPS. Soaps have so many uses and are so well known that it may be superfluous to attempt to give all the difierent uses to which they are applied, but they may be divided into several classes; thus soaps for domestic and laundry purposes and those most in common use, as the tallow and rosin soaps. Soaps for toilet purposes are a numerous class, and of great variety for bathing, shaving, etc., and the soaps for manu- facturers or for technical purposes, and those used for dyeing, for fulling, wool-washing, etc., and also for lithographic colors and numerous other purposes in the arts. The soaps for wool-washing and fulling should be those that lather well and have a slight excess of alkali and be free from starch or resin; the better classes of soft soaps are made for these purposes. The soaps used in dyeing establishments should be of a still better class, free from all adulterations, entirely neutral and without any free alkali; those for the lithographic tints as perfectly made as possible, and without any culinary salt ; while the toilet soaps should receive espe- cial care in the selection of the purest materials, and in their manipulation great regard to the correct equivalents of the fat with the bases to insure their. neutrality, and the admix- tures they may contain should be such as are entirely harm- less in using, or such as would improve their quality for the purpose they are designed for. The action of soaps in washing is but little understood, and is based upon their decomposition in a large excess of water. When a diluted solution of the sebacic acid with alkali is decomposed into an acid salt, that being insoluble floats away while the alkali dissolves the grease and dirt. 196 TECHNICAL TREATISE ON SOAP AND CANDLES. We have explained that soaps are really acid salts, as stearic acid salt, oleic acid salt, etc. Thus, if we take one part of these salts to 500 parts of cold water, the diluted caustic pot- ash or soda, becoming free, acts as a solvent of the dirt or grease, without injuring the fabric or the skin of the hands as a solution of pure alkali would do. It thus appears that the separated acid salts afford to sebacic acids a certain pro- tection at the same time that they are themselves useful for cleansing, because many substances especially the fats sus- pend themselves as emulsions in the water and can be rinsed off with additional water. A further advantage that soap has in its applications over other detergent matters, is in its form, Avhich admits of its being used in any desirable quantity. When applied with water and assisted by friction, we make an emulsion of the dirt, then by adding more water the alkali is set free and exerts its effects, yet by the large quantity of water it is so diluted that it cannot act destructively. THE ESTABLISHMENT OF A SOAP FACTORY. 197 SECTIOI^ X. THE ESTABLISHMENT OF A SOAP FACTORY WITH THE NECESSARY PLANT. Much might be said and many instructions given on this important subject which perhaps would find but little direct a[>plication by the person intending to establish a factory for making soaps, for they might not suit the conditions of his case; yet there are general maxims founded upon just principles which may apply to nearly all, such as — The location ; The building; The water; The plant; The machinery, etc. etc. Of the location it would naturally be of advantage to have such an one that the raw materials might be readily and cheaply obtained, as well as that the products of manufacture might with facility be sent to market. The location will also depend upon the kind of soap made, for certain kinds may be needed for certain localities or certain materials can be procured to advantage in others that would be a saving in the cost of production. All this cannot be a matter for discus- sion, as eacb manufacturer must naturally be the best judge of where to establish himself and what to make in order to suit the wants of his customers. But wherever located it is our province to give such hints as may improve his facili- ties, control his expenses, raise the quality of his work, and above all enhance his profits. This industry is an eminently progressive one, and there are being constant!}^ invented many new kinds of machi- nery and labor-saving appliances, which tend to a more 198 TECHNICAL TREATISE ON SOAP AND CANDLES. economical and improved manufacture. This is particularly the case in the United States, where new and convenient appliances have done much to improve the quality of soaps generally, while they serve to economize time and labor and 80 cheapen the production. Concerning the building much must depend upon the space and usually a good deal is required, as well as a large yard. The building had better be of an oblong or square form. That part where the soap is boiled should have extra facilities for carrying off the steam and the vapors that are not agree- able to people generally. It is best to have the large chim- ney situated in the centre of the building, that the kettles may surround it. If they are to be heated by an open fire, the furnace is usually in the basement, while the rim of the kettle is extended above the first floor sufficiently high to facilitate the stirring. This arrangement also holds good for the heating by open fire or by super- heated steam. Two large kettles answer in most cases for a large business, 80 that two other kettles may serve for making the lye. The tanks for preserving the caustic lyes are best made of cast iron, and are very frequently inserted in the ground. This arrangement is in itself convenient, room is economized and the lyes are always on hand. They must be well covered and it is best to cover them with cast-iron lids. The taking out of the lyes is much more easily performed if the tank is somewhat elevated so that the lye may be drawn by siphons or by spigots. We prefer the so-called water levels, since be- tween these and the lye kettle the apparatus for filtering the lyes may be fixed. These water levels or pits may con- sist of walled and well-cemented vats. It is much cheaper to use barrels sunk into the ground and well cemented inside. Adjoining the boiling house, there should be on the one side rooms for storing the raw materials, the potash, soda, and lime, and the oils and fats. The first room must be tolerably warm ; the room for the fats as cool as possible. To keep the fats in the cellar is, on account of taking them up and down, not advisable, and in the building of a new factory THE ESTABLISHMENT OF A SOAP FACTORY. 199 is easily avoided. On the opposite side are situated the rooms for the soap, where it is cut into bars after it comes out of the forms, is dried, and finally packed for transporta- tion. The upper rooms are most desirable for drying the soap. Since, for the producing of lyes, the application of the purest possible water is of the greatest advantage, the build- ing should be supplied with roof-gutters, in order to receive all descending rain-water into a cistern, which should be situated adjacent to the factory, and, by means of a force- pump, the water should be carried to the respective places. Besides this, there should be in the yard a well of good water. The folloynng is a description of the soap manufactory for Marseilles Soap of Gontard in St. Quen, near Paris (France), — Although in Marseilles, w^hich is favored by local condi- tions, the soap manufacture is carried on on a very extensive scale, nevertheless that industry does not there excel in es- pecially good appointments. A more complete soap manu- factory is at St. Quen. This establishment is situated in an open field, in the immediate neighborhood of the railway depot and the canal basin of St. Quen, and is in immediate connection with the Paris belt-road, and this with all other French roads. There are high airy rooms on the ground-floor. The kettles are of wood with bottoms of wrought-iron plates, and fixed in the ground, extending to subterranean vaults, that their lower parts may be easily reached to discover every spot which may leak. The soap is boiled therein with surcharged steam, which is admitted by serpentine pipes fixed in the bottom. Steam is furnished from three boilers of 25 horse- power, then carried through a system of drawn tubes (or conduit pipes) which, by a special fire, are heated almost to a red-heat. All labor being carried on on even ground, besides water and lye pumps, there is no especial lifting apparatus necessary. Gontard manufactures only solid (grain) soap, and its com- position which in 100 is 60 per cent, sebacic acid, 6 per cent, soda, and 34 per cent, water, is kept very constant. This soap is perfectly neutral, and therefore for the washing of the 200 TECHNICAL TREATISE ON SOAP AND CANDLES. hands and for technical operations is excellent. Especially olive-, sesame-, and ground-nut oil are worked into soap; the latter oil is pressed in the establishnrient itself, the former brought from the south of France. Caustic soda lye is preserved of various degrees of strength in five large, immured, water-tight kettles. By mixing, a lye is obtained of the medium strength, which is = 10° B., and the dry alkali used is usually 30 per cent, caustic soda, about 9 per cent, sulphate of soda, 6 to 8 per cent, sulphite of soda, 4 to 7 per cent, carbonate of soda, and 6 to 10 per cent, culinary salt, while the rest consists of water. Two kettles are always used for boiling the soap at the same time. In each are filled 1500 litres (330 gals.) lye of medium strength, which is gently heated by the steam worm. Thereupon the barrels, which contain in the aggre- grate about 3500 litres (770 gals.) of oil, are rolled over a conduit lined with lead, which is inclined towards the boiler. They are tapped, the oil runs into the canal, and flows thence into the kettles. Here it meets the tolerably warm lye, and now the forma- tion of soap-paste soon takes place. In this manner the combining of the sebacic acids with the alkali progresses, the mass thickens, and, if after 24 to 28 hours, the saponifi- cation proves snfliciently advanced and the caustic soda amply bound, they proceed with the first cutting of the pan or separation. On this first operation of saponifying {empatage) success mostly depends. The boiling is now interrupted, and 600 to 800 litres (132 to 176 gals.) salted lye are put into the kettle, while the soap is pushed together with a square piece of board of about 90 centimetres (3.51 inches) long, which is fastened to a long stick, and thus is the lye incorporated. The mass becomes grainy, the superfluous water, the separated glycerine, and the uncombined salts separate as sub-lye. The steam is completely turned ott', and the mass is left for a few hours to settle, whereupon tbe lye, by means of the opening of a conical valve situated on the bottom, is permitted to run off". It may be condensed, and, after separating the salts, THE ESTABLISHMENT OF A SOAP FACTORY. 201 worked up for glycerine, bj distilling it with surcharged steam. Should the soap not yet be sufficiently pure and solid, the ''cutting of the pan" is to be repeated, with a stronger salted lye. ^ow the process of boiling is proceeded with. The soap receives the addition of 1200 to 1400 litres (264 to 308 gals.) of good and strong lye, and is left boiling for several hours. The soap grains, which are insoluble in this strong lye, thicken still more and more, and they absorb alkali and separate water. The culinary salt and the surplus water re- main in the sub-lye. It is permitted to settle, and thus but a very weak alkali is drawn off, in order to renew the addi- tion of fresh and strong lye. This is proceeded with until the soap no longer absorbs any caustic soda, and the lye, by the longer boiling and evaporation, becomes specitically heavier, while the soap, by absorption of water and the solution of alkali specifically lighter. The soap, thus finished boiling, has a characteristic smell. It dissolves in hot water without separating any oily drops, and gives, when pressed between the thumb and index finger, a solid touch, and shows in this condition a dark blue-black color of sulphuret of iron. If fitted soap is to be produced from it, it must be made more fluid by adding more water. A workman climbs over a platform, which is placed over the boiler, and pushes the above-mentioned paddle down to the bottom. In the open- ing formed thereby, a second workman pours a few litres of weak lye or water. The first workman withdraws his paddle and pushes down in another place, and so on until 800 litres (176 gals.) water have been consumed, then a little less steam is admitted ; the grains dissolve, and the muddy impurities fall to the bottom. To produce the peculiar marbling of the grain soaps, about 1} kilogramme (3.3 lbs.) of iron red or kalkothar" are mixed with just as much strong lye as is necessary to dis- pose the formed precipitate into the peculiar division of flames and stripes. For this marbling a peculiar skill is re- quired. If the soap is too watery or if it cools off too slowly, the precipitate settles too easily and the marbling is lost. 202 TECHNICAL TPEATISE ON SOAP AND CANDLES. The finished soap is poured by means of copper scoops into the canals which lead to the frames, large basins which are about 75 centimetres (29.4 inches) high. The Ije settles on the bottom, and the hardening occurs in 5 or 6 days. The soap mass is cut with long knives into large blocks which are divided by wire into smaller pieces. The soap, being still soft, is not yet suitable for shipment, and in order to make it hard without the loss of the latent water or to suffer too much shrinkage, it is dipped into a very strong lye, after which the hardening is accomplished by 12 or 14 days' drying. The soap is now finished and ready for shipment. The establish- ment in St. Quen possesses 8 soap boilers of 15,000 litres (3300 gallons) capacity, 24 basins for filtering the lye, and 30 receiving vessels. Every day 14,000 kilogrammes (30,800 lbs.) of soap are finished, which amounts to 4,000,000 kilo- grammes (8,800,000 lbs.) annually. The workmen, 40 in number, cost daily for wages but 200 francs ($40), while the value of the soap daily produced amounts to at least 1:^,000 francs ($2400). The market of Paris is nearly one-half supplied by this manufactory, while the northern provinces are almost en- tirely furnished by it. The proprietor of this establishment receives his orders six months in advance. Of course it is not in the power of many manufacturers to possess such extensive establishments, yet there is so much of interest and instruction in this description, that for this reason we give the details. We have often mentioned the importance of pure water in this manufacture, as well for soap as for the solution of the lyes as the usual impurities of water cause a waste in both; for a fuller treatise on this matter the reader is referred to another part of this work, in the section on materials. In the arrangement of the plant of a soap manufactory, much must depend upon the means at hand, yet so much depends upon the completeness of the different implements and machinery, for the rapid and economical production of the soaps, that we must endeavor to describe all the most use- ful and the latest inventions for conducting the different pro- THE ESTABLISHMENT OF A SOAP FACTORY. 203 cesses with the greatest facility. We will precede this with illustrations of two French soap factories which may prove useful as hints. Fig. 13. First, one for making the mottled Marseilles soap, with an open fire. A A. Factory Building. — This building has the form 204 TECHNICAL TREATISE ON SOAP AND CANDLES. of a parallelogram, the dimensions of which vary according to the importance of the manufacture. It is divided into three compartments; the middle one is occupied by the kettles, frames, and lye vats. That on the left contains the lixiviating apparatus. That on the right is employed as a store-room. A basement about 9 feet below the first floor forms passages and cellars, a part of w^hich is occupied by the furnaces and rcvservoirs of masonry to receive the waste lyes drawn from the kettles during the boiling of the soaps. The communication with the first floor is by the stairways KK. B B. Kettles, — It is in these kettles that oils and fatty matters are saponified, by means of caustic lyes of soda. They are placed on a parallel line; below these kettles are passages and arched cellars, in which are placed the furnaces and masonry vats, to receive the waste lyes, which collect at the bottom of the kettles below the soap. Their capacity varies from 1250 to 5000 gallons. Their upper level is about 3 feet above that of the floor of the cellar, which is ordinarily paved with bricks or hard flagstones. C C. Fireylace, — The fireplace is the space which separates the grate from the bottom of the kettle. The space varies from 13 to 20 inches, according to the capacity of the kettles. The inside of the fireplace is constructed of good refractory bricks, and has the form of a truncated cone. D D. Grate^ or the part of the fireplace destined to support the fuel. It is composed of cast-iron bars placed near each other, at the distance of about one-third of an inch. These bars are generally one inch in thickness, so that the grate presents a surface of draught equal to one-fourth of its total surface. Experience has shown that these proportions are the most convenient for producing a complete combustion of the fuel. E E. General chimney into which all the products of the combustion are discharged. The higher the chimney the better the draft. Its inside diameter must always be pro- portioned to the total opening of the flues of the furnace. To hasten or slacken the combustion in the furnaces, each chimney is provided with a good register. THE ESTABLISHMENT OF A SOAP FACTORY. 205 F F. Ash-pan. — The ash-pan is the vacant space between the ground and the grate. It has two different objects. First, it gives passage to the air between the bars of the grate, an essential condition to keep up the fire ; secondly, it is a kind of magazine for the ashes. Its dimensions are varia- ble, but it is ordinarily as wide as the grate. It is import- ant not to let the ashes accumulate in it, for in this case the obstruction to the entrance of air under the grate would re- tard the combustion. G G. Cisterns in masonry placed under the kettles. They are used.to receive the waste lyes. A pump placed in each cistern is employed to raise the lye they contain, into a large masonry or sheet-iron vat placed on the first floor. H H H. Large masonry vats in which are kept separately the difterent qualities of oil used in the saponification. Their capacity is very variable — from 2500 to 12,500 gal- lons. They are ordinarily covered by an arch of bricks, in the middle of which there is a large opening closed by a wooden trap-door. 1 1. Cellars below the first floor. L L L. Basins of brick or stone. They are used to lixiviate the crude soda for the preparation of caustic lyes. Their number, like their capacity, varies according to the importance of the manufacture. They are located on the first floor, and parallel with the kettles ; immediately below, large cisterns are constructed, from six to nine feet deep, specially intended to be used as receivers for the different lyes obtained by the lixiviation of the crude soda. M M M. Frames constructed of brick and cement, which have the form of a parallelogram, and their height varies be- tween seventeen and twenty-three inches. The upper part must always be lower than the edges of the kettles, so that by means of a wooden trough, inclined towards the frames, the soap, after being boiled, may be run into them. Their capacity varies according to the size of the kettle. Generally each kettle requires three frames, which are simultaneously employed. M M. Store-rooms containing the crude sodas. It is also 206 TECHNICAL TREATISE ON SOAP AND CANDLES. in this room that the sodas are pulverized and mixed with the proper proportions of lime to form the carbonate into caustic soda. The pulverizing of the soda is done in K The powder must not be too line, for in such case the lixiviation would be impossible or very difficult. Description of a General Plan for a Manufactory of Soap Heated hy Steam.— The application of steam to the fabrica- tion of soaps has become nearly general. This system pre- sents advantages so evident, over the heating by open fire, that it is now very generally adopted. In the following figure we give the plan of a manufactory in which all the kettles are heated by steam. A. Boiler to produce steam. B. Fireplace provided with a cast-iron grate, in which the fuel is burned. C. Chimney for the discharge of the products of the com- bustion. Fig. 14. D. Dome from which the steam is discharged by means of the pipe F F, into flat coils, placed at about one inch from the bottom of the kettle. This dome is necessary to prevent THE ESTABLISHMENT OF A SOAP FACTORY. 207 the boiling water from entering the pipe, and thence passing into the coil. F F. Kettles to boil the soap. Their shape is the same as the ordinary kettles, only at the bottom there is a horizontal worm in which steam continually circulates during the boil- ing of the soap. Each worm is provided with a waste pipe, which traverses the bottom of the kettle to discharge the water of condensation. The worms are designated by the letters E E, and the waste pipes by G G-. These pipes are provided each with a valve which is opened or closed at will. H H. Fipes^ to draw off the lyes from the kettles. 1 1. Cisterms of masonry, used to receive the old lyes drawn from the kettles. K K. Cellars, communicating with the cisterns and the furnace by a stairway. M M. Foundation of the kettles. This foundation is made of brick and cement; and its object is to render the kettles more solid, and prevent the loss of heat. IsT I^. Sheet-iron vats, used to receive new lyes. O 0. Frames, into which the soap, when finished, is drawn. These frames are of w^ood, and open in four parts. P. Table on which the soap is divided into bars and cakes. Q. Dry- in g-rooin, using hot air in which the soap is dried. Illus- trated and described elsewhere. E-. Ram. This machine is used to mould the soap by means of a copper matrix. A heater for superheating the steam is now very customary, and has its advantages. The advantages of the system by steam may be summed up in the following points : 1. Economy in fuel, since several ket- tles can be heated by the same fire. 2. Facility and rapidity in the work. 3. Products of a quality superior to those ob- tained by heating with an open fire. 4. Economy of labor. The indispensable necessity of water in soap factories, either for the preparation of lyes, or the cleaning of the apparatus, must determine the manufacturer to establish his factory near a stream of clear and limpid water. This condition ought to be attended to, whenever circumstances will permit it, for it is of great importance in the fabrication. In case 208 TECHNICAL TREATISE ON SOAP AND CANDLES. well water has to be used, it will be more economical to use a pump than to draw by hand. Then it will be convenient to prepare a large cistern below the surface of the ground, and to have it full at all times, for the various uses of the manufacture. The drying-room mentioned we here illustrate in the an- nexed cut, and remark that all soaps do not require drying, but many do, and a drying-room is very necessary — ojie with warm air or a steam heat, or one well ventilated hy air. The latter does not require any heating apparatus, but can be used only in fine weather. It is generally established in the upper story of the building, where the air circulates freely. Shelves or racks, on which are placed the pieces of soap to be dried, are fixed in the room, eight or ten inches apart, one above the other; this separation has the advantage of accelerating the drying of the soap, by putting it in contact with a greater mass of air; the desiccation is more rapid when the tempera- ture of the air is elevated. This mode of drying is incontest- ably the most economical, because it does not require either apparatus or fuel; it is also the most regular and the best for the drying of soaps, and it may be used whenever circum- stances will permit; unhappily it is subject to the variations of seasons and weather so frequent in our climate. The dry- ing-rooms with warm air have the advantage of being used at all seasons. In many manufactories, the drying-room con- sists of a more or less large room around which shelves pro- vided with trays are disposed, and upon which are placed the pieces of soap to be dried. In the middle of the room is a stove heated with wood or coal. The temperature must not be above 26.6° C. (80° F.); openings must be made in different parts of the room to permit the air, saturated with moisture, to escape freely. This arrangement quickly has- tens the drying of the soap. A temperature of 26.6° C. (80° F.) is sufficient to dry in fifteen or twenty hours pieces of olein soap destined to be moulded. Drying-rooYti with Warm Air. — The drying of soaps in the free air cannot be practised at all seasons, and has to be stopped in rainy or damp weather. As for the drjnng THE ESTABLISHMENT OF A SOAP FACTORY. 209 in a room heated by a stove— while this mode is gener- ally employed, it presents the inconvenience of localizing and causing an unequal distribution of the heat. Some shelves are remote from the source of heat — being but little affected by 27— from which it results that the soap does not dry equally in all parts of the drying-room. This is not the only inconvenience; stoves often smoke, especially when first lighted, and the smoke stains and blackens the pieces of soap. These different inconveniences, and particularly that of the smoke, have obliged some manufacturers to use dry- ing-rooms heated by hot air. By this system, they completely utilize the heat produced by the fuel, and the hot air which flows into the room is always pure, without either odor or smoke. What distinguishes this system from all others is, that the desiccation of the soap is rather produced by an energetic ventilation, occasioned by the abundance of the hot air continually renewed in the room, than by a high temperature; and experience proves that, in rooms heated by a good stove, it requires twenty-five to thirty hours to 14 210 TECHNICAL TREATISE ON SOAP AND CANDLES. dry the soap, while witli a much smaller expense of fuel a treble quantity of soap can be dried in eight or ten hours in a room heated by hot air. Fig. 15 presents a longitudinal section of a drying-room with hot air. A. Furnace in which the fuel is burned. B. Grate. C. Ash-pan. D. Door of the fireplace. E E. Cast-iron flue through which the fire and smoke pass to the chimney. F F. Chimney for the exit of the products of combustion. G. Register in the chimney, used to regulate the draft of the fire, and thus control the temperature of the hot air in the room. H H. Opening for the introduction of cold air ; this air grows warm hy circulating round the furnace A, and passes into the room by means of proper apertures. I 1 1 I. Walls of the room which must have the thickness of a brick. K K K. Chimneys by which the air escapes, more or less saturated with the moisture of the room. L. Door by which the trays, full of soap, are introduced into the room. M M M M. Squares representing the pieces of soap to be dried. N, Vacant space between the trays and the bottom of the room. 0. Vent holes in the masonry which traverses the room in all its length, and which is provided with many openings to allow the hot air to pass into the room. P P P P P. Stone or brick foundation on which the room is built. The manner of using this drying-room is very simple. After filling the trays with pieces of soap, they are introduced into the room by the door L ; the door is closed, and the fire lighted. The cold air enters by the openings H H, grows warm by circulating around the furnace, and flows continu- ally into the room by the openings 0. The temperature THE ESTABLISHMENT OF A SOAP FACTORY. 211 must not be too high but must be kept between 26.6° C. (80° F.) and 30° C. (86° F.). With an ordinary room, it is possible to dry 20,000 pounds of soap in a day. Kettles.— li\ our description of the necessary plan, the first item should be the kettles, which are of various kinds. Kettles are vessels in which, by means of heat, the manufac- turer combines fatty bodies with lyes of potash or soda to form soap. Their dimensions vary according to the quantity needed. It is always advantageous to operate with large ket- tles, because they present a greater economy of labor, fuel, and lyes than the small ones. As for the capacity, we have ascertained that, for the treatment of every 100 pounds of fatty matter, we require a capacity of about 87| gallons, thus: to saponify 1000 pounds, a kettle of a capacity of 375 gallons ; for 2000 pounds, 750 gallons ; and for 3000 pounds, from 1000 to 1125 gallons, which represents the ordinary size of the kettles of Marseilles. Whatever are their dimen- sions, these kettles have always a circular form, and gradu- ally widen up to the top, so as to form a cone. Some have flat bottoms, others have convex or concave bottoms. Ex- perience has shown that the latter arrangement is the best, and the most convenient for the work. Whatever is their capacity, they are always provided at their lower part with a pipe, with valve used to draw off, after each operation, the sub-lyes collected under the soap. Masonry Kettles. — At Marseilles nearly all the kettles of soap manufacturers are made of masonry, except the bottom, which is of copper or sheet iron. The most essential condition for the construction of such a kettle is to establish it on a s^ood solid foundation. This foundation is covered with a thick mass of masonry, constructed of good materials, which is rendered tight with hydraulic mortar, a little soft, so that it may pene- trate into all the interstices of the mass ; by which means the infiltrations of liquid are rendered impossible. The kettle is afterwards built on this mass, beginning at the hearth and the surrounding w^alls, to which a thickness is given propor- tioned to the capacity of the kettle. When the level is reached on which the bottom of the kettle has to rest, it is 212 TECHNICAL TREATISE ON SOAP AND CANDLES. important to employ materials of the best quality, and the least apt to be destroyed by the action of heat and lyes. Some stones are not good for these kinds of construction, because the heat quickly injures them. Good stone must be used for the outside walls. As for the inside of the kettle, it is always formed of a thick counter wall, of hard and well-burned bricks, and of pozzuolana cement, employed with a certain quantity of fine sand. It is very important to fill all the interstices exactly, for, independently of the loss of material, they would have the effect of accelerating the destruction of the masonry. To preserve the kettle, it is surrounded outside with hoops of very thick iron. It is by these precautions that great solidity is given to these kettles. It is true, their construction is costly, and they require frequent repairs, but these inconveniences are well repaid by the advantages they present. The superiority attributed to these kettles over those made of metal, is gen- erally recognized by the manufacturers of Marseilles, who use no others. Besides the advantage of better retaining the heat of the mass during the saponification, they are said to have that of not coloring the pastes, as is done by metal kettles. We do not know if there be any foundation for this assertion, but we can afiirm that very white soaps are prepared in cast-iron or sheet-iron kettles ; then, if the alter- ation of the whiteness and puritj^ of the pastes were due to the use of metallic kettles, necessarily colored soaps would have been obtained, since these kettles were the only ones used ; but it is not so — it is sufficient to see fine white soaps manufactured in such kettles, to be assured that there is no foundation for the statement. The only condition to be ob- served, is to keep the kettles always clean and dry, to pre- vent the formation of oxide of iron, which, by combining with the soap, would communicate to it a yellow coloration. Cast-iron Kettles. — Cast-iron kettles are not much used in soap manufactories, because they are more costly than those of sheet iron, and also, because it is very diflicult to have them of a large capacity, made of a single piece. In France they are used only in small manufactories, but in Belgium THE ESTABLISHMENT OF A SOAP FACTORY. 213 and England their use is more general. The first care to be taken in purchasing such a kettle, is to choose it without defects, and as thin as possible, for experience has shown that in this state it resists the action of fire better than when thicker. For the same reason soft cast iron must be prefer- red to hard. The first has a fine and soft grain, and can be more easily filed. It presents less inconvenience than the hard, brittle cast iron, and is capable of lasting much longer than the latter Indeed, a soft cast-iron kettle may last a very long time when well managed, besides, when warm, it requires very little fuel to keep up the heat. Sheet-iron Kettles. — These kettles are now generally used in nearly all the soap manufactories. For a long time it was diflicult to construct them, but since the progress in the me- chanic arts, they have been constructed with great perfec- tion. When a sheet-iron kettle is made, the dimensions must be calculated according to the quantity of soap to be manu- factured. As we have said before, for every 100 lbs. of fatty matter, it requires a capacity of 37J gallons ; starting from this base, the maker will always succeed in giving to the kettle the capacity necessary for the work for which it is in- tended. As for the thickness of the metal, it varies accord- ing to the capacity of the kettle. For a kettle of 750 to 1000 gallons, the iron should have 3 millimetres (0.11 inch) of thickness for the lateral sides, and 4 to 5 millimetres (0.15 to 0.19 inch) for the bottom. All the solidity of such a kettle depends entirely on the riveting; however, as well riveted as a kettle may be, it often happens that the first time it is used it allows a little liquid to escape, but soon the soap, by stopi»ing all the crevices, completely prevents the leaking. Heating of Kettles by Fire. — In the heating of ordinary kettles by fire, the furnaces are constructed so as to absorb the most of the heat produced by the fuel, by applying at first the heat under the bottom of the kettle, and directing it afterwards around the sides, before losing it in the chim- ney. In soap kettles, on the contrary, a great part of the heat developed 'by the fuel is lost, because these kettles can 214 TECHNICAL TREATISE ON SOAP AND CANDLES. be heated only at the bottom, so as not to burn the soap, which would be the case if the heat circulated around the sides. iTotwithstanding the imperfection of this kind of construction, and the enormous loss of fuel, experience has demonstrated that it cannot be modified without great in- convenience. To diminish as much as possible the loss of heat, it is necessary : 1. That the fireplace should be right in the central axis of the kettle. 2. That the lining of the hearth should be of refractory brick, in order that the heat may be thrown back below the bottom of the kettle. 3. That the fuel which produces the most intense heat with the least flame should be used; hence hard coal should be selected. 4. That the openings through which the products of the combustion enter the chimney should possess together the same surface as the grate, experience having shown that this Fig. 16. is the best arrangement for obtaining a good draft and effect- ing a complete combustion of the fuel. It is by fulfilling these conditions that the greatest amount of coal is utilized THE ESTABLISHMENT OF A SOAP FACTORY. 215 in heating the kettles. Bat to obtain this result, it is essen- tial to have a well-constructed furnace, with all the recent im- provements. The furnace must be very dry before using it. The figure (Fig. 16) represents a kettle heated by an open fire. The sides are composed of brickwork erected and lined with cement. The upper part/,/,/,/, which never comes in contact with the fire, and is intended to afford space for the soap to rise, expands in the form of a cone. The fire- place B, is separated from the ash-pit H, by the grate r. The fire, after having heated the bottom of the pan, passes by the flue ^, ^, ^, half round the side of the pan into the chimney A. This is accessible for the purpose of cleaning by the door x ; the soot is thrown into the pit L. A tube with a cock leads from the lowest part of the pan for the removal of the spent lye. The whole of the pan is sunk into the floor of the boiling house, which is made of planks, stone, or iron plate, in such a manner that the brickwork of the upper part pro- jects to about three feet above the floor. Heating of the Kettles by Steam. — The most important in- vention introduced into the heating of the kettles, is incon- testably the heating by steam. For a long time numerous experiments were made, but it is only within about fifty years that this new system has been advantageously applied. The first manufacturers who used steam discharged it directly into the mass of the soap; the result was that the water produced by the condensation of the steam consider- ably lowered the degree of the lyes used to saponify the fatty bodies. They were then under the necessity of using more concentrated lyes. Soon after, other manufacturers — to obviate the above inconveniences — conceived the idea of causing the steam to circulate in the kettle, within a double casing, in such a manner that water produced by the con- densation of the steam should not mix with the lyes, and weaken their degree. This system is still followed in some manufactories, but it has the inconvenience of heating the sides of the pan too much, and the bottom not enough. The result is that the ebullition is never very regular, and is 216 TECHNICAL TREATISE ON SOAP AND CANDLES. more pronounced on the sides than in the centre. Now, in new manufactories, pans with a double casing are suppressed, and the soap is heated directly by means of a flat worm of strong wrought iron, placed at about 3 to 4 inches from the bottom, and in which the steam circulates. This arrange- ment — as simple as it is. ingenious, produces the best results, and the heating is so rapid that it requires only half an hour to boil a kettle containing 1000 pounds of soap, while the heating by an open fire will require from 3 to 4 hours. This advantage is not the only one this system presents; it enables us to heat with a single boiler, and consequently with the same furnace, several pans at a time, which presents a notable economy in fuel, time, and labor. There is no chance to burn the soap, as in heating with an open fire. The use of superheated steam presents greater advantages than those obtained by ordinary steam. Experience has shown that, by the use of superheated steam, the operation is more rapid, and the expense in fuel greatly diminished. We give a representation of the whole arrangement, consist- ing of three caldrons, one for white, anf)ther for yellow, and a third for palm, and the finer soaps. G designates the main pipe or feeder, which is attached to the steam boiler W, of the establishment. It is stationary, and generally fitted against the wall, immediately above the kettles. The boil- ing caldrons are partly of iron and partly of wood — the upper portion or curb A being of wood, well hooped round by iron rings, and the lower portion D of cast iron, and so shaped that the worm may hug closely to the sides without loss of room, and the "blowpipe" fit snugly to the bottom. For the convenience of drawing ofi" the spent lyes, there are attached a pipe and cock I. Each of these kettles, resting upon a hollow pile of circular mason work M, is furnished with a welded wrought-iron worm, which connects with the main feeder at and serves as the boiling medium of the soap paste. The steam is let on or off", by opening or shut- ting the cock H, and the waste steam is conducted through the other end of the worm X, which passes upward by the side of its inlet, and thence out in any convenient way through the wall of the laboratory. Also affixed to the main feeder is another pipe, with a stopcock attached, and leading immediately downwards to the bottom of the kettle, 218 TECHNICAL TREATISE ON SOAP AND CANDLES. where it is affixed to a circular iron tube, pierced around its circumference with holes. It is set immediately below the worm, and is called the blowpipe," serving to give addi- tional heat occasionally to the contents of the kettle, as well as to stir it up when necessary — an operation more effectually executed in this way than by a crutch in the hands of a workman. Tlie whole interior arrangement of the boiling pan is seen at the figure AD, the worm detached at K, and the " blowpipe" at L. These kettles are worked much in the same manner as the ordinary fire caldrons, except that they require less attention. The charge of material is put in and melted by a rush of steam through both the blowpipe and worm, the cock of the latter being shut off when it is necessary. The cock P serves to regulate the current of steam from the generator. We have inserted three caldrons in our figure. In large factories it is convenient to have this num- ber; one, however, will answer in a small laboratory, though there will necessarily be a loss of time in cleansing it always, when the charge is to be changed from yellow to white soap. The curbs of conical form are preferable, though other shapes are used. Some manufacturers dispense with the iron bot- toms entirely, and boil in water-tight vats, or tubs, made wholly of wooden staves, hooped together with strong iron clamps. This series of kettles is well adapted for bleaching palm oil. In the steam series above described, the steam is intro- duced directly into the material. But as it is desirable for some soaps to apply the steam upon the outer surface of the kettle, we present below (Fig. 18) a suitable arrangement for that purpose. A is the interior of a cast-iron kettle, surrounded by brick- work. B is the outer cast-iron caldron, which should fit to the inner kettle tightly, so as to prevent any escape of steam. D D is the tube leading from the steam boiler, and convey- ing the steam to the kettles. It is fitted with a cock, which is opened or shut, according as the steam is to be let on or off, for accelerating or retarding the boiling of the soap. C C is the tube by which the condensed vapor is discharged. THE ESTABLISHMENT OF A SOAP FACTORY. 219 The cock in this tube can be left slightly open so as to ope- rate as a safety-valve, when one of these necessary appen- dages is not fixed to the apparatus. The tube E is the dis- charge-pipe of the caldron. The brick-work F F is similar to that for other furnaces. Fig. 18. 1.1 , 1 nzzi Hiiberfs Appa?'atus for Boiling Soap by Means of Surcharged Steam. — This apparatus, represented in Fig. 19, was patented by Mr. II. G. Hubert. "A is a steam boiler of ordinary construction. B is a steam pipe provided with a sto.pcock C. D is a steam super-heater. E is a pipe leading from the super-heater D to the receiver F. G is a pipe supplying air from a force pump. H is a valve for regulating the intro- duction of air into the apparatus through the pipe I. F is a receiver, where the steam and air are mixed together. K is a pipe conveying the mixed air and steam to any number of soap-boiling apparatus. L L are pipes conveying the steam and air to the bottom of the vats M M ; S, S, S, S, are radia- ting pipes perforated with holes, turned in opposite directions, so that when the air and steam issue from them, they will cause a rotating motion of the whole mass of supernatant liquid in the vats MM. R is the tank for receiving the lye drained by the cocks P P. The operation of this apparatus is easily understood. The lye and fats being introduced into 220 TECHNICAL TREATISE ON SOAP AND CANDLES. Fig. 19. the vats M M, steam is allowed to escape gradually into the apparatus D, where it becomes super-heated, and is carried THE ESTABLISHMENT OF A SOAP FACTORY. 221 over and injected through the mass in the tanks MM. When it is required that the mass be stirred, then air is introduced into the apparatus by turning the valve H. It will be observed that the workman has perfect control of the opera- tion, being able by simply turning the cock C or H, to in- crease or diminisVi the heat, and to stir or leave the pasty contents of the vats M M at rest." St. John^s Steara Jacket. — Tliis apparatus accomplishes the mixing and boiling of the soap ingredients simultaneously. As the steam circulates around the kettle, and through tubes, instead of being admitted directly into the paste, a uniform temperature may readily be established. The whole arrange- ment is shown in longitudinal vertical section, by Fig. 20. The boiling pan a a is enveloped by a steam casing or jacket 6, adjusted to which is a tube /:, communicating with the steam generator, and leading the steam into the space c e, between the pan and outer casing. The exit pipe t/, with its stopcock :r, is for drawing oft' the condensed steam, as may be necessary; and the safety valve is a protection against excessive pressure. The stirring is accomplished by means of the revolving, horizontal arm d carrying teeth /"/, and mounted upon a perpendicular shaft e. The stirring- apparatus is put in motion by suitable gearing, consisting of the bevel wheel ^, mounted horizontally on the vertical shaft and working into a similar wheel on the horizontal shaft ^, which has a pulley J o\\ its other end, driven by a band or strap E. When the boiling is completed, the con- tents of the kettle or pan are drawn off' through the pipe/, and its branches m m. The tubes p p closed at their u[)per ends, and communicating with the space between the pan and jacket, by conveying the steam throughout the con- tents of the pan extend the heating surface of the latter. They also serve the purpose of stops for breaking the mass as it is carried around by the stirrers//. The swivel or T joint u is so constructed that the arms m r/i niay be turned horizontally in a circle, so as to bring the cocks x x over a range of receivers. J. is a cock for letting the charge into the branch pijtes m m. Another cock, is for regulating 222 TECHNICAL TREATISE ON SOAP AND CANDLES. the admission of steam to the chamber c, and the tubes j) p. The clutch lever n is for adjusting the cog-wheel h with the Fig. 20. cog-wheel g, when the stirrers are to be put in motion, JE is a driving-band, connected with the pulley J on the shaft i, F F are stay bolts for coupling the kettle and jacket. Morfifs Steam Jac/i:^^.— This jacket produces the same effects as the above. The following figure represents a vertical section of it. A is the soap kettle, which may be made of any shape and of any material, having a waste-cock C, and THE ESTABLISHMENT OF A SOAP FACTORY. 223 mounted upon a frame B. D is an upright shaft, hollow- both in its upper and lower parts, but solid in the middle. F is a stuffing box in which the shaft D runs, and is pro- vided with suitable packing and a circular chamber, so that Fig. 21. steam from the pipe G may be admitted through openings in the hollow top part of the shaft D. The lower end of the shaft D runs through the bottom of the kettle A, fitting suffi- ciently tight to prevent the soap and lye from escaping, yet loose enough to be easily turned. Tw^o, three, or four pipes H, so bent as to take the configuration of the kettle A, are connected at both ends with the hollow part of the shaft 1). K K K are a number of slats fastened to the pipes H H, to strengthen them, and at the same time to oSer more resist- ance to the materials to be stirred. A set of gearings S, and 224 TECHNICAL TREATISE ON SOAP AND CANDLES. a shaft T, mounted on the heam 0, are so arranged as to give motion to the shaft D. The advantage derived i'rom this arrangement is obvious, as the steam entering the pipe D finds no other outlet than the pipes H H, through which it rushes, following their sinuosities, till it reaches the bottom of the shaft D, where the condensed water is drawn off at E. The heat thus conveyed into the pipes H H, is communicated to the materials contained in the kettle A, which being con- tinually stirred, have the heat more uniformly distributed throughout their mass than could be effected by the ordinary methods. This is a most useful kettle for the extempore soaps. Caldrons or Boiling Pans. — In smaller factories the old mode of boiling soap by the naked fire may be employed, and we proceed to give a description and drawing of the kind of kettles most advantageous for the purpose. The size of the caldrons should be proportioned to the amount of soap intended to be made at each boiling. The bottom pan may be of cast iron, but in England they prefer Swedish wrought-iron plate. This bottom pan is built in brick ma- sonry, so that the heat acts solely upon its bottom. Fig. 22 Fig. 22. — 1 — p 1 - - 1 1 ' > ' ^ 1 1 tr, 1 1 1 i 1 1 N 1 0000 \\ - 1 \ 1 1 I I 1 1 1 i 1 1 \ shows one of these caldrons. Should there be several, they are placed on a line with each other, and over a furnace beneath. To the caldron a tube of about two inches dia- meter is adapted, which serves as an outlet for the sub-lye which remains under the boiled paste. The furnace is made in the usual manner. The arrangement of the mason work THE ESTABLISHMENT OF A SOAP FACTORY. 225 is generally, however, left to the skill and ingenuity of the bricklayer. These soap pans or caldrons are cast with a flange at their top, so that, when necessary, an adjunct cylinder of wood, in the shape of a cone, may be fastened to them. This is called the curb. Fig. 23, or upper part Fis. 23. of the caldron. It is nothing more than a hollow cone of iron-bound staves, made to fit the flange of the iron ket- tle. It can extend as high as desired, and is made of wood, so as to save the cost of metal, and the mason work neces- sary to inclose it. The cones stand erect, but they should be strongly and tightly fastened, and jointed to the lower pan. In this way a pan may be enlarged at much less cost than for a caldron wholly of iron requiring to be entirely inclosed within mason work. Jjye Vats, — The lye vats, in very extensive factories, are m.ade of brickwork, smoothly cemented within ; but much the better material would be lead ; for then one set of vats would answer for all kinds of soaps, as the lye prepared in them, not being acted upon by the metal, wnll be perfectly clean. Large tuns lined w^ith sheet lead, and with cullen-, dered false bottoms, Fig. 24, are perhaps the best and most durable fixture of this kind that could be put up. In this case there is a cock fitted near the bottom of each tun, and through it the clear lye collecting in the lower part of 226 TECHNICAL TREATISE ON SOAP AND CANDLES. the tun, between the diaphragm and the bottom, can be drawn off into tubs below for use, as may be wanted. Close Fig. 24. by these vats there must be a pump or hydrant, with its out- let spout conveniently arranged for a supply of water, in quantity as required. An excellent substitute for the cock is a long-handled plug of wrought iron. Fig. 25. Its conical tip must be Fig. 25. tightly and smoothly wrapped with tow, so that when in use, it may make a tight joint. It is placed in the hole from the interior of the vats, so that being always in position, it is only necessary to give the handle a push when it is desired to draw off the lye, and draw it outwards again when the flow is to be stopped. In large establishments, where there are a number of lye vats in constant operation, it is necessary to have a tightly covered reservoir for the reception of the lye as fast as it runs through ; for there is not space enough below the false bottom for any great accumulation of liquid. There are generally several vats to each laboratory, but the THE ESTABLISHMENT OF A SOAP FACTORY. 227 number depends entirely upon the amount of soap manu- factured, and consequently the proportion of lye necessary for the steady prosecution of the work. In a Marseilles soap house, the lye vats are in sets of four. 1^0. 1 is the fresh vat which receives the fresh mix- ture of alkali and lime ; the next one, or ITo. 2, being the avancaire^ or an advanced stage. Ko. 3 is the small avan- caii^e^ being two steps in advance, and, therefore, contain- ing weaker liquor; and l^o, 4 is the t(;«^er-v«^, because into that the water is directly introduced. Into No. 3 the moderately exhausted or somewhat spent lyes are thrown. From ISTo. 3 the lye is pumped into ISTo. 2, to be strength- ened, and in like manner from No. 2 into No. 1. Upon the lime paste, in No. 4, which has been taken from No. 8, water is poured, and the lye thus obtained runs upon the paste of No. 3, which has been taken from No. 2. No. 3 is twice lixiviated, and No. 2 once. The receiver under No. 1 has four compartments, into No. 1 of which the first and strongest lye is run ; into No. 2, the second lye ; into No. 3, the third lye ; and into No. 4, the fourth lye, which is so weak as to be used instead of water, for lixiviation. The lime in vat No. 4, when exhausted, is emptied out of the window near which it stands, in which case the water is poured upon the contents of No. 3 ; and upon No. 2, the somewhat spent lyes. No 1 is now the avancaire of No. 4, because this has become, in its turn, the fresh vat, into which the fresh soda and quicklime are put. The lye discharged from No. 3 comes then upon No. 2, and after having been run through it, is thrown upon No. 1. In some factories iron vats in the form of inverted cones are used, the outlet for the lye being through an opening at the apex of the cone. Then it is judicious to have, also, a lead-lined vat for the finer qualities of soap ; as it is requisite, especially for toilet soaps, to have the lye perfectly clear and colorless, and free from iron. In the apartment containing the lye vats there should be two pieces of auxiliary apparatus for the preparation of the lye materials. These are a mill for grinding the alkali when 228 TECHNICAL TREATISE ON SOAP AND CANDLES. lumpy ; and a drum sieve for thoroughly mixing it with the lime. Both are to be driven by steam power. The siphon should be of half-inch lead pipe, and may be made after Coffee's pattern, for moderate volumes of liquid, as it possesses many advantages over the usual forms in delivering the liquid without any inconvenience to the ope- rator. It is shown by Fig. 26, and consists of a bent tube. Fig. £G. one leg of which is longer than the other, and a smaller late- ral tube B, capped with a large, hollow India-rubber ball A. The long leg has also a stopcock near its lower end. It is put in operation by closing the cock, compressing the bag, and quickly immersing the short leg in the clear lye, to within an inch or less of the subsident carbonate of lime, as represented in the drawing. The act of compressing the ball produces diminution of the elastic force of the internal air by expelling the most of it, so that as soon as the hand is removed from the ball, the outward pressure of the air drives the liquid up to the highest point of the bend, whence it drops, by the force of gravitation, on the opening of the cock, and flows out in a continuous stream, as long as the mouth of the short leg is covered by it. THE ESTABLISHMENT OF A SOAP FACTORY. 229 The best form of grinding apparatus is Bogardus's eccentric mill, Fig. 27; for it does its work economically, both as to time and cost; and, moreover, is not an expensive machine. It is so constr-ucted that "both plates revolve in the same direction (with nearly equal speed) on centres, are apart Fig. 27. from each other one inch more or less. The centre ot the one, or axis thereto affixed, rests and revolves upon a stationary point; whilst the prime mover, by means of a belt or gearing, communicates motion to the other plate. The circles which are cut in the plate act like revolving shears by cutting every way ; and when the mill is in opera- tion, they cause a peculiar wrenching, twisting, and sliding motion, admirably adapted for every species of grinding. The ground substance is delivered promptly without clog- ging the mill." The drum sieve. Fig. 28, is merely a wooden framework cylinder A, covered with wire gauze, the meshes of which are larger or smaller, according to the degree of fineness which it is desired to give the mixture of alkali and lime. They should 230 TECHNICAL TREATISE ON SOAP AND CANDLES. not, however, exceed the eighth of an inch. It is mounted upon uprights B, and is made to revolve by means of the Fig. 28. shaft and pulley C. The shelf D is an inclined platform for the delivery of the mixture into tubs, as it passes from the seive. Soap Frames. This name is given to square reservoirs made of masonry, iron, or wood, into which the soap is run, when drawn from the kettle, in order that it may cool. Frames of Masomry, — The first thing to do when building a masonry frame is to carefully level the ground on which it has to be established. This done, a platform of good masonry is constructed on it, at about four or five inches above the level of the ground, and the dimensions of which exceed, in every direction, from seven to eight inches the outside line of the walls of the frame. To build the walls, employ well- burned and very smooth bricks. For large frames, the walls have generally from twelve to fourteen inches of thickness, their height varies between twenty-four and twenty-six inches above the level of the platform. In the front of the frame leave a lateral opening of about two feet, in which is fixed a kind of movable door, which is used for removing the soap after its cooling. The mortar used in the construction con- THE ESTABLISHMENT OF A SOAP FACTORY. 231 sists of three parts weight of good cement, and one of fine sand. When the walls are raised to the proper height, and have stood for two or three days, the joints are cut down smooth, and the walls are thoroughly washed with a broom. The next day they receive a perfectly smooth coat of cement, about one inch in thickness. As for the bottom of the frame, a coating of cement is applied about one or two inches thick ; and then sufi*ered to dry for a few days; on this coating of cement a floor of hard bricks is laid; these bricks are laid flat, and well cemented with mortar. It is proper to give a slight inclination to the bottom of the frames in the direc- tion of the door, so as to permit the lye to run off into a small tank, also built of masonry, and sunk in the ground below the door of the frame. The dimensions of a frame are generally regulated by the capacity of the kettle for which it is destined. It has been ascertained that for regular and continued work, three frames are required for the service of each kettle, so as to have no interruption in the different operations. Frames of masonry are completely water-proof, and do not allow the escape of any liquid, when properly prepared. Good frames last very long; they are used prin- cipally in the manufacture of marbled soaps; their employ- ment is general at Marseilles. Frames of Iron. — These frames generally have nothing re- markable in their construction. They ordinarily have the form of a parallelogram; their dimensions vary according to the quantity of soap to be run into them. They are formed of strong iron plates, so firmly riveted together as to render im- possible the loss of liquid. These frames have on one of their sides a vertical opening from top to bottom, the width of which is from 16 to 20 inches; this opening is closed by a sheet of iron and is used as a door to the frame. It is by this open- ing that the soap is taken out after its cooling. The con- struction of these frames is costly, but they have the advan- tage of being perfectly tight, and of not allowing any leakage of soap or lye. They are of the same form as the wooden frames ; but differ in size. The sides are of wrought-iron plate, and the remaining 232 TECHNICAL TREATISE ON SOAP AND CANDLES. portions of cast iron. Fig. 29 presents a side view, Fig. 31 the bottom, and Fig. 30 a top view of them, as made by Poole & Fig. 29. Hunt, engineers and machinists, Baltimore ; and the clamp, which fits on the ends, and holds them together, is shown Fig. 30. by a. They are drawn to a scale of three-eighths of an inch to a foot. Being mounted on wheels, these frames can readily Fig. 31. Mmrnmrnmrnrnt iniinimin be moved from place to place. The good conducting power of the metal promotes the cooling and solidifying of the soap paste. Whitaker's Fatent Soap Frame. — One of the most approved forms is that made by Messrs. Hersey Brothers, of Boston, Mass., Whitaker's Patent Soap Frame. It consists of two THE ESTABLISHMENT OF A SOAP FACTORY. 233 sides of plate iron, flanged at their upper edges, and strength- ened by ribs of corrugated plate iron, riveted to their outer surface, running in the direction of their length (Fig. 32). Fig. 32. These corrugations prevent the bending or twisting of the side plates, and the soap cools into the exact rectangular shape of the frame. The trouble and expense of the ordi- nary stays and supports are here avoided, as the frame is self- sustaining. The sides are connected by ends of two-inch plank, secured by clamps. The frame is very light, easily managed, and can be adjusted and unadjusted by one work- man almost momentarily. The soap cools very rapidly — ordinary soap cooling sufliciently to strip in twenty-four hours in cold, and in forty-eight in warm weather. Frames of Wood. — These frames are made of oak or pine. Those of oak are costly, and have the disadvantage of color- ing the soap ; the others do not present this inconvenience, and are to be preferred. IsTearly all the frames are constructed of four movable parts, which are made of boards of pine wood, about two or three inches thick. To preserve the 234 TECHNICAL TREATISE ON SOAP AND CANDLES. wood from alteration the inside is lined with very thin sheet iron, fixed to the wood with tacks about half an inch long. By this means these frames may be used five or six years without repair. The floor is of wood or brick. When the soap is cold and ready to be taken oft*, the sides of the frames are removed, and the cake of soap remains standing on the bottom. In this country, frames are made of pine Avood, for light-colored and fine soaps ; and of cast iron for common yellow soap. The iron frames need not exceed half an inch in thickness; but those of wood should be made of two or three inch stuff. The shape is that of a parallelogram, as Fig. 33. should be about 36 inches deep, and smoothly jointed, so that when they are placed on top of each other in piles of three, THE ESTABLISHMENT OF A SOAP FACTORY. 285 four, or five (Fig. 34), they may form a water-tight well, which will hold the hot paste without leaking. The wooden frames are lifted off, one at a time, and the soap remains upon the movable bottom ready to be divided into bars, as shown by Fig. 33. Fig. 84, No. 1, shows the w^ell of five frames, ready for receiving the soap paste. A single frame and the bottom of the well are severally presented in JSTos. 2 and 3. The German frames, like those of this country, are also constructed so that they may easily be separated into pieces, being set up by nuts and screws, as shown in Figs. 35 and 36. Their floor is also movable; and is shown in longitudi- Fig. 35. Fiff. 36. nal section by Fig. 37, and in breadth by Fig. 38. It con- sists of two layers of deal boards, in the upper of which are four grooves, fitting with the projections in the sides. The tw^o narrow sides are also supported on the inside by cross- Fig. 37. Fig. 38. pieces. All the sides are strengthened by supports. When the several parts are put together, the bolts, screw cut at the other end, have only to be inserted through the projecting parts of the longer sides, and made fast by the nuts at the ends, to form the whole into a solid box. A cloth spread over the bottom prevents any soap from passing the holes, through which the lye drains off. A frame with its sides and ends dow^n is shown by Fig. 39. By the side of it is the clamp used for holding the different parts in position when 236 TECHNICAL TREATISE ON SOAP AND CANDLES. the frame is set up. Many, to prevent the too rapid cooling of the soap, are covered with a mattress of soft material on the outside, etc. The Her&ey's Patent Rotary Soap Pump of Hersey Bro- thers, of Boston, combines in itself more excellences and is better adapted to the requirements of the trade than any- thing of the kind ever presented, and there are now very few large manufacturers in the United States who use any other appliance for taking off soap. The pump may be set up in any convenient position adjacent to the kettle, and not over ten feet above the bottom of the same, and con- nected to it by means of a two-and-a-half-inch iron pipe tapped through the iron plate at a distance of about two feet above the worm or coil. Each kettle is thus connected with the pump by the iron pipes, which have valves placed upon them on the outside (of the kettle) so that any one of them may be readily pumped off* and framed without disturbing the others. The pipe inside of the kettle has a suitable swing-joint so arranged that it can be raised or lowered at pleasure. The cuts represent the pump — perspective and sec- tional. Fig. 40 represents the pump complete ; when the pump is rotated in the direction of the arrow, the outlet marked S is the suction ; when rotated in the opposite direc- tion, the opposite outlet becomes the suction. This is an important feature, as it enables the discharge pipes to be emptied of their contents in stopping, by giving a few revo- lutions by hand in the opposite direction. Fig. 41 is a view of the interior of the pump when the cover is taken off. Fig. 39. THE ESTABLISHMENT OF A SOAP FACTORY. 287 When turned in the direction of the arrow, the blade F sweeps around, drawing the fluid in at I and forcing it out at H, the contents of the pump being twice emptied during Fig. 40. each revolution. The blade F swings on a pivot ; the end F, when reaching the point B, at the lowest point, gaining the position there sliown, and gradually returning to its former position on completing the revolution. The fluid is pre- vented from passing from one side to the other by the con- tact of the cone with the cover. The set screw, shown in Fig. 41, bears against a step at the end of cone, and keeps the cone forced against the cover, and is screwed up to compen- sate for any wear that takes place. Fig. 42 shows the cone Fig. 41. Fir. 42. and blade, and forms the entire working part of the pump; no valve being used, there is no chance of any derangement 238 TECHNICAL TREATISE ON SOAP AND CANDLES. in the operation of the pump By means of the pump the soap can be forced any distance or lieight. The soap can be pumped from one kettle into another, which is a special ad- vantage when it is necessary to transfer the nigre," either in the state of a soft curd, or in the unseparated state into another kettle, to make room for a fresh boiling with clean stock, and thereby keep up a uniform quality of first-class soap. By lowering the pipe attached to the swing-joint in- side of the kettle, the lye of the strengthening change" can be pumped from the very lowest point in the bottom of the kettle, Avhile still hot, into another in which stock is being saponified, thereby economizing steam. In certain cases where it is undesirable to pump the lye over the curb into the kettle, because of the froth which it may occasion, an- other plan can be adopted, which admirably brings into play the whole system of pump, valves, and swing-joints of the two kettles, from the bottom of one of which it is required to pump the hot lye, and force it through the iron piping down to the bottom of the other. Lye of any kind, whether spent lye, or strengthening change lye, strong caustic lye, either hot or cold, grease or thick oil can be easily and quickly pumped by this pump. The pump is 10 inches in diameter and 2J inches in outlet, revolutions 120 per minute, Capacity 6000 gallons per hour. Cutting Operation. — When the soap sets firmly, the frames, according to their construction, are either lifted off or un- bound, by loosening the clamps, and removed, so as to leave resting on the bottom a solid mass of soap, corresponding in size with the interior of the wells, as shown in Fig. 38. It is then divisioned oft' on the sides by means of a scribe, Fig. 43, which is a wooden slat, carrying on its smooth side a number of slender iron teeth. The workman, then taking a brass wire, Fig. 44, directs it in the track of the teeth, and thus cuts oft* one slab of the pre-arranged thickness, as shown by Fig. 45. When the whole block is thus divided into slabs, the latter are in their turn reduced to bars and lumps of smaller dimensions, the usual size of the bars being 12 to 14 inches long, by 3 inches every other way. The THE ESTABLISHMENT OF A SOAP FACTORY. 239 pound lumps are about 5 or 6 inches long, 3 inches deep, and the same width. The size of the slabs must, therefore, be Fig. 43. Fig. 44. regulated accordingly ; and, therefore, it is convenient to have a scribe with several sets of teeth, as shown in Fig. 33. Fig. 45. Such an instrument is used in the factories, and is nothing more than a piece of hard ^vood, about two inches square, with each of its four sides smoothly planed, and bearing slender teeth. On one side they may be set 1 inch apart from each other; on the second, 2 inches; on the third, 2J inches ; and on the fourth, 3 J inches; care being taken, how- ever, that the distance between the teeth of the respective sides is uniform. In this manner, slabs and bars may be smoothly and accurately cut, according to the size traced out upon the block by the teeth of the scribe. A much more rapid method of dividing the blocks into bars, is that invented by Yan Haagen, of Cincinnati, and which requires the use of two pieces of machinery, as shown by Figs. 46 and 47. The first is called the slabbing and bar- 24:0 TECHNICAL TREATISE ON SOAP AND CANDLES. ring machine^ and consists of a carriage A, which is so grooved at the top as to allow the wires to pass entirely through the block of soap. This carriage is then moved back to the driver B, and on it is placed a whole block of soap as it comes from the frame. This is done by a peculiar Fig. 46. truck, as shown in diagram ]^o. 46, made and constructed expressly for the purpose. The block of soap having been first cut loose from the bottom of the frame; this truck is run to the side of it, and, means of rack and pinions worked with a lever, the block of soap is slipped on . the truck, brought to the machine, and, by the same power, there- upon placed. All this is done with great ease and despatch, and by the same power. THE ESTABLISHMENT OF A SOAP FACTORY. 241 The range of wires C is regulated by corresponding gauges in the upright posts, which allow it to be set to cut slabs of any desired thickness. The block of soap is forced up to those wires by the driver B, propelled by means of racks and pinions and a winch. It will be seen that in this way the block will be converted into slabs. There is a similar hori- zontal arrangement of cutting-wires D, and confined to a vertical motion by the posts of the frame. These wires are also arranged as above, so that any desired bars may be cut. It is caused to descend by the action of the rack and pinions and winch as above; and with this part of the machine the slabs are converted into bars without handling the same. They, consequently, are much neater and smoother than they could be cut otherwise. The wires, being fastened at one end to a spring E E, will easily yield and form the required loops at the beginning of Fig. 47. the operation; and then both ends become fixed, so that the loops cannot get any larger, if the soap be very hard ; in which case the long loop is more apt to warp and cut uneven. The steady motion of this machine permits the use of much 16 242 TECHNICAL TREATISE ON SOAP AND CANDLES. smaller wire than will do for hand-cutting, and consequently the work is much smoother. This apparatus cuts the blocks of soap into bars as long as its width. To make pound lumps or small cakes and tablets, the slabs must be transferred to the second, or caking machine^ Fig. 47. The slabs are placed in as great number as can be got on, upon a range of rollers A, and forced through the range of wires B, by the driver C, which is propelled by racks and pinions and a crank. The soap having been forced through lengthwise, and the crank being shifted, it is then forced through the range of wires D, by the driver E. Both the drivers are connected with the same crank, and, by displac- ing it from the one, it gears itself into the other. The wires Fig. 48. Champion soap slabber. are arranged in the same manner as in the slabbing machine. They may be readily shifted so as to cut any desired shape or size. THE ESTABLISHMENT OF A SOAP FACTORY. 243 This mode of cutting gives great smoothness and uniform- ity of weight and size to the bars and lumps, saves handling, scratching, and bending, and effects a larger gain over the usual method, in time, labor, and expense. Two of the most recently invented machines for cutting soap are those made by Hersey Brothers, of Boston, Mass., and here illustrated by Figs. 48 and 49. Ihe Champion Slabber (Fig. 48) is similar to that of Van Hagen, already described, with some improvements that make it more rapid in its working. Ealston's cutter (Fig. 49) has an attachment for spreading and stamping, so that the cakes are furnished ready for packing ; it is simple and fast in action, and large quantities of soap can be cut and stamped in a working day. Fig. 49. Ralston's patent cutter with stamping and spreading attachments. Grutching Machines. Stephen Strum's Soap-erutching ma chine, also made by Hersey Brothers. (See Figs. 50 and 51.) This machine is simple in construction, and perfect in its action. It crutches the soap completely within three minutes, 244 TECHNICAL TREATISE ON SOAP AND CANDLES. and gives it a smoothness and transparency which can never be obtained by any other machine. Size, 1200 pounds. The speed of main shaft, with the working paddles on, should be forty-five to fifty revolutions per minute, and should turn so as to work the soap to the valve and pump it out. When the machine is charged, the soap should cover the paddles two inches before the machine is started. When running the soap into the frame, the machine should be stopped until the soap commences to run slowly, otherwise it will force it out too rapidly. Very little power is neces- sary for this machine. To clean the machine, put in four Fig. 50. Strunz's Crutching Machine (outside view) . or five bucketsful of boiling salt water about 22 degrees strong, and run the machine three to four minutes; which should be done while the soap remaining in the machine is warm. The machine must always be cleaned after using. THE ESTABLISHMENT OF A SOAP FACTORY. 245 Fig. 51. Strunz's Crutching Machine (working part of machine). The Jacket Crutching Machine (Fig. 52). — The jacket on this machine is a circulating one, and is said to have no equal in its rapid heating or cooling power. There is no dead point in the jacket as in other jackets where the warm water re- mains for a long time outside of the current. The drawing shows two pipes on one side; one is to be connected with steam and the other with water. The escape should be left always free, and no cock or valve should be on the escape pipe. The little cock on the bottom is to let the water out of the jacket to prevent it from freezing, or else the jacket would burst. The steam should never be let on unless the jacket is free from water, otherwise it may strain the machine. These crutching machines are very useful for mixing the colors and perfumes of toilet soaps. We have now left little to add to the needed implements except the minor ones, as hand stirrers, or paddles and crutches, which are too well known to need description, scales, weights, shovels, and spades for cutting out tallow, etc. 246 TECHNICAL TREATISE ON SOAP AND CANDLES. Almost all soaps are now stamped, and many wrapped ; for stamping there are numerous presses in use, the most im- portant have a full description in our chapter on toilet soaps. Fig. 53. Strunz's Jacket Crutehing Machine. Minor Implements. — The minor implements of the soap laboratory are, a crutch, Fig. 53, composed of a long wooden Fig. 53. 1^ □ handle adjusted at the end to a board, and used for stirring the soap paste in the operation of " mottling large, cullen- dered, iron ladles, with long, wooden handles (Fig. 54) for THE ESTABLISHMENT OP A SOAP FACTORY. 247 dipping out the hot paste from the kettles, and copper buckets (Fig. 55) for conveying it to the frames. Fig. 54. Fig. 55. Copper dippers, with handles of two or more feet in length, Fig. 56, are used for dipping the soap into frames and for many other purposes. Fig. 56. 248 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIOJS" XI. THE FABRICATION OF SOAPS. Soaps by Boiling. — The suitable preparation of the lyes for the decomposition of the fatty bodies is beyond doubt the most important process in the art of making soap, and it therefore requires the closest attention and study, for with- out the knowledge and experience this study gives, much loss of time and material may result. We here repeat that the alkalies of commerce are never pure, and in our previous sections we have described these impurities and the modes of analysis. We will now give instructions for the proper preparation of the lyes for use, with suitable tests for strength and purity. For ordinary purposes the caustic lyes of soda as now received are gene- rally of sufficient purity when freshly prepared for making common soaps, though there are none of them that do not require an investigation before entire confidence can be given to them. With potash the soap-maker will find still more difficulty as it is usually still more impure, as has also been shown, though in making soft soap with the potash lyes the process is quite different from that in use for the hard soaps from soda lyes. Yet a pure and caustic alkali is essential to nearly all methods. Whether we need a potash or a soda lye it is necessary in almost all cases to render them caustic, that is, to remove their carbonic acid by means of lime, and this lime should be reliable and be tested to discover if it contains any impurities or at least such an excess of them as to make it unfit for use. These tests are also shown else- where. The action of the lime is to remove the carbonic acid, by the power it has of great affinity for that acid, causing a decomposition by absorbing it and forming an insoluble car- bonate of lime which is precipitated, after giving a greater part of its oxide to the alkali. THE FABRICATION OF SOAPS. 249 Of the quantity of hydrate of lime necessary to make caus- tic a given quantity of alkali, there is great diversity of opinion, yet there is a rule which must be studied, for an alkali may work wrong that has too little or too much lime, or, as is technically called, too low or too high in lime. Thus it is necessary to give due regard to the properties of lime and to its action in strong or weak lyes which is quite differ- ent, as lime will not act in strong solutions of alkali. We have heretofore given the proper instructions for the alkalimetric tests for these materials, and they should re- ceive attention to aid the necessary calculations, yet we will give an example as a further guide. The carbonate of potash is a combination of 1 equivalent potash = 47.11, and 1 equivalent carbonic acid = 22, and its equivalent is therefore 69.11. If we desire to change this into caustic alkali, we must extract the carbonic acid. This is done by offering an equivalent of caustic lime, which, when changed into carbonate of lime, will absorb likewise 1 equi- valent of carbonic acid. Since, however, the equivalent of the caustic lime is = 28, it follows that to 69.11 parts in weight of carbonate of potash 28 parts in weight of caustic lime must be applied, to make the former completely caustic. To 50 kilog. (110 lbs.) of pure carbonate of potash, therefore, 20.3 kilog. (44.66 lbs.) of caustic lime are added. We, however, have never to do with pure carbonates of the alkalies, nor with pure caustic lime, so that in practice other corresponding proportions are required than are just given by theoretical calculation. Supposing, for instance, the potash for preparing the caustic lye contains 72 per cent, of carbonate of potash and the lime contains 82 per cent, pure caustic lime, then we must in the same ratio, as the potash contains less than 100 per cent., take less lime; while in the same proportion as the burned lime contained less caustic lime, apply more of the lime. In the suggested ex- ample the calculation would be rendered thus: X(that is 40 6 X 72 the necessary quantity of lime) = — '- — = 35.65 ; that 82 is, we would apply 100 kilog. (220 lbs.) of a 72 per cent, potash 250 TECHNICAL TREATISE ON SOAP AND CANDLES. 35.65 kilo^. (78.43 lbs.) of slaked lime of 82 per cent, pure caustic lime in order to obtain a perfect caustic lye. The pure carbonate of soda contains also to 1 equivalent = 31.0 parts soda, 1 equivalent = 22 parts carbonic acid, and for its separation again 1 equivalent lime = 28.0 parts would become requisite. 100 kilog. (2::0 lbs.) of pure carbonate of soda require, therefore, for its change into caustic soda 52.83 kilog. (116.23 lbs.) of pure caustic lime. The weaker a soda is the less lime, and the more inferior the lime, the more is to be used in order to make a certain quantity of soda caustic. The following calculation is exactly the same as under the same proportion of the potash. Supposing we have a soda of 92 per cent, and a lime of 80 per cent., we have the following equation : X = ^^-^^ ^ 80 where X again represents the necessary amount of lime, and thus is found 60.76 kilog. (133.67 lbs.). According to this the tables below are calculated ; they contain the respective changeable quantities of the lime to be applied in proportion to the contents of potash and soda to pure carbonate of alkali, and the contents of the pure slaked lime, each from 5 to 7 per cent. This is for practice sufficiently accurate ; meanwhile the tables may be easily changed if other proportions occur by means of interpola- tions. I. Table for Potash, Of lime if the same contains degree require 90 85 80 75 70 65 60 55 50 100 per cent, potash, 45.11 47.77 50.75 54.01 58.00 62.46 67.67 73.82 81.20 95 " " 42.86 45.38 48.21 51.43 55.10 59.34 64.28 70.12 77.12 90 " " 40.60 42.99 45.67 48.96 52.20 56.22 60.90 66.44 73.08 85 " " 38.35 40.60 43.14 46.01 49.30 53.15 57.52 62.75 69.01 80 " " 36.09 38.21 40.60 43.31 46.40 49.97 54.13 59.06 64.96 75 " " 33.83 35.82 38.06 40.60 43.50 46.85 50.75 55.36 60.90 70 " " 31.58 33.44 35.53 37.90 40.60 43.74 47.37 51.68 56.84 65 " " 29.32 31.05 33.00 35.19 37.70 40.60 43.98 48.00 52.78 60 " " 27.06 28.66 30.47 32.48 34.80 37.48 40.60 44.31 48.72 55 " " 24.81 26.27 27.92 29.77 31.90 34.36 37.22 40.60 44.66 50 " 22.56 23.88 25.37 27.06 29.00 31.23 38.83 36.91 40.60 THE FABRICATION OF SOAPS. 251 IL Table for Soda. 100 kg. soda of appended degree require Of lime if the same contains 90 65 SO. 75 70 65 60 55 50 100 per cent, soda, 58.70 62.18 66.21 70.44 75.47 81.28 88.05 96.06 105.66 95 55.7 7 59.02 62.93 66.91 71.70 77.21 83.64 91.25 100.38 90 52.83 55.93 59.43 63.40 67.92 73.15 79.24 86.45 95.10 85 u u 49.90 52.83 56.13 59.88 64.15 69.10 74.84 81.65 89.81 80 u u 46.73 49.72 52.83 56.35 60.37 65.02 70.44 76.84 84.53 75 44.02 46.61 49.52 52.83 56.60 60.95 66.03 72.04 79.24 70 41.09 43.51 46.25 49.30 52.83 56.89 61.63 67.24 73.96 65 u u 38.15 40.41 42.92 45.78 49.05 52.83 57,23 62.42 68.68 60 u u 35.22 37.20 39.62 42.26 45.29 48.77 52.83 57.26 63.39 55 u u 32.28 34.30 36.32 38.67 41.51 44.70 48.42 52.83 58.11 50 u u 29.35 31.07 33.02 35.22 37.73 40.64 44.03 48.03 52.83 "While we insist on the maintenance of the proper propor- tions between the carbonate of alkali and the lime, we do not merely look to a saving of the latter, because the slaked lime can be had cheaply everywhere, so that the greatest overplus of lime will not influence the expense of making caustic lyes. The advantage of accurately maintaining the equivalent proportion of the materials which come into con- sideration, rests on the fact that a carbonate of lime is ob- tained, which may be lixiviated with the greatest ease so that not only is time saved, but also nearly all the alkali is recovered, without being compelled, in order to reach the same object, to be overburdened with a mass of weak lyes, as their storage often occasions more inconvenience than the alkali contained therein is worth. Of scarcely less importance for preparing pure lyes is the proportion between them and the water necessary for solu- tion. In this respect the carbonate of alkalies seems not to be proportionately equal, since, according to the experiments of Liebig, carbonate of potash to become perfectly caustic must be dissolved in at least twelve times its weight of water, while for carbonates of soda (anhydrous) about seven times the amount of water is required. We have, however, for finding out this proportion made some experiments, and found that 252 TECHNICAL TREATISE ON SOAP AND CANDLES. carbonate of soda, even if dissolved in thirteen times its weight of water and boiled with a small overplus of lime, does not yet impart all its carbonate to the lime. The fol- lowing are the results of these experiments: — By 1 part anhydrous carbonate of soda and 5.8 parts water, remain undecomposed .... 15.62 p. c. NaO.COa. " 1 part anhydrous carb. of soda and 8.2 parts water 8.78 " " " " " " 13.3 " 1.29 " " Even by the application of thirteen and one-third parts its weight of water to that of carbonate of soda, and the re- quired amount of lime, there were 1.29 per cent, remaining undecomposed ; it also made but a trifling difference when a larger overplus of lime was applied. Since it is known by experience that lyes which contain 9 per cent, of their con- tents in carbonate of soda will saponify the neutral fats, those who deem this an advantage, may dissolve the soda in eight or nine parts its weight of water, and then add the necessary quantity of lime and boil it. Meanwhile the solu- tion becomes somewhat weaker by changing the lime into hydrate of lime, which imparts its water to the lye, because the carbonate of lime retains no water. To acquire a per- fectly free carbonic acid lye, we would, according to the above experiments, probably have to apply fifteen times the amount of water of the weight of the pure carbonate of soda, and obtain hence a lye of 3.9 per cent, caustic soda, which, of course, is tolerably weak. But a lye of from 5 to 7 per cent, is in most cases suitable, i. e., such as is obtained by dissolv- ing carbonate of soda in ten times its weight of water. For pure carbonate of potash, the same proportion must be used, and a lye is thus obtained of nearly 7 per cent, caustic potash. By these calculations it is self-evident, that we should only consider the contents of pure carbonate of alkali, so that for instance 50 kilogrammes (110 lbs.) of a potash, which contain but 65 per cent, pure carbonate of potash, we dissolve in 325 kilogrammes (715 lbs.) of water, and a soda of 35 per cent, pure carbonate of soda in 425 kilogrammes (935 lbs.) of water. THE FABRICATION OF SOAPS. 253 After having in this manner made the solution, and having brought the entire quantity to a boil, we begin with the addi- tion of the previously weighed and slaked lime (milk of lime) in gradual portions, while the liquids are kept slowly boil- ing, and continue thus for a short time, after having added the last portion of lime. By this operation the lime which at first was of a gelatinous consistency is changed into the crystalline or grainy state, and may then be lixiviated with the o^reatest ease. When the boilinof has lasted about half an hour, the fire is removed, when the carbonate of lime will soon settle on the bottom and the finished lye stand clear above it. After having cooled ofl:' so far, that the finger may be placed in it without scalding, the drawing ofl:' is com- menced. This is best performed by means of a copper siphon, or in place of such by one made of tin-plate. The siphon is filled with water and boths ends are closed with the thumbs of both hands, which as they have to come into contact with the lye are previously rubbed with fat, or still better with parafiine. The residue, the carbonate of lime, is carried into the filtering apparatus, which has a sieve bottom, covered with coarse canvas, or cotton cloth, in such a way that none can escape spreading, the pulpy mass as evenly as pos- sible thereon, to allow of a complete filtration, and fill the sjtace above it with pure water, until it forms a layer equally as high as the carbonate of lime, and filters completely. If the necessary care and attention have in every particular been given, the lixiviation may be considered as finished, and the lime exhausted; but for a second time pure water may be poured upon the lime, and this very Aveak lye may be used for preparing the lye in the next operation. Preparing Potash Lye from Wood-ashes. — Where there ia opportunity to purchase large quantities of good wood-ashes cheaply, their use offers, for the preparation of potash-lye, immense economical advantages over the use of potash. The manipulation is somewhat different from that of potash. After having, in the manner heretofore described, ascertained the contents of carbonate of alkali of the wood- ashes, the required amount of lime is calculated that is 254 TECHNICAL TREATISE ON SOAP AND CANDLES. necessary to change it into caustic potash. The lime is slaked to powder and mixed with the wood-ashes as thoroughly as possible. This mixture is placed in a wooden, or still better in an iron vat, in which is inserted a sieve bottom covered with straw, now adding sufficient water to it so that a thick paste is formed which is left at rest for 24 hours. It must be observed that the layer is everywhere of equal height, and no gutters are formed, through which the water might flow off without having previously absorbed the caustic potash. 'Now pour water into the yet empty part of the vat and permit the lye to draw off. The space between the blind and the real bottom must have an opening imme- diately under the former, so that the air can escape. The lye which collects between the two bottoms is drawn off by means of a stopcock, and carried to a second vat, which is prepared in the same manner as the first. It may also be passed into a third vat, but in every case the quantity of water must be so proportioned, that only lyes of 7 per cent, caustic potash are produced. Of this strength, the lyes may be used for saponification of the fats; but they contain as a rule such large amounts of sulphate of potash and chlorate of potash that muddy soft soaps would be obtained. It is therefore necessary to condense them to 22 to 25° B., when after cooling off the greater part of these foreign salts crystal- lize. For use the lyes are again diluted with water till they reach the desired strength. Preservation of the Lyes. — Although it is not common to prepare large quantities of lyes in advance and to preserve them for a longer period, yet it may be advantageous under certain circumstances, especially if the necessary vessels are at hand, to lay up a supply of caustic lyes; to avoid the absorption of carbonic acid, and to lose thereby more or less of their efficacy. Strictly hermetically tight vessels would be necessary, the constructing and acquiring of which would not only be very expensive but also difficult. We have in order to reach this end used paraffine, of which we have caused to be thrown according to the size of the vessel a sufficient quantity upon the yet warm lye. The paraffine melts, spreads THE FABRICATION OP SOAPS. 255 upon the lye and forms upon it a cover, which completely shuts out the carbonic acid. For this no special vessels are needed, find it may be placed in tanks or in the so called pits; — as thereby the paratRne is in no wise changed, we can always make renewed use of it. In testing the strength of lyes, formerl}^ an egg was used — and in many instances this is yet done — for the approximate estimation, whether a lye possessed the necessary strength for the paste or preliminary operation, the lye had to attain such a density that a hen's egg would float upon it. At a more progressive period hydrometers were used for this purpose and are yet frequently applied. There is no doubt that the latter instrument would show with suflicient accuracy the quantity of alkali dissolved in the water if for the production of lyes pure carbonate alkalies were used. But as such is not the case, and the potash as well as the soda contains larger or smaller quantities of foreign salts, soluble in water, this method of testing, based upon the specific gravity, can never furnish positive results, and there may be lyes which al- though they prove themselves high on the scale of an hydro- meter, yet may be proportionately weak in caustic alkali. On the other hand, the alkalimetric test offers the most perfect security, and the modus operandi is similar, as we have already related, in the case of testing potash and soda. The main thing is, that a correct testing acid be provided, and it would be best to prepare it for the purpose, and, more- over, such an one, as may be applied as well for potash as for soda-lyes. e have, heretofore, for a testing acid, recom- mended nitric acid ; but its treatment offers to those who are not chemists certain difficulties, and for this reason we would recommend to soap manufacturers crystallized oxalic acid. It has in its crystallized state always the same composition, and can, as it is dry, always be accurately weighed. 63 grammes (2.2 ozs.) of purified oxalic acid (in case of necessity the comnaercial oxalic acid may be used) are dissolved into 1 litre of water. It corresponds to 47.11 grammes (1.65 ozs.) caustic potash, and 31 grammes (1.09 ozs.) caustic soda, each cubic 256 TECHNICAL TREATISE ON SOAP AND CANDLES. centimetre, therefore, 0.047 grammes (0.725 grains) potash and 0.031 grammes (0.478 grains) soda. If a lye is to be estimated, take into a beaker glass, or still better, in a porcelain cup 10 cubic centimetres (2.70 flui- drachms) thereof, then add about 10 drops of litmus tinc- ture, and then by means of a -^q cubic centimetre (0.027 flui- drachm) graduated pipette, add the oxalic acid solution until the blue color of the liquid has changed into an onion-red. Supposing now we had by this transaction used upon a pot- ash lye 10 cubic centimetres (2.70 fluidrachms) oxalic acid, then there are in the 10 cubic centimetres of the applied lye 0.47 grammes (7.25 grains) potash, or, if soda lye had been estimated, 0.31 grammes (4.78 grains) soda contained in the lye; the one lye contains, therefore, 4.71 grammes (72.7 grains) or per cent, potash, the other 3.10 grammes (47.83 grains) per cent. soda. To show at once that in such like tests it is not important to obtain the highest degree of accuracy, that is to have absolutely pure oxalic acid, we will suppose the applied oxalic acid had contained but 95 per cent, pure oxalic acid, an amount of impurity hardly ever found. In fact there would in such a case as is shown above if 10 cubic centime- tres (2.70 fluidrachms) oxalic acid had been used, not 4.711 grammes (72.69 grains) potash, or 3.10 grammes (47.83 grains) soda, have been the proper conteiits of the lyes, but only 4.711 : 0.95 = 4.4 (67.9 grains) potash, respectively 2.945 per cent, soda, so that the difl:erence in both cases amounts to about ^ per cent. But another test of the lye can be made in this manner, by placing with a pipette 4.71 cubic centimetres (1.27 flui- drachms) potash-lye, or of a soda lye 3.1 cubic centimetres (0.84 fluidrachm) in a cup, bluing it with litmus tincture, and then by means of normal oxalic acid solution titrate until an onion-red color appears. In this case the cubic centimetre of acid used, multiplied by 10, gives the content of the caustic alkalies without further calculation. But it is always best for such tests to apply purified oxalic acid, for which purpose the crude oxalic acid is dissolved in double its weight of heated distilled water and the solution filtered, when after cooling off, the acid will crystallize in a THE FABRICATION OF SOAPS. 257 sufficiently pure condition. It is then brought upon a filter, and dried in the open air upon tissue paper without warming it, until a crystalline powder is formed. Whenever the application of oxalic acid seems too trouble- some, the test acid may be sulphuric acid, of which 55 grammes (1.93 ozs.) are weighed off and diluted with water to 1000 cubic centimetres, one litre (2.1 pints). To have this acid mixture correct, dissolve 5.3 grammes (81.78 grains) fresh heated pure carbonate of soda in 100 cubic centimetres (3.38 fluid ozs.) liquid ; of this transfer 10 cubic centimetres (2.70 fluidrachms) by the pipette into a porcelain cup, adding tincture of litmus, and also from a graduated pipette so much sulphuric acid until the liquid has assumed an onion- red color, and by warming again does not again turn blue. If the sulphuric acid had been correctly mixed, then 10 cubic centimetres of it would have been accurately used ; to occa- sion that change of color, generally, however, there will be — according to the above proportions between water and sul- phuric acid — less than 10 cubic centimetres used of the test- ing acid, and the deficiency must be made up of pure water. Supposing, instead of 10 cubic centimetres (2.70 fluidrachms) but 9 cubic centimetres (2.43 fluidrachms) had been applied, then to the litre of testing acid, 99 cubic centimetres (3.34 fluid ozs.) water must be added. We have already explained, that in order to determine the strength of a lye with some degree of accuracy, we carmot depend upon a hydrometer, but will prove by an example what difierences may ensue under certain conditions. Thus a lye containing 14.52 per cent, of caustic soda of the specific gravity of 1.255 = 29.5° B., and according to this should have contained 16.635 per cent, of soda. If the requisite quantity of the lye for decomposing the neutral fat had been deter- mined by means of a hydrometer in this case, we should have applied 2 per cent, of soda less than was necessary for a com- plete saponification. The soda from which that lye had been prepared contained 72 per cent, anhydrous carbonate of soda, hence we have an inferior article. Under certain conditions a hydrometer may, of course, be used for determining the 17 258 TECHNICAL TREATISE ON SOAP AND CANDLES. value of alkali contained in certain (equal) sorts of potash or soda; that is when large quantities thereof are on hand and have to be worked up. In such case the contents of the alkali are discovered in the alkalimetric way and compared w^th the specific gravity or the degrees Baume or those of another scale. Then as long as that supply holds out the alkalimetric tests may be dispensed with and the hydrometer may be used. In order to obtain a certain basis for this, there have been found by experiment — for soda lye — the results indicated in the two following tables, from which it may be seen about how much of the caustic soda has to be deducted from the degree of Baume's hydrometer. One of the tables contains experiments with 86 per cent, soda, the other with 72 per cent. soda. I. 86° Soda. Specific gravity. Degrees Bauifle. Should contain. Contains. 1.2333 = 32.15 14.554 13.890 1.1166 = 24.20 7.635 6.945 1.0583 = 9.60 4.231 8.472 II. 72° Soda. 1.2548 = 84.5 16.636 14.360 1.1274 =;= 19.5 8.646 7.180 1.0637 = 10.2 4.574 8.590 If the estimations of the hydrometer have been compared with the results of the alkalimetric test, we can as long as the same sort of soda is worked, for approximate determination of the lyes of caustic soda, apply the hydrometer also. This is done by deducting according to the degrees of soda a certain portion from the per cents, show^n by the scale of the hydro- meter. We do not wish to recommend this method, but there are many soap factories where the hydrometer cannot be dis- pensed with, and for such the statements above may have some value. THE FABRICATION OF SOAPS. 259 Table of the contents of Anhydrous Potash with the corresponding specific gravities and degrees of the hydrometer according to Baume {calculated by Tunnerniann) at 15° (7. (59° F.). Specific gravity. Degrees according to Baume approximate Per cent, of potash. 20 1. (6.29 gal.) contain kilogr. NaO, Quantity of fat which in 100 1. ('.^6.5 gallons) of the corresponding lyes will saponify. 1.3300 36° 28.290 7.52 228 kg. 215 " 1.3131 34 27.158 7.09 1.2966 33 26.027 6.75 205 '* 1.2803 32 24.895 6.37 193 " 1.2648 30 23.764 6.02 182 1.2493 28 22.632 5.66 171 " 1.2342 27 21.500 5.30 161 1.2268 26 20.935 5.14 156 1.2122 25 19.803 4.80 145 1.1979 23 18.671 4.50 136 " 1.1839 22 17.540 4.15 126 " 1.1702 21 16.408 3.84 116 '* 1.1568 19 15.277 3.53 107 " 1.1437 18 14,145 3.22 99 1.1308 17 13.013 2.94 89 1.1182 15 11.822 2.64 80 1.1059 14 10.750 2.38 72 1.0938 12 9.619 2.10 64 1.0819 11 8. 437 1.85 56 1.0703 10 7.355 1.57 48 1.0589 7 6.214 1.32 40 " 1.0478 6 5.022 1,05 32 " 1.0369 5 3.961 0.82 25 " 1.0260 3 2.829 0.58 18 1.0153 2 1.697 0.34 10 " 1.0050 1 0.5658 0.11 3.6" The second and fourth columns are added by Perutz, and the latter is especially calculated for the convenience of soap boiling establishments, and is valuable for reference. Dalton has lii<:ewise furnished a table respecting the potash contents of lyes, according to their specific gravities, which, however, differs 2 per cent, from the above. But as it ex- tends also to lyes of greater specific gravities we deem it desirable to add it here. 260 TECHNICAL TREATISE ON SOAP AND CANDLES. Specific gravity. Degrees according to Baum6. Per cent, of potash. Quantities of fat which in 100 kil. (220 lbs.) of the lyes are saponified. i bo 58 01. Z OA'7 1^-^ 307 Kg. l.bv K A 04 46. 7 1 KO A Q 4y /ion O K O ii zoo 1 A 7 1.4/ 4d O 'I A 1 A A 1.44 44 3b. o o o O ( ( 1 A A 1.44 A O 4o OA A o4.4 OA/? ( ( zUb 1 QQ l.OtJ /I A 4U Q O A 1 y4 1 .OO Q O oo OCk A 1 < b O K OO ib..i 1 f; 7 < t 10 / 1.28 31 23.4 140 " 1.23 27 19.5 117 " 1.19 23 16.2 97 " 1.15 19 13.0 78 " 1.11 14 9.5 58 " 1.06 8 4.7 26 " In the above table it is supposed that 141 parts potash, on an average, saponify 860 equivalents of fat; but we can operate more accurately when the equivalents for the dif- ferent fats are the basis for this calculation. The figures in the fourth column are then changed in the same ratio as the equivalent becomes greater or smaller than that accepted by Perutz, viz., 860. THE FABRICATION OF SOAPS. 261 Table of the contents of Anhydrous Soda with the corresponding specific gravity and hydronieteric degree of Baume^ according to Tunnermann^ to which Perutz has likewise added the quantities of the fats^ v^hich are saponified by lyes of various strengths. vity. a soda. ^ . sa- fat. >3J s soda. 1 00 , -w ej bo u 03 o CO ■^rd a ci pa o « -.^^ to " 7* *9 s o ^i! ,^ a 100 1. (5 of the ponitj CO Ph o o o « « 1.4285 43 30.220 8.63 416.7 1.2392 27 15.110 3.74 181.2 1.4193 43.5 29.616 8.41 406.5 1.2280 26 14.506 3.56 172.3 1.4101 42.0 29.017 8.18 395.7 1.2178 25 13.901 3.38 163.7 1.4011 41.0 28.407 7.96 385.0 1.2058 24.5 13.297 3.21 155.0 1.3923 40.5 27.802 7.74 374.3 1.1948 23 12.692 3.03 146.6 1.3836 39.7 27.200 7.53 364.0 1.1841 22 12.088 2.88 139.4 1.3751 39 26.594 7.31 353.7 1.1734 21 11.484 2.70 130.3 1.3668 38.5 25.989 7.10 343.6 1-1630 20 , 10.879 2.53 122.3 1.3586 38.0 25.385 6.89 333.5 1-1528 19 10.275 2.37 114.6 1.3505 37.3 24.780 6.69 323.7 1.1428 18 9.670 2.21 106.8 1.3426 36.7 24.176 6.50 314.0 1.1330 17 9.066 2.05 99.4 1-3349 36 23.572 6.30 304.3 1.1233 16 8.462 1.91 91.9 1.3273 35 22.967 6.08 294.1 1.1137 15 7.857 1.75 84.6 1.3198 34.5 22.363 5.90 285.4 1.1012 13.5 7.253 1.59 77.4 1.3143 34.2 21.894 5. 75 278.3 1.0948 12 6.648 1.46 70.4 1.3125 34 21.758 5.70 276.2 1.0855 11 6.044 1.31 63.4 1.3013 33.5 21.154 5.52 267.1 1.0764 10 5.440 1.17 56.6 1.2982 33 20.550 5.53 258.0 1.0675 9 4.835 1.03 49.9 1.2912 32.4 19.945 5.16 249.0 1.0587 7 4.231 0.89 43.3 1.2843 31.6 19.341 4.97 240.2 1.0500 6 3.626 0.76 36.8 1.2775 31 18.730 4.79 231.4 1.0414 5.6 3.022 0.63 30.4 1.2708 30.5 18.132 4.61 222.9 1.0330 4.2 2.418 0.50 24.1 1.2642 30 17.518 4.43 214.2 1.0246 3 1.813 0.37 17.9 1.2578 29 16.923 4.26 205.9 1.0163 2 1.209 0.25 11.8 1.2515 28.5 16.319 4.09 197.5 1.0081 1 0.604 0.13 5.9 1.2453 28 15.714 3.92 189.3 For finding the contents of soda in the lye, Dalton has also furnished a table, showing the various specific gravities of soda contained in the lyes. The results vary materially from those stated by Tiinnermann, which perhaps have their reason, because the latter may not have used a perfectly pure — carbonic acid free — lye, for his analysis. 262 TECHNICAL TREATISE ON SOAP AND CANDLES. Specific gravity. Degrees Baume. Contents of soda. 100 kg. (220 lbs.) or the lye (ia the margin) sa- ponify fats. Specific gravity. Degrees Baume. Contents of soda. 100 kg. (220 lbs.) of the lye (in the margin) sa- . ponify fats. 2.95 70 77.8 720 kg. 1.40 41 29.0 270 kg. 1.85 66 63.6 596 1.36 38 26.0 242 " 1.72 60 5-4.8 498 " 1.32 35 23.0 224 ' 1.63 56 46.6 431 " 1.29 32 19.0 168 i.se 52 41.2 381 " 1.23 27 16.0. 149 " 1.50 48 36.8 346 1.18 22 13.0 121 1 47 46 34.0 314 1.12 16 9.0 83 " 1.44 44 31.0 287 " 1.06 8 4.7 44 " The fats and oils and the fatty acids as they are received by soap manufacturers, are usually in a condition for imme- diate use, but occasionally there may be impurities of such a character that they will require to be removed hefore they are made into so^p. If they are merely foreign substances a melting and straining may prove sufficient, or there may be adulterations. This falsification we have pointed out and given some tests for in another section ; should the tallows, greases, or oils prove very impure they can be improved very much by melting to about 40° C. (104° F.), and adding about two per cent, of strong alkali, say 38^ B., stirring gently at this temperature for ahout a quarter of an hour and then allowing to rest and cool. The impurities will fall to the bottom, and the purified grease can be removed therefrom. It is generally conceded, and in our judgment very truly, that there is no oil or fat, though in itself containing several constituents, which used alone makes a faultless soap. Thus tallow or curd soap becomes in drying too hard and almost insoluble, and so with olive oil soap, which has the same pro- perty, and on the other hand, soaps made with the drying oils (linseed, poppy, etc.) are too soft and cannot be made sufficiently hard for use as solid soaps, and are consequently mostly made into soft soaps with potash lye, which, by its hygroscopic property, always remain soft and when exposed to the air absorb water and are constantly getting softer. So that knowing the different properties of the fatty bodies with their behavior when combined with the alkalies, it is THE FABRICATION OF SOAPS. 268 necessary so to mix the diflerent oils and fats, and in such proportions that considering the diflerent properties of each, bj judicious mixture, may be produced a soap having proper- ties suitable for its intended uses. The mixtures of the dif- ferent ingredients will be given when we discuss the manu- facture of each kind of soap and with them several formulas if necessary. In making soaps by boiling with an open fire, with steam, or surcharged steam, or by whatever appliance or methods the manufacturer may possess, it is necessary in the first place to determine the proper proportions. According to the information already given as to the equivalents for the fiits, we suppose that 50 kilog. (110 lbs.) pure fat (which must not be mixed with cocoa-nut oil) de- mand about 6 kilog. (13.2 lbs.) caustic soda or 8.5 kilog. (18.7 lbs.) caustic potash. This is indeed somewhat in excess of the real necessity, but a little surplus is not injurious, as the lyes are seldom perfectly free from carbonate, and carbo- nated alkali does not easily combine with neutral fats. On this supposition, we will answer the question, How many kilogrammes of fat might be saponified by 1000 litres (265 gallons) of a soda lye of 20° B. = 1.163 specific gravity = 10.879 per cent.? 1000 litres weigh 1163 kilog. (2559 lbs.); with 10.879 per cent, soda, the same contain 126.5 kilog. (278.3 lbs.) caustic soda; since according to our supposition 6 kilog. (13.2 lbs.) of this 50 kilog. (110 lbs.) fat saponify, hence 126.5 kilog. saponify ^^^'^^^ ^ = 1054.2 kilog. (2319 lbs.) fat. If, on the other hand, we have 1000 litres (265 gallons) pot- ash lye of 20"^ B. or 1.163 specific gravity, which according to the table (heretofore given) contains 15.842 per cent, potash, and suppose, that 50 kilog. (110 lbs.) fat require 8.5 kilog. (18.7 lbs.) for saponification, then those 1000 litres (weighing 1163 kilog.) contain 184.2 kilog. (405.24 lbs.) potash and hence g ^ = 1083.5 kilog. (2384 lbs.) fat would be saponified. 264 TECHNICAL TREATISE ON SOAP AND CANDLES. Although in the two preceding examples we have supposed the quantity of the lye according to weight, yet it is more convenient for all operations on a larger scale to measure the liquids instead of weighing them. But the proportions there- by become the more varied the stronger the lyes are. Though 500 cubic centimetres (16.9 fluid ozs.) water weigh also J kilog. (1.1 lbs.), yet 500 cubic centimetres of lye weigh so much more than J kilog., as this lye is stronger. It is therefore easier and more to the point in question to give the contents of a lye as to its value of caustic alkali, according to its measure than its weight. The figures in the tables as to the contents of the lye relate, how^ever, to weight proportions ; but they can be easily changed into" volume per cent, by multiplying the former by the specific gravity of the lye. In the preceding examples, there would hence be in the case of soda of 10.879 weight per cent. 12.67 volume per cent., and of 15.842 weight per cent, potash, we would have 18.42 volume per cent. ; hence in 1000 litres (265 gallons) are con- tained 126.5 kilog. (278.3 lbs.) soda, or 184.2 kilog. (405.24 lbs.) potash, the same as above. The measuring method at once commends itself for this reason, because we obtain directly by the investigation of the lye the volume per cent. If in this manner the supply of lye is made the issue for determining the quantity of a boiling, we will never be in a quandary on account of the want of lye during the operation of boiling. That we may also proceed in a reversed way, as soon as we are sure of having a suflicient supply of lye, and as soon as we are acquainted with the strength of the same, and how much of this lye is required to saponify, for in- stance 500 kilog. (1100 lbs.) fat, will thus become obvious. Supposing it is intended to make a boiling of 375 kilog. (825 lbs.) fat by means of soda, then we would need of pure lye, which contains 6 percent, caustic soda for each 50 kilog. (110 lbs.) fat 100 kilog. (220 lbs.), and hence for those 375 kilog. fat 750 kilog. (1650 lbs.) of this lye would be required. We use for these calculations the tables of Perutz, which we have given on pages 259 and 261, and, for the sake of convenience, we have here also added the weight of potash or THE FABRICATION OF SOAPS. 265 soda contained in 10 litres (2.6 gallons) lye — and have recal- culated into measures. These tables containing all sorts of lyes, from the strongest to the very weakest, it is by their aid very easy to find the correct quantities of alkali, even if we are compelled to apply lyes of various strengths. A few examples will make this still more apparent. Sup- posing we had 2000 kilog. (4400 lbs.) fat to boil into soft soap, it would require, if 8.16 kilog. (17.95 lbs.) potash saponify 50 kilo. (110 lbs.) fat "^^''^^^/^^^ = 326.4 kilog. (718 lbs.). Of lye we have one of 21° B. and another of 10° B. ; each of the lyes is to furnish one-half of the requisite potash ; hence 163.2 kilog. (359 lbs.). In the table for potash we find that in 20 litres (5.29 gal- lons) of the lye of 21 ° B. 3.84 kilog. (8.45 lbs.) potash are con- tained, hence we have the rate 3.84 : 163.2 == 20 : a: ; x = 950, and we have therefore to take 950 litres (251 gallons) of this lye. Of the lye of 10° B., 20 litres (5.29 gallons) contain 1.57 kilog. (3.45 lbs.) potash, hence 157 : 163.2 = 20 : ; a: = 2079 ; of this lye there are consequently to be measured ofi' 2079 litres (550 gallons). If | of the strong lye is to be taken and f of the weak, the calculation would be fixed as follows: 5 X 326.4 16,320 2 x 326.4 652 y = — >^ — = 2334 kilog., and ~ 93.2 kilog. (205 lbs.) ; we have hence to take 3.84 : 233.14 20 : 1214 litres (321 gallons) of the strong, and of the weak 1.57 : 93.2 = 20 : :c = 1187 litres (314 gallons). In the same manner the calculation is carried out if the point in question is the saponification of, for instance, 1000 kilog. (2200 lbs.) tat, by means of caustic soda. To do this 107.4 kilog. (236.28 lbs.) caustic soda would be requisite, whereof one-half is applied for the so-called process of boil- ing the paste (preliminary operation) with a weaker lye. On hand are : a lye of 30° B. and another of 12° B. The former contains in 20 litres (5.29 gallons) 4.43 kilog. (9.75 lbs.) of 53 7 X 20 caustic soda (one-half of the entire quantity) take — — = 250.4 litres (66 gallons). 266 TECHNICAL TREATISE ON SOAP AND CANDLES. The weaker lye of 12° B. contains in 20 litres (5.29 gallons) 1.46 kilog. (3.21 lbs.) caustic soda, and to obtain also in this case 53.7 kilog. (118 lbs.) caustic soda, we will have to apply 53 7 X 20 ~\jQ = 736 litres (194 gallons). These few examples will suffice to show how to use the tables, and also how, by means of the same, the correct pro- portion between fat and alkali may be calculated in advance. Hard Soaps (Soda Soaps). We begin with the fabrication of the solid (curd or grain) soaps made with soda lye. They are such soaps as in the process of boiling are cut, or freed from their superfluous water by means of culinary salt, and are the white, yellowish, or marbled soaps. To make a good Marbled or Marseilles Soap the operation is divided into the following different parts. 1. The pasting or empatage. 2. The separation or relargage. 3. The clear boiling or eoction. 4. The mottlino; or marblino:. 5. The framing. In making the paste, only one-half of the quantity of caus- tic soda is applied, which is necessary for a perfect saponifi- cation of the fat which is taken to be worked up; but this quantity is also divided into two lyes of different strengths, and for the first application the weaker \yQ is used, so that the boiling commences with the fourth part of the entire quantity of caustic soda. A certain quantity of lye is now placed in the kettle to be boiled, and then the fat is added, and for marbled or Mar- seilles soap olive oil with about 10 to 20 per cent, of a drying oil is put in. After a short time the mass is again brought to a boil, whereby it bubbles up under ebullition. For check- ing the boiling over the fire is diminished, and while the mass is being gently stirred it is permitted to continue to boil until all frothing has ceased, and the so-called paste is THE FABRICATION OF SOAPS. 267 formed. The mass has, in this condition of the operation, a yellowish white appearance, and if a sample of it is taken out with a spatula, it can be drawn into long threads of a white color. The soap after continuous boiling having as- sumed a greater consistency, receives a gradual addition — at intervals of about half an hour — of the second portion of lye, and the boiling is kept up during several hours, the better to perfect the combination of the soda with the fat. In order to facilitate this combination, a little carbonate of soda is occasionally added; much better suited for this purpose, however, is a small portion of finished soap, which causes the formation of an emulsion-like mixture, a condition which greatly hastens the saponification. When a perfect union of the fat and the alkali has taken place the second operation, called the cutting of the pan or the separation of the surplus water from the soap, thereby to make the same more consistent, is attended to, when after the preliminary boiling a perfect union of the fat with the lye has taken place. For this ope- ration we take either a strong salted soda lye or culinary salt. The latter, for reasons stated when this subject was under discussion, must be refined. It is applied dry or in solution, and of the one or the other we add as long as the soap and the lye become separated, which is ascertained by noticing when the soap begins to boil into broad and smooth plates, and upon the spatula separating from the lye in pieces, and a sample of it, being cooled off on a glass plate, is no longer soft and smeary, but can be removed tolerably dry. Another sign of the complete separation is that the hot, clear lye after cool- ing off does not congeal to a jelly-like mass. There is gene- rally no danger that the soap will not completely separate, because a little surplus of culinary salt does not injure it. How much of salt is necessary, in proportion to the mate- rials which are being worked up (fat and alkali) to cause separation, cannot be reckoned in advance, since this is de- pendent on the concentration of the lye applied and the greater or less time required for boiling, whereby it concen- trates. The surest mode is repeated proving, whereby we convince ourselves of the state of the mass. 268 TECHNICAL TREATISE ON SOAP AND CANDLES The action of the culinary salt does not always succeed at once, even if it is applied in soluble form, although it may thus cause a somewhat quicker operation. The more diluted the lye is, the more culinary salt will be needed for separation. Then, when, in consequence of an increased boiling, a greater concentration of the lye has been produced a separation will ensue ; for as has already been stated, the separation of the soap does not so much rest upon the absolute quantity of culinary salt to a given quantity of soap, as upon the insolubility of the latter in a lye containing culinary salt, of a certain concentra- tion. The manner in which the soap boils, is likewise a crite- rion as to whether the separation is complete. If instead of a smooth, lustrous surface, which is furrowed into small sections and circles, larger and rough divisions are visible, which are broken by steam under formation of bubbles, whereby the soap begins to rise, it may be presumed that the separation of the soap is completed. Moreover, the sub-lye must on no account have a touch or caustic taste, nor will this occur if the operation has been correctly performed, because the oil on hand is in double the quantity that the alkali present can absorb for forming a neutral soap. But if there should despite all this be some unsaponified oil therein, then a mistake has been made, the cutting of the pan has been pre- mature, and must now, after the soap has been again rendered into paste by adding water, again boil until all the alkali becomes bound, and the sub-lj^e assumes a sweetish-salt taste. A further addition of culinary salt is not needed, and the soap reseparates without this, when the sub-lye, by the evapo- ration of water is again so concentrated, that it will no longer dissolve any soap. After a complete separation havi ng ensued, the soap must remain a few hours longer in the kettle, during which time, the lye settles on the bottom, and is then drawn out by means of the waste pipe, which is in the bottom of the kettle. Where such a pipe is not present, the removal of the sub-lye is by a portable pump, which has its barrel on the lower end, or the soap is ladled from off the sub-lye into the cooling vat, which stands close to the boil- THE FABRICATION OF SOAPS. 269 ing kettle. The soap is now prepared for the third opera- tion of the coction or Clear-boiling. — For this operation, after removal of the sub-lye, the necessary lye is added to the soap, or if this is still in the cooling vat, then it is placed in the kettle, adding the soap from the cooling vat to it, and heating the entire mass till it boils. Some manufacturers divide even the lye necessary for a perfect saponification, and boil the soap first with one-half of the same, and allow all the sub-lye thus produced — having imparted all its alkali — to flow out, whereupon the same operation is repeated with the other half. This may be suitable in those cases where a very im- pure fat is worked up, but whenever the fats are pure, such a custom is at least superfluous. It would be best, from the start, to pay more attention to a careful cleaning of the fat by remelting and depositing, a process which under all circumstances is much easier than a boiling upon the so-called second, third, and fourth waters. Pure fats may even be boiled and finished upon one water, so that the letting oflc' of the sub-lye, or a repeated scooping of the soap into a cool- ing vat, becomes entirely superfluous. Only if dark colored fats are used, which in a great measure impart their color to the sub-lye, and partly also to the water which is con- tained in the soap, it may be necessary to boil in two or three waters. This of course is dependent on the color, which each withdrawn lye should show. During the clear-boiling, the soap should boil as tenaci- ously as possible, that is, it should slip ofl:* with difficulty, when a sample is taken out with a spatula. It must become almost pasty, and whenever this does not take place at once, after adding a new quantity of lye, then the mass must have so much water added thereto, till it again returns into a glue- like substance. In this state, the lye acts upon the not yet completely saponified mass, and the process of saponification takes place much faster. It may hardly be necessary to re- mark, that, even if by a too abundant addition of water, the soap has turned into a real paste, this fault may be easily remedied by the addition of a little more salt. The boiling 270 TECHNICAL TREATISE ON SOAP AND CANDLES. is continued, until all the caustic soda is bound, and a perfectly neutral soap is produced. This is ascertained, by separating a small sample of the soap-mass with a solution of culinary salt, that is by refining the soap, and then dissolving it in a little distilled water. Thereby a clear, opalescent, on no account milky solution must result; otherwise there is surely yet some unsaponified fat. After a complete saponification of the fats, the soap will become thicker and opaque, boiling with little bubbles, by continuous, not too violent boiling. The more water evapo- rates, the more lye collects upon the bottom, and the soap becomes hard, and shows even at this high temperature an inclination to become solid ; deep furrows are formed on the otherwise nearly smooth surface. Large and shiny bub- bles appear, and the soap now boils into slabs. By taking a sample and placing it in the palm of the hand, and rub- bing it until it becomes cold, it will harden into dry and glistening scales, which must show no adhesion, and may even be ground into powder. Should these characteristics be wanting, should it yet have a smeary touch, then the soap is either deficient in alkali, or the alkali used is not suffi- ciently caustic, or it has not yet been boiled long enough. The first case could hardly occur if the proper proportion of oil and alkali had been applied from the start, but if such is the case, we should not endeavor at once to mend this, by a fresh addition of alkali, but by continuing the boiling for a longer period of time. Thus even the carbonate of soda is bound — if its quantity is not excessively large — with the fat, and thus a neutral soap is obtained. If longer boiling proves insufficient, then carefully add some caustic \ye until the object is reached. Frequent investigation of the soap, as to its solubility in distilled water, should not be omitted. Many manufacturers, especially when they think that the unpropitious result is caused by an insufficient causticity of the lye, add some lime-water. This, however, is for reasons heretofore stated most emphatically to be reproved. Although a complete saponification may thereby be reached, the lime- soap formed in this manner impairs the quality of the soap THE FABRICATION OF SOAPS. 271 far more than the small portion of unboiled fat would. In how far, by a continued boiling, a good result may be at- tained, can be observed by the appearance of the sub-lye. For this purpose a portion of the soap is taken out of the kettle, placed in a saucer, the lye completely separated and cooled off, and the lye tested as to its contents of alkali. If by this test, no free or carbonated alkali, or at least 'but very little of it, is found, we may presume that the soap is yet wanting in it, if it does not show as yet the normal condition. A slight touch, which the sub-lye may have, does not injure the soap, since it is almost impossible to finish the boiling of soap, without any touch at all. This is quite natural too, since entirely caustic lye rarely or never is ap- plied. At the first, the free alkali is bound ; much more difficult and slower is the combination of the fat with the carbonated alkali, so that to hasten the process more caustic lye is added. In this manner nearly all tlie carbonated alkali remains uncombined and passes into the sub-lye. When taken out it appears upon the tongue as being too caustic, and this touch must not be deadened by the addition of fat. The soap boiling correctly into slabs, is now kept boiling until it becomes grainy. Ti]is last o[teration is the real grain or cleaj^-boiling. The soap now loses all superfluous water, and unites into a small grain- like homogeneous-curdle — while all froth vanishes, and when filled into the frames, produces the common grain — (curd) soap. But if the curdle by ad- ding water or weak lye, is again changed into a mass of a gelatinous consistency, which, however, remains separated from the sub-lye, then the so-called ground (or filled) soaps are produced. The Grinding or Filling of the Soap^ whereby the soap is again changed into the semi-liquid or gelatinous state, has for its object the purili cation of the soap from its yet mecha- nically combined dross. This is done by imparting greater liquidity to it, and by allowing it before casting it into the frames to remain for several hours in the no lon2:er heated kettle. This grinding is performed by two different modes, but is always carried out with water or a very weak lye. 272 TECHNICAL TREATISE ON SOAP AND CANDLES. Either the lye still in the kettle from the clear boiling remains in it, and so much water is added until the soap grains be- come liquid — for this water may be used, as has been noted above — there will still retain in most cases a touch (this is termed "the grinding from above) ;" or the salt lye is drawn off and the necessary lye or water with a little salt is added to perform the grinding, which is termed " the grinding from below." The adding of salt is to avoid the formation of paste. The grinding from below is only necessary when very impure materials have been worked up. The operation of grinding is undertaken over a very hot fire so that the lye is constantly thrown up, and the boiling is continued until broad slabs appear, the surface shines in a honey yellow color or turns up in rosettes, and a sample taken out of it will prove the correct quality of the soap. The fire is now extinguished, and while the kettle is covered with the lid the soap is allowed to settle for a few hours and is then poured into the frames. The Marbling of the Soap. — To impart to the soap the pecu- liar clouding or marbling, we add to it during the prelimi- nary process of boiling, sulphide of sodium and sulphate of iron. Thus sulphate of iron and iron-soaps are formed, which admix with the soap and impart to it, when quickly cooled off, a greenish-black color. If allowed to cool off slowly the colored and insoluble soaps contract into smaller points and give to the soap a granite-like mottled appearance. If the cooling ofiT is still more prolonged and the manipulation while stirring (an operation by which the soap before cooling ott' is stirred with an iron rod) is conducted with a certain regularity, we obtain a beautiful marbled soap. This isespe- ecially to be done with tallow soap, the crystallized grain of which has a great inclination to separate, and which consists essentially of stearic soda soap that at first congeals into a solid mass. If it is intended to increase the marbling, we add, towards the end of the boiling, Frankfort-black or bole Armenian — of the former for 500 kilog. (1100 lbs.) grain soap 16f to SSJ grammes (0.57 to 1.14 oz.), and we obtain in this way a black- THE FABRICATION OF SOAPS. 273 grayish marble ; and of the latter to the same quantity of soap 100 to 133|- grammes (3.52 to 4.69 ozs.), and a brownish- red marbling appears. To attain a handsome marbling the operation must be performed with the purest possible sub-lye which contains at the utmost but J per cent, of the alkali and is of about 14° B. strength, and we must not add enough weak lye or water to liquefy the grain — that is, no more than is requisite to diffuse the dyeing matter equally through the soap. Finally it must be observed that the temperature during the running out, does not vary much below or above 100° C. (212° F.). The marbling will be imperfect or does not take place at all, when the soap mass is too thin, or the temperature is too high. Therefore the adding of lye must be attended to with care, commencing with the stronger and leaving off with the weaker. The operation is ended, when the soap shows flakes of a greenish color, which float upon the lye, and when the grain becomes semi-liquid without losing its rounded form. The marbling may, however, become faulty by running the soap into the frames when too much cooled off, as it solidifies too fast without tyivino; the various combinations (stearic and oleic soda soap) time to separate by crystallization of the former. Because as the stearic and palmitic acids solid- ify at 69° C. (156.2° F.) and 62° C, (143^^.6 F) respectively, while the oleic acid is still liquid at 15° C. (59° F.), so also the soaps of the former acids harden much sooner than the oleic acid soap. The more cooled off the soap is when run into the frames, the sooner the moment of congealing of both soaps is found to be reached, and only an imperfect separation of the same takes place, and the coloring matters, which are especially absorbed by the elaidin soap, remain likewise divided in the entire substance. If on the other hand the temperature is too high, then the elaidic soap impregnated with coloring matter precipitates, and after the stearic acid and palmitic acid soaps have crystallized the marbling does not ensue. As marbled Marseilles (Castile) soap is now made nearly everywhere, and is no longer confined to Marseilles, we will 18 274 TECHNICAL TREATISE ON SOAP AND CANDLES. note the dift'erent proportions that obtain in various locali- ties. The calculations are for about a ton of fats. In Eng- land are used of — Olive oil, 550 pounds, or Olive oil, 700 pounds. Palm oil, bleached, 1000 " Lard, 700 Tallow, 350 " Cocoa-nut oil,200 Cotton-seed oil, 350 Tallow, 650 " 2250 2250 or, Palm-kernel oil 1500 pounds. Sesame oil 450 " Tallow oil . . ' 300 2250 In the United States the usual formulas are — Olive oil, 700 pounds, or Palm oil (bleached) 1000 pounds Ground-nut oil, 700 " Cotton-seed oil, 500 Lard, 850 " Tallow, 750 " 2250 2250 In Marseilles we have noticed that the proportions also vary with each manufacturer, and the olive oil is in greater quantity, though there are in addition more or less ground- nut oil, poppy oil, hempseed oil, sesame oil, etc. etc. White Marseilles {Castile soap). — This truly tine soap may be considered a standard as to what a pure soap should be, and has with the mottled Castile soap given character and popu- larity to the soaps of France and particularly to those of Marseilles. While the mottled soap cannot be well made to retain its proper marbled appearance witli an excess of water, the white soap from the difference in the manner of manipu- lation contains more water, though nearly all impurities have to be removed to obtain the proper whiteness. White Castile soap is now made in almost all countries, and generally with the artificial sodas, and even in Marseilles these sodas are now being used. Yet in some factories the barilla is still used as the base ; this alkali, containing a certain percentage of potash, gives a plastic consistency to the soap which has added to its popularity. This effect is now usually produced by the addition of a drying oil, such THE FABRICATION OF SOAPS. 275. as hempseed, sesame, ground-nut, poppy or cotton seed oil to the amount of 15 to 25 per cent, of the olive oil. These oils, instead of being a sophistication, may be considered a benefit, as they prevent the soap, which if made with olive oil alone becomes too hard in drying, from having that undesirable property. This soap is the purest to be found in commerce, when it has been prepared and purified according to the proper rules of the art. It is very much used in industrial operations, particularly in the bleaching of raw silk. By its extreme purity and its nearly absolute neutrality, it does not alter the brilliancy and elasticity of the silk, which renders it supe- rior to all the other kinds of soap. When prepared in all its purity, it has for its basis, with the additions above mentioned, pure olive oil, saponified by caustic lyes of artificial soft soda. These lyes are pre- pared in the same manner as indicated for marbled soap ; but as the presence of salt would render the soap less soluble in water, the lyes must be prepared only with soft soda free from salt and containing as little as possible of sulphuret of sodium. By this precaution too much coloration of the paste is avoided, and the operation is much more easy. In Belgium, soda ash is substituted for crude soda in the preparation of the lyes. The soap thus made is of a fine pure white color. Thus by using a colorless and a purer alkali, the refining of the soap is easier, and the amount obtained much larger than with lyes made from crude sodas. This is rational, and we have seen soaps of olive oil thus prepared, which were perfectly white and as pure as the best Marseilles soap. Independently of the purity of the alkali, the nature of the oil emploj^ed to prepare this soap exercises a remarkable influence on its consistency and whiteness. To obtain good results, the whitest and most limpid oils must be used. Experience proves that oils much colored have the prop- erty of communicating their shade to the soap. Sometimes a proportion more or less considerable of another oil is mixed with the olive oil, especially earthnut oil ; this oil, being 276 TECHNICAL TREATISE ON SOAP AND CANDLES. * white, has no influence on the color of the soap, but it changes its consistency and renders it more soluble and lathering. Pasting. {Empatage) We suppose a saponification made with 2250 pounds of oil. For this quantity use a kettle of a capacity of from 1000 to 1250 gallons. Pour into the kettle from 175 to 200 gallons of caustic lye of soft soda at 8° to 10° B., which is heated. When the lye begins to boil, pour on the oil, and to facilitate its combination with the lye, stir the mixture all the time; the stirring may be continued for half an hour after the last portion of oil has been introduced. This being done, boil the mixture. The ebullition must be very gentle to prevent the formation of too much foam. If, notwithstanding this precaution, the mixture rises, the heat is to be slackened, then the ebullition becomes less rapid, the foam diminishes, and the mixture boils regularly; but it is essential to watch the operation, for in the state of dilatation the paste is in, it would soon boil over. A gentle ebullition has also for its object to facilitate the combination of the oil with the lye. It is known that the paste is quite homogeneous, when neither oil nor lye is seen at the surface. This result being obtained, pour into the kettle lyes at a higher degree than the first, at 12° to 15° B., for example. The quantity of lye to be added is not well determined, but from six to eight gallons may be added without inconveni- ence every half hour, to take the place of the evaporated water. A slight excess of weak lye in the pasting is not injurious, and has the only inconvenience of making the operation a little longer and more expensive ; but as a com- pensation, the oil is better saponified, and more completely deprived of its coloring and mucilaginous matters, and the soap is finer and better. After a gentle ebullition of eight or ten hours, the paste becomes thicker, and more homogeneous. To finish, intro- duce 25 to 50 gallons of lye at 5° B., and after stirring for THE FABRICATION OF SOAPS. 277 half an hour, 8top off the heat, and proceed to the separation, or cutting of the pan. Separation. {Belargage.) This operation is conducted in the same manner as indi- cated for marbled soap, that is, by pouring little by little into the kettle perfectly limpid lyes of coction, ^. g., salted lyes at 20° to 25° B. During the introduction of the lye, a man stirs the mass all the time. It is known that the quantity of lye is sufficient, when the soap separates from the lye, and acquires a clotted appearance. The more concentrated the lye, the less the quantity to be used to efiect the separation. The operation being finished, cover the kettle, let it rest five or six hours, and then draw off the exhausted lye. If not sufficiently pure in color, this cutting of the pan can be repeated, when proceed to the coction. Clear-Boiling, or Coction. 1. First Service of Lye. — To begin the operation, pour at first into the kettle from 125 to 150 gallons of soft lye, at 15° to 18° B., heat gently, and when the soap is very warm, stop oft' the heat. This done, the soap is briskly stirred for three-quarters of an hour or an hour. By stirring thus, the soap is brought into contact with the lye, and by combining with the alkali it acquires more consistency, at the same time that it is deprived of the larger portion of the foreign salts that it has absorbed during the saponification and sepa- ration. Eendered purer by this first washing, the soap is more fit to combine with the concentrated lyes which bring it to the proper point to be purified. After a settling of a few hours the lye is drawn off. 2. Second Service of Lye. — For this second service, pour into the kettle 100 gallons of caustic and concentrated lye, at 22° to 25° B. Boil the mixture gently for eight or ten 278 TECHNICAL TREATISE ON SOAP AND CANDLES. hours, adding every hour six gallons of pure lye to take the place of the evaporated water. During the ebullition, a very abundant foam is formed on the surface of the soap, but its development is moderated by slacking the heat or beating it down with the stirrers, when during the ebullition the soap is entirely granulated, and floats in the lye. By pressing it between the fingers, it is found to have more consistency, but it is yet greasy, because it is not yet completely saturated with alkali. To bring it to the state of saturation, the heat is stopped off, and the mixture left to settle for a few hours; then a third and last service of new lye is given. 3. Third Service of Lye. — For this service, use a new lye marking 28° or 30° B. Pour into the kettle 110 gallons of the lye and then heat. After an ebullition of five or six hours, the grain of the soap is well developed, and when pressed be- tween the fingers forms hard and dry scales. Continue the ebullition for a few hours, and when the soap is saturated, the foam which covered it disappears almost entirely, and that which is left is very light and white. If the oil used is of a good quality, the kettle emits an odor somewhat similar to that of the violet; the heat is stopped ott", and after resting for a few hours, the lye is drawn off. This lye, by being passed over a mixture of soda and lime half exhausted, becomes clear, limpid, and caustic, and may be used anew to separate the soap in a subsequent operation. When thus saturated, this soap contains only 16 per cent, of water, and is very alkaline and caustic. Its coloration is due to the use of crude sodas, and especially to the pres- ence of the sulphurets of soda and iron, always existing in these sodas, which combine with the oxide of iron, also ex- isting in them, and give rise to a sulphuret of iron which colors the soap. To refine it, it is necessary to submit it to a last operation called fitting and by the French soapmakers liquidation. THE FABRICATION OF SOAPS. 279 Fitting. To transform into a pure white soap the mass of soap which has a bluish-gray color, it has to be dissolved by degrees in weak lyes with the aid of heat. To begin, pour into the kettle from 125 to 150 gallons of soft lye at 8° to 10° B. and apply heat. When the soap is very warm, stir it briskly. 0nder the influence of the heat, of the lyes, and the stirring, the grain dilates, softens, and looks as if half melted in the lye. When in this state slacken the heat, and after a few hours' rest, draw off the lye. By this first operation, the paste begins to be deprived of the coloring matter and the excess of alkali it contains, but it is still caustic. To complete its refining, pour into the kettle from 50 to 60 gallons of soft lye at 5° or 6° B. and heat gently, stirring the paste all the time from the bottom to the surface. By agitation and heat, the paste becomes more and more fluid, and is yet separate from the lye. As its refining can take place only when completely liquefied, to obtain this result, add from time to time a few pailfuls of lye at 2° or 3° B., continuing the heat and the stirring. When it has become fluid, and the liquid, brought to the sur- face by the stirring, has a blackish color and is viscous, the operation is finished, because the coloration is due to the precipitation of the alumino-ferruginous soap — and the vis- cosity to the complete liquefaction of all the parts of the paste. When in this state, stop off the heat, cover the kettle and surround it with woollen blankets, so as to retain the heat as long as possible. By resting and the heat of the mixture, the metallic soap, i. e., iron oxide soap, and the excess of alkali precipitate to the bottom of the kettle, as well as the excess of weak lyes used in this operation. After a rest of 36 to 40 hours, uncover the kettle, and take off carefully the scum formed on the surface. Dip off the soap with large iron ladles into frames. When the black soap begins to appear, the operator must be careful not to 280 TECHNICAL TREATISE ON SOAP AND CANDLES. disturb it, since its mixture with the white soap would render it less neutral and less pure. When all the soap is in the frames it is well stirred so as to have it perfectly homoge- neous ; if not stirred it would present veins and even spots of color. When the soap is completely solidified in the frames, it is flattened by beating it with large wooden beaters. This operation renders the soap more compact and heavier, it is useful also to fill the vacant spaces due to the air in the soap. In conclusion, the beating of the soap fulfils two essential conditions : 1. It increases its specific gravity ; 2. It destroys its porosity. A few days after the frames are uncovered, and the soap is divided into bars or cakes by the usual methods. Recently manufactured, this soap is always a little soft. To give it the firm consistency required in commerce, it is exposed for a few days to the air in the drying-room, then it becomes solid enough to be packed in boxes. Exposure to the sun, or to too elevated a temperature, must be avoided, for heat always communicates to it a more or less yellow shade. Another method of hardening is to dip the bars of soap into a very strong lye, which hardens the surface and makes them the sooner marketable. When the soap is not to be sold immediately, the boxes containing it are stored in a cellar. A few weeks after it will have acquired the whiteness and solidity which dis- tinguish fine Marseilles soap. Well-prepared White Soap from Olive Oil constitutes, as we have before said, the purest soap of commerce. One hundred parts of this soap are composed of: — Fatty acid3 50.20 Pure soda 4.60 Water 45.20 100.00 Ey operating under favorable circumstances, that is, using the purest and whitest olive oil, and the best quality of arti- ficial soda, the 2250 pounds of oil will give : — THE FABRICATION OF SOAPS. 281 Soap of scum Pure white soap Black soap . 157 to 225 2925 to 3040 675 to 790 We see by these numbers that 2250 pounds of oil give as a maximum 3040 pounds of soap, or 135 pounds of soap for every 100 pounds of oih The black soap left in the kettle as a residuum of the operation is separated, while warm, from the weak lyes with which it is combined, by means of salted lyes at 20° to 25° B. It is then run into a frame and allowed to cooL In a regular mode of working, this black soap is utilized in a new operation, and gives by refining a new quantity of pure soap by the precipitation of the coloring matters it contains. This method is not without inconvenien-ces, because this mass of black soap introduced into each new coction impairs the whiteness and purity of the soap. It would be more rational to use this residuum in the fabrication of marbled soaps which are not required to have the purity of color of the w^hite soap. The formulae for the marbled soap may apply to this soap, though there should always be a large percentage of olive oil. White Castile {Marseilles) Soap, when made in countries where olive oil is not abundant and is high priced, is now usually made with but a small percentage of that expensive oil. Thus in England, Germany, and the United States are used bleached palm oil, palm-kernel oil, ground-nut oil, poppy oil, cotton-seed and hemp-seed oil, tallow oil or olein, tallow in combinations. Having a due regard to their purity and whiteness we give some suggestions of proportions : — Olive oil 40 parts. Olive oil 30 parts. Ground-nut oil . . 30 " Lard 30 " Tallow 30 " Palm-kernel oil . . 40 " Olive oil 30 parts. Palm oil (bleached) . 50 parts. Cotton-seed oil . . . 3t) " Sesame oil 20 " Tallow oil .... 40 " Tallow 30 " The fabrication of this soap is in general the same as that of the olive oil soaps. When tallow is used it is freed Tallow Soap. (Curd Soap.) 282 TECHNICAL TREATISE ON SOAP AND CANDLES. from all admixtures and impurities by melting and deposit- ing. Thus prepared, the soap may very well be finished in one boiling. When impure tallow of a brown color is used, it becomes necessary to finish the soap upon two or more w^aters. In this case also a lye of 2° B. at the most 6 per cent, soda is used, which should be caustic and free from culinary salt. Since the tallow consists chiefly of stearin and olein with but little palmitin glyceryl oxide, the amount of materials necessary for saponification is calculated accord- ing to the heretofore mentioned equivalents of tallow, to wit, 887.0. According to this there are 100 kilog. (220 lbs.) tallow corresponding to 10.5 kilog. (23.1 lbs.) of soda (anhydrous), so that for a boiling of 2000 kilog. (4400 lbs.) 210 kilog. (462 lbs.) of soda are required, which in four portions of lye are separately brought into use. Since the first portion, or the fourth part = 52.5 kilog. (115.5 lbs.) is to be taken not above 6 per cent, lye, and whereas in 20 litres (5.29 gallons) of such a lye 1.31 kilog. (2.88 lbs.) soda are contained, there would have to be taken thereof ^^-^^^^ goO litres (211 gallons). The lye is placed in the kettle, heated to boiling, and then the tallow is added. The melting fat mixes immediately with the lye to a milky fluid wherein fat and lye can no longer be plainly discovered, although a real chemical com- bination does not yet ensue. The entire mass soon begins to boil, and at first it froths very much, but gradually begins to clear, becomes more translucent and also thicker. But if an open fire be used, the heat must be diminished, to avoid burning. The entire mass becomes turned into a translucent lustrous liquid, the soap paste runs from the spatula in fine threads, the lye and fat of which upon the paddle no longer appear separate. Sometimes it takes very long before the fat and lye unite into a paste. Usually the reason for this is found : — 1. In a too concentrated Xye. The mass boils at starts, very violently, since the lye, because it cannot mix with the fat on account of its concentration, settles upon the bottom, THE FABRICATION OF SOAPS. 283 becomes strongly heated and breaks with violence, the fatty mass floating above. This fault is remedied by weakening the lye with water, and constantly stirring the mass. Tlie production of some soap causes a corresponding weakening of the lye as a consequence, and the process again proceeds in a regular way. 2. In a not sufficiently caustic lye. This is discerned when by testing the lye with acid it foams up very strongly. A gradual addition of caustic lye remedies this defect. 3. In too much lye. Here we may help ourselves by the addition of fat, or, still better, by an addition of scrap- soap. After the first quarter of the soda has united with the fat or becomes pasted, the second quarter is added, for which a strong lye 15° to 18° B. will best serve. 20 litres (5.29 gal- lons) of such a lye contain about 2 kilog. (4.40 lbs.) soda, so we must therefore to reach 52.5 kilog. (115.5 lbs.) lye take of this lye 26.25 x 20, that is 525 litres (139 gallons) lye. All further operations are entirely the same as in the case of Marseilles soap. The soap must be run hot into the frames, and for the first two days be well covered with cloths. On the second day it is cut on the edges and pressed or stamped down, to avoid its becoming hollow in the centre by shrinking. The touch or alkali of the sub-lye is removed by boiling it in a sufficient quantity of oleic acid, which also absorbs the carbonate of soda. Instead of oleic acid another fat can be ap- plied, but the fat in this case must be previously made pasty. This is done by means of a small portion of weak caustic lye. The cutting of the pan is now performed with the still caustic sub-lye and adding ad libitum so much fat and salt to it until all trace of a touch in the lye has vanished. The last boiling is kept and applied to the next boiling of soap. Many manufacturers use rosin for the removal of the touch, that is, for regaining the soda contained in the sub-lye, w^hich is entirely rational, because the rosin combines as well with the carbonate as with the caustic soda. The rosin soap is to be, as usual, separated from the salt (cutting up of the pan) and afterwards added to another soap boiled in fat. It is 284 TECHNICAL TREATISE ON SOAP AND CANDLES. self-evident that every other soap may be thus treated whose Bub-lye still shows traces of a touch or presence of alkali. Palm Soap. In saponifying palm oil it is customary to mix it with other fats and oils, either in its natural state, or deprived of its strong yellow color which will remain unchanged in the soap and will stain linen and other fabrics. The process of decolorizing the oils has been fully described elsewhere. In England many of the soaps for domestic uses are made of this oil, though usually in combination with tallow, cocoa- nut oil, and rosin, while in other countries where the oil is not so abundant it is principally used for toilet soaps, bat rarely by itself. A jpure palm-oil socqo we will take for example : To 1000 kilog. (2200 lbs.) pure palm oil 110 kilog. (242 lbs.) soda are needed ; this first, stronger lye must therefore contain 55 kilog. (121 lbs.) soda ; lye of 18° B. is used, and, whereas such a lye con- tains in the litre 0.161 kilog. (0.35 lb.), we must for 55 kilog. (121 lbs.) soda take 342 litres (90.3 gallons) of lye. As soon as the fat combines with this lye, there should be added gradu- ally 360 litres (95 gallons) of a 20° B. lye having a tolerably strong touch. Since the palm oil often contains a consider- able quantity of free palmitic acid, a certain quantity of carbonate of soda may be applied at once, and when this becomes saturated with the palmitin, then the rest is to be saponified with pure caustic lye. This is, however, not the same as if a carbonated soda lye were to be used. In this case, the intention would not be fulfilled, since the free pal- mitic acid absorbs at first the soda, while the carbonate of soda remains uncombined. The soap having finished boiling is separated by culinary salt, boiled until all froth disappears, gently ground or fitted, and the soap is run hot into the frames, where it is well covered and left to stand. In this case too, the rims of the soap in the frames are cut on the second day, and the soap pushed together. Palm-oil soap is always hard and brittle, and to divest it THE FABRICATION OF SOAPS. 285 of this peculiarity, which is by no means desirable, 5 per cent, of the soda is substituted by potash, which makes it more plastic. We submit a few of the combinations in vogue for palm soap. Palm oil . . . . 50 parts. Palm oil . . . . 85 parts. Tallow . . . . 30 " Cotton -seed oil . . 35 " Resin .... . 20 " Pure tallow . . . 30 " Palm oil . . . . 40 parts. Palm oil . . . . 60 parts. Tallow . . . . 30 " Tallow . . . . 20 " Cocoa-nut oil . 30 " Cocoa-nut oil . . . 20 " RosiN Soap. (Yellow Soap.) Eosin in soap may be styled an ameliorator, for, though in itself it will not form with alkali a useful soap, yet combined with fats, or when saponified added to other soaps made with the fatty bodies, it counts as so much grease, and contributes the popular qualities of being readily soluble and forming a copious lather when used for laundry and other domestic purposes. The methods for forming this soap are various : Either the rosin is saponified separately, or it is melted with the grease and boiled with the lyes. The latter is the usual mode in England, where is also added to the better qualities of rosin soaps a portion of palm oil, which tends to improve both their odor and color. Rosins in the United States are usually prepared for the soap boiler at the place of their production, and are of difi^'er- ent qualities depending upon their color ; of course the lighter and clearer in color the rosin is the better will be the quality and appearance of the soap. Yet it may be that the rosin at hand is dark and contains many impurities. If so, it is necessary to submit it to a purification, which is usually done by boiling it with a solution of common salt, when the impurities and much of its color are precipitated with the salt water. This is often repeated a second or a third time to insure a bright color. 286 TECHNICAL TREATISE ON SOAP AND CANDLES. Cocoa-nut oil is often added to rosin soaps, and is said to simplify the process and take less boiling; this oil moreover making the soap more solid. The usual formula is: — The usual method used in England is, to charge the pan with 2000 pounds of tallow or soap grease, about 600 pounds of rosin, and 150 to 1.75 gallons of soda lye marking 10° to 20° B. ; and, when the whole is melted and thoroughly combined, heat up the mixture to ebullition, being careful to stir all the while to prevent the adherence of the rosin to the bottom and sides of the pan. If the mass seems disposed to intumesce or swell, the fire must be lessened. This boil- ing should continue but two or three hours, because of the facility with which the union of the fat and alkali is effected. After six hours' repose, the exhausted lye is drawn off, and fresh is substituted, and the whole is again boiled for three hours more. Another repose of six hours is allowed, and the spent lye is again drawn off and renewed by fresh additions ; the boilings are thus continued until the soap shall have ac- quired consistency — a fact determined by taking a sample, and when cool, squeezing it between the thumb and finger. If hard, thin scales are formed, it is finished, or nearly so; if greasy, clammy, and soft, it is, on the contrary, not perfect, and must have more lye, and another boiling. In the first case, give a brisk boiling to the paste, and then put out the fire. Cool the soap by adding three buckets of weak lye, and two hours after, draw oflt' the sub-lye. ^^ext throw in six or eight buckets of water and boil briskly, stirring the mixture until the soap is melted ; then, with a wooden spatula, take a little of the boiling paste, hold it up and observe whether it runs from the lye clear; if it does, add water to the pan, and continue the boiling. If it does not run from the lye, too much water has been added already, and there must then Palm oil Cocoa-nut oil Tallow " Rosin " 20 parts. 20 80 30 " THE FABRICATION OF SOAPS. 287 be poured in half a bucketful of strong solution of common salt. The most delicate part of the operation is that of finish- ing or fitting, and should, therefore, command the particular attention of the workman. If the fitting is perfect, the soap will, when the spatula is held obliquelj^not run ofi:', but shake and disperse tremulously like jelly. It is then that the fire ma}^ be withdrawn, and the soap be regarded as finished. If it is desired to give a better color to this soap, about 20 pounds of palm oil may be added before finishing; and after two days it must be run into the frames, whence, after a week or less, it should be taken and cut into bars. When cocoa-nut oil is added, it is best to saponify sepa- rately with a strong lye, and add at the finish. By a still more simple process, the English now prepare this soap as rapidly as economically. Caustic lye of soda ash at 25^ . . . 175 gallons. The whole is introduced into a large Papin's digester, and the mixture submitted for one hour to ebullition under pres- sure, at a temperature of 122.2° C. (252° F.). After this time the soap is finished and run into the frames. This seems to be all that is necessary to say about these useful soaps. Of course if a soap is wanted by the old methods, we can but refer to the tallow soap, adding the rosin soap which has been made separately. Resinous Grain Soap and Turpentine Soap. The first is a dark brown soap, which with 100 parts fat are combined 80 to 90 parts brown rosin. Turpentine soap possesses a light-yellow color, and is obtained by saponi- fying 100 parts of fat with 25 to 30 parts light rosin. For the fat sometimes tallow or palm oil alone is used, or in con- nection with olein, i, e., oleic acid. In the latter case an Take- White tallow Palm oil Powdered rosin 800 pounds. 200 " 400 288 TECHNICAL TREATISE ON SOAP AND CANDLES. addition of about 5 per cent, cocoa oil is made ; the soap there- by attaining the property of frothing very well. The rosin- grain soap is always produced with very caustic lye, which is best prepared by dissolving caustic soda in water. The rosin must be well pulverized, before it is placed in the ket- tle, and immediately well stirred, as the matter easily ascends and runs together into lumps, which can only be re-separated with difficulty. A preliminary boiling in this case is not necessary, though the lyes should be added in portions, the boiling being well sustained, care being taken to add weak lyes or water to make up for evaporation. When the soap has assumed the true gelatinous appearance, it can be separated from its superfluous water with salt, and afterwards fitted or ground to bring it to the proper consistency. This is often done with a solution of carbonate of soda. Olein Soap, Oleic Acid Soap, Elaidin Soap. Under these various names is the soap made from oleic acid (commonly known as " red oil") called. This acid, being a by-product in the making of stearic acid, stearin, and glycerine by means of lime, sulphuric acid, etc., though it is limpid at ordinary temperatures, contains some stearin and palmitin, but no glycerine, and as it is generally low in cost, it makes an economical and useful soap, either by itself or in combination with other greases, as tallows, cotton-seed oil, rosin, etc. There are numerous modes of saponifying this valuable sebacic acid, and it is difficult to say which produces the best soap, yet we must confess to a preference for that made by the regular process of boiling as certainly the most reliable. We will, however, give what we consider the best processes for some of the others. Owing to the presence of some free sulphuric acid and other impurities, the oleic acid requires generally more alkali for its saponification, though it need not be entirely free from other salts or carbonic acid. Thus owing to its easy saponi- fication it is sometimes made in an extemporaneous way by THE FABRICATION OF SOAPS. 289 simply adding the crystalline carbonate of soda to the olein, putting into an air-tight vessel having a stirrer, and under the pressure and agitation causing a rapid admixture, the water of crystallization being in sufficient quantity to form the soap. This process requires a close calculation of the several quantities and some experience to produce a good and uniform product. Being a cheap material and comparatively pure, it can be economically combined with other greases, such as kitchen and bone fats and other refuse greases. It also makes one of the most useful soft soaps for manufactures. For making a pure olein soap in a large way we will take say 6750 lbs. of oleic acid. The saponification is elFected in a kettle of a capacity of 1870 to 2000 gallons, into which the oleic acid is introduced and melted with the help of a gentle heat. The acid being completely liquefied, pour into the kettle 125 gallons of new lye at 25°, and 250 gallons of lye of coction perfectly limpid at 25° to 30° B. It often hap- pens that by the reaction of the lyes on the oleic acid, the mixture considerably thickens and forms a compact mass. This eftect is due to the spontaneous formation of stearate and margarate of soda, but as the heat increases, the mixture becomes clear, the grains gradually disappear and the mass becomes fluid. Continue to keep up a gentle heat, and when the ebulli- tion begins a considerable quantity of foam is developed on the surface of the soap. This effervescence is moderated either by slacking the heat, or by stirring all the time, or by pouring a few pails of cold water into the kettle. This rapid reaction is due to the action of the carbonate of soda, which, in contact with the oleic acid, abandons its carbonic acid. But this effect would not take place if the lyes used were entirely caustic. When this first effervescence has ceased, increase the heat, and continue to boil quickly ; care being taken to stir all the time. By continuing the ebulli- tion, the lye becomes more and more concentrated by the evaporation. The nature of the paste is modified, and by a progressive saturation with alkali, it acquires consistency. 19 290 TECHNICAL TREATISE ON SOAP AND CANDLES. However, when the pasting is finished, the paste has not the consistency of the ordinary soaps, which difference is ex- plained by the nature of the oil on which we operate — this oleic acid being almost entirely formed of the oily and liquid part of the tallows, that is, of the part the least apt to form hard soaps. It is only after the paste is completely saturated with alkali that it forms a very consistent soap. This re- mark may be applied, at least generally, to every fatty or oily substance in which olein predominates. The time for the first operation, on 6700 lbs. of material, varies from ten to fifteen hours. It is ascertained that the pasting is terminated, when the grains of soap formed at the beginning of the operation are entirely dissolved ; then the heat is stopped ofi:', and after resting ten or twelve hours the lye is drawn off. Observations. — The pasting being finished, it is important to let the mass rest for ten or twelve hours, to permit the lye not combined with the soap to separate as completely as possible. If much of it is left in the paste, it will be trou- blesome in the coction, for two reasons : first, on account of the great quantity of neutral salts it contains, and which would render the soap less hard ; then because it would weaken the degree of the new lyes of the first service, in such a manner that the action of these lyes on the olein would be less efficacious than if the operation had been con- ducted with a paste less saturated with neutral salts. Whilst colored, this sub-lye is generally limpid ; but as it marks from 18° to 22° B., it has to be reduced to 8° or lO'^ by the addition of water. It is then left to settle for a few days, and passed through an old residuum of exhausted soda ash and lime. For 6700 pounds of oleic acid, the quantity of lyes drawn ofi' after ten or twelve hours' rest, amounts to 175 to 200 gallons, and, though marking from 18° to 20° B., containing very little useful alkali but many other salts. The coction is effected with new caustic and concentrated lyes of soda ash. Two services are generally sufficient to bring the soap to the point of complete saturation. THE FABRICATION OF SOAPS. 291 First Service of Lye. — All the Ije of the first operation being drawn off, pour into the kettle from 225 to 250 gallons of fresh Ije at 27° or 28° B. Heat and keep the mixture to boiling. At the beginning the ebullition must be gentle; too active boiling would dilate the mass considerably, or cause the soap to stick to the bottom of the kettle. Thus, for the first hours the kettle must boil gently. It is true the soap is separated from the lye but slightly ; its grain is not completely formed, and it is yet soft, flaccid, and dilated ; but it is proper to have it so, for in this half-viscous state, the action of the lye on the oleic acid is more direct and more rapid than if the grain of the soap were prematurely formed. During all this first stage of the operation it is very im- portant, we repeat, to boil gently and uniformly. A more complete and equal saturation of the oleic acid by the lye is obtained. The formation of too much foam is also to be avoided. Later — that is, after five or six hours of ebullition — the heat is progressively increased; by evaporation the lye concentrates, and the grain of the soap becomes larger and firmer. While the lyes do not separate as completely as in the first service, it is easy to see that the soap is not so viscous, and is less greasy than at the beginning of the op- eration. To render the separation more complete, and to compensate for the loss due to the evaporation, add every hour, for the first six hours, from ten to twelve gallons of new lye at 27° or 25° B.; add also, towards the end of the first service, fifteen gallons of salted water at 25° B. This addition of salted water contracts the soap, and facilitates its separation from the excess of lye with which it is mixed. Lastly, after twelve or fifteen hours of continual ebullition turn ofi* the heat, cover the kettle, and let it rest eight or ten hours. This time is necessary to have a complete separa- tion. Draw oflt* the lye, which is strongly colored brown, and marks while warm from 22° to 25° B. ; frequently, on cooling, the lye solidifies into a gelatinous mass. Alone, or mixed with new lye, it is used in the pasting of oleic acid. Second Service of Lye. — This service, which is generally the last, consists of new lye at 28° or 30° B. 292 TECHNICAL TREATISE ON SOAP AND CANDLES. The lye of the first service being drawn off, pour into the kettle about 175 gallons of new 1 ve at 28° or 30° B. Heat ; very soon the mass begins to boil ; at first moderate the heat; but when, by an ebullition of five or six hours, the paste has acquired more consistency, the heat is increased; then add every hour, for six hours, about twelve gallons of lye of coction at 28° to 30° B. These successive additions of strong lyes have for their object the complete saturation of the soap, and to replace the evaporated water. Towards the end of the operation — that is, after an ebulli- tion of twelve to fifteen hours, add, as in the first service, from twelve to fifteen gallons of salt water, at 25° B. By this addition, the paste becomes denser and harder; its great consistency presents obstacles to the ebullition, which then becomes tumultuous. The foam w^hich covered the soap has entirely disappeared ; the soap is then in hard and dry grains, of a brownish color. However, the end of the operation is indicated by the following signs : — 1. When a little of the warm soap is put into the hand and quickly rubbed with the thumb, it instantaneously forms thin and hard scales, which fall from the hand without leav- ing on it any adhering particles. 2. When the foam which covered the surface of the soap has disappeared. 3. When, after fifteen hours of continual ebullition, the lye is yet caustic. To obtain the soap well grained, it is necessary that the lye extracted from the kettle, at the end of the operation, should mark 28° to 30° B. When these indications are well defined, the soap is com- pletely saturated wnth lye. Turn off the heat, cover the kettle, and, after resting ten hours, draw oft' the lye. Fitting. — For this operation, the lye of the pasting (em- patage) or a new lye can be used. The first slightly colors the soap, but deprives it more completely of the excess of caustic alkali it contains; the second does not color it, but sometimes causes an efilorescence of carbonate of soda ; it is then better to use the first. As it generally marks from 18° THE FABRICATION OF SOAPS. 293 to 20° B., it is reduced to 8*^ or 12° B., by diluting with water. The Operation is conducted as follows : — Two men stir the paste continually, while a third pours in the lye at 8° to 12° B. Heat strongly, so as to keep the mixture very warm, for it is by the combined action of heat, stirring, and the successive additions of weak lyes that the grain of the soap is broken and refined, by depriving it of the excess of caustic alkali and saline substances it contains. It is only w^ien the paste is sufficiently impregnated with weak lye, and has acquired a temperature near the boiling point, that it becomes homogeneous and fluid ; the soap has then the form of soft, dilated, and flat grains. Generally from 250 to 300 gallons of lye at 8° or 12° B., are used in the operation. When the soap is entirely melted and floats in the lye, boil the mixture gently for a few hours ; and to prevent the soap from again becoming granular by the con- centration of the lyes, add from time to time a few pailfuls of water or of lye at 2° or 3° B. In consequence of the movement caused by the ebullition, an abundant foam appears on the surface of the soap ; this foam consists of the most impure parts of the paste, and is strongly salted. It is known that the operation is finished, when the paste which is under the foam is smooth, fluid^ and homogeneous ; the density of the lye at the bottom of the kettle is also a sign to indicate when the paste has been boiled long enough. When cold this lye marks from 17° to 18° B., at the end of the operation. If below 15°, the soap would be less consistent and less firm; above 19° or 20°, it would be too hard. Thus, the proper degree of density of the lye ought to be, when cold, from 17° to 18° B. This result being obtained, the heat is stopped off, and the kettle well covered, so as to retain the heat in the mass as long as possible — an essential condition for a complete separation of the saline matters and the lye. Indeed, if the cooling should be too rapid, not only will the soap not be deprived of its heterogeneous and saline parts, but it will 29i TECHNICAL TREATISE ON SOAP AND CANDLES. contain a considerable portion of lye, which then renders the soap less neutral and less pure. After resting forty to fifty hours, the kettle is uncovered, and the scum on the surface of the soap carefully removed. This scum is utilized in a new operation. The soap which is fluid, syrupy, and well melted, is dipped or pumped into the frames. If an iron-wire sieve is placed above each frame, and the soap passed through it, the foreign substances contained in the paste will be separated. The bottom of the kettle being reached, care must be taken not to dip up any of the lye with the soap ; the latter is always easy to recognize by its golden color, while the lye has a brown, blackish shade. As soon as the lye appears, manage the ladles in such a manner as only to remove noth- ing but the surface matters ; but whatever be the care taken there is always a small quantity of the lye mixed with the soap. To prevent the inconveniences which would result from the mixing of the lye with the refined soap, it is better to pour the last portions of soap into a cylindrical vessel, provided with a cork at the bottom. By resting, the lye precipitates, and the soap specifically lighter floats on the surface. Then draw oflf the lye, and pour the soap into the frames. Paris manufacturers slightly perfume this soap, to mask the generic odor of the oleic acid ; they generally add two ounces of artificial oil of bitter almonds (oil of myrbane) for 100 pounds of soap. Stirring the Soap in the Frames. — It would not have been enough to bring the soap to the proper point of coction and purification, if it could not be had perfectly homogeneous. It is true the soap would have the essential qualities which constitute a good oleic-acid soap. It would foam and be detersive, but by the slow and gradual cooling it experiences in the frames, irregular marblings would be formed. It might even be often spotted by the lye, which would give it a very defective appearance. To obtain the soap in a smooth and homogeneous paste, it must be submitted to the stirring operation, which con- THE FABRICATION OF SOAPS. 295 sists in agitating the soap in the frames. The stirring must be continued until the soap becomes nearly pasty, which is easily ascertained by the difficulty of moving the stirrer. The new crutching machine illustrated elsewhere is well adapted for this purpose. The equality and perfect homogeneity of the paste, depend essentially on the stirring in the frames; the more complete the stirring, the finer will be .the soap. This operation is performed on almost all soaps, except the marbled soap, the marbling of which would be destroyed by stirring. The time of the stirring varies according to the nature of the pastes, their more or less complete liquefaction, and their temperature at the time they are introduced into the frames. But, as a general rule, soaps composed of fatty matters in which stearin exists in small, proportions, and the lique- faction of which has been pushed too far, require a longer stirring than those made of fatty matters very rich in stearin. The stirring of olive soaps run into frames of about 2000 pounds, lasts from eight to twelve hours, according to the season; the stirring may be discontinued when the tempera- ture of the mass is reduced to 43.3° or 48.9° C. (110° or 120° F.). After eight or ten days the frames are opened, and the soap divided into cakes. Thus prepared, this soap is brownish-yellow, but by being exposed to the air, it becomes white. At first its consistency is somewhat soft, but it becomes hard in a short time. When well prepared it is very detersive. In water it produces a very abundant lather, and is one of the best soaps. By the saponification of 6750 pounds of oleic acid of good quality, the amount of soap obtained is 10,687 pounds, or 155 per cent. The viscous lye from which the liquid soap has been drawn off, being mixed with 10 per cent, of salt water at 25° B. and boiled for seven or eight hours, produces from four to five per cent, of its weight of a good soap, which only requires to be dissolved in a weak lye to get rid of the excess of saline substances it contains. This soap being mixed with the other increases the amount obtained from 155 to 158 or 160 per cent. 296 TECHNICAL TREATISE ON SOAP AND CANDLES. When the soap is to be moulded it is divided into cakes, usually weighing one pound, and dried in the open air in summer, and in a drying-room in winter. We give rather full directions for this soap, as it is a very important article of commerce, utilizing a material that otherwise would find few uses, and we shall have occasion to refer to it again in describing the Swiss soaps and soft soaps. Of soaps made by boiling we have given those chiefly known to commerce, with hints that any skilful operator can apply with the materials on hand and make any modifi- cation of the kinds given, calling them by whatever names he may choose. There are several boiled soaps known in Europe as wax soap or bleaching soap made from tallow and cocoa- nut oil, containing a larger percentage of water. Almond- grain soap^ is a modification of the mottled soap of tallow, wherein the coloring is applied in a different manner, causing white lumps to appear, called almonds. The soaps made in this country as imitations of Marseilles soap or Castile soap are now made with a good deal of cotton-seed oil in combi- nation with tallow, etc., and as they possess much interest we will here give the formulas for Castile soap, either white or mottled, made from cotton-seed oil as a base. Castile Soap from Cotton-seed Oil. In our Southern States, where cotton is grown in the greatest quantity and of the best quality in the world, the seed has long been known to have an abundance of oil, the extraction of which was very difficult on account of the ad- hering fibre. From this cause the seed was allowed to rot, and was used for manure. When, however, machinery was invented for hulling the seed, the oil could be extracted with facility. The large amount of hull and adhering fibre these seeds possess will be understood when it is known that it sometimes takes five bushels of seed to make one bushel ready for the mill. The hull and fibre are used for paper stock, and are, of course, very valuable. When it was found possible to remove the hull and make THE FABRICATION OF SOAPS. 297 the oil, another difficulty arose in the large amount of objec- tionable color the crude oil contained, and which was due to dark resinous spots contained in the seed ; the color, how- ever, has been overcome, for it is now refined by means of chemicals, caustic lye, etc., and bleached with sulphuric acid, and pressed to remove the large amount of stearine it con- tains, and which, with the oils, is used for a great many purposes, this latter being sometimes sold and bottled as salad oil from its sweet nutty taste when fresh and pure. Cotton-seed oil, when well refined, is a bland, bright yel- lowish oil, very similar to almond oil, though it has some of the properties of a drying oil, but taking a very long time to dry. This drying property does not seem to deter the maker of cheap perfumery from bottling large quantities for common hair oil, or from buying it for that purpose under the name of olive oil, often not knowing from what source it is obtained. To the soap-maker it possesses very valuable properties, for nothing has yet been discovered that is so good and eco- nomical a substitute for olive oil ; and when a portion of lard and bleached palm oil is mixed with it, for making Marseilles or Castile soap, it is difficult to distinguish the imitation from the genuine soap. The importance of this oil in the manufacture of soap is, to us, so great that we deem it necessary to devote some space to its description, to give soap manufacturers some hints for its manufacture into a soap that may be called Castile soap, from its close resem- blance to it. In saponifying cotton-seed oil, there is no peculiar difficulty more than in making a good Castile soap from olive oil, though the soap is made somewhat sooner if the stearine is left in it, which stearine is generally pressed out to permit the oleine to remain fluid in the coldest weather. To make a white Castile soap, take: — Cotton-seed oil 80 pounds. Lard, good quality 10 " Olive oil 10 " 298 TECHNICAL TREATISE ON SOAP AND CANDLES. And prepare the lye by close calculation in this manner : 50 pounds to mark 15° B., 50 pounds at 21° B., and 50 pounds at 27°, making 150 pounds for this quantity of grease — the lye to be made of the English caustic soda, and rendered clear and caustic with about one-fourth of lime. To the melted grease in the kettle pour the first 50 pounds of lye at 15°, keeping it stirred as the heat is raised to boilings and as it froths beating it down quickly to prevent its over- flowing; boil for three or four hours, when add by degrees the 50 pounds of lye at 21°, and boil for five or six hours longer, keeping up the stirring, and, when it becomes a per- fectly smooth mass, turn off the heat and let it rest for the lye to separate. After some hours' rest the spent lye is drawn ofiT, the heat is raised, and the last 50 pounds of lye at 27° are poured in, and allowed to boil briskly for four or five hours, when the soap ought to grain and appear flakey when pressed between the fingers ; when again turn off the heat and allow the lye to separate, and draw off after some hours' rest. In finishing or fitting a lye of carbonate of potash of 6° or 8°, say 25 pounds are stirred in with a gentle heat until the soap presents a perfectly homogeneous syrupy mass, when it may be left to divide — the scum to the top and the gray soap to the bottom, with the fine soap between, w^hich is dipped into the frames, and the scum and dark soap kept to make the mottled soap. The result should be about 150 pounds of the best soap having a fine white appearance, and 30 to 40 pounds of in- ferior soaps that can be mixed with the mottled Castile soap. To make a Mottled Castile Soap from Cotton-seed Oil. Cotton-seed oil 80 pounds. Lard, good 10 " Palm oil, bleached 10 " The bleached palm oil improves the odor, causing a greater resemblance to Marseilles soap, and is cheaper than the olive THE FABRICATION OF SOAPS. 299 oil. Sulphuretted soda lyes are preferred by the French soap-makers for their mottled soap; but, as we are using the English soft lye or artificial lyes, we will have to adopt a modified process. The sulphuretted crude soda forms the colored mottling, the sulphur combines with the iron of the kettle and other impurities, and forms the oxide giving the blue color, which turns red on all those parts exposed to the air. To make this soap, proceed very much as for the white soap. To the melted grease pour on the 50 pounds of the weaker lye at 15°, gently raising the heat while they are mixing, which should be done by gently stirring, and keep- ing down the froth by beating, and regulating the heat to prevent too rapid boiling. After three or four hours, pour in the 50 pounds of lye at 21°, and continue the stirring, and as the froth subsides bring to a more rapid ebullition, and when it granulates shut oiF the heat and let it rest for four or five hours. Now draw off the sub-lye and pro- ceed to the coction, by putting into the melted soap the third 50 pounds of lye at 27°, which is added while con- stantly beating and stirring. Stir in also 5 pounds of common salt, and continue the boiling for six or eight hours, as may be required, or until the grains separate, as can be seen by taking out a portion with a knife or pressing between the fingers, when a little experience will show a flakey scale free from the lye ; let the heat be stopped and the soap allowed to settle until next day, when after drawing off the salted lye it can be finished. The soap is finished with weak sal- soda lye, or, if the soap is neutral, with water having a little salt in solution, for if it needs water the grains will appear hard and dry, when the soap will have to be boiled until it forms a smooth mass. The soap is again allowed to rest, and the next day again thoroughly stirred and put in the frame, when it is ready for the mottling. This is done by putting into a small watering-pot with a rose-spout about 4 ounces of sulphate of iron, dissolved in a pint of warm water, and pouring it from the rose on to the top of the soap in the frame, while the crutch is plunged up and down to give the streaky 300 TECHNICAL TREATISE ON SOAP AND CANDLES. marbled appearance. Of course this requires some practice, as it should present a uniformity throughout the entire mass, but is not difficult to accomplish with a little experience. If this soap is carefully made, it will be as good as most of the mottled Castile soaps we import, and should be made so economically as to yield a good profit while being sold at a less price than the imported article. We have devoted some space to the description of the man- ufacture of these soaps from cotton-seed oil, believing that the cheapness and other advantages of the raw material will induce soap-makers to give it the consideration it seems to deserve for making a good and cheap soap, and that they may see a source of profit in its manufacture. THE FABRICATION OF SOAPS. 301 SECTIO^f XII. THE FABRICATION OF SOAPS (Continued). Extempore and other Soaps. Extempore soaps, as we term them, are called in France little pan-soaps^ because they can be made in the smallest quantity. They differ from the boiled soaps in containing all the glyce- rine that may be in the neutral fat, which, as we have shown, is precipitated with the sub-lye in the process of separation with culinary salt, or by other means. Thus, soaps are made in several ways, but, by whatever mode it is necessary clearly to calculate the requisite quantity of alkali, for the saponifi- cation of a given quantity of fats, or the equivalents. When this is done, and the proper skill is used, the result is gener- ally satisfactory, although such soaps are never so neutral as those made by boiling. On the score of economy there are divers opinions, while much time is saved, and the necessary plant is not near so costly, there is some additional expense in the preparation of the lye, yet on the whole, we would say that they cost less to make, than the soaps made by boiling, particularly at the present time, when the alkalies are obtained with so much facility. These soaps are now made largely in nearly all commercial countries. Under this head may be classed all these soaps called half- boiled soaps, which we consider better entitled to the name we propose, Extempore soaps, as they are made with rapidity and retain their glycerine. Thus, when cocoa-nut oil enters into their composition, it is customary to saponify it sepa- rately in strong lye, and add it to the previously boiled tal- low, or tallow and palm oil, or rosin, which have been boiled in a lye of 15° to 21° B. They are also marbled in the frame 302 TECHNICAL TREATISE ON SOAP AND CANDLES. by adding ultramarine for blue, vermilion for red, bole Ar- menia for brown, bone black for gray. This, when skilfully done, gives an attractive appearance, particularly when the soap is of a clear white color. For all cold soaps, attention must be given to have the al- kalies as pure and as caustic as possible, otherwise, a com- plete admixture of the material is almost impossible. As a rule, lyes of 38*^ B. are taken. Such a lye of soda contains 0.3445 kilog. (.758 lb.) of soda to each litre (2.1 pints) ; so for 100 kilog. (220 lbs.) of cocoa-nut oil we require 36.8 litres (9.7 gals.), and we obtain about 150 kilog. (3B0 lbs.) soap having but 25 per cent, of water. This is simply an example. A larger percentage of water may be taken, though of course the lye will be weaker, but when cocoa-nut oil is present, it is best to use strong lyes. As mechanical aid in making cold soaps facilitates the process, there are made several styles of kettles and appa- ratus for the purpose. We illustrate two : one being like the ordinary soap kettle with a mechanical stirrer ; the Fig. 57. Fig. 58. other a cylinder placed horizontally, having a shaft through the centre to which are attached a number of arms like a churn ; this mode of usage needs no further description. (Figs. 57, 58.) THE FABRICATION OF SOAPS. 303 Tallow Soap by the Cold Process. Take, say, 1000 kilog. (2200 lbs.) of tallow, purified and cleared by rendering in a kettle, of twice its capacity, heated to a melting at about 37° C. to 43° C. (98.6° to 109.4° F.), and the 30° B. lye, being heated to attain the same temperature, is run from a vessel provided with a stopcock into the kettle. After having added all the lye, the entire mass is stirred gently, until it has thickened so that one part of it, spread out to a ribbon, no longer runs together with the other. The thin pasty mass is now run into the previously warmed frames, in which after a little while a tolerably strong heat takes place, which denotes the act of union between the alkali and the sebacic acid. As long as the soap is still soft, it shows a strong alkaline touch ; but after the combination has taken place, this vanishes almost entirely, provided the proportions between the alkali and the fat have previously been correctly taken. The soap thus produced is of brilliant whiteness, very hard and brittle, but will be more pliant, if about 10 per cent, of the alkali used is potash. This soap lathers very well, and is on occount of its hardness very economical for use ; a little addition of cocoa-nut oil makes it lather still more freely. CocoA-I^'uT Oil Soap by the Cold Process. The operation is performed exactly in the same way, as has been stated in the case of tallow soap, in which case it is generally perfumed and artificially marbled. The latter is done in this manner. The soap is put into the moulds in layers, upon every layer some vermilion or other coloring, mixed with a little lye, is spread, until the last layer, when it is stirred in certain directions with an iron rod. To give the soap a blue flame-like appearance, ultramarine is used in lieu of vermilion. The soap remains for twenty-four hours well covered in the frames, during which time the real com- bination of alkali with the sebacic acids with evolution of heat occurs. 304 TECHNICAL TREATISE ON SOAP AND CANDLES. Cocoa-nut oil possesses in a high degree the property of forming soaps which are capable of retaining large quantities of water, without thereby losing much of their hardness. Thus water, or salted water may be added in the frame, to the amount of 50 per cent. For the fabrication of all so-called Cold Soaps, the applica- tion of lyes entirely free from carbonic acid is a necessary condition, if a good product is expected, while only the absolutely required quantity of alkali needed for saponifica- tion is used. Rosin Soap by the Cold Process. The quantity of rosin, which is applied to a given quantity of fat, is from 15 to 50 per cent. The more rosin is added to a soap, the more it attains a soft and pasty nature, if the quantity of cocoa-nut oil or other fats is not correspondingly increased. The number of rosin soaps, that is the names by which they are designated, is according to the kinds of fat used, extraordinarily large, and almost every large soap manufactory has its own receipts, after which the favorite soap is made. For the saponification of the rosin suitably concentrated lyes are applied, because they furnish a firmer soap. Caustic soda could be substituted by carbonate of soda, but, for reasons already stated, one cannot well recommend this practice. E-osin and fat are either saponified separately and after- wards stirred together, or the fat is first saponified when the pulverized rosin with the necessary quantity of lye is added to the soap and boiled until all froth disappears. So also of a mixture of 100 kilog. (220 lbs.) rosin, 55 kilog. (121 lbs.) cocoa oil, and 55 kilog. palm oil, a rosin soap may be manu- factured in the cold way. These substances are melted to- gether, adding gradually while constantly stirring 100 kilog. (220 lbs.) or 72 litres (19.0 gallons) of a 25° B. soda lye, until it becomes stifi*, when it is put in the frames. The frames are now covered up and left to rest until the next day. THE FABRICATION OF SOAPS. 305 Transparent Rosin Soap. For the fabrication of this soap Dr. Deite gives the follow- ing directions: 80 kilog. (176 lbs.) cocoa-nut oil, and 20 kilog. (44 lbs.) palm oil are saponified with soda lye of 24° B., ad- justing it to a very weak "touch," and boiled until the froth disappears. Then 15 kilog. (33 lbs.) of pulverized rosin are thrown into it; he then dissolves 133J grammes (4.67 ozs.) sugar of lead in 100 kilog. (220 lbs.) salt water of 10° to 20° B. which by adding soda has been enhanced to 20° B., stirs this among the soap, and then ceases the boiling. It is then run into the frames and well covered, and the result is a semi-translucent hard soap. Another receipt for making this soap is as follows : — 70 kilogrammes (154 lbs.) cocoa oil 80 kilogrammes ( 66 lbs.) palm oil 20 to 25 kilogrammes (44 to 55 lbs.) rosin, are saponified over a slow fire with a slightly carbonated caustic soda lye of 86° B. which adjusts it for a strong touch. When this is done, the fire is extinguished, pouring 20 kilog. of a solution of potash of 20° B. over it, stirring it well under, then adding under constant stirring 70 kilog. (154 lbs.) solu- ble glass (40° B.), which has previously been diluted with 3 kilog. (6.6 lbs.) alcohol and 3 kilog. of a weak lye, keeping the soap covered for a period of half an hour, run it into the frames and cover. Borax Soap, * "Row much in vogue, is generally made by the cold process. The soap is made with a weak "touch," and there is a por- tion of the alkali left out and substituted by a solution of borax marking about 12° B., of which about 10 per cent, is used. White greases are used, and the soap has a brilliant whiteness which is very popular. Soluble glass is also added to this soap by some makers, though it is quite likely to show in a white powder as the soap dries. 20 306 TECHNICAL TREATISE ON SOAP AND CANDLES. Swiss, or Half-boiled Soaps. Among the various names given to this class of soaps, we prefer this title as distinguishing them, believing them to have been first made in Switzerland, where they are known as gluten soaps, a very unmeaning term and one calculated to mislead. They are soaps that by their characteristics claim a preference with many people. For illustration we will take for a Swiss Palm Soap 1000 kilogrammes (2200 lbs.) bleached palm oil, 500 kilogrammes (1100 lbs.) cocoa oil, 1380 kilogrammes (3036 lbs.) 25° caustic soda lye, and place in the kettle, and dissolve with a moderate fire. 1000 kilog. palm oil require for their saponification 110 kilog. (212 lbs.) soda. 500 kilog. cocoa oil require for their saponification 62.5 kilog. (137.5 lbs.) of soda; total = 172.5 kilog. (379.5 lbs.) soda. A 25° soda lye contains 13.90 per cent. soda. We need therefore of such 1365 kilog. (3003 lbs.); ac- cording to direction 1380 kilog. (3036 lbs.) shall be taken in consideration of the fact that the areometric degrees may also show the degree of foreign salts, hence indicate the soda somewhat too high. The work can also be commenced with one-half of the lye, and the soap must not cease to boil. As a substitute for the evaporated water, there must be added, in order to make the saponification perfect and cause the combination to take place, the other half of the lye which is added at five or six ditterent times. It must also be observed that the soap does not fail to boil continuously for four or five hours. The soap must have but a very weak touch. Should it be strong add oleic acid carefully until the soap ceases to irritate the tongue. That the soap is sufliciently boiled is ascertained by its boiling up in large bubbles and being of apparently pasty consistency, while the surrounding THE FABRICATION OF SOAPS. 307 portion forms a honey-yellowish bright ring when a sample of it is cooled and hardened upon a glass plate, and when, as soon as a spatula is placed in the mass and quickly with- drawn, dry spots become visible upon it and now and then knots of soap adhere. If the soap has a fat surplus it boils very dull, and in this case so much caustic lye is added until it shows a weak touch upon the tongue. Before testing a complete cooling off of the sample must take place, since the hot soap easily causes a poignant touch similar to that which caustic lye produces, nor must the biting taste of the cocoa- nut oil or the cocoa soap deceive us. The soap should only be considered as finished when it ceases to produce any foam at all, and is of a honey-like yellow, and telescoping slabs or rosettes are produced. The soap now boils in the kettle so that it can be heard, since the steam which originates upon the bottom of the kettle must break its way through the more consistent and dense mass of the soap and the burst- ing steam bubbles cause the loud noise which is called the "talking" of the soap. When the soap approaches a finish and is inclined to burn, it must be constantly stirred. If the soap now, as is stated above, falls off the spatula, becomes dry rapidly, and if a siunple taken between the thumb and index finger draws no threads, then it is finished, and can, after removal of the fire under the kettle, be run into the frames. This of course is a soap boiled in one lye, and where there is no separation of any of the materials, which should be well selected and purified before beginning the process, and it is particularly applicable to making toilet soaps, which will be more fully explained under that head. So, in like manner, with modifications applicable to the nature of the materials, the various soaps of commerce can be made, of which we give a few formulas for a guide. Swiss White Wax Soap. Swiss Yellow Soap. Tallow (white), 50 parts. Tallow oil, 30 parts. Cocoa-nut oil, 20 " Cocoa-nut oil, 20 " Cotton-seed oil, 30 " Palm oil, 25 " Rosin (pale), 25 " 308 TECHNICAL TREATISE ON SOAP AND CANDLES. Swiss Eosin Soap. Swiss Olein Soap. Palm oil, 40 parts. Oleine (red oil), 50 parts. Cocoa-nut oil, 30 " Tallow, 30 " Rosin, 30 " Ground-nut oil, 20 " Tliese are merely hints, and the manufacturer like any one else must cut his coat according to his cloth." A very fine and very hard Swiss rosin soap is obtained as follows : — Tallow .... 100 kilog. (220 lbs.) Rosin 50 (110 ) Caustic soda ... 87^ " (82.5 " ) The soap is boiled in two waters and the fat substance ia in the first place saponified, with a 13° or 14° B. soda-lye, then the rosin is added, and the boiling continued until a soap mass becomes visible ; when the heat is turned off, and on the following day the sub-lye is drawn out. In the second operation it is boiled with a 10° B. lye, but, if it should show; a smeary or weak condition, it can be remedied with a lye of 12° B. The boiling is now continued until no defect is visible, and after a rest of three hours, the soap is run into the frames. Another modification of this process is, when the sebacic acids or fats are saponified with the requisite quantity of caus- tic soda, of about 20° B., in a moderate heat of about 49^ C. (120.2° F.), the ingredients being slowly combined with con- stant stirring, the heat gently raised to a boil, and sufficient water added at times to keep up the due proportion of loss by evaporation. The combination is thus efl[*ected, and when the paste becomes too thick to stir it is framed and allowed to cool slowly for at least two days. This process involves some experience, and cannot be recommended to those who are novices in soap making. The main feature in the fabrication of these soaps is, to keep up the correct proportion between alkali and fat. It may occur, that a little too much or too little lye is applied ; because, on a larger scale the materials cannot be weighed or measured with the accuracy of an analytical test. But if THE FABRICATION OF SOAPS. 309 we have manipulated as accurately as possible, it will only be an equalizing of a small overplus of fat or lye, and we must not always be too ready with ammunition of large cali- bre, and add large quantities of lye and fat all at once. This it is that leads to confusion, out of which it is difficult to cor- rectly find our way again, and by which the soap instead of improving is made worse. All manipulations which are undertaken with extempore soaps amount finally to this, to produce the most neutral soap, and to fix the proper propor- tion between fat and alkali; since an overplus, be it of the one or of the other, works equally injurious. Hard Soap from Potash Lye. Prior to the introduction of artificial sodas, the lye from wood ashes was extensively used for making household soaps, and for making hard soap it was the custom to boil in potash lye, and cut with culinary salt, either directly, or in solution. Where wood is burnt as fuel, and wood ashes abound and are cheap, or where potash can be procured economically, this process may possess interest and be of useful applica- tion, although at present in commercial centres this class of soaps is rarely made. Yet it is necessary, for the reasons stated, to give a description of the processes. Tallow Curd (grained) Soap. To transform 1000 lbs. of tallow into grained- or curd- soap, 400 lbs. of potash have to be taken. The tallow is placed in the kettle, about 400 lbs. of lye of 10° B. added, and the fire is kindled. Within a short time of the com- mencement of boiling, the fire is kept well up* but then it is moderated. After the seething up, examination should be made as to whether the fat has united with the lye. This is perceived by the yellow-brown mass, which under gradual upheaving continues quietly to boil. What adheres to the spatula, when inserted and withdrawn, has a gelatinous, gray- ish-white appearance, without separation of lye. When lye 810 TECHNICAL TREATISE ON SOAP AND CANDLES. and fat are not united, it moves in the kettle noisily to and fro, without rising upwards, only now and then pushing up in single places, with a bouncing noise. The reasons why fat and alkali do not at first combine, are in general the same as are stated in the section on soft soaps, and the remedy is the same. When the combination succeeds there are added, at short intervals, in four to five portions, about 1100 lbs. of lye of 16° to 17° B. The boiling now becomes dense and languid, and the mass appears a yellowish-brown, and runs ofi^' the spatula in cohesive, long, translucent strings. The soap boils to a paste. If some of the soap is dropped upon a glass, and the sample while yet hot does not appear perfectly clear, lye is yet wanting. A small portion of lye should hence be added, until the soap while hot appears perfectly clear. As soon as this moment arrives the cutting of the pan begins. The salt has here a double purpose to fulfil. It must transform the potash soap into soda soap, and must separate it from glycerine, superfluous Avater, lye, and dross. The entire portion of salt necessary for this purpose is not added all at once, but a repeated " salting out" should be performed. After each salting out" the under lye is separated from the soap, and the latter is again brought into contact with water and salt. Such an operation is termed by the soap-boiler a water^ and he speaks of a first, second, and third water. By a boiling of tallow and potash, when the materials are not very impure, the " salting out" is performed usually in three operations, hence the soap is finished boiling in three waters. In order to separate the under lye from the soap, the latter is either scooped from the kettle into a vessel which stands close by the kettle, and afterwards the first is removed ; or the soap remains quietly in the kettle and only the under lye is removed therefrom. This may be done in two difterent ways, either the kettle is provided below with a stopcock, or a pump with a movable barrel at its lower end is used. The salt is either thrown into the boiling soap "dry," or what is better, previously dissolved in boiling water, and used as a solution of 20° B. When the salt is used in the THE FABRICATION OF SOAPS. 311 dry state, it must be constantly stirred up from the bottom to prevent its burning. To the quantity of fat taken for our example, we apply in the beojinning 80 to 100 lbs. of salt. Whether the applied salt is sufficient, is discerned by the previously brown color of the soap now turning into white, and in the kettle there appear all round ebullitions of the size of the hand (the soap boiling " in slabs"), the soap beginning to rise with force, and the froth vanishing. Until these signs appear salt must be added. Hereupon the boiling should continue for another hour and be then stopped, in order to cause any impurities yet in the mass to have time to settle. The fire being ex- tinguished, the separation of soap and the sub-lye follows. When the sub-lye is removed from the kettle, 700 to 800 lbs. of w^ater with 70 to 80 lbs. of salt are again put into it, and it is heated to the boiling point. After boiling up it should be investigated whether the "cutting of the pan" has been sufficiently attended to, which is discerned by the signs described above. Leaving the soap to boil for some time, the sub-lye is again removed. Although the second water has greatly increased the hard- ness of the soap, yet this hardness is not yet sufficient, so the third water must be prepared to cause the hardness to become perfect. To this «nd 700 to 800 lbs. of water, and 50 to 60 lbs. of salt are again heated to boiling, and again put into it. When it begins to seethe up it should be critically investigated to find if the proper quantities of salt and of lye have been applied. If salt is wanting then froth appears upon the surface of the boiling soap, and the latter burns easily. In this case salt should be yet added, until it boils up in regular slabs of soap. If too much salt has been taken, or more correctly speaking, the salt solution is too concentrated, the soap appears upon the spatula without connection, the lye drops rapidly oflT, and little gutters are formed. This fault is remedied by adding a few buckets of water. The soap must yet be investigated by pressure. Upon the thumb of the right hand some soap is taken and rubbed on the palm of the left hand. The soap hardens there almost 312 TECHNICAL TREATISE ON SOAP AND CANDLES. instantly, and now the thumb is pressed hard upon it and rubbed. If the sample there remains a cohesive slab, then the soap possesses the required firmness, is solid ; but if the sample crumbles, it needs water; if smeary, then lye is want- ing. Then lye and salt of 15° B. must be added till the proper state of the soap is reached. Thereupon commences the ope- ration of clear boiling or fitting. To attain this the kettle is covered one half with planks, and a sti rrer beats down the mass, so that it does not run over. The soap particles dra^w more and more together into globular grains — the soap "grains." The soap grains sink, and on the surface the kettle is filled with a light, flaky froth. To prevent the falling of the mass great heat is now needed. The fire is diligently kept up, the entire kettle is covered with planks and cloths spread over it. The soap seethes up with ebullition, and, to avoid running over, one of the boards is lifted and the froth is beaten with a long rod until it falls. Then the kettle is again tightly covered, a renewed ebullition ensues, and the overflowing is again pre- vented in the manner described. Gradually the violence of the ebullition diminishes, but in place of it a whistling sound is perceived in the kettle. From time to time one of the boards is lifted and the soap is watched. As soon as merely large perfectly translucent bubbles rise up, the soap is finished. After the fire is extinguished, the planks are removed, and for cooling the soap a few buckets of sub-lye are poured into the kettle. The soap is now ready to be run into the frames, when care should be taken that but very little of the sub-lye is transferred. After all the soap is in the frames they are covered with cloths. From time to time the sides of the soap in the frames are pressed back, as in becoming cold it contracts. Boiling with wood ashes is very similar to that with potash, and difters only in so far that the lyes of ashes are less con- centrated. In consequence of this it is not possible to saponify the fat in the first water completely, this succeed- ing only after the second and third waters. Therefore, for the second and third waters \veak lye is taken, and not water, as in case of potash. In order to saponify 453 kilog. THE FABRICATION OF SOAPS. 313 (996.6 lbs.) of tallow, about 50 hectolitres (140 bushels) of wood ashes are to be put in. The boiling with soda lye presents this advantage, that the soap may be finished in one water. The first lye is applied at a strength of from 10"^ to 20° B. The entire fat is placed in the kettle with one-quarter of the requisite lye for saponifi- cation, with proper attention to the fire. After boiling up, it should be examined as to whether the combination has taken place. This being the case, further portions of lye are added. Commonly this is taken of a strength of from 16° to 18° B. The adding of lye is continued, until a sample of the soap upon the glass plate appears perfectly clear. Thereupon the "cutting up of the pan" follows. This op3ration has here only the purpose of freeing the soap of glycerine and surplus water, hence much less salt is required than in the boiling with potash lye. For 100 lbs. of fat 10 to 12 lbs. of salt are required. The salt may be applied dry or in solution. After this the operations are the same as previously described. Soda soaps made by the process above described have some advantages, principally because it is impossible to remove all the potash, and they are generally very neutral and plastic. 314 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIO^^ XIII. THE FABRICATION OF SOAPS (Continued). Soft Soaps. Soft soaps are essentially a combination of the sebacic acid soap in a solution of potash with glycerine. On accoiint of the great affinity of potash soaps for water, these soaps do not dry in the open air, but always retain their soft con- sistency ; and the glycerine dissolved therein to a certain degree adds to this peculiarity. In its fabrication linseed oil, hemp-seed oil, sesame oil, cotton-seed oil, 'oleic acid of the stearic acid manufactories, with or without the addition of tallow or palm oil, are used. For winter soaps, the more liquid fats are chiefly used, such as linseed oil, hemp-seed oil, etc., since these do not congeal so easil}^ ; while in summer principally south sea train oil and rapeseed oil are applied in varied proportions. A good soft soap (except the so-called Elaidin soap) must appear as a clear mass, in which at times, especially if it has been standing for a long period, white grains are formed — crystalline separations of stearic acid potash or soda. It must possess the requisite consistency, not draw into threads like rosin, but when taken between the finger and thumb break off short like butter or lard. According to temperature it should be somewhat more consistent than these latter articles. It may have a somewhat sourish touch when tasted with the tongue, but not too strong, i. g., have a little overplus of pot- ash. A large surplus is denoted by the dulness of the soap. When the soap is in want of alkali, it does not appear clear, has, however, in that case no sourish touch; so that it may be easily discerned, whence the surplus or the want of alkali originates. THE FABRICATION OF SOAPS. 815 Until lately, all soft soaps were manufactured only by saponification of the neutral fats with caustic potash, and contained therefore only the small portions of soda that are naturally in the potash. But later, caustic soda was used simultaneously in a fixed proportion to the potash, partly to obtain a somewhat more consistent soft soap, and partly too, in order to enhance the yield, in a certain given quantity of ingredients. Gentele has given a certain proportion for this, where, without a muddiness of the soap occurring, the maxi- mum yield is reached. For this purpose 5 parts neutral fat are boiled with 3 parts of potash and 2 parts of soda. There are 3 equivalents of potash and 2 equivalents soda, or 7 weight parts potash, about 3 weight parts soda; and the soft soap thus produced consists, therefore, of 3 equivalents sebacic acid potash and 2 equivalents sebacic acid soda, besides the glycerine and water. A very advantageous re- sult was obtained by Grentele by the application of the fol- lowing weight proportions: — 1420 kilogrammes (3124 lbs.) 73 per cent, potash. 970 kilogrammes (2134 lbs.) pure crystallized soda. 8753 kilogrammes (8256 lbs.) liempseed oil. 40 kilogrammes (88.0 lbs.) tallow. 102 kilogrammes (224 lbs. ) oleic acid. These materials yield 9720 kilog. (21384 lbs.) of good soft soap, hence almost 250 kilog. (550 lbs.) soap from 100 kilog. (220 lbs.) fat. It must, however, be remarked, that this soap contains a great surplus of alkali ; for the 3895 kilog. (8569 lbs.) fat taken, to be worked up, require when they are saponified with | potash and f soda, of the former 658 kilog. (1448 lbs.), of the latter 201 kilog. (442 lbs.), whereby it is supposed that to saponify 100 kilog. (220 lbs.) fat for soft soaps 19.6 kilog. (43.12 lbs.) potash or 12.75 kilog. (28 lbs.) soda are necessary. But since 1420 kilog. (3124 lbs.) of a 73 per cent, potash correspond with 706.5 kilog. (1554 lbs.) caustic potash, and 970 kilog. (2134 lbs.) crystallized carbonate of soda correspond to 210.3 kilog. (463 lbs.) soda, it follows that Gentele has applied 2486 kilog. (5469 lbs.) potash and 9.3 kilog. (20.5 lbs.) soda too much. With such an overplus 316 TECHNICAL TREATISE ON SOAP AND CANDLES. nearly 1300 kilog. (2860 lbs.) more fat could have been saponified. There is of course no account taken as to loss ensuing in the preparation of the lye. But the deviation is, however, too great not to suppose at once an error in the hypothesis; perhaps if the oleic acid were to be increased tenfold a near correspondence of the common proportions between fat and alkali would take place in the soft soaps. We have ourselves, by investigating these soaps, repeatedly found in 100 kilog. (220 lbs.) fat as much as 21 kilog. (46 lbs.) potash. By applying 2 equivalents soda to 3 equivalents potash, the soap remains clear, if otherwise the right pro- portions are maintained, and alkalies of a high degree are used in the making of lyes. With equal equivalents of potash and soda, however, the soap becomes muddy ; the same occurs when the soda contains much culinary salt, and the potash much sulphate of potash or chloride of potassium. Calculating the proportion^ when the fats are to be boiled with I potash and § soda. As we have already stated, that all soft soaps must be adjusted with a certain *' touch," i. e., with a surplus of alkali, which on an average amounts to I more than if we had to do with the production of a neutral soap, consideration of this matter should be taken from the first. To boil 100 kilog. (220 lbs.) into soft soap we apply 12.8 kilog. (28 lbs.) soda, or 19.5 kilog. (43 lbs.) potash. These proportions are based on the calculation made for saponification of 5000 kilog. (11,000 lbs.) fat for 3000 kilog. (6600 lbs.) with potash saponified. ^^^^100^^^ = 585 kilog. (1287 lbs.) caustic potash and 2000 kilog. (4400 lbs.) with soda saponified ^^^^ ^ ^^'^ 100 256 kilog. (563 lbs.) soda will be required. The potash lye applied is J at 20° to 21° B. and | at 25° B.; the first contains ^ ^^^^ = 438.75 kilog. (965 lbs.) potash, the latter = 146.25 kilog. (322 lbs.) potash. THE FABRICATION OF SOAPS. 317 The 20° B. lye contains 16.408 per cent, potash ; there are hence to be taken of it ^^^'^^ =2674 kilog. (5883 lbs.) 16.408 or 1630 litres (431 gallons.) The 25° B. lye contains 19.803 per cent, potash, and of it should be takeni^fA^^ = 740 kilog. (1628 lbs.) or 610 19.803 ^ ^ ^ litres (161 gallons). The soda is only applied as 20° lye, and since it contains 256 X 100 10.88 per cent, of soda there are required of it ——^^^ = 10.88 2353 kilog. (5176 lbs.) or 2028 litres (536 gallons). The total quantity of lye contains therefore: — Potash lye at 20O 2674 kilogrammes or 1630 litres " " at 250 740 kilogrammes " 610 litres Soda lye at 20o 2353 kilogrammes " 2040 litres 5767 kg. (12,687 lbs.) 4280 litres (1132 gals.) Whereas from 5000 kilog. (11,000 lbs.) fat (100 : 250) 12,500 kilog. (27,500 lbs.) soft soap are to be realized, there must needs be added to the soap mass in the kettle 1737 kilog. (3821 lbs.) of water, that is, the lyes must be diluted to the amount of 7500 kilog. (16,500 lbs.) and the evaporating water during the process of boiling must be replaced. Great competition often compels the manufacturer to enhance the yield (100 : 250) by other means, filling with salt lye, carbonate of soda, etc. With such intention the fats are also augmented by adding four to five per cent, cocoa-nut oil, and by this means the yield is still further enhanced to 300 kilog. (660 lbs.) soap from 100 kilog. (220 lbs.) fat. The Boiling of Soft Soap, — The fabrication of soft soaps offers no particular difficulties, if the proper proportions of alkali and fat are accurately calculated and applied. The lyes and all the fat can be taken at once into the kettle, the mixture heated to boiling, and kept thus, until a perfect saponification ensues, and the soap has attained its correct consistency. More to the purpose it appears, however, either all the lye, or perhaps one-half of it, is stirred together with 318 TECHNICAL TREATISE ON SOAP AND CANDLES. the fat in a temperature of 80° to 40° C. (86° to 104° F.) and to leave the mixture stand overnight. By this operation a cer- tain emulsion is formed, and on the day following, the further union advances extremely fast. If at first only one-half of the lye had heen taken, then during the continuance of boil- ing, the other half must be added. From time to time, the soap is tested as to its nature, whether it has an overplus of fat or alkali, whether it has steamed or not. This is ascer- tained by placing a small sample upon a glass plate, upon which it is cooled off in a temperature not exceeding 8° C. (46.40° F.). The soap is good if a sample of it, held up to the light, is clear and translucent, and when the soap dropped upon the glass, after a lapse of from 12 to 15 minutes, shows but a very small ring. It must not glide or be slippery upon the glass, and when taken between two of the fingers, it must not draw into threads when the fingers are extended. Particular Remarks. — Should the soap at the commence- ment become thick, then it is wanting in lye, which must be added at once. If the soap turns muddy from the first, when placed upon the glass, and runs like water from the spatula, then the lye is excessive and must be relieved by adding some fat. If the soap runs out of the trial-spoon in flakes, it is too much evaporated, and must then be diluted with a corresponding quantity of potash lye of about 4° B., and again be somewhat condensed. The ring of lye and the gray fat, by the trial upon the glass, the first as a rim encircling the soap-drop, the latter as a muddy point in the centre of the drop, appears only after the soap is so far boiled that it is out of the paste, hence almost finished boiling. A small ring of lye, every soft soap must show, because every soap must needs have a cer- tain surplus of caustic potash. On the other hand, all fatty gray (a gray spot in the centre of the soap-drop) must be removed by adding potash lye. If this is not done, then the soap after a short time turns in the kegs or barrels into a thick, slimy, and thready mass. The barrels into which the soft soap is placed must be en- tirely clean and dry, or the soap will easily turn, that is, THE FABRICATION OP SOAPS. 319 will become thin and muddy. It is filled while 3^et hot into the barrels, which are closed only after the soap has cooled off. The magazines or storehouses for the finished soaps must not be too warm. The soaps made of hempseed-oil possess a more or less greenish color; all other fats furnish a brownish soap. But since hempseed-oil soap is now very much favored, it is sought to impart also to the soaps made of other fats a greenish hue. This is done by dissolving finely powdered indigo in the sixfold part of its weight of fuming sulphuric acid, and this solution is stirred into the soap. Instead of this indigo solution, indigo carmine (indigo-blue hyposul- phide, potash or soda) may be applied. So much of this is taken until the desired shade is attained. The soft soaps are likewise filled, and for this various means are applied. Some add rosin soap to them. Such a mixed soft soap cannot be used for washing wool nor in fulling-mills ; besides the profit which the soap manufacturer thus obtains is very doubtful, because the soaps have to be boiled more in order to attain the proper consistency. A frequent mode of filling is that with starch dissolved in weak lye. By this operation a transparent, and almost colorless gluten, is stirred into the soap, which must be done with great care, if not, little lumps will form. Others fill with alum and a solution of salt ; of the first 1 kilog. (2.2 lbs.) dissolved in water, and 30 to 40 kilog. (66 to 88 lbs.) salt lye of 5° B. are taken to 700 kilog. (1540 lbs.) finished soap. On the one hand, clay is separated by this operation, which partly dissolves again in caustic potash ; on the other, some soda soap is produced. The filling is added after the soap has attained its proper consistency. Of this soap, worsted spinning manufacturers can make no use, which is to be well noted. The filling with carbonate of soda in a lye of 5°, to w^hich, upon 100 kilog. (220 lbs.) finished soap, 2 to 4 kilog. (4.4 to 8.8 lbs.) are added. In this case it is the formation of a small quantity of hard soda-soap, which makes the soap more consistent, so that it need not be boiled so lonsf. 320 TECHNICAL TREATISE ON SOAP AND CANDLES. In more modern times, much filling is also accomplished by the use of soluble glass. This is carried out by taking 36 kilog. (79 lbs.) soluble glass, for 100 kilog. (220 lbs.) oleic acid or fat. Inasmuch as the soluble glass contains an over- plus of silicic acid, it becomes necessary to admix to each 25 kilog. (55 lbs.) soluble glass, 1 kilog. potash lye of 25° B., since the soap may otherwise become too weak. The mixing of the soap with the soluble glass is performed by stirring in well, without heat. Grained Soft Soap. {Fig Soap.) — By this appellation such soaps are known whose brown, trans|)arent mass is more or less filled with smallish white grains, crystals of stearic acid, or palmitic acid, potash or soda. The formation of these soaps succeeds best in a temperature of between 9° and 18° C. (48.2° to 64.4° F.). Below^ 9° C. (48.2° F.) the mass congeals too ra[)idly, so that no crystalline separation will ensue; above 14° C. (57.2° F.) the crystals all remain dissolved. To produce this soap, the purest potash-lye must be applied. The potash from which this lye is prepared must not exceed 5 per cent, of carbonate of soda, and must also be free from other foreign salts. Otherwise, the entire mass becomes muddy, and the grains can no longer be discovered therein. There are various directions for producing this soap, of which a few are here given : — I. 55 parts palm oil and 45 parts oleic acid, or II. 55 " " " 15 parts tallow and 30 parts linseed oil, or III. 70 " *' 30 parts linseed oiL These soaps are also adjusted upon a certain "touch"; just as the applied fats are more or less hard, the crystallizations are also more or less numerous, so that by the choice of the fats it is in our power to produce more or less crystals in the soap. Perutz communicates the following directions for the fabrication of an excellent fine soda-grain soap, which upon its clear green ground has but a few white grains. This soap is made of f oil of hemp-seed, and J tallow. Artificial Grain Soap. — The above explained grain soft soap is also as to its exterior appearance, produced in an artificial manner, by admixing with the finished soap certain grainy THE FABRICATION OF SOAPS. 821 substances. The so-called "artificial grain" consists usually of starch, lime, or clay, which is made into the shape of grains. The most suitable is clay, if we at all desire to assist in lend- ing a helping hand to such a deception. Elaidin Soft Soaps. — These soaps contain, in comparison to potash, a larger proportion of soda than the common soft soaps, in consequence of which they become muddy when cooled off, and wlien stirred again, assume a silvery or golden shiny appearance. According to the nature of the fat, they show a yellow or yellowish white color; for their production, more hard fats are used than others. The first half of the fat boiled in potash, the other in soda, furnishes a good and smooth soft soap. IN'umerous are the receipts for the fabrication of elaidin soaps, which differ partly on account of the various fats, partly on account of the proportions of the various mixed fats which are to be saponified. The manipulation is the same as in the case of the common soft soaps. They are adjusted until a sample, placed upon the glass plate, shows a small lye ring when cooled off. The disappearance of the froth in clear boiling here also designates the approaching end of the boiling. And this offers a tolerably sure sign that all the alkali has combined with the sebacic acids. For our ownselves, we have no doubt that the carbonate of alkalies, when tlie saponification does once take place, will to a certain degree decompose the neutral fats and change them into soap. At first the caustic alkali is absorbed while boiling, further also the carbonate of alkali is changed as long as fat is still on hand. This transformation ensues under the development of carbonic acid, which is really the cause of the frothing. The ceasing of frothing, or, what is the same, of carbonic acid development, is therefore a sure sign that a reciprocal influence of the materials no longer takes place. Inasmuch now as the lyes which find application in the manufacture of soap — as may be boldly asserted — are never perfectly caustic, we would, when the carbonate of alkalies in the presence of caustic alkali and finished soap were not decomposed in all cases from the be- 21 822 TECHNICAL TREATISE ON SOAP AND CANDLES. ginning, have to employ a so much larger overplus of alkali, as the lyes contained carbonate of alkali. A certain limit, however, it seems must, in this case, not be transgressed, if we do not desire to run the risk of continuing the boiling very long, or until a perfect saponification ensues, and cause a loss of time and fuel. The following receipts are effective for making good elaidin soaps : — 600 kilog. (1320 lbs.) palm oil (bleached), 300 " (660 lbs.) linseed oil, saponified part with potash, part with soda, with say 3 parts potash and 2 parts soda. These are about the proper equiva- lents. Another formula is, 45 parts palm oil, 55 parts oleic acid; 40 parts palm oil, 30 parts oleic acid, and 30 parts linseed oil. The more the quantity of the soda is increased in proportion to the potash, the greater the consistency, the harder, but also the less clear the elaidin soaps appear. But in this respect we must govern ourselves according to the desires and the customs of the consumers. Many give to the elaidin soaps an addition of rosin ; but in most cases there ensues from this no profit, either for the consumer or for the manufacturer. White Soft Soaps. — By this name a soap is known in many places, which really cannot be counted among the soft soaps, since as to its main substance it is composed of a soda soap, filled with chloride of potassium. It is produced by saponi- fying 75 parts tallow and 25 parts cocoa oil with 2 parts caustic potash and 1 part caustic soda lye. The previously mixed lyes are added by degrees until the soap attains a strong ''touch." Thereupon so much salt lye of 20^ B. is stirred in, until a sample, when cooled off, forms a stiff paste, which by a pressure of the fingers, extends upon the glass plate. The soap is now finished and is to be filled into the barrels, where, after it becomes cold, it will be found to be so firm that it cannot — like other soft soaps — be taken out with the spatula, but must be cut out with a knife. 100 parts of the fats furnish 400 parts of a cheap, but very inferior soap. THE FABRICATION OF SOAPS. 323 A very pure soft soap, much esteemed by manufacturers, is the English Crown Soap (first quality). In England, the lyes are made perfectly caustic, and of two strengths, the weakest being 8° B., and the strongest 25° to 30° B. For eighteen bar- rels, prepare 400 gallons of lye, with good potash made caustic with lime; and put a third of it in the kettle, and then add 52 pounds of suet, and as much of lard. When the whole is melted, pour in 70 gallons of olive oil, and leave the liquor to settle for two hours ; kindle the fire anew, and turn 19 gallons of lye into the kettle. As soon as ebullition com- mences, add from time to time a little lye in order to allay the frothing. Continue this addition until the liquor in the kettle has been reduced one-half. At this time examine whether the soap has been dosed too little or too much with lye. This test, or proof, should be made frequently during the saponification. It is merely to withdraw a sample from the kettle upon a spatula and to examine it. If it becomes whitish, and falls in short pieces, it is too alkaline, and re- quires oil ; if, on the contrary, lye is needed, it drops in long, ropy strings. If it is proper, that is, deficient neither in lye nor in oil, the sample should be viscid, white, and semi- transparent. Then the fire must be extinguished, and the soap run off into barrels. It may be as well to say that, after the second time the fire is kindled, the soap should be kept in lively ebullition, until its preparation is well advanced ; and, at that point, it must be carefully managed until the soap has acquired its requisite clarification. Croion Soap (second quality). — For this soap, take 286 pounds of suet or tallow; lye, 135 gallons; sperm oil, 80 gallons. Place in the kettle, first, 94 gallons of lye and the tallow, and when the latter is melted, add the oil, and put out the fire. Two hours after kindle it anew, add 19 gallons of lye, and carry the whole to boiling, and keep it so until the soap becomes half made. Then dose with 9 gallons of lye, and finally resume and continue the ebullition, taking care to add the remaining 9 gallons of lye to finish the soap. Green Soft Soap. — Two hundred and seventy-three gallons of whale or cod-liver oil, and 400 pounds of tallow are put 324 TECHNICAL TREATISE ON SOAP AND CANDLES. into the soap pan with 250 gallons of potash lye, containing 250 pounds of dry caustic potash. Heat heing applied to the pan, the mixture froths up very much as it approaches the boiling temperature, but is prevented from boiling over by being beaten down on the surface. Should it soon subside into a doughy-looking paste, it is to be inferred that the lye has been too strong. Its proper appearance is that of a thin glue. There should now be introduced about 42 gallons of a stronger lye, containing 55 pounds of potash, and after a short interval an additional 42 gallons; and thus successively till nearly 600 such gallons have been added in the whole. After sufficient boiling to saponify the fats, the proper quality of soap will be obtained, amounting in quantity to 6400 pounds, from the above quantities of materials. THE FABRICATION OF SOAPS. 325 SECTIOIS' XIV. THE FABRICATION OF SOAPS (Concluded). SiLICATED AND OTHER FiLLED SOAPS. The filling and the sophistication of soaps is conducted to a greater or less extent in all business centres, and when the materials used are harmless and do not detract from the de- tei'sive power of the soap, they may be somewhat excused from that censure which all adulterations should receive. The materials generally used are water, soluble glass, dex- trine, starch, clay, silica, sand, salt, etc., and there are many common soaps made from offal fat, bones, etc, in which are retained the many impurities natural to these substances. In regard to water it may be stated that the soaps made from cocoa-nut oil have the property of absorbing large quantities of water, without essentially losing thereby their hardness. This property the cocoa-nut oil transfers also to the soaps in which, in combination with other fats, it ap- pears. The common soaps contain 35 to 50 per cent, of water, but there are some cocoa-nut oil soaps in the mar- ket, which contain as much as 75 per cent, of water. Such soaps shrink greatly in drying, and are covered — when they contain an overplus of alkali — w^ith a crust of fine white crystals. Since the cocoa-nut oil soaps are not separated even by greatly concentrated solutions of culinary salt, they may be impregnated with a large amount of salt water, without injur- ing their exterior appearance in the least. This may also be done to a less extent with soaps which are fabricated with cocoa-nut oil and other fats. In relation to this, the action of the different soaps is this: pure cocoa-nut oil soaps bear a great deal of salt ; those of palm oil very little, and those of olive oil and tallow no salt at all. 326 TECHNICAL TREATISE ON SOAP AND CANDLES. For filling these soaps there are applied, besides water and culinary salt, starch, offals (bones and greaves), chalk, clay, barytes, pumice stone, sand, soluble glass, and carbonate of soda. Of these substances, chalk is beyond dispute the very worst, because it does not merely make the soap thin, but in a great measure entirely destroys it, and causes it to be ineffi- cient. Common Cocoa-nut Oil Soaps. — 1000 kilog. (2200 lbs.) cocoa- nut oil are boiled with 1660 kilog. (3652 lbs) of a 7.5 per cent, caustic soda lye into a clear paste and filled with 1000 kilog. of a salt solution of 22° B. The frames must be well greased, because the soap is very thin, and scarcely combines. It may be marbled in the frames, with some ver- milion or ultramarine, and perfumed with essential oils. Common Filled Rosin Soaps : — 1000 kilog. crude palm oil. 110 kilog. (242 lbs.) caustic soda. 1000 " cocoa-nut 112.5 " (247.5 " ) " " 1000 " rosin. 104.0" (228.8 " ) " " The soda is applied as a lye of 20° B. = 10.677 per cent., and hence uses ^'^'^ ^ = 3060 kilog. (6732 lbs.) = 2240 10.677 ^ ^ ^ litres (593 gals.), which, added in three portions, is boiled until the potash shows but a slight touch." The boiling is continued until the paste becomes thick, and after cooling off upon the spatula becomes firm. When in the frames, 50 to 75 kilog. (110 to 165 lbs.) of a solution of sulphate of pot- ash of 20° B. may be stirred in, which must be continued until the soap becomes tolerably cool, stiff and thick. The frames should not hold more than 200 to 250 kilog. (440 to 550 lbs.) of soap, and not exceed 60 centimetres (23.62 inches) in height. They can be also filled with clay, using for each frame 15 to 20 kilog. (33 to 44 lbs.). The stirring must be con- tinued until the crutch draws furrows, and upon the surface partly dry spots make tbeir appearance. Sometimes a solu- tion of potash is stirred into the frames, i. e., to 200 kilog. (MO lbs.) add 15 to 20 kilog. solution of 20° B., which makes the same very plastic. THE FABRICATION OF SOAPS. 327 Soluble Glass Soap {Silicated Soap). — The manufacture of soluble glass soap became a real necessity when, some years ago, rosin became so expensive on account of the war, that it could no longer be used for making soaps, and manufacturers were compelled to substitute other ingredients. The directions for making this soap vary, principally as to the quantity of soluble glass which is to be incorporated into a soap, and which is from 25 to 60 per cent. The method of manufacture consists in adding to the hot soap paste the desired quantity of soluble glass, which must be thoroughly stirred under, up to the moment of congealing. The soluble glass must also be saturated as much as possible with silicic acid, because a salt wliich is poor in silicic acid combines but in small proportions witli tlie soap. This soluble glass soap, when made with unbleached palm oil, attains a yellowish color. It often contains 60 per cent, of soluble glass, and has a tolerable consistency, is not stickj^ like rosin soap, is free from the disagreeable smell of the latter, and foams like common soaps. It is deserving of especial mention that these soaps are frequently sold for rosin soaps, although they contain no trace of rosin. The crutching machines illustrated elsewhere are used for the mechanical admixture of the soluble glass and other tilling. Silicated soaps are also a numerous class of soaps now found in all markets under a great variety of names, as sand, crys- tal, diamond, etc. They are simply a common soap usually containing rosin, as that appears, by its tenacious consistency, to have the power to best hold their heavy materials. We give several processes. Gossage's Process. — This method consists in the mechanical mixture of soluble glass with the soap paste. The soluble glass is a thick, viscid liquor, made by fusing together, in a reverberatory furnace, 9 parts of 50 per cent, soda ash, with eleven parts of clean sand, or powdered quartz, for hard soaps ; or equal weights of dry pearlash and sand, for soft soaps. When the mixture has combined, it is drawn off into moulds, quenched with water, ground in the eccentric mill, and boiled with alkaline water. The solution, when com- 328 TECHNICAL TREATISE ON SOAP AND CANDLES. plete, is next evaporated until it reaches 49° B. It is then ready to be mixed with the soap paste in the pan, and just as it has reached the condition in which it is generally trans- ferred into the frames. The temperature of both glass and soap paste should be about 71.1° C. (160° F.) at the moment of mixing, which must be thorough, to promote perfect homogeneity of the soap paste. This is accomplished by machinery described below, or with the crutching machine. When the mixture has cooled to 65.5° C. (150° F.) it is put into the frames and again stirred with the crutch until it begins to stiffen. Rosin soap which is to be treated by this process may contain rosin in as large proportions as one to two of fatty matters. The solution of glass must, for this soap, mark 51° B, , and be added to the paste when it is "fitted" and ready to be "framed." The apparatus referred to consists of a circular tub or ves- sel (Fig. 59), marked A in the drawings hereunto annexed, having the shape of an inverted cone, and an internal diameter of about two feet two inches at its lower part, and three feet six inches at its upper part, and a depth of about six feet. Adapted to this vessel is a central upright shaft, marked B in the drawings hereunto annexed, supported by a foot-step C, fixed to the bottom of the tub or vessel, and by a journal D, adapted to a metallic bridge-piece E, which is fixed over the tub or vessel, and secured by screws-bolts to the sides thereof. A bevelled cog-wheel to the upper part of the said upright shaft, and a horizontal shaft, supported by suitable bearings attached to the said tub or vessel, and on such horizontal shaft another bevelled cog-wheel in such manner that its cogs will work in gear with the cogs of the bevelled wheel on the said upright shaft. A driving pulley on the said horizontal shaft, runs by means of a band passing around such driving pulley, also around another driving pulley, which is caused to revolve by some mechanical power, which com- municates a revolving motion to the driving pulley on the said horizontal shaft, and through this to the bevelled w^heels and upright shaft. The speeds and diameters of the pulleys • THE FABRICATION OF SOAPS. 329 and wheels emploj-ed, are so that the said upright shaft may be caused to make from sixty to eighty revolutions per min- ute. Fixed on the said upright shaft is a closed tub or vessel (marked F, in Fig. 59, 1), which said tub or vessel is of such diameter as to admit of its being placed in the larger but or vessel A, and to leave a space of about two inches be- tween the said two vessels at their lower part, and a space of about six inches at their upper part. Attached to the out- side of such inner tub or vessel (by means of screws or other- wise) are a number of projecting blades marked I I, made by preference of sheet-iron, of such length as to approach within about half an inch of the inside of the larger tub or vessel A. G is a spout, having a movable stopper H, to the lower part of the vessel A, through which to run off the Fig. 59. 1. 2. contents of the vessel. In place of fixing a smaller tub or vessel on the upright shaft B, on which to attach projecting blades, can be attached projecting blades to the said shaft as shown in Fig. 59, 2. When this arrangement is adopted, other projecting blades, marked K K, are attached to the inside of the vessel A, which projecting blades, K K, are so placed as to admit of the blades I I revolving between them, 330 TECHNICAL TREATISE ON SOAP AND CANDLES. as shown in Fig. 59, 2. When about to use this apparatus for the production of compound soap by mixing genuine soap with viscous solution of soluble glass, it is well to ascertain previously the highest temperature at which the mixture of such genuine soap, with the proportion of the vis- cous solution employed, will become too thick to admit of its flowing from such mixing apparatus. It is then preferable to make a preparatory mixing, by means of paddles or crutches, of the genuine soap with the viscous solution employed, in such a tub or vessel as will contain about half a ton of soap, adding the soap and viscous solution at such temperatures as will yield a mixture, having a mean temperature about ten degrees higher than the previously ascertained tempera- ture hereinbefore referred to. Then transfer the soap, which has undergone a preparatory mixing, into this apparatus, and cause rapid revolving motion to be given to its vertical shaft, which communicates corresponding motion to its pro- jecting arms or blades. Then withdraw the sliding stopper of the said spout to such extent as to allow the compound soap, in the state of perfect mixture, to flow from the mix- ing apparatus, and then put further quantities of genuine soap and viscous solution of soluble glass, which have under- gone a preparatory mixing, as hereinbefore described, into the said mixing apparatus. The mixed compound soap pro- duced is conveyed to the ordinary 'frames' in which it be- comes solid by cooling. In mixing viscous solution of soluble glass with genuine soap (whether such mixing may be sub- sequently completed by ' crutching' in frames or by means of the improved mixing apparatus), it is best to commence such mixing by adding a portion of such solution at a specific gravity of about 1.300, and to add the remaining portions required for the mixing at increasing specific gravities, so that the average specific gravit}^ of the whole solu- tion used may be equal to that which has been found (by previous trials) to be suitable to yield a compound soap of proper hardness when using a genuine soap of the composi- tion employed. When it is desired to })roduce a compound soap, having less detergent power than the compound soaps THE FABRICATION OF SOAPS. 331 obtained by mixing genuine soaps of ordinary qualit}^ with solution of soluble glass, let a portion of the alkali con- tained in such solution be combined with rosin or with fatty or oily acids obtained from tallow or oil by well-known pro- cesses. Such combinations are effected by boiling rosin or fatty or oily acids with solution of soluble glass, in the same manner as rosin and other soap-making materials are com- bined with alkali in the ordinary process of soap-making, and we use the product thus obtained to mix with genuine soap, and thus produce less detergent compound soap con- taining solution of soluble glass. Dunn's Silicic Soap. — In this process, the silicic matter is made to combine with the soap under pressure. Mr. Dunn, the author, says that it is as applicable to all other kinds of soap, even where silica is not an ingredient; and with the advantage over the usual mode of boiling soap materials, of effecting a more perfect union of the ingredients, in a shorter time, with less waste, and at a diminution of expense. Fig. 60. Take the materials for soap in the usual proportions, say for yellow soap, 7 cwt. of tallow, 3 cwt. palm oil, 8 cvvt. of rosin, and 140 to 150 gallons caustic soda lyes, 21° B., and place the whole in a steam boiler, such as is represented by TECHNICAL TREATISE ON SOAP AND CANDLES. Fig. 60. The boiler should be furnished with a man-hole, safety valve, and all the ordinary appendages of such an apparatus, with a thermometer plunged into a mercury chamber. There should be a feed pipe as at A, and a dis- charge pipe as at C, through which the soap may be dis- charged into a pan or frame as at D. The fire being kindled, the pressure on the valve should be such as to allow the temperature in the boiler to rise gradually to about 154.4° C. (310° F.). When it has remained at this height for about an hour, the ingredients may be discharged from the boiler into the pan or frame, and allowed to cool down, when the process of saponification will be found to have taken place. When silica is to be added, it must be put through a pre- paratory process, which is as follows: Crushed flint or quartz mixed with caustic soda or potash lye, in the proportion of one cwt. of silica to 100 gallons of lye of 21° B., is placed in a steam-tight boiler, or apparatus, such as above described, and the whole heated to a temperature of about 154.4° C. (310° F.), and kept at this pressure for about three or four hours, when it is discharged and cooled down, and a silicate is thus obtained, of potash or soda, according to which alkali has been used in solution ; and this solution is added in the proper percentage to the soap paste in the pan, after the saponification is complete, and before it has cooled down. Gui^-pifs Process. — To the above invention, in its applica- tion to ordinary or silicic soaps, a gentleman by the name of Guppy has proposed certain improvements, such as the in- troduction of stronger lyes and in separate portions into the boiler or steam-tight vessel, to be injected from a reservoir by a force-pump, properly appropriated and arranged, and in connection with both the boiler and reservoir. For every 24 pounds of tallow, 10 pints caustic soda lye, of 17° B., are added to the boiler, and the mixture heated to 148.9° C. (300° F.); and by means of a force-pump about 30 pints of soda lye, of 25° B,, to every 24 pounds of tallow, are then injected or thrown in, and the mixture maintained for two hours at 148.9° to 154.4° C. (300° to 310° F.). At the end of that time the saponification will be complete, a fact deter- THE FABRICATION OF SOAPS. 333 minable by drawing out samples through a try-cock fitted in the boiler for the purpose. The stronger lyes are kept at hand in a special reservoir, and from thence drawn by the pump, through pipes suitably connected, and forced in through other tubes. The advantages gained by this mode of opera- ting seem to be a saving of time and fuel; but whether these expectations are to be realized in practice, must be determined by experiment. Davis's Alkalumino Silicic Soap. — This soap is a patent in- vention, by which, as the patentee says, the cost of the soap is diminished, whilst its detergent and normal properties, instead of being impaired, are much improved. The plan consists of a combination of fuller's earth, pipe-clay and pearl- ash, with the soap as soon as it is poured into the cooling frames. When pearlash or soda is employed, it is necessary that it should be calcined and then ground together with the clay and earth so as to form as intimate a mixture as possible. In this mixed state it is incorporated with the soap. To every 126 pounds of soap already made and in paste, take 56 pounds of fuller's earth, slaked or dried, 56 pounds of dried pipe-clay, and 112 pounds of calcined soda or pearl-ash, all reduced to powder, sieved as finely as possible, and tho- roughly incorporate the whole by stirring or crutching. The mixing must be very perfect, and done as quickly as possible before the paste soap cools. To obviate any objection against the use of this soap for washing white linens, a modification of the above process is proposed, by which the use of fuller's earth is entirely omitted, leaving the proportions then for every 120 pounds of soap, 112 pounds of dried pipe-clay, and 96 pounds of calcined alkali. A soap produced by these quan- tities, the patentee says, is useful for general purposes at sea, and for washing white linens in salt water. For wasliing white linens in fresh water, the process is still further modified by using 112 pounds of soap, 28 pounds of dried pipe-clay, and 36 pounds of calcined soda; and as a toilet soap, either for fresh or salt w^ater, by employing 28 pounds of fuller's earth, slaked or dried, and 20 pounds of calcined soda to 112 pounds of perfumed curd soap. 334 TECHNICAL TREATISE ON SOAP AND CANDLES. Sand Soap is made with the admixture of fine sand to the amount of 20 or 25 per cent, in weight, which is best added to the hot soap when in the frames, being crutched in until the soap is too stiff to stir. Quartz Soap is also known by various names, as diamond soap, crystal soap, etc., and is made by crutching into the still hot soap in the frames about 20 per cent, of finely pow- dered quartz or spar, as in the manner for sand soap. Poncein Soap is also a useful detergent much used for cleaning the dirty hands of those engaged in mechanical trades. The process is the same as for sand soap, using a very finely powdered pumice stone. This soap is also made of very select materials, and used as a toilet soap with the requisite amount of perfume. For the mechanical admixture of these various substances with soap there are a number of new crutching machines that greatly facilitate the filling of all soaps ; we have illus- trated the one lately invented by Mr. Stephen Strunz. Greaves or Crackling Soap. — For the manufacture of this soap, we use the oftals and remnants of rendered tallow, hogs' lard, etc. When for the melting of the tallow sulphuric acid has been employed, the greaves must at first be washed out with water. For 100 kilog. (220 lbs.) greaves place 100 to 110 kilog. (220 to 242 lbs.) of 20° B. soda-lye in the kettle, which is to be heated to boiling, and leave this mass to rest for 48 hours, during which time the greaves dissolve into a gelatinous mass. The boiling is then continued until it becomes pasty ; add cocoa-nut oil with the requisite alkali to it, and boil until it becomes a paste soap ; after the dis- appearance of froth, or, if this takes too long, and the soap proves to be firm, it is run into the frames, after previously skimming off the froth. Bone Soap. — By this name we designate a mixture of com- mon soap, for instance tallow, palm-oil, or rosin soap, which has by soda-lye been loosened of decomposed ani malic gelatinous matter or bones, and has been so treated that a solid mass (soap) is produced. With regard to the soap THE FABRICATION OF SOAPS. 335 made of bones, this can be performed by two difterent methods. According to the one, the bones are manipulated with con- centrated muriatic acid, and they need not be previously broken up. This acid dissolves the carbonate and phosphate of lime, while it leaves the animal gluten as a strong trans- parent mass, in the form of the bones. By repeated washing it is entirely freed from the muriatic acid; this gluten is added to either of the above-named fats during the process of saponification. According to the other method the entire mass of bones is embodied with the soap, and not the jelly or gluten alone. For this purpose, the previously bruised bones are softened by pouring a strong caustic lye over them in an iron vessel. The lye dissolves the gluten, and leaves' the earthy paste as a residue, in the shape of a powder. After a period of two or three weeks, the bones are perfectly loosened and are easily re- duced to a pulp. The finely ground mixture is now boiled in the kettle for one hour, in order to saponify with this caustic liquid the fat, for instance cocoa-nut oil, in the same manner as is done with common lye. Such an article was formerly produced and sold under the name "Liverpool Poorman's Soap," and much used. By the presence of the gluten and the bone clay, the soap loses but little of its firmness and its property of foaming. It shows, however, nothing of that which is termed "^ram," and it appears, when cut, of dark- brown color, and is not as transparent as the rosin soaps. Other Filled Soaps. — By a change of the proportions between cocoa-nut oil and the other fats and rosin, and these again among themselves, and by applying a solution of salt-soda or potash for the filling of the soaps, the number of the variety of these filled soaps may be multiplied indefinitely; but all of them resemble each other in this one particular, that of having more the interest of the manufVicturers at heart than that of the consumers, and, to say it plainly, they are in- ferior and only apparently cheap. The following are a few more formulae for making these soaps: — 336 TECHNICAL TREATISE ON SOAP AND CANDLES. I. Cocoa-nut oil Palm-kernel oil . . . . Crude palm oil ... . Tallow Caustic soda-lye 28° B. . Solution of potash 25° B. Salt solution 25° B. . . . II. Cocoa-nut oil , . . . Tallow Caustic soda-lye 20^ B. . Solution of potash 30O B. Salt solution 250 B. . . . Ill Cocoa-nut oil Caustic soda-lye 250 B. . Solution of potash 120 B. Solution of potash 20o B. Salt solution 30o B. . IV. Cocoa-nut oil Caustic soda-lye 40o B. Solution of potash 30o B. Salt solution 25^ B. . . . Water . . . 2000 kilog. ( 4400 lbs.) 2000 " ( 4400 " ) 630 " ( 1386 " ) 370 " ( 814 " ) 5350 " (11,770 " ) 350 " ( 770 " ) 5200 " (11,440 " ) 1000 kilog. (22,000 lbs.) 500 " ( 1100 " ) 960 " ( 2112 " ) 360 " ( 792 " ) 1680 " ( 3696 " ) 2720 kilog. ( 5984 lbs.) 750 ( 1650 " ) 1760 " ( 3872 " ) 960 " ( 2112 " ) 2000 " ( 4400 " ) 1680 kilog. ( 3696 lbs.) 600 " ( 1323 ) 800 " ( 660 ) 860 " ( 1892 " ) 630 " ( 1386 " ) NEW SOAPS BY NEW METHODS. 337 SECTION XY. NEW SOAPS BY NEW METHODS. Innumerable new soaps by new processes are constantly seeking notice, and for many of which patents are granted nnore for their novelty than for their intrinsic merit, for often in their composition they set at defiance all chemical rules and are worse than useless. There are, however, many others that being based on science may be considered as im- provements, and have a useful application in our art. As we have said, there are many other means of saponifi- cation besides soda and potash, and these have been utilized to decompose the neutral fats, for various uses in the art. Yet, in as far as a detersive soap is concerned, they have not been successful in practice. But for making the stearic acid for candles many of these new processes have found a practi- cal use. Thus, we have the saponification by lime, by a small portiofi of lime assisted by surcharged steam, l>y water and distillation, by water under high pressure, by sulphuric acid, by sulphate of soda, etc. When we come to treat of the manufacture of candles these processes will receive that attention which they deserve. Yet, there are some of these processes that here claim our attention and are of interest. Saponification of Fats by means of Carbonated Alkalies,—^ Under ordinary conditions, the carbonated alkalies do not possess the power to separate the glyceryl oxide from the neutral fats, and to combine with the sebacic acids. By an increased temperature, however, a lively reaction ensues, whereby the carbonated alkali does lose its carbonate, while the sebacic acid and the base combine for a real soap. When, for instance, a mixture of 100 parts tallow and 22 to 25 parts anhydrous carbonate of soda is gradually heated, vigorous 22 338 TECHNICAL TREATISE ON SOAP AND CANDLES. action takes place, at 260^ C. (500^ F.), and the mixture becomes much puffed up, in consequence of a great develop- ment of carbonic acid gas. Towards the end, the tempera- ture must be somewhat increased, in order to decompose the last portions of neutral fat. After a few hours a semi-liquid, yellowish mass is obtained, which, during its cooling off, becomes more consistent. In water it dissolves gradually to an opalescent liquid, which in every respect acts like a solution of common soap. The car- bonated alkalies, as also culinary salt, cause therein a separa- tion of soda-soap, which collects upon the surface of the liquid. Saponificaiion of Fats by Sulphuretted Alkalies. — This method has been proposed by Pelouze. Despite this authority, we have not been able to discover in this new method any special advantage; for although an equivalent of sulphide of so- dium, where this, like the soda, is produced on a large scale, may be cheaper than an equivalent of caustic soda, there are nevertheless other inconveniences which are much greater, since the alkalies form in themselves a proportionately cheap ingredient of the soap, and there is therefore caused, by the cheaper sulphide of sodium, no essential reduction in the prices of the soaps. In the practical performance, the fats are treated in ex- actly the same manner with a solution of sulphide of sodium, as the common method with soda-lye. The saponification ensues by means of sulphide of sodium very quickly and under a development of sulphuretted hydrogen gas, which, on account of its very disagreeable smell and its poisonous properties, must be made harmless. Tliis may be done most advantageously by burning it, and the sulphurous acid which is produced by the process of burning may be applied in the fabrication of sulphuric acid. But this presupposes a very extensive and complicated business, such as would hardly he suitable for many soap-manufactories. Moreover, according to Dullo, the soap made with sul[)hide of sodium retains a had smell, which cannot be removed, and finally the manufacture of white soaps with sulphide of sodium would become en- NEW SOAPS BY NEW METHODS. 339 tirely impossible, on account of the unavoidable admixture of coloring substances. ' Tke Process of Mege Mouries — This process requires a par- ticular notice here, as when first made known it attracted great attention, which has however subsided, though it has resulted in suggestions which have been utilized particularly in France, especially for making the sebacic acids in the manufacture of candles. He found that the neutral fats in the oil seeds during germination, as well as in the animal organism during life, are in the condition of movable globules, which ofifer a great surface to the action of reagents. In this globular state, fats exhibit some peculiar properties of which we shall only notice such as are interesting to the soap-maker. Fat, as for example tallow, in the ordinary state, becomes rancid by exposure to the air; in the globular state, in a milky form, or in a dry state, or in the form of a white powder, it remains unaltered any length of time. In practice it is obtained by mixing melted tallow at 45° C. (113° F.) with water at the same temperature, holding in solution 5 to 10 per cent, of soap. It is difiicult to combine tallow, in its ordinary state, with hot salty caustic lyes ; but in the globular state the lye is immediately absorbed in ])r()portions varying with the temperature. Each globule, as it is attacked by the alkali, quickly gives up its glycerine, and in a, very short time each globule of fat is transformed into a globule of perfect soap. This result is obtained in two or three hours. These saponi- fied globules heated to 60° C. (140° F.) give up the excess of lye with which they are charged, and retain only water sufiicient for ordinary soap. They become eventually trans- parent, and by stirring form a layer of melted soap above the lye. The saponification is so complete, that to prepare commercial stearic acid, it is only necessary to add a cor- responding quantity of diluted sulphuric ncid, and the fatty acids may be separated from the solution of sulphate of soda. By melting with steam, crystallizing and pressing when cold, a conmiercial stearic acid is obtained perfectly pure, melting at from 57.7° to 58.8^ C. (136^ to 138^ F.), while the oleic acid flows off nearly colorless. This latter acid is of a 340 TECHNICAL TREATISE ON SOAP AND CANDLES. better quality than many fixed oils, and more useful to manu- facture white soap of first quality either alone or mixed with some other fatty substances. By using it alone, it has only to be neutralized by weak lyes; the formation of the soap takes place immediate!}^, and it can be melted at once. If mixed with some other fat, this fat has to be transformed into the globular state and the saponification is eft'ected in, six hours; and in twenty-four hours a soap may be prepared which is as neutral and nearly as good as the best olive oil soap. Thus not only is time saved, but there is no loss of fat as in the ordinary process of boiling soap. Knapp attributes the great efficacy of the globular state not so much to the globular form as to the microscopic size of the tallow globules, which may be attacked to their centre by the lye, while a large lump of tallow, under the same circumstances, would soon be coated with a stratum of soap of a thickness which would render it impossible to penetrate it. As to the saponification in the kettle, there is, strictly speaking, only an emulsion of fat obtained, a homogeneous milky mass, formed by the union of the melted tallow with the lye; moreover, soap is simultaneously produced by the first contact of these substances. This emulsion, after stand- ing a few hours in the cold, becomes gradually saponitied. It might be expected that the process would be more rapid under the influence of heat and agitation, but this is not the case, and the hypothesis is that, in the boiling, each fat glob- ule is immediately enveloped in a coating of stearate of soda, which protects the nucleus from further saponification. In like manner, and upon the same principle, heated soap bub- bles are only denuded of their gelatinous coating, and the mass becomes a thickish soap solution rather than a chemical com- pound. Again, concentrated soap in the heated mass will retain a considerable quantity of fat in solution, consequently dimin- ishing the action of the alkali. This may be remedied by the addition of a middling strong lye ; but in any case, cool- ing and quiet are found to promote the combination of fat with alkalies, after having been heated for a sufficient length NEW SOAPS BY NEW METHODS. 341 of time to effect as minute a division of the molecules as possible in the characteristic form of an emulsion. For this jturpose a temperature greater than 48.9° C. (120° F.) is not required. Perutz affirms that the facts discovered by Mege Mouries have been successfully applied in soap making. " To every ra- tional nanufacturer," he says, "it must be known that sapon- ification is produced with greater ease when the fat is stirred for about an hour under a slight heat — about 60° C. (140° F.) — with the so-called combination lye, and suffered to remain undisturbed for one night." As this mixture never reaches the boiling point, it follows that the globular emulsive state must be produced and saponification expedited. With the view of improving this discovery, and shorten- ing the time of boiling, Perutz proposes to add to the fat the whole quantity of lye necessary for the saponification, and then proceed according to Mege Mouries' plan, leaving the mixture quiet all night. Until now, soap boilers have not, at the beginning, added the entire quantity of lye required, because experience has shown that saponification is thereby rendered more difficult; but, on the other hand, it has also been ascertained that the saponification is more rapidly ef- fected at a low temperature. Whether this process of fabri- cating soap, as Mege Mouries asserts, is essentially cheaper than the usual method, could only be decided by experiment on a large scale, but that, if we work only with pure mate- rials, a very beautiful pure soap is obtained, we have satisfied ourselves by experiments. Methods of M. D'Arcet. — These suggestions have an interest here as they throw some light on our subject and have a scien- tific basis, and may be a guide to new methods. He remarks, there are two very distinct operations in the fabrication of soaps; the first has for its object to chemically combine the alkali with the fatty bodies, while in the second, the formed eoap must be made to contain the j)roper quantity of water, by the processes of liquefaction or mottling if a white soap containing 50 per cent, of water, or a marl)led soap contain- ing only 33 per cent, is to be manufactured. 342 TECHNICAL TREATISE ON SOAP AND CANDLES. The first operation, called saponification, presents numer- ous (lifiiculties; it is important to add to the fatty body the necessary caustic lye, little by little, and of a proper density, so that the soap when formed will not dissolve in the liquor, nor be transformed into too large and too hard grains. If the soap dissolves in the boiling lye, the whole will soon form a mass, the soap will burn at the bottom of the kettle, and the operation thus conducted will be impossible. If, on the contrary, the saponification is effected by using too much of, or too concentrated a lye, the ebullition will with diffi- culty bring about a sufficient contact between the fatty bodies and the lye, which will retard the saponification, and in- crease the expense in fuel, work, etc. The necessity of keeping the soap during all the time of the saponification in a state of half solution in the boiling lye, presents great difficulties of execution, and renders the operation much longer and too costly. The saponification being finished, the soap is boiled down, that is, until the lye on which the soap floats is concentrated by evaporation to the density at which the grain contains just the necessary quantity of water. It is thus, that after the saponification, the soap contains more than 50 per cent, of water, while towards the end of the coction the grain of soap contains only about 16 per cent. This operation has for its principal object to leave in the grain of the soap only the proper quantity of lye, but it pre- sents at the same time the advantage of completing the saponification, if this first operation has not already been completely effected, and besides, of rendering the soap homo- geneous in all its parts. After the coction of the soap comes its liquefaction, if it is to be converted into white, or its mottling, if it is to be manufactured into marbled soap. The liquefaction or fitting has for its object to soften the grain of the soap, to introduce into it as much as 55 per cent, of water, instead of the 16 per cent, that the coction has left in it, to render the paste nearly liquid, and to favor thus, during the cooling of the soap in the frame, the precipi- tation of all foreign substances that the grains may contain, NEW SOAPS BY NEW METHODS. which contributes to bleach this kind of soap, and to give it much homogeneity^, and a great degree of purity. As for the marbling of the soap, it might be improved. It is true that soap has been marbled at Marseilles for many years, and when the art of soap-making is well understood it strikes me that since the origin of the art, the manufacturers have obtained soaps more or less well marbled. At the time of the saponification, the iron which is held in solution in the lye of sulphuretted soda combines with the fatty bodies and the iron of the kettle, and forms a soap of iron, and the manufacturer is often obliged to add some green vitriol; on the other hand, the alumina and lime con- tained in the lyes are also converted into soaps of alumina and lime, and these three soaps dissolve in the nearly liquid mixture of oil and soap submitted to the saponification. Later, when the saponification is finished, and even at the end of the coction, the soaps of iron, lime, and alumina are so uniformly divided in the mass, that it may be said that they are in a state of true solution. They color it a gray- ish-blue in all its parts, if the lye on which the soap boils has not ceased to be sulphuretted; and the soap, suddenly cooled and cut into thin plates, looks then like damp slate. The soap, being finished and colored as we have just stated, is too dry on account of the high density of the boiling lyes on which it floats. It must be brought back to contain at the most 36 per cent, of water. This is done by the operation called mottling, which has for its object to swell and soften the grains of soap. (See Marseilles Soap.) When this is done, the mass of soap ought to be evenly penetrated with water throughout; the grains must be soft and voluminous, hardly separated from the warm lye on which they float, and the greater part of which is interposed between the grains of soap properly softened. The soap is then run into the frame, and the operation is finished. Let us see what takes place in the frame. If the soap is run into a thin dish, and if a portion of the soap, taken at the time it is run into the frame, is quickly cooled down, a soap uniformly colored blue like damp slate 344 TECHNICAL TREATISE ON SOAP AND CANDLES. is obtained ; the soap then is not marbled at the time; the mixture of the soaps of iron, alumina, and lime, colored by sulphuretted lye, is still in solution in the mass, but by de- grees, and by the progressive cooling, the soaps of alumina and lime, being less soluble and less fusible than the soap of soda, separate and divide in the mass of soap, which is white for the greater portion, but is streaked with strongly colored runs, which are formed by those portions of the soap in which has concentrated the mixture of the soaps of iron, lime, and alu- mina, colored blue by the action of the sulphuretted lye. The marbling of the soap is not an effect produced by a simple mechanical mixture of two soaps, one of which is col- ored ; the cause which controls its formation belongs to a more elevated order, for the separation of soaps having different bases, during the cooling in the frame, is effected by the ac- tion of that force which separates alloys at the time of their solidification, the effect of which is known by the name of liquation ^'dv^ii to which we attribute the formation of granites, etc., and in genera), that of all the primitive crystallized rocks. In the fabrication of the bar soap by using sulphuretted lyes, a white soap is obtained, because the liquefaction is carried to the point where the paste is fluid enough to permit the whole of the blue colored soaps of iron, alumina, and lime being heavier to separate completely and fall to the bottom of the kettle. The mixture of soaps of iron, alumina, and lime, dissolved in ordinary soap, and colored by the action of the sulphuretted lye, quickly loses its color in the air under the influer)ce of water and the excess of alkali the soap contai)is; the blue color by disappearing leaves a yellow trace, so much darker wdien there is more iron in thesoap, which is d ne to this, that the mixture of the soaps of iron, alumina, lime, and soda, being desulphuretted, is colored only by the iron soap which has an ochreous yellow color. These yellow lines are not wanted by the consumer, and they result in a loss to the soap-maker. It is required that the soap shall have a marbling of a line NEW SOAPS BY NEW METHODS. 345 dark blue, and that the part of the soap thus shaded shall become red in the air, by absorption of oxygen. In conclusion, for the marbling of soap, the following con- ditions have to be fulfilled : — 1. To have in the mass the quantity of iron soap necessary to give the required degree of coloration. 2. That the iron soap shall be combined with a suiRcient quantity of soap of lime and alumina, so as to produce a transparent, homogeneous, and properly shaded marbling. 3. To have all the time, but especially at the end of the coction, a proper excess of sulphuretted lye in contact with the soap. 4. That the cooling in the frame is managed in such a manner as to produce the required marbling. Instead of saponifying with weak lyes, and in deep and conical kettles, I operate in large sheet-iron vats being three times as long as they are wide, heated below only by the waste heat of the ordinary kettles, and I use strong caustic lyes containing a little common salt, instead of using weak lyes and gradually increasing their density. The heat communicated to the vats is not above 50^ C. (122° F.), and may be sufficient only to keep the fatty body perfectly liquid. Instead of stirring the mixture by ebullition, I use a mechanical stirrer conveniently fixed, which multiplies, more economically than the ebullition, the points of contact be- tween the fatty body and the lye. The stirring is continued until the chemical combination which constitutes the soap is completed, which is ascertained l)y the strength of the lye, which must remain the same, and the complete solubility of the soap in boiling water. The soap is then converted into small round grains without adherency, and swimming on the excess of caustic lye; the saponification is then finished. The vat in which this operation takes place has its edges elevated about three feet above the large, deep, and conical kettle in which the coction is finished. A wooden gutter is used to transfer the soap from the vat into the kettle; the old lye, remaining in the bottom of the vat, is drawn ofl:*, and 346 TECHNICAL TREATISE ON SOAP AND CANDLES. a new operation may be begun. As for the soap in grains which has been introduced into the hirge kettle with new lye, its saponification is completed, and the coction is con- ducted as usual; it is also converted into white or marbled soap. To manufacture white soap, it is not necessary to add coloring matter ; but for the marbled soap, the mass must be colored in the vat at the beginning of the saponification. This coloration is managed as follows: — In a kettle, I prepare a mixture of soaps of alumina, lime, and lead, by decomposing in the order indicated below, by an excess of soap dissolved in water, solutions of acetate of lead, chloride of calcium, and alum. The mixture obtained is kept under water, and is used to color marbled soap, which is done by adding at the beginning of the operation enough of the mixture to give to the mass the proper shade. The sulphuretted lye used in the saponification quickly gives to the soap of lead the blackish-blue color necessary to color the marbling, and consequentlj^, it is easy by diflferent trials to obtain the required shade. What we have said of the marbling of soap, proves that there is a necessary relation between the beauty or the per- fection of the marbling of the soap, and the quantity of water it contains. A well-marbled soap cannot contain more than 33 to 34 per cent, of water, while white soap may re- ceive more without losing its good appearance, and it is even whiter when it contains more water. To manufacture white soap containing, like the marbled soap, 33 per cent, of water, lyes free from sulphides must be used, which may increase the expense of fabrication. We have noticed this fact, because it is generally believed that the preference given to marbled soap is ridiculous and without foundation, while on the contrary, this preference is the result of a long ex- perience. Soaps by Steam Pressure. In the processes for making soap by pressure and by agita- tion, using carbonated alkalies, we would call attention to NEW SOAPS BY NEW METHODS. 347 848 TECHNICAL TREATISE ON SOAP AND CANDLES. the two together, for which they took out a patent in 1865. Their process consists in agitating the saponifiable materials with caustic or carbonated alkalies in solution in water in a closed vessel while under heat and pressure, in such a manner as to cause a thorough mixing of the fats with the alkaline solution, and producing an instantaneous combination of the fatty acids with the base of the alkaline solution. We suppose a quantity of fatty matter inclosed in a vessel with a solution of carbonate of soda in water, and heat applied to produce a pressure of 220 to 280 pounds per square inch, and atemperatureof 176.6^ to 204.4° C. (350° to 400° F.). A combination between the fatty acids and the soda of the solution will take place only at the upper surface of the solu- tion when in contact with the under surface of the grease, the heavy lye occupying the lower part of the vessel, and soap will only be produced when the fat and alkali unite. If we now agitate in such a manner as to stir together and thoroughly mix the contents of the vessel, the whole will be instantly converted into a homogeneous and even quality of soap. It is advisable to use no more water than is wanted in the soap. The inventors use a boiler or cylinder similar in shape to a plain cylinder steam boiler, resting horizontally and heated in any convenient manner; one or both heads of the cylin- der is made so as to be removable, and is about the full size of the inner diameter of the cylinder, so as to admit of the insertion of a revolving shaft a a a (Fig. 61), which should be as long as the cylinder itself. The bearings of this shaft should be in the centre of the cylinder, and either or both ends worked through a stuffing box for the conveni- ence of applying to the pulley A, power to revolve the shaft. On the shaft are fastened arms g with floats /, or stirrers, ex- tending nearly to the sides of the cylinder; the arms, floats, or iigitators on one side of the shaft when revolved carry the fat down into the alkali, wiiile the agitators on the other side carry the alkali up into the fat, thus, while under heat and pressure, thoroughly mixing the whole and causing the conversion of the wdiole contents of the vessel instantly into NEW SOAPS BY NEW METHODS. 349 a uniform, even, and good quality of soap. At the fire end of the cylinder are placed two safety valves, one on the top of the cylinder, the other on an outlet pipe inserted in the head of the cylinder ; they also use a mercury bath A*, of about four inches in length of gas pipe, and which is screwed into the boiler or cylinder in any convenient place for the insertion of the thermometer bulb. At the opposite end of the cylinder is an opening r, for the insertion of a supply pipe ; at the fire end is also an opening ^, for the insertion of a second outlet pipe, and which is intended to be used only when it is desired to draw off the whole contents of the cyl- inder. The contents of the cylinder when operated upon should be subjected to a pressure of about 220 to 280 lbs. per square inch, and under a heat of about 176.6^ to 201.4° C. (350° to 400° F. ). When the shaft is revolved, all of the ingredients in every part of the cylinder are immediately and thorouglily mixed, and the same will take place by means of any other revolv- ing machinery. Perfect saponification is at once effected, and the soap produced is of uniform and good quality. When the machinery is first put in operation, it is necessary to allow some carbonic acid gas to escape by one of the safety valves, if carbonate of soda is used, in order to prevent un- due pressure by the liberation of the carbonic acid when combination of the fatty acids with the alkali takes place. If any of the liquids be allowed to escape before the tem- perature reaches 162.7° to 190.5° 0. (325° to 375° F.), they should be returned to the cylinder. The safety valve on the outlet pipe may be so loaded as to allow an escape of soap at a pressure of 250 to 270 lbs., and a quantity of lye and oil may be pumped in at the oppo- site end, the agitation by the revolving shaft being still kept up, and thus a continual stream of soap is kept u|) as long as the feeding is continued. The product may then l)e pre- pared for market by the cooling, moulding, and cutting pro- cesses in ordinary use. By this process the soap is made in less than one hour from the time the ingredients are introduced into the boiler, 350 TECHNICAL TREATISE ON SOAP AND CANDLES. but a uniform and thorough saponification is obtained at the instant that the heat and pressure arrive at the required degree, be the time long or short; if this degree is reached in five minutes, the soap is made. The inventors use from 30 to 33 lbs. of carbonate of soda at — 48°, and 100 lbs. water to 100 lbs. of lard, tallow, or oil ; 27 lbs. of carbonate will make a neutral soap for soft water. The product obtained is 200 lbs. of soap for every 100 lbs. of grease. Any kind of soap can be made by this process; soft soap is prepared with the same rapidity as an}^ other, and is much more perfect and requires a less quantity of potash than by the open kettle process; four lbs. of potash being required for one barrel. To conclude, we would state that the advantages claimed for this process are: — 1. The rapidity of manufacture. 2. The improvement in quality. 3. The increased quantity. 4. Economy in labor. 5. Saving of fuel. 6. The use of clieaper material. 7. The saponification of all the grease. 8. The uniform certainty of the results. 9. The saving of the valuable property of glycerine which greatly improves the quality of the soap. 10. The ability to use alkaline salts instead of caustic lye, obviating the necessity of using chloride of sodium, which is required by the common process, in order to get rid of the waste lye. Professor Dussauce examined some specimens of soap made by this process, and found them perfectly neutral, and entirely saponified, without a trace of carbonated alkali, and not con- taining as much water as soap made by the ordinary process. SOAP ANALYSIS. 851 SECTION XYI. SOAP ANALYSIS. There are few articles of industry or commerce that are subject to so much falsification as soap, and it is partly be- cause the public ignorantly wish a cheap one, hence there is always a desire to find a suitable and often an unsuitable substitute with which to adulterate it, to enhance the profits of unprincipled makers. There are many methods of analyzing and appraising soaps, but they are not so easy or simple that every one can per- form them with the necessary accuracy. Soaps differ accord- ing to their value in alkali and to their organic ingredients, i. e., fat and rosin. Thus in the valuation of soap we have to consider: 1st. Tlie contents of water ; 2d. The proportion of sebacic acids to the alkali ; 3d. The nature of the alkali and of the sebacic acid ; 4th. The intentional or unintentional admixture of foreign substances. Although the amount of water in a hard soap appears easily determined, it is nevertheless a somewhat difiicult matter. This is easily seen when we know that each part of a cake or bar of soap contains a different amount, the outer part being, denser than the centre, so a sample for testing should be a mixture of all parts to make an average. The sample obtained is to be scraped fine, the different parts uni^ formly mixed, and from this the quantity to be investigated weighed off; both operations, of mixing and weighing, must be carried out quickly so that the soap can neither absorb nor lose water. The sample, say about 10 grammes scraped soap, is placed in a small porcelain saucer, weighed, and placed over a water-bath and heated until the soap no longer loses in weight. At first the soap is left entirely untouched, and 352 TECHNICAL TREATISE ON SOAP AND CANDLES. only when it has passed from the liquid into the pasty state the lumps are pressed with a glass spatula which has pre- viously been weighed. If the two last weighings correspond, the soap is removed and weighed, and the loss is the weight of the water contained in the. soap. Determination of the Amount of Alkali, — For this purpose it is well to use the dry soap left b}^ the determination of the amount of water. This is placed in a glass flask, the porcelain saucer and glass spatula are repeatedly washed olF in strong alcohol, putting all the liquid of the rinsing opera- tion into the flask, then add from 50 to 60 cubic centimetres (1.69 to 2.03 fl. ozs.) of the strongest alcohol, the whole heated in a water-bath putting the stopper loosely on. The soap is dissolved, allowed to precipitate, and to cool off. The liquid, having cleared ofi:' perfectly, is decanted carefully into another larger flask. Pour over the residue some alcohol, let it settle, and operate as in the fi.rst case. The residue is then placed upon a filter and completely washed out with alcohol. The residue left on the filter consists principally of carbonate and sulphate of alkalies, carbonate of lime, and other mechanical admixtures. The residue is dissolved on the filter and with distilled water, washed out, when test the carbonate of alkali in the filtration, by alkalimetry, as also the sulphuric acid present, by chloride of barium in the liquid soured with muriatic acid. The sulphate of barium is placed upon a filter, washed out with distilled water, dried, calcined, and weighed. We calculate thus the sul- phuric acid present, respectively, in the sulphate of potash and the sulphate of soda: 116.5 parts sulphate of barium corre- spond to 40 parts of anhydrous sulphuric acid, 87.11 parts anhydrous sulphate of potash and 71 parts anhydrous sul- phate of soda. The liquid filtered oflT from the sulphate of barium is mixed for assaying the surplus addition of barium first with ammonia, then w^ith carbonate of ammonia, filtered and washed out. The filtered liquid is eva])orated in a small porcelain saucer until dry, and the muriate of ammonia ejected by calcination. The saucer is now placed upon a sensitive scale and balanced, emptying its co?itents without SOAP ANALYSIS. 353 loss into a 100 cubic centimetre (3.38 fl. ozs.) measuring flask, rinsing the saucer with water, drying it by warming, placing it again upon the scale, and b}^ additional weights causing it to balance. The weights placed on after deducting the calculated sulphate of potash found in the sulphuric acid, show the alka- lies present as chloride of potassium and chloride of sodium. We will designate this weight by A. To find herefrom the respective quantities of soda and potash, we determine the quantity of chloride in A, by dissolving the salt mixture to lOO cubic centimetres (3.38 fl. ozs.), then placing a certain part of this solution (10 to 20 cubic centimetres = 0.338 to 0.676 fl. oz.) in a white porcelain saucer, adding a few drops of neutral chromate of potassa, and then from a -^-q cubic centimetre graduated pipette so much standard nitrate of silver solution until the ensuing precipitate shows a reddish coloring. By determining, the chloride, the data for con- tinuing the calculation are given. We know now, 1, the weight A, and, 2, that of the chloride contained therein = C. If the two unknown quantities are designated chloride of potassa with x and chloride of sodium with y, there is X + y = A. I. The chloride of potassa contains the 0.47552 of its weight of chloride, the chloride of sodium the 0.60657 part of its weight of chloride. X parts chloride of potassa hence 0.47552 x parts chloride and X parts chloride of sodium hence 0.60657 y " " 0.47552 X + 0.60657 y = II. If we place of equation I. for x its value, to wit, x = A — y, and substitute it in the equation II., then we obtain : 0.47552 A + 0.13105 y = C, and herefrom ^ C — 0.47 552 A ^ 0.13105 ^ _ 0.60657 A — C 0.13105 From the figures thus found for the chloride of potassa and the chloride of sodium, we calculate the potash and the soda according to the proportions. 23 354 TECHNICAL TREATISE ON SOAP AND CANDLES. 74.56 parts chloride of potassa are = 47.11 parts potash and 58.45 " chloride of sodium = 31.00 " soda. These salts do not form a constituting ingredient of the soap, they are an intentional or accidental surplus present. The sulphuric acid is, in the first place, calculated as sulphate of potassium and a surplus as sulphate of sodium, the rest is carbonate of potassa or carbonate of soda. The alkaline chloride, and also the free caustic alkalies, are found in the alcoholic solution, and are determined in the following man- ner: This alcoholic solution is well and constantly shaken, with an accurately weighed quantity of bicarbonate of soda, or potash. By this process the caustic alkalies change into carbonates, which, as they are insoluble in alcohol, will precipitate to the bottom, l^ow we decant, rinse the resi- due with alcohol, and then place upon a filter, where it is fully washed out with alcohol. The residue upon the filter, dissolved in distilled water, determines in the filtrations by means of standard nitric acid the carbonate of soda, and deducting from the quantity thus found, the applied bicar- bonate of soda, the rest is that surplus carbonate of sodium, which was present in tlie soap. In the alcoholic soap solution now only remains for deter- mination the chloride of potassa, as also the alkalies com- bined with the sebacic acids. For this purpose, the solution is divided into two equal parts. The one of these parts is analyzed by a measured quantity of standard nitric acid, which is warmed until the separated sebacic acid melts, separating them, after they congeal, melting them again in distilled water, and uniting the here obtained acidy liquids. The surplus of the acid is now titrated back, and finding now from the nitric acid neutralized by the alkalies, the alkalies present potash and soda. In the same liquid, after having been made somewhat alkaline by a few drops of car- bonate of soda ; and having colored it yellow, with neutral chromate of potassa, we determine by means of j-q nitrate of silver, the value of chloride of potash. A more simple, although less accurate, yet in most cases amply sufficient method, by which to determine the value of SOAP ANALYSIS. 355 free alkalies (caustic as well as carbonate) contained in soaps, consists in weighing a portion of the soap, dissolving the same in distilled water, and separating it with culinary salt, which has no earthy salts, gypsum, chloride of calcium, or chloride of magnesium, etc., or rock-salt. We must not warm it, so that the soap separates grainy, and it is then washed out upon a filter with a concentrated solution of pure chloride of sodium. In the filtered liquid^ the alkalies are found dissolved. In order to determine the carbonate and the caustic alkali separately, the solution is mixed with chloride of barium, gathering the precipitate upon a filter, washing it out, and putting it into a beaker glass, wherein it is dis- solved in a surplus of measured standard nitric acid, and the surplus of the latter is then analyzed by means of the standard alkali. From the nitric acid used, the quantity of carbonate of potash or soda, or both together (specifically only the quantity of the carbonates) is ascertained. The liquid filtered ofl:* from the carbonate of barium, contains the caustic alka- lies, which may then be determined by alkalimetry. In the testing of soda-soaps, as a rule no consideration need be taken as to their value in potash ; but if this is nevertheless in- tended, one part of the liquid is to be concentrated and mixed with bichloride of platinum. If no yellow precipitate ensues then no potash is present. It yet remains to determine the relative quantities of pot- ash and soda, which have really formed the soap. To this end, the other part of the alcoholic soap solution is to be analyzed. This is done by muriatic acid, separating the sebacic acid from the liquids, washing it well with water, and finally evaporating theacidy lye with the washing water in a porcelain saucer, until it becomes entirely dry. Here great care must be taken, so that no loss is experienced. The porcelain saucer, while yet a little warm, is placed on the scale and balanced; it is then removed, emptied, rinsed, and dried by warming, and again placed while yet a little warm upon the scale and again ^weighed. Thus the aggregate quantity of alkaline chlorides is obtained, from which the chloride of potassa found in the first test is deducted, and 356 TECHNICAL TREATISE ON SOAP AND CANDLES. from the rest, by the above stated process, the proportion between the potash and soda is calculated. The quantities thus found are to be doubled for the soap which is tested We have yet to consider the residuum, which in dissolving in distilled water remains upon the filter. It consists of car- bonate of lime, carbonate of dolomite, clay, and silicic acid. Its quantity is as a rule very small, and the determination of these substances can be taken simultaneously, by taking the dried precipitate from the filter, calcining in a platina crucible and burning the filter, and weighing the whole. Another method for determining the alkalies combined with the sebacic acids, has the advantage that the potash is at least directly determined, and consists in this: The alco- holic soap-solution is evaporated by the volatilization of the alcohol, diluting with water; the solution is decomposed by oxalic acid to a weak acidy reaction, the sebacic acids are separated, the liquid evaporated to dryness, the residue calcined, and the coaled mass completely washed out with distilled water. It is now filtered, the coal washed out and determined in the filter, the value of the alkali by titrating with a solution of tartaric acid (75 grammes (2.63 ozs.) to 1000 cubic centimetres (1 litre = 2.1 pints) dissolved), then adding of the solution of tartaric acid again as much as had been used for neutralization, evaporating the liquid in the water-bath until dry, cooling to the temperature of the room, and treating the salt residue saturated at the same temperature with a solu- tion of bitartrate of potassa. This now dissolves the foreign salts, and leaves the potash as bitartrate of potash, which is dried by a gentle heat, and then weighed. From the weight the potash contained therein is calculated. 100 parts of the dried bitartrate of potassa correspond to 25.04 potash. If the potash thus found is deducted from the aggregate quantity of the alkalies, obtained by titration with tartaric acid, then the rest is soda. By the chloride of platinum also, the potash can be di- rectly determined ; this method is however rather expensive. For discerning the free alkalies in soap. Stein has proposed a very simple method, by which it becomes obvious, without SOAP ANALYSTS. 357 further trouble, whether free alkali is present or not. Stein applies to this end corrosive sublimate (bichloride of mercury), which furnishes with the sebacic acid a white sebacic peroxyd of mercury combination, while in the absence of a free alkali (caustic as well as carbonate) red peroxyd of mercury is formed. Stass has proposed for this same purpose calomel, which, if free alkali be present, becomes black. The subli- mate has however the advantage over calomel, that it can be applied in solution, and also that soaps may be tested with it without dissolving them, by moistening a fresh cut sur- face with a solution of sublimate. On the other hand, for determining the free alkalies in rosin soaps, binitrate of mercury is well adapted. By its application for testing rosin soaps, the heating of the liquid must be avoided, because by the resinous acid protoxyd of mercury may suffer a decom- position. Determination of the Amount of Sebacic Acids and of the Rosin. — For this operation the sebacic acids may be used, as we have separated them by the two preceding methods. Especial care must be taken that no loss is incurred, which might easily happen, because the sebacic acid will adhere to the sides of the vessels, and from thence cannot be again removed by water and be regained. This is attained by washing with benzine, which by heat is entirely volatilized again. If by this means all sebacic acid has become re- united, the sebacic acids are melted, thus ejecting the ad- hering water and benzine. But these acids being mostly too soft to be accurately weighed, they are usually melted together, with dried white wax or stearic acid, which sub- stances have been previously accurately weighed. The fat cake is placed upon a filter, and washed out with distilled water, until the washing water is no longer acid. The dry- ing is performed under a glass cover with concentrated sul- phuric acid. The drying may also be performed in a porce- lain saucer over a water bath, and can be continued as Ions: as the saucer no longer loses in weight, whereupon the melted acid is poured out, the saucer cleansed with a little lye, dryed off, and when thus empty is weighed. From the aggre- 358 TECHNICAL TREATISE ON SOAP AND CANDLES, gate weight is deducted in the first place that of the wax or stearic acid. The rest represents the hydrates of sebacic acid, in case rosin soap is not investigated. The hydrates of stearic acid, palmitic acid, and oleic acid have nearly the same value of water, which with sufficient accuracy may be placed at 3.25 per cent. From the weight of sebacic acid found, 3.25 per cent, are therefore deducted and the rest as the sebacic acid is taken into the analysis. Very frequently it happens, that the hydrate of the sebacic acids is not de- ducted, and the hydrates of the same anhydrous sebacic acids calculated. By the error thus committed, the value of the sebacic acid in the soap appears too high. Under certain circumstances the melting points of the various acids may give a basis as to the kind and derivation of the sebacic acids, especially if the point in question is to determine whether two samples of soap before us are equal or varying. For this experiment a small quantity of sebacic acid is melted and the temperature observed. While slowly cooling olf, the mercury in the thermometer will be observed remaining somewhat longer at a fixed degree, whenever the point of congelation is reached, and the temperature thus indicated is the melting point. If but little of the sebacic acid is at our disposal, then according to Douis we operate as follows: A thin glass tube is taken, drawn out to a very narrow tube, and the narrower part, which is turned down- ward, is filled up with the melted acid. After the congeal- ing has taken place, the apparatus is placed in water, which is slowly heated. At the moment of melting, the partly melted sebacic acid is forced upward by the pressure of the water. The temperature of the water, at which this obser- vation takes place, is also the melting point of the acid. According to Stockhardt the sebacic acids congeal as follows : — of pure tallow soap at 44o to 450 C. (111.20 to 113° F.) of pure palm oil soap at 38o to 39o C. (100.4O to 102.2O F.) of 1 part tallow and I part cocoa oil at 32© to 350 C. ( 89.60 to 95^ F.) of 1 part tallow and ^ " " at 290 to 30o C. ( 84. 20 to 860 F.) of 1 part tallow and 1 " " at 27° to 280 C. ( 80.60 to 82.40 F.) of 1 part palm and ^ " " at 270 to 280 C. ( 80.6O to 82.40 F.) of pure cocoa-nut oil at 23o to 240 C. ( 73.4o to 75.20 F.) SOAP ANALYSIS. 359 A less accurate, but for all common cases amply sufficient method to determine the value of sebacic acid in a soap, when the separated fat, instead of being weighed, is measured, has been proposed by Buchner. To this end is used an alem- bic of glass, with a long and not too wide neck in which is inserted a scale graduated into i cubic centimetres (0.054 flui- drachm). In this apparatus are placed 16 1 grammes (0.58 ounce) soap, with diluted muriatic acid, and heated. If the decomposition is perfect, lukewarm water is used to fill up, until the division mark between the watery and the fatty layer reaches the zero point of the scale, or is somewhat above it. After leaving it to cool off to the temperature of the room, the height of the fatty layer is read. If the specific gravity of sebacic acid is calculated at 0.93 and multi- plied by the indicated cubic centimetres, we obtain the weight of the hydrartes of the sebacic acid, and can thereby calculate the quantity of fat which has been applied in the fabrica- tion of the soap. According to Buchner, 50 kilog. (110 lbs.) fat furnish 77J kilog. (170.5 lbs.) of the fine grain soap, and about ^\ glycerine. For an easy mode of calculation, Buchner furnishes the following table : — The sebacic acid separated from 16f g. soap mea- sures in cubic centimetres Specific gravity of the oils and fats. The separated se- bacic acid hence weighs in the mean in grammes. The fat used for 100 l<:ilog. soap. The grain soap contained iu loo weight parts of soap. 100 weight parts soap contaia of waier, lye, and glycerine. 100 weight parts soap contain of real grain soap. 1 0.93 0.46 3.13 4.85 97 3 5 ( i 4.65 31.30 48.50 69 31 6 a 5.58 37.56 58.20 63 37 7 i i 6.51 43.82 67.90 57 43 8 i i 7.44 50.08 77.60 51 49 9 I i 8.37 56.34 87.30 44 56 10 i I 9.30 62.60 97.00 38 62 11 10.23 68.86 106.7 32 68 12 a 11.16 75.12 116.4 26 74 13 li 12.09 81.38 126.1 20 80 14 1 1 13.02 84.64 135.8 13 87 15 u 13.95 93.90 145.5 7 93 Determination of the Amount of Rosin. — Pure rosin soaps do not generally exist, and it would be easy if such were the 360 TECHNICAL TREATISE ON SOAP AND CANDLES. case to distinguish the rosin soap from a fat soap. On the other hand the determination of the amount of rosin in a soap, particularly if the point in question is the investiga- tion of an imitation, is very often of great importance, in order to find out the accurate composition of such a soap, to which as is self-evident the determining: of the amount of rosin contained in such an imitation belongs. There are several methods, according to which the quantity of the rosin contained in a soap can be determined. Chemistry, however, must confess that it has not yet succeeded in find- ing a ready technical method. The following method, which furnishes reliable results, originated with Sutherland. According to this, the soap is cut up into small pieces, weighing a certain quantity, for instance 33J grammes (1.17 ozs.) accurately, and pouring over it, in a porcelain saucer, some strong commercial muriatic acid. The saucer is covered with a glass plate, and heated over an alcohol flame until all soap pieces are perfectly dis- solved and decomposed, and the sebacic acid with the rosin floats above. 'Now 133i to 166f grammes (4.67 to 5.83 ozs.) warm water are added, and the saucer allowed to cool off. The now congealed fat-cake, thereupon, is carefully taken oft\ and can be already judged by its appearance, whether rosin is contained therein, or not. It is remelted with warm water, in order to remove all adliering acidy solution, and again cooled ofi*, carefully dried with blotting paper, and melted again without water, until the boiling degree is reached. This is for the purpose of removing the last vestige of water. After cooling oft', the fat-cake is placed upon the scale, to ascertain its exact weight. In all these operations, all loss must be carefully avoided. If the soap were a pure fat soap, the fat cake thus ob- tained, after the deduction of 3.5 per cent, for the hydrate, would be 95.5 per cent, of the originally applied fats, and the latter can be easily calculated. But if rosin be present in the soap, it is found in the sebacic acid cake, and this must now be treated as follows. It is placed in a porcelain saucer, holding about J kilog. (1.1 lbs.) water, pouring strong SOAP ANALYSIS. 361 nitric acid over it. Then it is heated very cautiously until the boiling point is reached. At this moment a violent ebul- lition will ensue, and thick red vapors will develop. As soon as this occurs, the lamp is immediately removed ; and is placed under it again when the violence of the reaction has ceased. It is now left to boil a few minutes, while frequently stirring with a glass rod, adding now and then small portions of ni- tric acid, until no more red vapors develop. All these ope- rations are performed in the open air, on account of the de- velopment of acid vapors. It is again cooled off, removing the cake of sebacic acid, which floats upon the strong acidy and deei)ly colored acid of the rosin, washing it off, and re- melting it in nitric acid. After cooling oft* it is finally dried, and once more melted, by itself at a gentle heat, until no more acid vapors appear, and then left to congeal. What remains is pure sebacic acid, and the difference in weight (the loss) against the weight of the cake first weighed, indicates the quantity of the rosin. The latter is thus obtained immediately, but the quantity of the pure sebacic acids found must, as was stated before, be calculated after the reduction of the neutral fat. This is done by deducting 4J per cent., corresponding to the glycerine present. If the soaps have been made with oil, i. e.^ liquid fats or oleic acid, then the separated sebacic acids do not congeal easily into a solid cake, and it would then be difficult to weigh them accurately. In this case also the condition of an exactly weighed small portion of white dried wax serves to melt it together, in order to obtain a firm cake, which can be weighed without trouble, and from the weight of this, in order to ascertain the quantity of the sebacic acids, the weight of the added wax is deducted. Of this mode of determination we have to remark, that too large a surplus of nitric acid must be avoided, nor should the same act upon the sebacic acid cake any longer than is necessary, since according to Heintz, a small portion of stearic acid or palmitic acid becomes easily oxydized. 362 TECHNICAL TREATISE ON SOAP AND CANDLES. Determination of Soap as to Admixtures. — To enhance the weight and quantity of soaps, they are frequently mixed with cheap, grainy bodies, such as clay, chalk, silicic acid, barytes, starch, etc. These substances remain — by treating the soap with strong alcohol — as a residuum, and may then be, as to their nature, further investigated. If the residue is boiled in water, and a thickish liquid is produced, which can be colored dark-blue by one or a few drops of tincture of iodine, then starch is present. If the liquid be strongly al- kaline, it must, before adding iodine solution, be neutralized by acetic acid. To determine whether lime, silicic acid, or clay is in a soap, the residue is treated with muriatic acid, and evaporated over a water-bath to dryness. If silicic acid be present, this remains as a grayish, coarse powder. Clay is present in the liquid, if it precipitates with ammonia to a glutinous substance, which easily dissolves in caustic soda- lye ; and if chalk be present, carbonate of lime is produced by the precipitate obtained of the filtered liquid. Oxalic acid produces a white precipitate of oxalate of lime. The various kinds of soap have often been treated as to their compositions or combinations, and from these analyses is learned how much the soaps which are found in commerce difi'er from each other. We annex some of these analyses below. Moreover, it also appears, as if in these investiga- tions and experiments lime and dolomite had not received tljat attention which they deserve as ingredients of a soap; since none of these analyses mention these minerals as ingredients of soap. And yet it is doubtful if there exists a soap in which they are not present. And in such a case, we may surely suppose, that they are present as sebacic acid salts, forming a portion of the sebacic acids. SOAP ANALYSIS. 363 -O ^3 bo O CO O 00 (N CO ci T}i o" 1-1 CO »0 CO i-H CO CO CO tH 03 M 2 c3 iO -5 1^ 00 ^CO ^ cc o CO o COOOTfOOOO '*00Q0C?G0OlOC0 05 C0C0T-lt> 00 TO 00 1-5 lo ^* C5 i> CO C?C3(MTHC3^T-ll-lWl-lT-IT-t tH O 00 »o C5 id d to CO CO CO CO CO d ^ ci ci CO CO o cS O • o P,oo s lOOOOOOOO o6do6£>do6dddddi>i> 00 i> o o lo 00 00 d 00 • ^ T- :e CO lO c o •07: a 5^ o C3 1-1 01 G 10 O lOOOOlCO ;rl> OJ-rH c OS 00 t> 00 i> o »000010000 C300C5 00C5iCCQCQC5CO»OTH -r-Ir-iQ6dwddididT-Hi>-rj^Ti^ oooioot-(r>£>j>cooot>r- 00 CO o o c? i> d d CQ ■rJH Tti ^ ^ C3 CO 00 o i> o ^ c? d d t> o^' CO --^ CO p4 C "3 O o m d ^ bo ^ c3 .2 i» III ^ m rn 1— 1 03 ■ q; P- S ^ o ^ ^p:S o) d:^ d § 9 S — CC ^ M GQ .2 p-S cj ^ p I • bo d b/3 o a ? o J3 (u ^ ^ V o .t^ -? o S o GO tn '+1 a c« ce P- S g o o ee o M 00 o S 03 CO O ^ 03 .t^ i-( Odd -I-^ a di«| s o c 03 o ;h d 03 bC g O d o d o d d *bb P. o d 364 TECHNICAL TREATISE ON SOAP AND CANDLES. Valuation of Soaps. — The value of soaps is determined gen- erally, according to their contents of neutral fats or sebacic acids. Although soaps with a certain excess of free or car- bonated alkali take better hold, that is, act stronger for the removal of dirt, it must not be overlooked that the free alkali not only hurts the hands, but also the textile fibres of the articles washed. For this reason, since soaps seldom are in the market with excess of fat, the sebacic acid value of a soap may be considered the correct rule and measure for the value of a soap. This however is subject to a limit, in so far, as the equivalents of the sebacic acids are some- what varying, so that equal weights of various sebacic acids, require various weight proportions of alkali, in order to be changed into neutral sebacic salts. If in this manner the Grain (curd) and Paste (cold) soaps are compared with each other, they correspond (if the greatly filled soaps are ex- cepted), in regard to their value of neutral sebacic acid soap, the former to the latter approximately as 15 : 11, and in re- gard to their value of sebacic acids as 10 : 7. In commerce the prices of grain soaps correspond approximately to the cold soaps, = 7:6. According to the sebacic acid — and sebacic acid soap value, the prices should compare as 8 : 6, and we find hence, that the cold soaps, in comparison with the grain (boiled) soaps, are sold too high. If despite this in modern times the use of cold soaps has overtaken that of grain soaps, the reason of this is partly found in the fact, that the cold soaps, by dint of their con- tents of cocoa-nut oil, foam very much, on which property a certain value is placed, and for the reason that it is really thought they are cheaper ; for the common consumer, who is not in a position to investigate or examine a soap more accurately, is constrained to regard such external, and in this case deceptive signs, as firmness and good frothing are. On the other hand, it has also happened that wool-wash- ing establishments, whose demands for soap amounted to several thousand pounds per week, very soon made the ob- servation, that they used i to J more of a good cold soap than of an equally good boiled soap. The proportion was also SOAP ANALYSIS. 365 here more unfavorable than was stated above, or perhaps for the reason that the greater solubility of the cold soap brought with it a larger consumption. Cailletet's Process. It may interest the manufacturer to read the details of this process, which we give in full from the Bulletin de la Societe Industrielle de Mulhouse (Eo. 144, vol. xxix. p. 8). Characteristics of the Aqueous Solutions of Soaps ^ Normal Acid, and Alkaline Liquor. — The soaps used in industry are formed of fatty acids, of soda and potash, and water. These acids, which are solid or liquid at the ordinary temperature, are extracted from fatty substances of animal or vegetable origin. The soap of oleic acid often contains rosin. The Avhite soap obtained by the Marseilles process is formed of : — 60 to 64 parts of fatty acids. 80 to 36 ^vater. 6 " soda. Some white soaps are met with in the trade which contain from 40 to 50 per cent, of water. The marbled soap cannot contain more than thirty-four per cent. When the soap separates from a saturated saline solution, it is formed of : — Fatty acids ....... 77 Soda .7 Water 16 When anhydrous the same soap contains: — Fatty acids ....... 91 Soda ........ 9 In certain industries, soaps are used into which there enters more than six per cent, of soda. These soaps by their ex- cess of alkali, and according to their mode of fabrication, may be hydrated enough to contain from 50 to 60 per cent, of water. 366 TECHNICAL TREATISE ON SOAP AND CANDLES. The fatty substances which enter into the composition of soaps are generally oleic, margaric, stearic, and palmitic acids. The more or less consistency of the aqueous solution of a soap is due to the presence of solid fatty acids, or to an excess of alkali. To prepare an aqueous solution of soap, take ten grammes of the soap to be tested, introduce it into a wide-mouthed bottle and add 90 grammes (3.15 ozs.) of cold distilled water, and dissolve over a water-bath. Introduce this solution into a test tube of a capacity of 100 cubic centimetres (3.38 fl. ozs.), and one hour after, examine its consistency. Hard soaps generally give a solution which by cooling forms an opalescent mass, in which crystallizations are often seen after it has been prepared for some time. Diluted with cold water, this solution divides into an acid salt which de- posits, and an alkaline salt which remains in solution. The acid salt sometimes deposits in the form of a flaky substance, without consistency ; it is ordinarily richer in solid acids than in liquid; sometimes, as with a solution of soap of cocoa-nut oil diluted with its volume of water, the acid salt which deposits assumes a crystalline form, and remains at- tached to the edges of the vessel in which the mixture has -been kept. A warm solution of 10 grammes (.35 oz.) of soap of olive oil, and 90 grammes (3.15 ozs.) of distilled water, is transparent as long as the solution is warm, but as soon as it cools down it becomes more and more opalescent, and lastly, when cold, it is entirely opaque. Its consistency has some anology with that of the white of egg ; it can be drawn in threads, and a few days after preparation it has lost some of its con- sistency. If in the soap which has been dissolved, there have entered fatty acids due to a mixture of sesame and olive oils, olive oil and earth-nut oil, etc., the solution is less opaque and has not so much consistency as that produced with olive-oil soap alone. If in the composition of this lat- ter there enters cocoa-nut oil, the solution is partly curded. A solution of soap of cocoa-nut oil diluted with its volume SOAP ANALYSIS. 367 of water produces, after a rest of twelve hours, an abundant and crystalline precipitate ; the liquor is colorless. Generally, a solution made with 10 grammes (0.3-^ oz.) of soap and 90 grammes (3.15 ozs.) of distilled water gives, by cooling, a solution much more opalescent and with more consistency, when it contains more solid acids and alkali. Soaps manufactured with solid fatty acids give a solution which is solid. Thus 3 grammes (46.29 grains) of soap of tallow, and 97 grammes (3.39 ounces) of water, produce a solid solution. Soaps in which liquid fatty acids predominate give gener- ally a colorless solution at a temperature of 85° to 100° C. (185° to 212° F.). When the fatty acids predominate, as in the tallow soap, the solution looks flocculent. If the soap contains rosin, the solution at 185° to 212° F. is very opaque, and after being prepared a few hours it separates into three parts. The upper part, which is nearly transparent, con- tains very little rosin and much alkali ; the middle part is entirely opaque ; the lower part is formed with a white sub- stance which has deposited and which looks like pure rosin combined with very little alkali. All soaps are heavier than water ; they do not act in the same manner when in contact with, warm water. If a piece of soap weighing 10 grammes (0.35 oz.) is introduced into a wide- mouthed bottle containing 90 grammes (3.15 ounces) of cold distilled water, and if the whole is heated over a water-bath, the soaps manufactured with olive oil, palm oil, tallow, oleic acid, etc., will float on the surface and become transparent from the circumference to the centre ; soon by their contact with -warm water, their transparency is complete. The contrary takes place, if the soaps have been manufactured with cocoa-nut oil or rosin ; they remain at the bottom of the vessel and dissolve very easily. The soaps of olive oil, tallow, etc., retain their transpa- rency all the w^hile they are in contact wnth warm water. If this transparent soap is taken from the warm water, it will retain its transparency for some time; but if the soap is half out of the water and is allowed to cool, the part in 368 TECHNICAL TREATISE ON SOAP AND CANDLES. contact with the liquid becomes white and opalescent, while the other remains transparent. Soap in contact with warm water loses at first a part of alkali, water, and fatty substance ; it becomes richer in solid acids and is less aqueous. Its transparency is as much greater as it contains less water and alkali ; afterwards its solution in warm water will be slower if it contains more stearic than margaric acid, and more of this latter than oleic acid. Lastly, each kind of soap by its solubility in warm water, by the transparency and consistency of its aqueous solution, presents to the observer shades more easily seen by the aid of a comparative examination. After studying the characteristics of the aqueous solu- tion of a soap, it is very easy to determine its composition by the following method : This process, which consists in measuring the constituent principles of a soap to ascertain its weight, is called saponimetry^ by which the manufacturer may, in half an hour, test several specimens of soap, com- pare them, and select the best for his use. To operate according to this method, it is necessary to prepare beforehand two liquors, one which is acid, the other alkaline. These two liquors ought to be kept in ground- stoppered bottles. Preparation of the Normal Acid Liquor, Take Monoliydrated sulphuric acid (660) . . 189.84 grammes (6.64 ozs.). Distilled water same quantity. and add, after the cooling of the liquor, enough water to make one litre (2.1 pints) at the temperature of 15° C.(59° F.). 10 cubic centimetres (0.338 fluidounce) of normal acid contain 1.8984 grammes (29.29 grains) of monohydrated sul- phuric acid, and are equivalent, in forming a neutral salt, to 1.2 grammes (18.5 grains) of soda, or 1.825 grammes (28.16 grains) of potash. The equivalent of monohydrated sulphuric acid is 612.5 (SO3, 500 + HO, 112.5 = 612.5). The equivalent of soda is 387.17. SOAP ANALYSIS. 369 The weight of sulphuric acid necessary to form a neutral salt with soda (1.2 grammes), is known by NaO SO.HO NaO SO3HO 387.17 : 612.5 : : 1.2 : == 1.8984 The weight of this acid, wliich has to be mixed with a sufficient quantity of water to form one litre (2.1 pints) of acid liquor, is known by 1.8984 grm.xlOOO c c. ^ _ grammes (6.64 ozs.). 10 c. c. To prepare 50 cubic centimetres of acid liquor, we have 1.8984 grm. X50 c. c. 493 grammes (0.33 oz.). 10 c. c. Preparation of the Normal Alkaline Liquor. Pure and dry carbonate of soda . . 41.016 grammes (1.44 ozs.). Distilled water enough to dissolve the carbonate and obtain one litre of alkaline liquor at a temparature of 15° C. (59° F.). 50 cubic centimetres (1.69 fluidounces) of this liquor ought to contain 1.2 grammes (18.5 grains) of soda, a weight rep- resented by 2.0523 grammes (31.66 grains) of carbonate of soda. To ascertain the weight of the dry carbonate of soda which ought to represent 1.2 grammes of soda to saturate 1.8984 grammes (29.3 grains) of monohydrated sulphuric acid con- tained in 10 cubic centimetres (0.33 fluidounces) of the normal acid, knowing that 612.5 of monohydrated acid saturates 662.18 of carbonate of soda (NaO 387.17-1-002 275 = 662.17), we have SO.IIO NaO, CO, SO3HO NaOCO^ 612.5 : 662.17 : : 1.8984 : a; = 2.0523 We find 2.0523 grammes of carbonate of soda without water, represeiiting 1.2 grammes of soda which, dissolved in a sufficient quantity of water, ought to give 50 cubic centi- metres of alkaline liquor at a temperature of 15° C. (59° F.). The weight of carbonate to dissolve in a sufficient quantity 24 370 TECHNICAL TREATISE ON SOAP AND CANDLES. of distilled water to obtain one litre of alkaline liquor is known by 2.0523 grms. XIOOO c. c. _ ^ _ ^^^^^ ^^^^^^ 44 50 c. c. These normal liquids are used in — Saponimetry. Soaps Composed of Solid and Liquid Fatty Acids. — The normal acid and the alkaline liquor being prepared, the question is to determine with rapidity the weight of the fatty matter, the alkali, and the water, without being obliged to use the balance. To obtain this result, take a graduated glass tube of a capacity of 50 cubic centimetres (1.69 fluidounces) divided into 100 parts (alkalimetry), to which a cork is adapted. Introduce into it 10 cubic centimetres (0.33 fluidounce) of normal acid. This acid must be carefully measured. After- wards, add to it 20 cubic centimetres (0.66 fluidounce) of spirit of turpentine carefully measured ; then weigh 10 grammes (0.35 ounce) of soap divided into very thin shav- ings which is introduced into the tube ; cork the tube; stir for a few minutes until the soap is dissolved and then let it rest. A quarter of an hour is suflicient to have a complete separation of the turpentine, of the dissolved fatty matter, and of the water.* The heaviest part, which is water, sul- phate of soda, and sulphuric acid, falls rapidly to the bot- tom of the tube ; the lightest part formed with turpentine and fatty matter occupies the upper part ; lastly, a layer formed of an albuminous or animal matter occupies the middle. This latter layer, which is neither fatty matter nor water, is sometimes voluminous enough to occupy the whole of the capacity of the tube containing the normal acid. A slight agitation is suflicient to collect it into a very thin * The solution of the fatty matter in the turpentine takes place without dilatation or contraction of the volume ; it is the same for the mixture of the normal acid with the water. SOAP ANALYSIS. 371 layer. In this state it is between the normal acid and the turpentine. When the soap contains rosin, this substance partly separates from the fatty matter, and forms a layer between the turpentine and the acid, but it preserves its volume whatever is done to unite it into a smaller space. The volume of the turpentine with the fatty substance must be diminished by about J a division, or J of a cubic centimetre (O.Od fluidrachm), and the volume of the water ought to be increased by that diminution. This correction must be made, because the water attaches itself to the edges of the tube and diminishes its diameter, which causes the lightest volume to be increased a little, and the heaviest to be diminished. If soap made with olive oil is tried, the total volume is about 79.5 divisions ; if the trial is made with oleic acid soap, the total volume is from 80 to 81 ; if the soap is made with greases or heavy oils, the volume is below 79.5 divi- sions. These volumes are very variable, because the soaps may contain more or less water, and the fatty substances may have a greater or less weight. Let us suppose that by the trial of a white soap from olive oil the volume was 79.5 divisions, and the volume of the normal acid and water contained in the 10 grammes of the soap was 26 divisions, we have: — Total volume ... . . 79.5 di v. Less the vohtme of acid and water 26.0 For the correction . . .0.5 Which gives 53.0 Less the volume of turpentine . 40.0 Balance . . . •^_ 13 c. c. = 6.5 c. c. (1.75 fldrm.). 2 As there has been used 10 cubic centimetres = 20 divi- sions of normal acid according to the composition of the soap, the volume of the acid water is 26.5 divisions, we have: — 26 5 r p —^-^ = 13.25 c. c. — 10 c. c. = 3.25 c. c. (0.88 fluidrachm). 372 TECHNICAL TREATISE ON SOAP AND CANDLES. Which make: — Fatty matter .... 6.50 c. c. Water and soda . , . 3.25 9.75 " (2.63 flmdrachms). The soap being heavier than water, the volume 9.75 cubic centimetres in soap represents the weight of 10 cubic centi- metres (2.70 fluidraclims) of water. To know the weight of the cubic centimetre of the fatty matter contained in various soaps, Ave remember that there have been introduced into the tube 10 cubic centimetres of normal acid, 20 cubic centimetres (0.66 fluidoz.) spirit of turpentine, and 10 grammes of soap. After the decomposi- tion of the soap, the height of the total volume of the spirit, fatty matter, and acid water, being exactly taken, has been of 79.5 divisions, the volume of the aqueous part being 26 divisions. By making the correction spoken of before, 10 grammes of the soap contain in volume: — Fatty matter 6.50 c. c. > 9 75 c c Water and soda . . . . 3.25 c. c. > On the other hand, the author has dissolved in a porcelain dish 10 grammes (0.35 oz.) of the same soap in a sufficient quantity of water, to which, afterwards, was added a suffi- cient quantity of the normal sulphuric acid ; after the sepa- ration of the fatty acids 10 grammes (0.35 oz.) of dried white wax were added, which after fusion became incorporated with the fatty substance ; and after cooling the cake was dried and weighed. The total weight was 15.97 grammes (0.56 oz.). From this weight, if we subtract that of the wax, vrhich is 10 grammes (0.35 oz.), the balance 5.97 grammes (0.21 oz.) represents the volume 6.5 cubic centimetres (1.75 liuidrachms) found by the turpentine. To ascertain the weight of a cubic centimetre of the fatty matter contained in Marseilles soap, we have: — X = 0.91846 gramme (14.17 grains). 6.5 c. c. The weight of the cubic centimetre of the fatty matter contained in several specimens of Marseilles soap made by SOAP ANALYSIS. 373 different manufacturers was 0.91846, 0.91875, 0.91921 ; the average of which is 0.91880 gramme. The weight of the cubic centimetre of fatty substances from cocoa-oil soap is 0.940 gramme. From palm-oil soap 0.922. From tallow soap 0.9714. From oleic-acid soap 0.9008. The weight of the fatty matter being known, we have to analyze the soda and water. Add to the tube which contains the mixture a sufficient quantity of distilled water to raise the level of the turpen- tine ; this substance and the fatty matter are removed, the tube is corked and well stirred to dissolve the acid sulphate of soda which may have crystallized, and the acid mixture is poured into a test glass. Pour a little more water into the tube so as to wash well the last portions of acidulated water, and add it to the first acid solution. Put into this so- lution a few drops of tincture of litmus, and in the graduated tube introduce 50 cubic centimetres (1.69 fluidozs.) of the alka- line liquor; pour little by little a sufficient quantity of this liquor into the glass containing the acid, mixing the whole with a glass rod until the litmus passes to the onion peel color. The liquor has to be tried from time to time with litmus paper, and when this paper does not turn red, the ad- dition of the alkaline liquor is stopped and its volume measured. Let us suppose that the -^q^ of the alkaline volume have been necessary to saturate the acid. The alkaline liquor contains in 50 cubic centimetres (1.69 fluidozs.) 1.2 grammes (18.50 grains) of soda. This weight forms a neutral salt with the sulphuric acid contained in the 10 cubic centimetres (0.33 fluidoz.) of normal acid used to decompose the soap. It the operator has only used the j%% of 50 cubic centimetres of alkaline liquor, it is evident that the soap contains the of 1.2 grammes (18.50 grains) of soda. Then the volume of the alkaline liquor which is not used contains exactly a weight of soda equal to that which is found in the 10 grammes (154.3 grains) of the soap. 374 TECHNICAL TREATISE ON SOAP AND CANDLES. To apply this process, if the operator has used the of the alkaline volume for the saturation of the acid, the soap contains the l-^ grammes (18.50 grains) of soda, or 0.84 gramme (12.96 grains), or 8.40 per cent. ; if the volume used has been j%% the soap contains 0.6 gramme (9.26 grains) of soda, or six per cent. If the analysis of a soft soap has to be made, what is left of the alkaline volume not used will represent the propor- tional equivalent of the potash contained in the soap. The equivalent of the soda being 1.2 grammes, that of the potash is 1.825 grammes (28.16 grains). If the volume not used is yYo? is evident that the soap contains in the 10 grammes of 1.825 grammes of potash ; if the volume not used is it is manifest that the soap contains j%% of 1.825, or 9.125 per cent, of potash. The weight of the soda or potash being determined, it has to be subtracted from the water. The analysis of a soap giving in volume: — Fatty matter .... 6.50 c. c. (1.75 fluidrachm) Water and soda .... 3.25 " ( .88 " ) if the weight of the soda is 0.60 gramme, we have : — Fatty substance 6.5 c. c. X 0.91846 grm. == 5.9699 grms. (92.16 grains). Soda 0.6000 " ( 9.00 " ). Water found by difference . . . 3.4301*" (52.84 " ). Soap 10.0000 " (154.00 " ). If the soap contains glycerine, this substance remains in solution in the normal acid ; if it contains flour, talc, clay, * If we take 10 c. c. of distilled water, and 5 grammes (77.15 grains) of potash, the volume of the solution at 60o is 11.75 c. c. (3.17 fluidrachms). Supposing that soda gives the same result as potash, we have to know the volume of 0.6 gramme (9.24 grains) of soda: — KO Vol. NaO. Vol. 5 grms. : 1.75 c. c. : : 0.60 : a? = 0.21 c. c. 77.15 grs. : 0.47 fluidrachms. : : 9.24 : a; = 0.056 fluidrachms. Which gives for the volume of the water : — 3.25 c. c. — 0.21c. c. =3.04 c. c. of water. 0.87 fluidrachm — 0.05 fluidrachm = 0.82 fluidrachm. SOAP ANALYSIS. 375 all these substances fall immediately to the bottom of the tube. Soap of Oleic Acid and Rosin.— li 10 grammes (154 grains) of rosin soap are treated b}^ 10 cubic centimetres (0.33 fluidoz.) of normal acid ; and 20 cubic centimetres (0.66 fluidoz.) of spirit of turpentine, the latter hardly dissolves any of the rosin. If a certain quantity of Marseilles soap, for example, enters into the weight of 10 grammes of rosin soap, all the fatty matter of the Marseilles soap is dissolved by the turpentine, and the rosin is dissolved only in the proportion of about the yYo" of a cubic centimetre (0.045 fluid rachm) ; it forms a voluminous layer below the turpentine. This easy separation of the rosin ought to be attributed to a special state it acquires while in presence of the water when separated from its combination with potash or soda by sulphuric acid. These results are described in the two following experi- ments : — First Experiment — 10 grammes (0.35 oz.) of olive soap containing very little water have given for the volume of the fatty matter 8.25 cubic centimetres (2.23 fluid rachms). Second Experiment. — 8 grammes (123 grains) of the same soap and 2 grammes (31 grains) of rosin soap have given a volume of the fatty matter and dissolved rosin equal to 6.75 cubic centimetres (1.82 fluidrachms). To know the volume from the 8 grammes of olive soap, we have : — lOgrms. : 8.25 c. c. : : 8 grms. : a; = Vol. 6.60 c. c. (1.78 fluidrachra). If from the volume of 6.75 cubic centimetres we subtract volume 6.60, the balance 0.15 indicates that the turpentine has dissolved only the yYo- of a cubic centimetre of rosin. In some woollen cloth manufactories, they use a soap made with oleic acid and rosin. Let us suppose that 10 grammes of this soap have given by the wax process a weight of fatty matter and rosin == 6.45 grammes (99.52 grains), that by the treatment with the turpentine the volume of fatty mat- ter and dissolved rosin = 6.25 cubic centimetres (1.7 flui- 876 TECHNICAL TREATISE ON SOAP AND CANDLES. drachm), and that in saturating the normal acid the volume of alkaline liquor employed was Subtract from the volume 6.25 cubic centimetres the vol- ume 0.16, which gives for the oleic acid 6.25 — 0.15 6.10 cubic centimetres (1.65 fluidrachms), we have: — Oleic acid 6.10 c. c. X 0.9003 grm. = 5.49183 grms. (84.74 grains). Bosin by difference grms. — n.mSS) —0.95817 " (14.78 " ). Soda 1.2 grms. Xt%^o 0.81600 " (12.59 " ). Water by difference 2.73400 " (42.21 " ). Soap of oleic acid and rosin 10.00000 (154.32 " ). The weight of the w^ax -will give that of the fatty matter and rosin; the volume x cubic centimetre of the fatty matter — the volume 0.15 of the rosin multiplied by 0.9003 weight of a cubic centimetre of oleic acid will give the weight of that volume. By difference the weight of the rosin wmII be known ; the volume of the alkaline liquor not used, will give the weight of the soda or potash ; lastly, by difference, the weight of the water is obtained. Mixtuj^es of Potash and Soda. — In some soaps there is a mixture of potash and soda. The weight of each alkali is known by the following method. Burn 10 grammes (0.35 oz.) of soap. Weigh the ashes and treat them by boiling distilled water: filter, wash the filter with a little warm water, and add the washings to the alka- line solution ; then burn the filter, deduct the known weight of its ash from the total weight of the ashes, and by ditter- ence we have the weight of the potash and soda mixed in the state of carbonates. Let us suppose that the mixture weighs 3 grammes (46.29 grains). The volume of normal acid necessary to saturate 8 grammes of the mixture is found by a direct experiment. Then the volume of normal acid necessary to saturate 3 grammes of carbonate of potash and 3 grammes of carbon- ate of soda is found by calculation. The volume of normal acid by which the three grammes of the mixture have been saturated will be intermediate between the volumes w^hich ought to saturate 3 grammes of carbonate of potash, and 3 SOAP ANALYSIS. 377 grammes of carbonate of soda. By a proportional division, we shall have fractions of potash and soda to compose the w^eight of the mixture examined. Let us suppose that the volume of normal acid used directly for the saturation of the 3 grammes of the mixture is 13 cubic centimetres (3.51 fluid rachms). The volume of normal acid to saturate 3 grammes of car- bonate of potash and 3 grammes of carbonate of soda is to be ascertained ; knowing that 10 cubic centimetres (0.33 fluidoz.) of normal acid contain 1.8984 grammes (29.29 grains) of monohydrated sulphuric acid, and that its equiva- lent is 612.5. For the carbonate of soda, we have: — NaO,C02 S03,H0 NaCCO., SO,, HO 662.17 : 612.5 :: 3 : a; = 2.774 grms. (42.80 grains). To know the volume of normal acid which contains 2.774 grammes of monohydrated acid, we have : — SOg.HO Vol. S03,H0 Vol. 1.8984 : 10 c. c. : : 2.774 grms. : a; = 14.612 c. c. (3.94 fluidrachms). In the same manner we ascertain the weight of monohy- drated acid and afterwards the volume of normal acid which contains the weight of monohydrated acid necessary to satu- rate 3 grammes of carbonate of potash. We have: — K0,C02 SO,, HO KO,CO, S03,H0 863.93 : 612.5 : : 3 : a; = 2.126 grms. (32.80 grains). S03,H0 Vol. SOg.HO 1.8984 grms. : 10 c. c. : : 2.126 grms. : a; = 11.198 c. c. (3.02 fldrms.) of normal acid, which contains 2.126 grammes of monohy- drated acid. By experiment 13 cubic centimetres (3.51 fluidrachms) of normal acid have been employed to saturate the alkalies found in the ashes of the calcined soap. It is evident that if the weight of alkali found in the ashes is formed only of carbonate of soda, the volume used should be 14.612 cubic centimetres (3.94 fluidrachms) of normal acid; if, on the con- trary, the 3 grammes are only formed of carbonate of potash, the volume used should be 11.198 cubic centimetres (3.02 878 TECHNICAL TREATISE ON SOAP AND CANDLES. fluidrachms) of normal acid. But as the volume of normal acid used has been 13 cubic centimetres, this volume alone indicates a mixture of carbonate of potash and soda. By a proportional division we have the weight of the carbonate of soda proportional to a fraction of the volume 14.612 cubic centimetres of normal acid; we have also the weight of the carbonate of potash proportional to a fraction of the volume 11.198 cubic centimetres of normal acid. To establish this division, we have : — 1. The gain that the volume 11.198 ought to make to give vol- ume 13 cubic centimetres which is 1.802 cubic centimetres (0.49 Jiuidrachm). 2. The loss that the volume 14.612 cubic centimetres ought to make to give 13 cubic centimetres^ which is 1.612 cubic centime- tres {0A2> Jiuidrachm). Which gives: — .... ^'^^^\=.^AU{i!).^2m^v^chm). Loss .... 1.612 > To compose the volume 13 cubic centimetres, we take: — 1. The Af^f of the volume 14.612 cubic centimetres^ corre- sponding to the \ of 2> grammes of carbonate of soda. 2. The If II of the volume 11.198 cid)ic centimetres^ corre- sponding to the -gfll 3 grammes of carbonate of potash. We obtain : — x= carb, of soda 1.5834 grms. corr. to soda 0.92.j8 grm. corr. to vol. of acid 7.7126 c. c. y " " pot. 1.4165 " " pot. 0.9656 *' " " " " 5.2873 a; + 2/ = mixture 2.9999 " both 1.8914 for volume found 12.99J9 (46.29 graias). (29.18 grains). (3.51 fldrm.) In this analysis, the followino; method due to Glav Lussac cannot be well used, because too much soap would have to be burned so as to operate on 50 grammes of mixed chlorides. Operate as follows : — Transform the two carbonates into chlorides and calcine to evaporate the excess of acid ; take 50 grammes (1.75 ozs.) of the mixture which is finely powdered, introduce this mixture into a bottle weighing 185 grammes (6.48 ozs.), and containing 200 grammes (7.00 ozs.) of water, stir with a glass SOAP ANALYSIS. 379 rod, and observe the falling of the temperature produced by the solution of the salt in water. The chloride of potassium produces a falling of temperature of 11.4° C. (20.6° F.). Common salt in the same condition produces a falling of 1.9° C. (3.4° F.). If we suppose that the thermometer marking 15° C. (59° F.) falls by the effect of the dissolution of the saline mixture to 10° C. (50° F.),we have a falling of 5° C. (9° F.). By proportionally dividing 11.4° and 1.9° to give 5° C, we have: 1st, a fraction of 11.4° corresponding to a fraction of 100 grammes (3.52 ozs.) of chloride of potassium ; 2d, a frac- tion of 1.9° corresponding to a fraction of 100 grammes of chloride of sodium. Therefore: — 1. Gain 5 —1.90 = 3.10 ) ^ 2. Loss 11.4 — 5.00 = 6.40 ^ Which gives : — 1. The |ig of 11.4° corresponding to the fig o/lOO grammes of chloride of potassium. 2. The f to o/ 1.9° corresponding to the ||g of 100 grarames of chloride of sodium. The results are : — Chloride of potassium 32.63 corresp. to temp. 3.720 C, 6.70 F. Chloride of sodium 67.37 " " 1.28 2.3 Total 100.000 falling of temp. 5.00O C, 9.0o F. The tests for determining the amounts of the alkalies of potash and soda are rather intricate ; we have, therefore, given the reader the choice of methods by giving Caillette's also. 380 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIOiT XYII. RE-MELTING OF SOAP. This operation to the inexpert is quite difficult, taking much time and being attended with some loss, but at the same time it is very important. In the manufacture of soap, in cutting, moulding, pressing, etc., a great deal of scrap soap accumulates, and it often happens, that, in the making of the soap, it may not turn out to suit, it may be discolored, may not be neutral, or may have too little alkali ; or, from whatever cause, and these are many, the soap even with the best of care will not be salable and will have to be re-melted and adjusted. To re- melt the scraps and soap there are several means. The simplest is where, in the case of having a steam jacket with cover, the soap is stripped or made into shreds and placed in the kettle with a limited quantity of w^ater, covered closely, and the steam turned into the jacket, this operation taking much time and requiring some attention in stirring, etc. Again, one of the best modes of re-melting by means of boiling and re-adjusting is to cut up the soap into small pieces; in which case it need not go into the stripper. Place it in the boiler with a suitable quantity of weak lye, say, of 2° or 3^ B. (half the w^eight of the soap), and with a gentle heat gradually bring to a boil until all the pieces are dis- solved, and a jelly like mass is obtained. Then add suffi- cient culinary salt, or a strong solution of it, to separate the soap — an operation frequently described — boil to a curd, turn off the heat, let it settle, and remove the sub-lye. If then the soap is too hard, it will be necessary to fit it. This is done by adding a portion of water, and again bringing it RE-MELTING OF SOAP. 381 to a boil that it may again form into a gelatinous state and be subjected to the usual tests, so frequently described. If finished it is framed. If the soap was not good before this operation, the boiling and adjusting will have improved it, though it may not be as white as it was before. If it was much discolored, the process of separation may be repeated several times. Soaps that have a filling with water-glass, sal-soda, or whatever substance should not be re-melted by the boiling process, as all the filling would be separated and lost. To re-melt such soaps, a valuable machine has been invented by Mr. Whitaker, and is made by Messrs. Hersey Bros., of South Boston, Mass., which has proved very successful. Fig. 62. The Whitaker Re-melter. The following is a description of the above machine: A, wrought iron cylinder with dishing bottom. B, coil of continuous steam pipe. C, horizontal scroll pipe connecting 382 TECHNICAL TREATISE ON SOAP AND CANDLES. with the upright pipe. D, wire diaphragm which serves to separate the soap. E, gate for discharging soap. F, small pipe for admitting direct steam through perforations into the body of the soap. K, inlet pipe and valve for direct steam. I, inlet pipe. J, discharge valve for condensed steam. H H, floor of building. Gr, spout for running in the cut soap. Directions for Use. — Fill the re-melter with the soap, put on the cover, close the bottom slide, and let on the open steam, until the soap begins to melt, which will depend upon the dryness of the soap. When sufficiently melted shut off the open steam, open the bottom to drain off the condensed steam. Then let on the steam through the coils and put the frames in place to catch the melted soap. When in the frames stir well when half-full and also when full, in order to insure a uniform soap. This machine will hold about 1000 pounds of soap, and can be used six or eight times a day. It is now used by many of our largest manufacturers both for domestic and for toilet soaps. The re-melting of soaps is a very important part of soap manipulation, for independent of the scraps and faulty soaps, this re-melter might be used to re-melt the stock soaps for toilet soaps described in that section, especially if they should become with drying too hard and brittle to mill. It may be unnecessary to say that with proper care in the first operation of making the soaps there will be less re-melt- ing to be done, and in toilet soaps the various appliances of stripper mill and platter generally cause a thorough blending of color and scraps, and the mixing of the soap is attained much more speedily and with less expense. MISCELLANEOUS USEFUL SOAPS. 383 SECTIOIS' XVIII. MISCELLANEOUS USEFUL SOAPS. Though we have given in our preceding pages the most important soaps known to commerce, there are many that have had a reputation more or less deserving or transient, that should receive some notice at our hands, and there are also soaps made in the household and for domestic and laundry purposes that have some merit and are economical. Altenburge's Eosin Soap. Cocoa-nut oil .... 100 kilog. (220 lbs.) Rosin 100 (220 " ) Soda lye, 280 . . . . 135 " (297 " ) Make by the cold process, and before framing cut with a salt lye of 24° B. Dresden Palm Soap. Cocoa-nut oil .... 1600 kilog. (3520 lbs.) Palm oil (crude) . . . .500 " (1100" ) Rosin 400 " ( 880 " ) Soda lye, 280 .... 1304 litres ( 353 gals.) Melt together the fats and saponify the rosin separately, taking care to add the rosin soap before it becomes too thick to stir. Offenbach Palm Soap. Palm oil (unbleached) . . . 1000 kilog. (2200 lbs.) Cocoa-nut oil . . . . 400 " ( 880 " ) Soda lye 15o B 2800 " (6160 " ) Place one-half the lye with the fats and let it boil gently to saponify slowly ; when combined add the last of the alkali, 384 TECHNICAL TREATISE ON SOAP AND CANDLES. keeping up the boiling until it becomes a jelly. If stringy, add a portion of 20° lye, and if too caustic correct with oleic acid. This is simply a good tallow soap or a mixed tallow, bleached palm oil, or cocoa-nut oil soap, but it must contain tallow, which, when it is boiled and nearly finished, is fitted or ground with a weak solution of carbonate of soda, the quantity depending upon the dr^^ness of the grain soap after its separation with salt. It has a smooth wax-like appear- ance, and being highly detergent, is very popular on the con- tinent of Europe as a laundry soap. Bran is boiled with 2 per cent, of soda-lye in a large amount of water and strained. It is supposed to be useful for washing cotton cloths for printing. The soap is cut into shavings and melted in the ox-gall at a moderate heat, evaporating until of proper consistency. The ox-gall is prepared by boiling it with 10 to 12 parts wood spirit and straining. Scouring Balls. White curd soap . . . .16 kilog. (35.2 lbs. ) Pearl ash 3 " ( 6.6 " ) Oil of juniper . . . . 1^ " ( 3.3 " ) Mixed together, having previously added a little water to the soap and pearl ash to dissolve them by a moderate heat; add the oil of juniper and mould into balls. Wax or Bleaching Soap. Bran Soap. Ox-Gall Soap for Scouring Woollens. Purified ox-gall White curd soap 1 part 2 " MISCELLANEOUS USEFUL SOAPS. 385 French Scouring Soap. Curd soap Water . 1^ kilog. (3.3 lbs. ) 20 litres. (5.3 gals.) Oil of turpentine . . . .16 grms. (0.56 oz. ) Aqua ammonia . . . .33 " (1.16 *' ) The soap is dissolved by heat in half the water, and the other ingredients added. This is used as a soft soap for the laundry. Good rosin soap . . . .16 kilog. (35 lbs. ) Oil of turpentine . . . . 2 " ( 4.4 " ) Sal ammoniac . . . . 1 " ( 2.2 " ) Melted toscether and formed into cakes used for removins: ink, wine, or vinegar stains. Good rosin soap . . . .16 kilog. (35 lbs. ) Pipeclay, or fuller's earth, in powd. 1^ " ( 3.3 " ) Melt the soap in a water-bath, and when perfectly melted add the powdered earth. This is used as an erasive for grease and other stains on clothing. It is usual to cut it into small cakes with printed directions. Labor-saving Soap. Good rosin soap .... 1 kilog. (2.2 lbs.) Sal soda f " (1.65 " ) Water 33 litres (8.7 gals.) One litre or 1 quart is added to each 5 gallons of water used in washing. It is particularly applicable for use with hard water. This is a hard soap usually made on farms, using the kitchen or other greases to make a soft soap with wood-ash lye, boiling well to a clear paste, and cutting with culinary Scouring Tablets. Erasive Soap. Country Soap. 25 386 TECHNICAL TREATISE ON SOAP AND CANDLES. salt. The only art is in making a clear glossy paste before cutting, when the soap is generally allowed to cool and rest for a day, when the cakes of soap are removed from the sur- face and cut up and dried in the shade. Domestic Soft Soap. Grease 3.64 kilog. (8 lbs. ) Potash 2.7 " (6 " ) Water 113 litres (30 gals.) The potash is dissolved in a portion of the water. About a third of the grease is added and heat applied. It is, when mixed, put into a barrel in the cellar and the rest of the water added in portions for seven days, and after repeated stirrings for a fortnight it is ready for use. Shaker Soft Soap. Strong lye from wood ashes . . 45 litres (12 gals.) Grease 2.83 " (6 pints.) Water sufficient to make up the 113 litres (30 gallons). Manipulation is similar to that for the domestic soft soap. Borax Soft Soap. V7hite fats 45.4 kilog. (100 lbs.) Soda lye, 15© B 45.4 *' (100 " ) Potash lye, lOO B. . . . 27.3 " ( 60 " ) Solution of borax, lOo B. . . 6.8 " (15 ") The soda lye is added to the melted grease and heated till it forms a clear liquid or is combined, when the potash-lye and borax solution are added. Et should be a semi-solid trans- lucent paste, and is usually sold in quart cans, and is quite popular. Lubricating Soap. Palm oil, crude .2 parts. Tallow 1 part. Solution carb. soda, 15^ 1 " Melt together. MISCELLANEOUS USEFUL SOAPS. 387 Agricultural Soap (Whale-oil Soap) Whale-oil foot . . . . . . .2 parts. Soda lye, 30^ B 1 part. Made in the cold way. Whale-oil foot is the residuum left ill refilling the oil. This soap is useful for destroying insects on plants. Fig Soap Is another name for the grained soft soap, so named because it resembles the seeds of fisis. Pearl Soap Powder. Curd soap, dried and powdered Sal soda, " Silicate of soda " '* 4 parts. Made as dry as possible and intimately blended. Curd soap, Soda ash. Silicate of soda, Borax, crude, Borax Soap Powder. in powder 5 parts. 3 " 2 " 1 part. Each ingredient is thoroughly dried and all mixed together by sieving. London Soap Powder. Yellow soap Soda crystals Pearl ash Sulph. soda . Palm oil 6 parts. 3 " 1^ " H " 1 part. These ingredients are combined as well as possible without any water, and they are spread out to dry and then ground into a coarse powder. Thus, in an infinite degree can the variety of soap pow^ders be multiplied. They are adapted for hard waters, as their excess of alkali neutralizes the lime. 388 TECHNICAL TREATISE ON SOAP AND CANDLES. Belgian Soft Soap. Tallow . Cocoa-nut oil 350 kilog. (770 lbs.) 150 " (330 " ) Palm oil, bleached . . . . 100 " (220 " ) This quantity of fats is boiled in a caustic potash-lye of 20° B. until perfectly saponified. Water is added to keep the proper consistency. This is a favorite soap for manu- facturers of cloths and woolens. To a good white soda cold soap yet warm add a solution of ammonia alum, say 10 per cent, of 8° B. solution, before put- ting in the frames. The ammonia will be set free and im- prove the detersive qualities of the soap. Under this name a pure soap is made with oleic acid and * caustic potash-lye, care being taken to obtain a neutral pro- duct. It is boiled with a moderately strong lye until the proper consistency is reached. Make as usual. Used for washing in sea-water. In our section on toilet soaps, we shall give a large num- ber of formulas of soaps that properly belong to that depart- ment. From a great number of useful domestic and manu- facturer's soaps, we have selected what we consider most reliable, and such as will give the intelligent manufacturer hints towards many more, should he have occasion to make them. Ammoniated Soap. Medicated Soft Soap. Marine Soap. Cocoa-nut oil soap Fuller's earth . Calcined soda ash 100 parts. 50 " 50 " TOILET SOAPS. 389 SECTIOI^T XIX. TOILET SOAPS. The increased demand and production of this class of soaps, has made their manufacture one of the most important of which it is our office to treat and explain. The writer, in his connection with the fat industry for nearly forty years, can readily trace, in the United States, the different improvements made during that period in this art: from the time when the chandler made the tallow curd soap, and marbled it with vermilion, perfumed it with sassafras, formed it into squares or rounded it into balls, and when this was a standard for a domestic toilet soap. This soap, being made of tallow and soda- lye, soon became so hard that it was almost impossible to coax a lather from it, even after a previous soaking in water. Then, later, the perfumer bought the different domestic soaps, remelting, perfuming, and forming into cakes with the plane, wrapping them in gorgeous wrappers, and applying to them names to suit the prevailing taste. Then again, when, some twenty years ago, toilet soaps were made by the cold or extempore process, the product was very inferior, the result of a very imperfect knowledge of the proper method and mani- pulation. But since, the progress has been a steady improve- ment to the present time, when we may be said to stand on nearly equal ground with the older nations, our products comparing favorably with any others. Owing to the prestige of time and many local facilities, Europe may produce many superior soaps, and may be said to be without rivals in certain kinds; yet in as far as the usual toilet soaps are concerned, we are, owing to our many • improvements in machinery, the abundance of superior ma- 390 TECHNICAL TREATISE ON SOAP AND CANDLES. terials, and the attention to the chemical rules of the art, producing goods that, for prices and quality, compete with any in the world. The fabrication of toilet soaps presents but few changes from those already given in the making of domestic and manufactured soaps, except a greater care in the selection of the raw materials, which should all be of the best quality. The fatty bodies and the bases should be purified as much as possible, the oils and fats from all odor and impurities, the alkali from all foreign salts and carbonic acid, and made as caustic as possible. For making a good and pure toilet soap, due care in puri- fying the fats and oils is perhaps the first stage of the pro- cess. When the manufacturer has the opportunity and the facility to render his own greases, there will be much advan- tage as insuring their purity and enhancing the quality of his soaps very much. To Render and Purify the Grease, — Fat of good quality and very fresh must be selected, the membranes of which are carefully removed. This operation being performed, it is spread on a strong piece of oak wood and strongly beaten to open the adipose cells in which the grease is contained; by this means the grease is more easily and quickly extracted. The fat is then washed five or six times in cold water, the water being renewed each time. This operation is performed in large buckets two-thirds filled with water; the water of the last washing must remain clear and limpid. The object of these washings is to remove, as completely as possible, the coloring and bloody parts which are adherent to the grease, and which would color and alter it during the trying out, and would render its perservation uncertain and difiicult. These washings being finished, the fat is drained on clean cloths, then melted in a copper kettle, in which is a quantity of water about equivalent to one-third of the weight of the fat. All being thus ready, heat the kettle, and, when the grease is melted, add from five to seven ounces of pure salt for every 45.5 kilog. (100 pounds.) Boil for eight or ten minutes, and as in boil- ing a scum is formed, it is carefully removed with a skim. TOILET SOAPS. 391 mer. The melting being finished, decant the liquid grease into large copper vessels having a conical form ; but to have clean grease, pass it through a hair sieve which prevents the solid and insoluble substances from passing through. Let it rest for two or three hours ; during this time the water sep- arates, carrying with it the dirt contained in the grease. It is then carefully decanted and put back into the scoured kettle, and melted with water, to which are added a few quarts ofrose or orange-flower water. Heat anew, and when the grease is melted, add to it two ounces of pure powered alum for 100 pounds of grease, boil gently for eight or ten minutes, and carefully remove the scum formed on the surface of the grease. Then turn off the heat, cover the kettle with care, which is essential for keeping the mass at an elevated tem- perature. Let this stand for eight or ten hours, or, what is surer, until the grease begins to whiten and solidify on the sides of the kettle. When in this state, decant it into clean barrels and keep for use. As the last portions of grease which swim on the water are less white and pure than the first, they are kept separate to prepare soaps of second qualit3^ The grease thus purified may be kept a long time without alteration, and forms the base of toilet soaps of the first quality. There are other methods for attaining this end. When the greases are ob- tained reasonably pure, one of the simplest is to melt in the kettle the requisite soap grease, and when at about 45° C. (113° F.) to add about two per cent, of strong alkali of 36° to 40° B., stirring some time and shutting off the heat. A soap Avill be formed of the impure fat, and will sink to the bottom, carrying almost all of the other impurities down with it, when the clarified grease can be carefully separated. In boiling a soap and separating with culinary salt, fats less pure may be used, as the impurities are usually carried down with the sub-lye, which separation can be repeated till the soap is pure and colorless, and to the improvement of its quality. But in the soaps by the extempore processes, all the contents of the fats are retained in the soap as well as 392 TECHNICAL TREATISE ON SOAP AND CANDLES. the glycerine, hence the necessity of a purified fatty body to produce a good and pure product. Toilet soaps are now nearly all made by this latter (cold) process, for several reasons : first, because the alkalies are now obtainable in a much purer state than in former years; sec- ondly, because, by the facilities of improved machinery, their quality is improved ; thirdly, because they retain their form much better than boiled soaps, which in drying warp and become misshapen; fourthly, because by means of these new appliances they can be manipulated, milled, colored, per- fumed, plotted, etc., in a cold state; finally their appearance is much more attractive. All these manifold labors tend to the improvement of a soap, as the more it is worked the more perfect is the union of its ingredients, and consequently the more perfect is the soap. Cocoa-nut oil has for many years formed one of the chief constituents of toilet soaps on the continent of Europe, and, when its natural rancid smell is not objected to, is a valuable material, as it has some desirable properties, making a very white and emollient soap, but it is not possible to remove all its unpleasant odor. For this reason it is not used in the better qualities of soaps, nor in but a small proportion, and then the best quality of Cochin China oil is preferred. Cotton-seed oil is another ingredient, that has lately claimed much attention as a material for toilet soaps, and has some peculiarities similar to the cocoa-nut oil without its unpleasant smell. We have used it in combination with tallow, castor oil, lard, etc., and the resulting soap was quite satisfactory. Being a cheap material, it would appear that it should attract great attention from the manufacturers of toilet soap. Toilet Soaps by Boiling. We have in this work given so many particulars, as to the processes of boiling soap, that it is scarcely necessary here to repeat them, as all of these methods apply equally to soaps for toilet purposes, but, as we desire to make this work as com- plete as possible, we will give some examples, remarking that TOILET SOAPS. 393 nearly all the appurtenances heretofore given apply to this branch also, and repeating the necessity of securing pure and neutral products and materials. In many large manufactories it is quite common to have the boiled soaps in stock in several kinds, which are mixed in certain proportions to form the various kinds; thus they make a white soap, a palm soap, a half-palm with rosin, a cocoa-nut oil soap, etc. These are usually kept in a cool room or cellar, and when wanted they are re-melted, or milled, colored, perfumed, etc. To make one of these soaps by boiling we give the formulas for the half-palm soap with rosin, and the process will apply to the rest except the cocoa- nut oil soap which is differently made. Half-Palm Soap. Either of the following formulas may be used: — White tallow 900 pounds. Palm oil 400 " Cocoa-nut oil 200 " Yellow rosin 100 " 1600 Tallow 700 pounds. Palm oil 300 " Cotton-seed oil 400 " Rosin 200 " 1600 " Lard 550 pounds. Tallow oil 400 " Cotton-seed oil 450 " Rosin 200 " 1600 " The proportions of these substances are not fixed, and vary according to the uses for which the soap is destined. In England this soap is prepared with common tallows and an addition of rosin. In France where it is used only for toilet purposes, it is better attended to, and its purification is more 394 TECHNICAL TREATISE ON SOAP AND CANDLES. complete. The above formulas give a soap of superior quality, and the use of which is very advantageous in the preparation of toilet soaps. The palm oil may be bleached or not, but must always be purified. Fasting. — By a gentle heat, melt the tallow and oils in a kettle of a capacity of at least 2633 litres (696 gallons). When melted, pour into the kettle 378 litres (100 gallons) of new lye at 8° or 10° B. ; heat slowly and gradually, stir- .ring from time to time, and when the ebullition begins, moderate the action of the heat, to avoid too rapid a reac- tion in the mass. After continuing the ebullition for about four hours, pour little b}^ little on the paste from thirty-five to fifty gallons of new lye at 15° or 18°, and incorporate it by stirring for fifteen minutes. This being done, continue to boil for three hours, or rather until the paste appears quite homogeneous and has acquired a certain consistency. Then a new quantity of thirty-five gallons of lye at 20° may be added, and after a new ebullition of two hours the first opera- tion is finished. Separation. — The pasting being finished, the heat is stopped off, and after a few hours' rest, pour into the kettle a limpid lye of coction, i. e.^ salted lye at 20° to 25°, or a new lye con- taining salt in solution. While one man pours in the lye, another stirs the paste all the time. When the quantity of salt lye introduced into the kettle is suflScient, the soap is transformed into small grains, and the lye separates abun- dantly. After resting five or six hours, draw off the lye. About two-thirds of the lyes which have been used are drawn off ; they have a yellowish color, and mark when cold from 15° to 16°. The pasty mass left in the kettle has a fine yel- low color. Coction. — The coction of this soap is very little different from that of pure palm-oil soap. Like the latter, it is effected with new and caustic lyes of soda marking 25° or 28°. When the operation is done in two services, lyes at 18° or 20° are used for the first service, and lyes at 25° or 28° for the second. When, on the contrary, the coction TOILET SOAPS. 395 is finished in a single operation, lyes at 25° are used. This last process is the quickest and most economical. The lyes being drawn off, pour into the kettle from 567 to 661.5 litres (150 to 175 gallons) of new lye at 25° ; heat, and give a gentle boiling, for in the first hours the soap dilates and swells considerably. Its surface is then covered with an abundant scum, which gradually disappears only as the coction progresses. It is necessary to stir from time to time during the whole of the operation. This agitation is very important, for it accelerates the coction of the soap. When the soap has been gently boiled for three or four hours, the heat may be increased without fear of burning the soap. Generall}^, after eight or ten hours of ebullition with lye at 25° the soap is completely boiled. The scum has entirely disappeared, or there remains very little on the surface of the soap, which then has the form of hard and dry grains. When these grains are pressed between the fingers, they form thin and hard scales. The rosin has been added at the beginning of the coction, so as to saponify it completely. When the soap is suflaciently boiled, which is known when it forms scales, stop off the heat, let it rest a few hours, draw off the lye, and proceed to the fitting. Fitting. — Two operations are necessary to completely re- fine the soap. The first has for its object to soften the grains of soap, and to separate the greater part of the free alkali and saline matters ; the second has for its object to completely dissolve the grains of soap and precipitate the coloring and heterogeneous substances, and the excess of caustic lye it contains. First lAquefadion. — When the lye has been drawn off, pour into the kettle 378 litres (100 gallons) of new lye at 8° or 9°, and heat gradually until boiling, being careful to stir the mixture well. When the grains of soap have be- come soft, cease the stirring ; and, to complete the precipita- tion of the strong lye contained in the soap, boil for five or six hours, or even eight hours. As by such a long ebullition the grain of the soap has a tendency to be formed again, pour from time to time into the kettle a few pails of lye at 396 TECHNICAL TREATISE ON SOAP AND CANDLES. 2° and even pure water. It is, however, necessary that the soap should be always separated from the lye ; this is ascer- tained by pouring some into a glass, and if so, the lye pre- cipitates at the bottom of the glass. It is important and essential to have, during the whole operation, the lye sepa- rated from the soap, to obtain the separation of the strong lye mixed with the paste. When this result is obtained, stop off the heat and cover the kettle. Let it rest six hours, then introduce the soap into another kettle and proceed to a second liquefaction. Second Liquefaction, — Whatever has been the care taken in the first liquefaction, the soap has not been completely de- prived of all its causticity — it always contains a certain quan- tity of caustic alkali, which must be eliminated to obtain a pure product. This is the object of the second liquefaction. But to obtain all the good results this operation may produce, substitute for the caustic lyes of soda ash, a non caustic solution of crystals of soda. By its extreme purity and the absence of causticity, this solution completely purifies the soap, depriv- ing it of all its caustic parts. Pour into the new kettle about 136 litres (36 gallons) of a solution of crystals of soda at 4J° or 5°, and heat to a temperature near the boiling point. Then introduce the soap from the first kettle into the second, being careful not to draw any of the sub-lye. This being done, boil thQ mixture gently for four or five hours, being careful to stir from ti me to time. By the ebullition with weak lyes (aqueous solution of crystals of soda), the soap entirely loses its granu- lar appearance, and becomes syrupy, fluid, and homogeneous. As in the first liquefaction, a scum is formed on the surface of the soap, and this scum is more considerable on account of the greater dilatation of the paste. As by evaporation the lye concentrates, add from time to time very small portions of water, so as to keep the paste always fluid. The heteroge- neous coloring and saline impurities will be precipitated by resting. The soap must not contain too much water, for in this case it would be too long in hardening. The signs by which it is ascertained that the paste is sufliciently liquefied, are manifested by a slightly blackish coloration which proves TOILET SOAPS. 397 that the black soap has been precipitated to the bottom of the kettle, and is brought up in the mass by the ebullition. When these characteristics have been observed, the operation is finished ; stop off the heat, cover the kettle and let it rest eighteen or twenty hours. By resting, the black soap pre- cipitates with the lye, and the pure soap is between it and the scum. After eighteen or twenty hours' rest, uncover the kettle and remove the scum on the surface of the soap. Re- move the pure soap and introduce it into the frames, passing it through a metallic wire sieve; all the foreign bodies in the soap remain on the sieve: — When all the pure soap has been introduced into the frames stir it well till cold ; this manipulation is necessary to make it homogeneous. By operating as we have indicated, the above quantities of fatty matters generally give : — Soap-scum, from 64 to 73 kilog. 141 lbs. to 161 lbs. Pure soap, " 954 " 983 " 2100 " " 2160 " Black soap, " 227 " 273 " 500 " " 600 " The scum and black soaps are mixed in the next operation or used for a common soap. The half-palm soap has a very pure yellow color when manufactured with good materials. It has also a good odor, and is useful for making many kinds of soaps, such as honey, glycerine, marshmallow, etc. For a palm soap for stock and for toilet soap, we refer to the formulas previously given for palm soaps, and for this purpose advise extra care in selecting the materials. For a white soap for toilet purposes use the same processes for tallow, grain or curd soap, given elsewhere, using only the whitest and sweetest greases and purest alkali. The cocoa-nut oil soap for toilet purposes should have a different manipulation. This oil not being saponifiable in w^eak lyes, it is always necessary to use lyes of 28° to 36° B. They need not be entirely caustic, as this oil can also be saponified in carbonated lyes, though it of course takes more of them and a longer time. For this soap it is now customary to use a portion of lard, cotton-seed oil, or any other white grease or oil, but the cocoa-nut oil for toilet soaps should be 398 TECHNICAL TREATISE ON SOAP AND CANDLES. the best Cochin China oil. By using a certain proportion of potash lye the soap retains a more plastic consistency and is much improved. The amount is usually from 6 to 10 per cent. "White Soap from Cocoa-nut Oil. To prepare 182 kilog. (400 lbs.) of this soap, introduce into a kettle of a capacity of 200 to 250 gallons 200 pounds of pure white cocoa oil ; add afterwards 200 pounds of colorless and perfectly limpid lye at 30°. All being ready, heat the kettle, and, to accelerate the combination of the substances, stir well from time to time. Under the influence of heat the material, which at first was in the form of grains, softens and becomes liquid. Continue to heat slowly and gradually until the combination between the oil and alkali is effected, which generally takes place when the ebullition begins. When properly made, the soap has the appearance of a fluid, homogeneous, and syrupy paste. Its color is amber white. It is useless to boil it ; stop off the heat and draw off the soap into the frame. If, on the contrary, it happens when the mixture begins to boil that a certain quantity of oil swims at the sur- face of the paste, it may be combined wnth the saponified mass, by adding ten to twelve pounds of cocoa-nut oil soap. The same result may be obtained by adding eight or ten quarts of pure water. After stirring a few minutes, the homogeneity of the soap is re-established, and the combina- tion of the substances is perfected. The heat is then stopped, and the soap drawn off into the frame. After five or six days, the soap is firm enough to be taken out of the frame. Obtained by the above process, this soap is very white, does not contain any excess of alkali or oil, and may be employed for toilet uses. From the quantities indicated above, from 396 to 420 pounds of soap are obtained, accord- ing to the quantity of water added. The operation lasts about one hour. It is not necessary to give further formulas for the different TOILET SOAPS. 399 soaps that this useful oil may form in any judicious mixture with other fats, as they are almost without number, and, with the hints already given, any others may be manipulated. Where a colored soap is desired, palm oil is a very suitable combination. The soaps here given may be called stock soaps; for from them nearly all kinds of toilet soaps can be formed, by a mixture of the different kinds in suitable proportions, mill- ing, mixing, coloring, plotting, moulding, and perfuming to suit the kinds needed. As in our formulas these soaps may be frequently called for, it were well to give them some attention. But as we haVe before remarked, almost all toilet soaps are now made by the cold or extempore process, when the soaps are colored and perfumed in the kettle, or what is better, when they are run into the frames, or still better, when put in a crutching machine, such as we have described else- where. 400 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIO^T XX. TOILET SOAPS BY THE COLD PROCESS. Extempore Soaps. These processes have become so universal for the fabrication of all toilet soaps, that they require special attention at our hands. Beyond what has been already given in the methods for making the cold or extempore soaps, there is but little to add, except in the care in selecting the purest materials, or making them perfectly pure before manipulation, and giving due regard to the proper equivalents of the fatty bodies with the alkalies to form a neutral soap. For fine toilet soaps there are many desirable greases and oils, that can be used to much advantage, their price being usually too high for the ordinary soaps, but in this class of soaps, the price generally obtained justifies their employ- ment. Thus almond oil, castor oil, olive oil, butter, lard, tallow oil, beef-marrow, cocoa-butter, bleached palm oil, palm- kernel oil, sesame oil, and other such like fats and oils of good quality could be advantageously used in a judicious admixture, for it seems that such a mixture produces a more desirable soap than any one used alone will do, the properties of one so blending with the other as to produce the most satisfactory results. From the facility with which this soap can be made, it is quite unnecessary to make the stock soap as mentioned and described in our last chapter. For a small quantity can be made as well as a larger ; indeed it is not convenient generally to make over five to eight hundred pounds at a time, and the kind of soap needed can be at once prepared, colored, and per- fumed at the finish as described. Some manufacturers prefer to mill all their soaps, and color and perfume while milling; TOILET SOAPS BY THE COLD PROCESS. 401 there are many advantages in this. The color is better, more uniform, there is no loss of color or perfume by heat, there is a more complete blending of the materials in the soap, which, when finished, retains its form, color, and per- fume for any reasonable length of time. Again, for the superfine soaps of the finest odors, made from the oils or pomades perfumed with flowers by the pro- cess of enfleurage, elsewhere described, such as rose, jasmine, orange-flower, etc., this extempore process is indispensable, as a boiling heat would cause not only a loss of perfume, but an undesirable change in it. Many mechanical appliances have been made to facilitate this process ; which usually have a stirrer or twirl placed in the kettle or cylinder, and are a great advantage in manipu- lating ; they are illustrated in our former chapter on cold soap for domestic use. The use of filling in toilet soaps must not always be con- sidered an adulteration, for there are some substances that may be regarded as an advantage, or at least in the light of ameliorators. Thus dextrine in moderate quantity gives smoothness without injury, while the mucilage of gum traga- canth gives both smoothness and emollience, which are desirable qualities in the best soaps. Soluble glass, while it cheapens the cost of soaps, does not, if used in moderation, and properly combined, injure its detersive quality or its value for use. It is, however, often used in such quantities as to become, with other adulterations, a means of unprincipled sophistication, giving a bad character to much of the toilet soap of commerce. Rosin, on the other hand, if added to other good materials, may have certain advantages, especially with a medium grade of soap, giving it a soluble and lather- ing property, which is always popular. A portion of potash lye also gives this soluble property. The alkalies for toilet soaps, as we have said, should be of the purest, and should receive strict investigation (see Alka. limetry). While the caustic lyes of commerce are, as a rule, sufficiently pure for ordinary soaps if freshly prepared and made caustic, for the finer grade of soaps, it is most desirable 26 402 TECHNICAL TREATISE ON SOAP AND CANDLES. to prepare the caustic lyes from the crystallized carbonate of soda ; from its mode of manufacture having less foreign salts than any other form of soda. To prepare this alkali it is only necessary to extract the carbonic acid with the purest lime attainable, and form a solution of 12 to 15°, and then concen- trate by evaporation to the desired strength, putting into well filled and stoppered bottles or carboys that it may not ab- sorb any carbonic acid, and that it may be always ready for immediate use. In making the soaps by the cold process our formulas gene- rally call for a lye at 36° B. Now this is subject to some modi- fication, as there are many circumstances and conditions where a lye of less strength would be more advantageous. When a weaker lye is used, there must of course be more of it (the tables given will show how much); and again the different greases act somewhat differently in connection with the weaker or stronger lye; all of this must be gained by expe- rience, for it would be impossible without a knowledge of all the conditions and materials to give exact details. With these preliminary remarks we think we can now proceed to give the necessary formulas, and begin with White Soap by the Cold Process. To obtain white toilet soap of the first quality, employ white grease. The following are the best proportions to use: — Pure white grease 160 lbs. Lye of crystals of soda at 360 B. . . . 80 " 240 Saponify as follows : Melt the grease in a cast-iron kettle of a capacity of about 75 gallons. To operate with great precision, dip a thermometer into the melted grease, and when the temperature has reached from 45^ to 50° C. (113° to 122° F.) pour in slowly the 80 pounds of lye at 36° B., stir the mixture all the time with an iron spatula until the entire saponification of the materials. It is important not to raise TOILET SOAPS BY THE COLD PROCESS. 403 the temperature above 122° F., for in that event a part of the 1 ve would separate from the fatty substances. For the quantities indicated above, the operation lasts about two hours. When the saponification is finished, which is ascertained when the fatty matters are exactly combined with the lye, run the soap into a frame. While the soap is yet soft, if almond soap is wanted, it may be perfumed with 12 ounces of oil of bitter almonds, and 4 ounces of oil of lemon for each 100 pounds of soap. For the above mixture may be substituted 13 ounces of artificial oil of bitter almonds, but this last oil communicates to the soap a yellowish shade. This soap may be also perfumed with the following mixture for 100 pounds: — Oil of vervain " lavender " bergamot " lemon ' ' thyme The oils must be added as soon as the soap is poured into the frame ; and well crutched to mix. A remarkable phenomenon, not produced with soaps boiled on the lye, occurs five hours after the soap is poured nearly cold into the frame; a spontaneous reaction takes place, which raises the temperature to about 82.2° C. (180° F.). Under the influence of this temperature the difierent constituent princi- ples of the soap combine more directly and intimately, and the product is better. It is important to hasten that reaction by closely covering the frame. A few days after the mass of soap is cooled and solidified, take it out of the frame and divide it into cakes, which are dried in the drying room, if necessary. The quantities of substances used give from 236 to 238 pounds of soap, or 149 per 100 of fat. When well prepared, this soap is of a very pure white, not very alkaline, and produces an abundant lather with water. Rose Soap. — The white soaps can be colored with four or five ounces of vermilion, and perfumed with 2| ounces. 2 2 2 3 404 TECHNICAL TREATISE ON SOAP AND CANDLES. Oil of rose 2 ounces. " geranium 4 *' " cinnamon 1 ounce. " cloves . . . . . . • 2 " " bergamot 2 ounces. to each 100 lbs. Windsor Soap can also be made of the white soaps or with the half-palm soap, coloring with caramel or other means, and perfuming each 100 pounds with Oil of cinnamon 4 ounces. cloves . . . . . . .1 ounce. " caraway 1 " " sassafras 2 ounces. " bergamot 2 Yellow Soap. — This soap, which has a fine yellow color, is obtained with tallow, palm, and cocoa oils. The following proportions give excellent results: — White tallow 50 lbs. Cocoa-nut oil 30 " Palm oil 20 Lye of soda at 360 B. . . . 50 to 52 " Melt the tallow and other fatty substances in a sheet-iron kettle, add the lye, and operate as for white soap. If the color is not dark enough, add a solution of annotto, pre- pared by boiling one ounce of annotto or cadmium yellow, in one quart of lye of soda at 10°, boil five minutes and pass through a cloth. Perfume this soap with the following composition, calcu- lated for 150 lbs. of soap: — Oil of lavender 10 ounces. " lemon 2 " *' vervain . . . . . . . 1^ '* " peppermint | ounce. " neroli petit grain 1 " White Windsor Soap. Take White tallow 80 lbs. Cocoa oil 40 " Lye of crystals of soda at 30° . . . . 68 " " *' potash at30o . . . 12 " TOILET SOAPS BY THE COLD PROCESS. 405 Melt the greases in a kettle of a capacity of about fifty gallons. When the fusion is complete and the temperature is at about 35° C. (95° F.), introduce the lyes little by little, stirring all the time, and continue until the substances form a homogeneous paste. The operation lasts about fifteen min- utes. This soap is perfumed with Oil of carvi (caraway) 4 ounces. " bergamot 6 " " Portugal 2 " *' cloves ^ ounce. " lavender 4 ounces. " thyme 2 " Add the oils to the soap a few minutes before introducing into the frames. When the soap has become solid divide it into cakes weighing from two to four ounces, according to the size of the mould. The soap thus prepared is of a very pure white, and does not contain too much caustic alkali. Honey Soap can also be made of the half-palm soap with rosin, by putting in the pan just before turning into the frame 8 ounces of citronella oil and 2 ounces of lemon-grass oil to each 100 pounds. Glycerine Soap can be perfumed in the same way; for each 100 pounds take Oil of cassia 2 ounces. " caraway 1 ounce. " lavender 4 ounces. " mirbane 1 ounce. Let both of these soaps be a bright yellow, the last of a somewhat darker shade to distinguish it. Marsh-mallow Soap can be made by an admixture of the palm and the half-palm soap, and perfumed to each 100 pounds with Oil of lavender 6 ounces. " lemon-grass 4 " " peppermint ^ ounce. *' petit grain ^ " To make a good rose soap take equal parts of the white 406 TECHNICAL TREATISE ON SOAP AND CANDLES. and cocoa-nut oil soap, and color 100 pounds with 12 ounces of French vermilion, and perfume with Oil of rose geranium 4 ounces. " rose 1 ounce. " cinnamon 1 " " bergamot 2 ounces. Old Brown Windsor Soap. This popular soap, when properly prepared, is made in the following manner : Take of boiled palm soap and half-palm soap each 50 pounds; put in the stripper, and make into thin shavings, and spread upon sheets of strong paper to dry; when dry, melt in a marine bath with a small portion of an .aromatic water, and when it is again hard enough pro- ceed to cut it up and strip it as before, drying it again and remelting and adding caramel to color ; and after the third operation add the following perfume to the 100 pounds: — Oil of bergamot 4 ounces. • " caraway 2 " " cassia 2 " " lavender 8 " " cloves 1 ounce. " petit grain 1 " Mould or cut into small square cakes, and wrap them in a neat paper wrapper. Brown Windsor soap owes its fine emollient properties to the amount of labor employed in its manufacture, for it is almost needless to say that the more soap is worked and handled, and melted and remelted, the better it becomes. This soap is, in large establishments, often made of the scraps of all other kinds of soaps that accumulate from moulding and other manipulations, but of course these do not generally produce so good a soap. Half Boiled Soap — Swiss Soaps. We employ the latter term to denote the soaps that are usually boiled in one lye and by one operation, and which TOILET SOAPS BY THE COLD PROCESS. 407 not being separated retain all their glycerine and are classed among the extempore soaps. There are several ways of working more or less perfect; we .will describe two. First, when a soap is composed of one part cocoa-nut oil and two parts of other greases, the cocoa-nut oil is saponified by the cold process separately, while the other greases are boiled with a weaker lye of 12° to 16° B., separated, and the lye withdrawn. The two soaps are then mixed and gently boiled, being careful that they do not separate, and that the due pro- portion of alkali and water is used to form a neutral soap. By the second method the process is simplified, and with careful manipulation the result is equally satisfactory, and the yield is greater, 100 pounds of fats forming 210 to 220 pounds of marketable soap. It is customary to make these toilet soaps with a percentage of potash \ye with the soda, say about 10 per cent. In this process the whole amount of fats or oils is at once placed in the kettle, and the lyes are made rather strong, 15 to 20° B. One half is put with the grease and heated to a gentle boil, which should cause a combination of the ingredients if the lye is not too strong. When this lye has been absorbed, the rest of the lye is added from time to time until all is taken up, and the froth disappears, and the soap has the proper consistency, and is of a gelatinous appearance, when it is run into the frames, crutched, colored and perfumed, while it is still soft. This operation occupies about four hours. In forming the Swiss soaps a certain amount of skill is very essential, and various precautions must be exercised in having the due equivalents of fat and alkali, and the proper proportion of water that the soap is to retain, and the final adjustment of the soap at the finish to insure its proper admixture and neutral character. Having a portion of cocoa- nut oil in their composition, they will hold a large percentage of water, and can also be filled with salt water, silicate of soda, etc. etc. Care must also be taken that the soap does not grain; if it does, a few gallons of hot water stirred in will generally restore it to a pasty condition. 408 TECHNICAL TREATISE ON SOAP AND CANDLES. Kurten^s Table, Showing the composition and product of soap by the cold process from con- centrated lye^ and mixture of cocoa oil with palm oil, lard and tallow. IS o d CO ® 00 05 Soap. o ej O o a « « 9 bo (D w iS "o bo « s O E-t o O 1^ CO Ph be o, Cocoa-nut, No. 1 . . 100 56 36 153 Paris toilet, round 20 30 's 31 36 5 36 87 io Kf\ oo 1 K(\ lOU Windsor, square. . . 66 34 77 30 13 30 185 Shaving, No. 1 . . . . 00 or 33 or 34 33 120 27 214 Shaving, No. 2 33 34 33 120 27 12 12 226 Washing, No. 1 . . . 60 40 or or 125 27 25 12 244 30 40 30 Washing, No. 2 . . . 40 60 or 60 40 135 27 50 15 278 Ordinary cocoa oil . or 100 or 10 90 or 90 10 225 21 75 12 400 MISCELLANEOUS TOILET AND MEDICATED SOAPS. 409 SECTIOi^' XXI. MISCELLANEOUS TOILET AND MEDICATED SOAPS, WITH FORMULAS. We have in our two preceding sections given the pro- cesses for forming the usual kinds of soaps used for making toilet soap, and those that are at once made, colored, and perfumed at the finish and are ready to be cut up and dried previous to moulding. We here give formulas for making the various soaps now known in commerce, with suitable hints towards many new styles. As we have said, the manipulation of soaps for the toilet is an important part in the production ; to make them market- able, good and uniform, well colored and smoothly finished, nicely perfumed, and neatly packed. To aid these ope- rations, various appliances are used, and much apparatus is needed, and in our next section we will give a careful de- scription with illustrations of all the latest machines now in use and which greatly facilitate the manufacture, saving time and labor, besides improving the quality and appearance of the products. Many of the finer soaps have to be made from the raw materials, though most of them are made from the stock soaps before mentioned. The different formulas will show in some instances that the soaps can be remelted to produce the best results, though many and most can be mixed, colored and perfumed by repeated passage through the mill, and this kneading that they receive will tend to benefit them. Cold Cbeam Soap. White soap Spermaceti soap Oil of almonds . Caustic potash, QO Gum tragacanth . 30 lbs. 20 " ^Ib. 1 " 2 ounces. 410 TECHNICAL TREATISE ON SOAP AND CANDLES. To manipulate, strip up the two soaps, place them in the hopper of the mill, dissolve the gum by previous soaking in a little water, mix with the oil and lye to a uniform con- sistency, then stir into the soap and grind in the mill until thoroughly combined. Care should be taken to have it as white as possible. Perfume the above with Oil of bergamot 5 ounces. " cloves 1 ounce. " nutmegs . . 1 " " thyme 3 ounces. " bitter almonds 1 ounce. Bouquet Soap. White curd soap 60 lbs. " cocoa-nut oil soap 40 " Dextrine ........ 3 " Perfume with Oil of cedrat 6 ounces. " asarum 2 " " cloves 2 " " thyme 3 " " petit grain 2 " Color a light yellow with cadmium yellow, manipulate as for the cold cream soap, dissolving the dextrine in its weight of warm water. Lemon Soap. White soap 50 lbs. Starch 2 " Perfume with Oil of lemon 4 ounces. " bergamot 2 " " lemon-grass 2 " " cloves 1 ounce. Color light yellow wnth cadmium yellow. miscellaneous toilet and medicated soaps. Orange Soap. White soap . . ' . . . .50 lbs. Starch 2 " Perfume with Oil of orange peel 8 ounces. " cinnamon ^ ounce. " thyme . , . ... . 2 ounces. Color dark yellow with naphthaline yellow. Elder Flower Soap. Half-palm soap 100 lbs. Dextrine 3 " Perfume with. Oil of bergamot .8 ounces. lavender , . 2 " " thyme 2 " " cloves 1 ounce. " cassia 2 " " almonds 2 " Color light green with Guinet's green. Heliotrope Soap. White curd soap 80 lbs. Palm soap 20 " Starch 4 " Perfume with Oil of rosemary . ... . . .4 ounces. " thyme 2 " " rose geranium 3 " " cloves 2 " " almonds 1 ounce. Balsam of Peru 3 ounces. Color light purple with a red and blue color. Frangipanni Soap. Palm soap 30 lbs. White soap 20 " Dextrine . . 3 " 412 TECHNICAL TREATISE ON SOAP AND CANDLES. Perfume with Oil of bergamot 4 ounces. " neroli 2 " " santal 2 " Tincture vanilla 4 *' " civet 4 *' Color light hrown with tincture of catechu. For toilet soaps made with other soaps, these recipes will give a proper idea and hints for any kind the manufacturer will desire. Superfine Soaps. We will now proceed to give the formulas for fine and superfine soaps, to which we would recommend the addition of a little wax as giving a consistency and smothness, besides improving their quality. Ambergris Soap (Ambrosial Soap). Grease perfumed with ambergris and musk . 25 lbs. Jasmine pomade of flowers, No. 24 . . . 10 " Rose " u "... 10 " Beeswax 1 lb. Gum tragacanth 3 ounces. Caustic soda lye, 33o B 25 lbs. Color light brown with caramel. This soap is made of select materials by the cold process, and after being made is allowed a few days to dry before milling ; the musk and ambergris have to be added to the grease some weeks before, frequently melting and stirring. Benzoin Soap. Lard with benzoin 30 lbs. Cocoa-nut oil 10 " Tallow 10 " Soda lye, 350 B 26 " Gum tragacanth . . .... 2 ounces. MISCELLANEOUS TOILET AND MEDICATED SOAPS. 413 Perfume with Oil of bergamot 8 ounces. " lavender 3 " " pimento 1 ounce. Flowers of benzoin . . . . . .3 ounces. Tincture of benzoin 3 " Saponify in the usual way. The lard with benzoin is made by infusing the lard with the powdered gum, two ounces to the pound for a month, occasionally melting and Stirring. Melt and strain off the clear lard before using. JoNQUiLLE Soap (superfine). Orange-flower pomade, No. 24 . . . .20 lbs. Tuberose " " .... 10 " Jasmine " " . . . . 10 " Castor oil 10 " White wax IJ " Gum tragacanth 2 ounces. Caustic soda lye, 360 B 27 lbs. Saponify as carefully as possible, avoiding too much heat. This soap will be a light yellow. To enhance the color add a little anatoline. MiLLEFLEUR SOAP. Lard with vanilla 20 lbs. *' ambergris 10 " Rose pomade (aux fleurs) No. 24 . . . 10 " Butter of cocoa 10 " Chocolate 2 " Caustic lye, 36° B 26 " Perfume with Oil of orange (Portugal) 8 ounces. " lavender 4 " " cloves 2 " " nutmegs 1 ounce. Tincture of musk 4 ounces. The chocolate will give the proper color. Operate with care, and you will have a very fine soap. 414 TECHNICAL TREATISE ON SOAP AND CANDLES. Savon a la Marechale (surfin). Lard with musk 10 lbs. " " ambrette 10 " Pomade (aux fleurs) No. 24 : Cassia, jasmine, and rose, of each . . . 10 " Olive oil 1 lb. White wax 2 lbs. Gum tragacanth 2 ounces. Caustic lye, 360 28 lbs. Saponify carefully and color with a little caramel. Savon Hygienique (extra fine). Orange flower pomade. No. 24 . . .10 lbs. Rose pomade. No. 24 5 " Palm oil (bleached) 20 " Cocoa butter 5 " Olive oil 10 " White wax . . , . . . . 1 lb. Caustic lye, 380 B 24 lbs. Gum tragacanth 2 ounces. . Perfume with Oil of santal 2 ounces. " geranium 2 " " valerian (rect.) 1 ounce. " melisse 1 " " orange ; . 4 ounces. " thyme . 2 " Avoid too much color ; the soap should have a yellowish- brown that needs no addition. Savon a la Violette de Parme. Violette pomade, 24 20 lbs. Eose " 24 10 " Cassia 24 10 " Palm oil (bleached) 10 " Soda lye, 360B 25 " Gum tragacanth 2 ounces. Give it a purple color, not too dark. MISCELLANEOUS TOILET AND MEDICATED SOAPS. 415 Lettuce Soap. Lard with lettuce 20 lbs. Cassia pomade, 24 10 " Spermaceti 5 " Castor oil 5 " Palm oil (bleached) 10 ^' Caustic lye, 360 B 26 " Gum tragacanth 3 ounces. Perfume with Oil of bergamot 6 ounces. " thyme 2 " " valerian 1 ounce. " cloves 1 " Color light-green with Guinet's green. The lard with lettuce is made by melting the lard with its own weight of lettuce leaves, keeping it at the melting point, about 32.2° C. (90° F.), for some hours, or until the leaves have parted with their color and juice, then strain off for use. Cucumber Soap. Operate as for lettuce soap, using the fruit. MoussELiNE Soap. Similar to marechale soap, using another color. Savon de Muguet. Lily Soap. Similar to jonquille soap, keeping it as white as possible. Rose-leaf Soap (extra fine). Rose pomade (aux fleurs) No. 24 . . .20 lbs. Lard 20 " Cocoa-nut oil 10 " White wax 2 " Soda lye, 360B 20 " Potash lye, SQo B 12 " Gum tragacanth 3 ounces. 416 TECHNICAL TREATISE ON SOAP AND CANDLES. Perfume with Oil of roses 2 ounces. " geranium 2 " rhodium 1- ounce. " bergamot 2 ounces. " cinnamon (Ceylon) . . . . ^ ounce. Color with aniline (fast red) a light pink. Violet Soap (yellow). Cocoa-nut oil 20 lbs. Palm oil 20 " Tallow oil 10 " Soda lye, 360 B. 26 " Orris root in fine powder 4 " Perfume with Oil of lemon 4 ounces. " rhodium 2 " " thyme 2 Tincture of musk 4 " Color with cadmium yellow. Vanilla Soap (superfine). Lard with vanilla ...... 30 lbs. Cocoa butter 10 " Palm oil 10 " Caustic lye, 360 B. 26 " Wax 2 Starch . 2 " Perfume with Tincture of vanilla 4 ounces. " " musk 2 " " " ambergris 2 " Oil of rose ^ ounce. Lard with vanilla is prepared by adding the vanilla to the lard (1 oz. to the lb.), keeping it at a moderate heat for some days, straining, etc. Rose Windsor Soap Is best made with the white soap as a body, coloring red, and perfumed nicely with any of the numerous formulas as here given. MISCELLANEOUS TOILET AND MEDICATED SOAPS. 417 YiOLET Windsor Soap. Take any good soap, say a mixture of white and palm soap, color yellow, and perfume nicely. Musk Windsor Soap. A palm soap perfumed with the tinctures of musk, civet, and vanilla, and colored brown with malline brown and well milled. These Windsor soaps are usually wrapped in neat wrappers. As French soaps have a just reputation for good quality, we append a list of names of some. French Toilet Soaps. Savon a Pambre. Savon a la verveine. an bouquet. (( a la tubereuse. a la fleur d'orange. (( a la limette. a I'acacia. (( au lilas. a la julienne. aux millefleurs. au narcisse. (( au myrte. a la jaciuthe. a la marechale. a la jasmine. ii orientale. a la jonquille. Occident. au vitevert. des Indies. a Toeillet. n a la balsamine. a la mousseline. i( au geranium. a la mignonette. c. 146. 1 at the ends with a large knife attached to an open tray, having a gauge board to regulate the length, and are sub- Fig. 147. mitted to the action of air and light, by being placed in a wire grating of lead upon a proper table or framework, as MANUFACTURE OF CANDLES. 529 shown by Figs. 146 and 147. This frame and wire are applied for bleaching stearic acid and other fine candles. The better class of candles are polished by hand by being rubbed with a soft woollen cloth moistened with ammoniated alcohol, or are polished by a machine made for the purpose. Fig. 148 is a drawing of a simple machine in general use in Fig. 148. France ; A, being the hopper in which the candles are arranged, and from which they are taken singly by the fluted cylinder B. This latter, in revolving gives them to the circular saw which cuts the ends, when they drop upon the erwiless belt of woollen cloth, running on the rollers G G G and passing around the drums H H. Three other rollers D D D covered with cloth, run by aid of pinions E EE, are run in an opposite direction. By these alternate motions the candles are made smooth and glossy, and delivered into the recep- tacle I. A more complete polishing machine is shown by Figs. 149 and 150 ; A A being the framework strengthened by the beam B, the belt C driving the pulley D or the loose one E, the moving axle carries the two fly-wheels HH, moving the shafts 1 1, and giving motion to the rubber J and the rubbing sheave M. The belt 'N connects M and The latter sheave is fixed in a horizontal shaft with a pinion wheel P at the 34 530 TECHNICAL TREATISE ON SOAP AND CANDLES. end, working into a large toothed wheel Q. The shaft also carries two small wheels with square teeth II, which give motion to an endless chain 2 composed of iron rods, and between which the candles 3 are placed. A small table covered with woollen cloth is fixed under the endless chain on which the candles roll as they are drawn forward from an incline, ranging parallel with each other. The candles are retained in their position under the rubber, by means of MANUFACTURE OF CANDLES. 531 lb the guide 7 regulated by springs 8 8, and when sufficiently rubbed and polished are deposited on the table at the other end of the machine. Almost all stearic acid, paraffine, and spermaceti candles and many of the composite candles are now made so per- fectly by finely finished moulds, that they require but little polishing and finishing; yet, some machinery for this pur- pose, however simple it may be, is indispensable to give a smooth and glossy appearance to the finished candles. 532 TECHNICAL TREATISE ON SOAP AND CANDLES. SECTIO]^ VIII. THE MANUFACTURE OF CANDLES (Continued). Composite and Patent Candles. From the nnmberof materials heretofore mentioned, there are a great variety of candles made with as many different names, yet they have much sameness in their characteristics as their composition is usually of two or more ingredients, thus w^e see stearo-palmitic, margaro-elaidic, stearo-cocinic, etc. etc., but with fancy names. The value of these candles depends upon their clean burning and light-giving properties as much as their handsome appearance, which in all cases should be as white and transparent as possible. Sometimes candles are. made having a part neutral fat with the stearic, palmitic, or cocinic acids, but as a rule they have not the illuminating power of the fatty acids ; then again their melt- ing point is generally too low. Belmmit spe?'m candles are made from a mixed body of stearic and cocinic acids combined with a portion of paraffine. Belmont wax candles are we believe stearic acid and a por- tion of wax tinted a creamy white with gamboge. Star candles have usually a base of stearic acid prepared from tallow and lard. Cerophane bougies, a French invention, are we think a composition of very white stearic acid, with ten to twelve per cent, of bleached beeswax, made transparent by careful moulding. Adamantine candles, named thus from their hardness, are made from a stearic acid produced from tallow which has the highest melting point, about 68.3° C. (155° F.). Though not so white or transparent, they give a good white light. Artificial wax candles are made in varying proportions of MANUFACTURE OF CANDLES. 533 stearic acid and wax, principally beeswax, though there are several vegetables waxes used which have to be previously bleached. Wax candles have a creamy white color which is usually imparted to the artificial wax by means of yellow pig- ment. There is also a certain art in the moulding of these candles necessary to give a waxy appearance and to deserve their name. This consists principally in so melting the mate- rial and keeping it quiet for about half an hour, while the temperature has reached the proper point, when it is carefully run into the previously warmed moulds which are gradually cooled. Diaphanous candles are also a French invention, and are we believe made of a superior stearic acid, from lard and some of the vegetable waxes (say Japan wax), which latter has been purified by chemicals. Care also is necessary in moulding to give a great transparency by a due regulation of the heat both of the moulds and the fatty bodies. Composition candles. — By this name so many different can- dles have been made that it would be almost impossible to give formulas. The term is applied to candles that have in their composition certain neutral fats or sebacic acids in certain proportions, one giving to the other a quality to improve either their consistency or lighting power. From these formulas the intelligent manufacturer should receive such hints as by experiment would enable him to make any candle he might desire. Various fatent candles. — From the many candles that have at times been patented, and which have been more ingenious than useful, we must select a few, for they may serve as hints to other inventions. In England candles have been moulded with a perforation through the centre (Fig. 153), the diameter regulated to the size of the candle; the wick is drawn through or a small wick having a weight attached (Fig. 154). which carries down the wick as the candle is consumed, and re- quires no snufiiing. Figs. 151 and 152 showcandles moulded in solid form, the wicks being but two or three inches long, and attached to a tube (Fig. 158) of a shape to fit the candle, and which descends as the fat is melted and consumed. Fig. 155 534 TECHNICAL TREATISE ON SOAP AND CANDLES. is a candle moulded in oval form in which is to be placed a flat wick for the purpose of giving a larger flame and in- Fig. 151. Fig. 152. Fig. 153. Fig. 154. Fig. 155. I i created light. Figs. 156 and 157 are devices for making candles in two parts, a hollow exterior cylinder 6, and an interior one a, the latter being one-eighth of an inch less in diameter than the hole in 6 ; this space between the two being Fig. 156. Fig. 157. Fig. 158. filled with the wick, and if the interior cylinder has a per- foration as seen in Fig. 157 the wick will be supplied with air similar to an argand lamp. Similar devices for supplying air to the flame of the can- dle have been patented, and also to prevent the candle gut- MANUFACTURE OF CANDLES. 535 tering when carried, the melted fats running into perforations beside the wick. For these candles it is usual to mould them in solid form and perforate them through their length with a suitably shaped tool. Fig. 159 shows one that makes a triangular perforation, through the centre of which a coated wick is drawn, leaving three channels for the access of air or for permitting the overflow of fat to run into w^hen melted faster than it can be consumed, or dropping when the candle is carried about. Fig. 159. Fig. 160. Many improvements in the moulds for candles might be mentioned. Fig. 160 represents one that possesses much merit ; a a is the shaft of the mould, 6 the box or trough. The lower portion of the mould is compressed at cc, to form a resting place for the tip which tip is widened at the outer end that it may be forced up to loosen the candle before being 536 TECHNICAL TREATISE ON SOAP AND CANDLES. drawn when it again falls into its place. These moulds are made of a hard material and of less weight and thinner sides that they may be the sooner cooled or heated ; moreover, they are susceptible of a finer polish to their interior surface, thereby moulding a better finished candle. To prevent the guttering of candles metallic cups have been devised as seen in Figs. 161 and 162, a simple cup of thin metal to be placed upon the top of a candle ; the wick coming through the hole is lighted, and, as the material is melted and consumed, the cup descends, preventing any overflow. The inventor proposes to place on top of this cup another holding a circular tube of glass or mica to act as a chimney, as shown in the cut. Fig. 163. Another ingenious invention of a candle or bougie to burn on water is represented by Fig. 164, very useful for a night light. They are made of stearic acid or wax. A plate of metal A covering the vessel of water has attached a tube in which the candle floats, and which acts as a guide for it while it is consuming and burns at the surface. There can also be placed upon the tube graduated marks showing the time of night by the length of candle consumed (Fig. 165). Fig. 161. Fig. 163. Fig. 164. ' Fig, 165. Fig. 162. It would be impossible in our limited space to give all -the ingenious devices and patents that pertain to these useful articles. What we have given may serve to stimulate the in- ventive powers of our readers who may make something much better. MANUFACTURE OF CANDLES. 537 SECTION" IX. THE MANUFACTURE OF CANDLES (Concluded). Decorated and Colored Candles, Tapers, I^'ight Lights, Etc. With the advanced taste for house decorations, illumi- nated, decorated, and colored candles find a conspicuous place, and there has been a rapid advancement towards per- fection in them, for they are seen in very handsome colors, with decorations that may be considered quite artistic, these being upon tints that form a suitable ground for their proper display. Colored Candles. — The usual base for these candles is stearic acid or spermaceti, though they are found of wax and of paraffine, but as parafiine will not hold color, there Las to be some other substance combined with it that can be colored. Thus we find nearly all the colored candles are a combination of several ingredients, but generally of fine materials, as the base should be as white and transparent as possible. Colored candles are sometimes made that are colored only on tbe outer surface. This is done by moulding them in very thin moulds, so that w4ien the colored material is placed in them, it cools rapidly, when they are emptied of the internal liquid part, while the solidified part has adhered to the inner sur- face of the moulds. They are then filled with the material for the body of the candle, taking care to have it of as low a temperature as possible, so that it wnll not melt the colored surface. When cold they are drawn as usual, and if they ad- here too strongly, the moulds are dextrously dipped in warm water, which expands them so that the candle is loosened. This process is seldom followed, as it entails too much labor for a large business, and is not rapid enough. The colors for candles have heretofore been of ^mineral 538 TECHNICAL TREATISE ON SOAP AND CANDLES. oriojin with but few exceptions, for there are few vegetable colors which will color fat that are permanent. And there are well-grounded objections to the use of many of the mineral colors in vogue, that, when combined with the fatty body and burnt, give off the oxides of the minerals to contaminate the air of the apartments with poisonous vapors. Thus arsenic, lead, copper, mercury, and zinc, the base of most of these colors, are volatilized and become deleterious to health, so that such colors must be avoided if possible. The vegeta- ble colors of alkanet for red, and gamboge or roucou for yel- low, are quite fugitive and soon fade on exposure to light, so that the use of minerals is to some extent necessary. Aniline colors have also had the same objections, and have not been permanent, but although they have in many instances a base of metallic oxide, yet at this time they are made so durable that they must serve to give nearly all the colors needed, and whatever metallic substances they may contain are in such minute quantity when burnt as to be almost imperceptible. For yellow there are used gamboge, roucou, chromate of lead, and naphthaline yellow. For red, alkanet root, minium, vermilion, and several permanent aniline reds. For blue, ultramarine, sulphate of copper, and aniline blue. For green, distilled verdigris, Schweinfurt green, or a mixture of yellow with blue. For purple or violet, a mixture of blue with red: and for the neutral tints, some of the brown oxides of iron, yel- low ochres, and Frankfort black. With the articles here mentioned, nearly any shade can be obtained. It has been quite customary for manufacturers to use a little ultramarine to give a bluish-white shade to the white candles, or to disguise the yellowish shade of their fats. Toy candles are the colored candles above mentioned, made of small size, and usually of a mixture of stearic acid and paraffine. They are made 20, 40, 60, and 80 to the pound. Decorated candles have become much in vogue, as are the MANUFACTURE OP CANDLES. 539 better class of candles generally, for lighting the drawing- rooms of society, and in fact are becoming more in use from the objection to gas as made in our larger cities being usu- ally quite impure, and when burning, throwing otf sulphur- etted hydrogen to the injury of the colors of fine fabrics used, as well as of valuable paintings. Thus we see the old- fashioned candelabra again in use, and candles more in vogue. From this circumstance we have given this subject some attention, for there is no good reason why, with our culti- vated taste, we should be dependent upon France and Eng- land for these useful articles. The base of almost all the decorated candles we have seen is a compound of stearic acid and wax or parafiine, and many that are called wax have really but little wax in their com- position, nor can it be considered much to their disadvantage for these composite candles, while costing one-half the price of pure wax, have nearly as good an appearance, and give as white and good a light. With the materials named, and in the proportions given in our last chapter, with suitable colors as we have just named, with care in the manipulations when moulding, there cannot be much difficulty in making very satisfactory candles. For this purpose, above all, care must be taken that the material has a high melting-point to insure their retaining their form in the warmest weather, and that they may not bend when placed in the candelabra. We here illustrate a few styles of decoration, but they are given merely as hints, for the colors and designs are innume- rable. Fig. 166 will serve to show how effective they can be made for the purpose of decoration. As a ground for these decorations, whether done by hand or transferred by the process of decalcomanie, a suitable var- nish is put on the candle. This varnish is made by dissolv- ing gum damar in rectified oil of turpentine or absolute alco- hol, and should be quite thick that it will not require renew- ing, or that one coating may be sufficient. These designs for decalcomanie are found in commerce for the purpose of the decoration of various articles, and are in nearly every con- ceivable design, and many are made for this purpose especially, TECHNICAL TREATISE ON SOAP AND CANDLES. and it is usual for the dealers in them to give instruction for their proper application. They are printed upon a porous paper : and when the design is pressed upon the warmed var- nished surface, and has hardened, the paper is wet with water Fig. 166. and afterwards gently rubbed off, leaving the design adhering to the candle. When the candles are decorated by hand, it is customary to have them of the best quality, and they are prepared with a coating of the damar varnish spoken of, or a still better varnish is now made with gum mastic. It is not our province to give further details for this art, as it pertains to another. Wax Tapers. — These useful articles have much importance as they are employed for many purposes: for lighting the gas, for melting the wax for sealing letters (the twisted taper), for night lights, etc. The twisted tapers are in a great variety of forms and sizes, and usually in bright colors ; a hollow coil is the commonest form. They are made of wax as a base with a small percentage of either stearic acid, pa- raffine, or fine resin. We illustrate a machine used for this purpose (Figs. 167-170), where it will be seen that the wick, MANUFACTURE OF CANDLES. 541 usually several fine yarns of cotton twisted to suit the thick- ness of the taper (generally about a quarter of an inch thick, often thinner), is wound from one wooden drum to the other. the wnck passing through an oval copper pan, D, having a raised rim, G G'. This pan contains the melted wax kept fluid by the brazier E, and passing through the hook H, 542 TECHNICAL TREATISE ON SOAP AND CANDLES. placed in the bottom of the pan. F is a metallic bevelled ring through which the dipped wick passes, and which serves to regulate the size of the taper. It can be made in any form to give other shaped tapers. In working this machine, it is only necessary to have the drums and copper in the position shown, and wind the taper from A to B, having B at such a distance that the wax may cool before reaching it. As the wick requires more than one dipping, the taper is next wound from B to A, changing the gauge F to the other end of the copper. Figs. 168-170 show the detached parts. If the tapers are to be gas-lighters, they are cut into lengths of about twenty inches ; if the twisted tapers, they are cut into suitable lengths, slightly warmed, and wound on suit- able forms to give them the desired shape. Night Lights or Tapers. — The most common form for these is a cylinder of wax, stearic acid, or a combination of other solid sebacic acids, in size about one and a quarter inches in diameter, by one and a half in length. They are moulded in tin tubes, generally six dozen in one frame, and made solid, the wick being placed in afterwards. This wick is usually quite small, that the taper may be consumed very slowly. APPENDIX. THF^ METKIC SYSTEM OF WEIGHTS AND MEASURES. The United States being the first to introduce the decimal system into the coinage of the country, and to demonstrate its superior utility, it is remarkable that we have hesitated so long in regard to the substitution of the same simple and rational system of weights and measures for the complicated and con- fused standards in general use. In May, 1866, the Committee on Coinage, Weights, and Mea- sures presented to the House of Representatives an exhaustive report, accompanied by bills authorizing the introduction of the metric system into the various departments of trade, and making all contracts, based on this system of weights and measures, valid before any court in the United States. They said : — ''THE METRIC SYSTEM. ''It is orderly, simple, and perfectly harmonious, having use- ful relations between all its parts. It is based on the meter, which is the principal and only arbitrary unit. The meter is a measure of length, and was intended to be, and is, very nearly one ten-millionth of the distance on the earth's surface from the equator to the pole. It is 89.37 inches, very nearly. ' The are is a surface equal to a square whose side is 10 meters. It is nearly four square rods. *' The liter is the unit for measuring capacity, and is equal to the contents of a cube whose edge is a tenth part of the meter. It is a little more than a wine quart. " The gramme is the unit of weight, and is the weight of a cube of water, each edge of the cube being one one-hundredth of the meter. It is equal to 15.432 grains. " The stere is the cubic meter. "Each of these units is divided decimally, and larger units are formed by multiples of 10, 100, &;c. The successive mul- tiples are designated by the prefixes, deka^ hecto, kilo, and myria ; the subordinate parts by deci, centi, and milli, each having its own numerical significance. "The nomenclature, simple as it is in theory, and designed 1 544 THE METRIC SYSTEM. from its origin to be universal, can only become familiar by use. Like all strange words, these will become familiar hy custom, and obtain popular abbreviations. A system which has incorporated with itself so many different series of weights, and such a nomenclature as 'scruples,' 'pennyweights,' 'avoir- dupois,' and with no invariable component word, can hardly protest against a nomenclature whose leading characteristic is a short component word with a prefix signifying number. We are all familiar with thermometer , haroraeter^ diameter^ gasometer^ &c., with telegram^ monogram^ &c., words formed in the same manner. " After considering every argument for a change of nomen- clature, your committee have come to the conclusion that any attempt to conform it to that in present use would lead to con- fusion of weights and measures, would violate the early learned order and simplicity of metric denomination, and would seri- ously interfere with that universality of system so essential to international and commercial convenience. "When it is remembered that of the value of our exports and imports,in theyear ending June 30, 1860, in all $762,000,000, the amount of near $700,000,000 was with nations and their de- pendencies that have now authorized, or taken the preliminary steps to authorize, the metric system, even denominational uni- formity for the use of accountants in such vast transactions assumes an important significance. In words of such universal employment, each word should represent the identical thing in- tended, and no other, and the law of association familiarizes it. "Your committee unanimously recommend the passage of the bills apd joint resolutions appended to this report The metric system is already used in some arts and trades in this country, and is especially adapted to the wants of others. Some of its measures are already manufactured at Bangor, in Maine, to meet an existing demand at home and abroad. The manufacturers of .the well-known Fairbanks' scales state: 'For many years we have had a large export demand for our scales with French weights, and the demand and sale are constantly increasing.' Its minute and exact divisions specially adapt it to the use of chemists, apothecaries, the finer operations of the artisan and to all scientific objects. It has always been and is now used in the United States coast survey. Yet in some of the States, owing to the phraseology of their laws, it would be a direct violation of them to use it in the business transactions of the community. It is, therefore, very important to legalize its use, and to give to the people, or that portion of them desiring it, the opportunity for its legal employment, while the knowledge of its characteristics will be thus diffused among men." WEIGHTS AND MEASURES. 545 WEIGHTS AND MEASURES. APOTHECARIES' WEIGHT, U. S. Pound. Ounces. Drachms. Scruples. Grains. ft 1 == 12 = 96 = 288 = 5760 § 1 = 8 = 24 = 480 3 1= 3 = 60 B 1 = gr. 20 The imperial standard Troy weight, at present recognized by the British laws, corresponds with the apothecaries' weight in pounds, ounces, and grains, but differs from it in the division of the ounce, which, according to the former scale, contains twenty pennyweights, each weighing twenty- four grains. AVOIRDUPOIS WEIGHT. Pound. Ounces. Drachms. Troy grains. lb 1 = 16 x= 256 = 7000. oz. 1 = 16 = 487.5 dr. 1 = 27.34375 Relative Value of Troy and Avoirdupois Weights. Pound. Pounds. Pound. Oz. Grains. 1 Troy = 0.822857 Avoirdupois = 13 72.5 1 Avoirdupois = 1.215277 Troy — 1 2 280. WINE MEASURE, U. S. Gallon. Pints. Fluidounces. Fluidrachms. Minims. Cubic inches. Cong. 1 = 8 = 128 = 1024 =* 61440 = 231. O 1 = 16 = 128 = 7680 = 28.875 f| 1 = 8 = 480 = 1.8047 f5 1 = TTj^ 60 = 0.2256 IMPERIAL MEASURE. Ado^pted by all the British College. Gallon. Pints. Fluidounces. Fluidrachms. Minims. 1 = 8 = 160 = 1280 = 76800 1 = 20 = 160 = 9600 1 = 8 = 480 1 = 60 Relative Value of Apothecaries^ and Imperial Measures. apothecaries' MEASUEE. IMPERIAL MEASURE. 1 pint 1 fluidounce 1 fluid rachm 1 minim IMPERIAL MEASURE. APOTHECARIES' MEASURE. Gallon. Pints. Fluidoz. Fluidrms. Minims 1 gallon = 119 5 8 1 pint = 1 3 1 38 1 fluidounce = 7 41 1 fluidrachm = 58 1 minim = 0.96 Pints. Fluidozs. Fluidrms. Minims. 6 13 2 23 16 5 18 1 20 1 2.5 1.04 35 3 546 WEIGHTS AND MEASURES. Belative Value of Weights and Measures in Distilled Water at 60^ Fahr. 1. Value of Apothecaries' Weight in Apothecaries' Measure. Pints. Fluidoz. Fluidr. Minims. 1 pound = 0.7900031 pints = 12 5 7.2238 1 ounce = 1.0533376 fluidounces = 1 25.6020 1 drachm == 1.0533376 fluidrachms = 1 3.2002 1 scruple = 21.0667 1 grain = 1.0533 3. Value of Apothecaries' 1 gallon = 10.12654270 pounds 1 pint = 1.26581783 pounds I fluidounce =. 0.94936332 ounces 1 fluidrachm = 0.94936332 drms. 1 minim = 0.94936332 grains asure in Apothecaries' Weight. Pounds. Oz. Dr. Sc. Gr. Grains. = 10 1 4 8.88 = 58328.886 = 1 3 1 1 11.11 = 7291.1107 = 7 1 15.69 = 455.6944 = 3 16.96 = 56.9618 = 1.9493 3. Value of Avoirdupois Weight in Apothecaries' Measure. Pints. Fluidozs. Fluidrms. Minims. 1 pound = 0.9600732 pints = 15 2 53.3622 1 ounce = 0.9600732 fluidounces = 7 40.8351 4. Value of Apothecaries' Measure in Avoirdupois Weight. 1 gallon = 8.33269800 pounds. 1 pint = 1.04158725 pounds. 1 fluidounce = 1.04158725 ounces. 5. Value of Imperial Measure in Apothecaries' and Avoirdupois Weights. Imperial Measure. Apothecaries' Weight. Avoirdupois Weight. Grains. Cubic inches. 1 gallon =12R)li 63 2B0gr. = 10Ib05 =70,000 =277.27384 1 pint = 1 6 1 2 10 = 1 4 = 8,750 = 34.65923 1 fluidounce = 7 17.5 = 1 = 437.5 = 1.73296 1 fluidrachm = 2 14.69 = 54.69= 0.21662 1 minim = 0.91= 0.00361 In converting the weights of liquids heavier or lighter than water into measures, or conversely, a correction must be made for specific gravity. In converting weights into measures, the calculator may proceed as if the liquid was water, and the obtained measure will be the true measure inversely as the specific gravity. In the converse operation, of turning measures into weights, the same assumption may be made, and the obtained weight will be the true weight directly as the specific gravity. 4 TABLES SHOWING THE RELATIVE VALUES OF FRENCH AND ENGLISH WEIGHTS AND MEASURES, &c. Measures of Length. Millimetre Centimetre Decimetre Metre Decametre Hectometre Kilometre Mjriametre « Inch Cj\ yard) Foot (i yard) Yard Fathom (2 yards) Pole or perch (5^ yards) Furlong (220 yards) Mile (1760 yards) Nautical mile 0.03937 0.393708 3.937079 39.37079 3.2808992 1.093633 32.808992 328.08992 3280.8992 1093.633 10936.33 6.2138 2.539954 3.0479449 0.91438348 1.82876696 5.029109 201.16437 1609.3149 1852 inch. (( inches. it feet. yard. feet. <( (( yards, miles. centimetres, decimetres, metre. metres. 5 648 VALUES OF FRENCH AND ENGLISH Superficial Measures. Square millimetre square inch. = 0.00155 u " centimetre 0.155006 li (( decimetre 15.50059 u inches. (I a 0.107643 foot. " metre or centiare 1550.05989 inches. 10.764299 <( feet. u n « 1.19f^033 yard Are 1076.4299 feet. 119.6033 ii yards. n 0.098845 rood. Hectare 11960.3326 square yards. 2.471143 acres. Square inch (( *' foot " yard " rod or perch Rood (1210 sq. yards) Acre (4840 sq. yards) = 645.109201 square millimetres. 6.451367 9.289968 0.836097 25.291939 10.116775 ares. 0.404671 hectare. centimetres decimetres, metre, metres. Measures of Capacity. 10 100 1000 Cubic millimetre " centimetre or millilitre ; " centimetres or centilitre : " *' decilitre = 6.102705 0.000061027 cubic inch. 0.061027 " " 0.61027 " " litre = Decalitre u Hectolitre Cubic metre or stere or kilolitre Myrialitre 61.0270515 1.760773 0.2200967 610.270515 2.2009668 3.531658 22.009668 1.30802 35.3165807 353.165807 " inches. U ii imp'l pint. " gal'n. cubic inches, imp. gal'ns. cubic feet, imp. gal'ns. cubic yard. " feeto WEIGHTS AND MEASURES, ETC. 519 Cubic inch " foot " yard = 16.386176 cubic centimetres. =^ 28.315312 " decimetres. = 0.764513422 " metre. American Measures. Winchester or U.S. gallon (231 cub. in.) = 3.785209 litres. " bushel(2150.42cub.in.)= 35.23719 " Chaldron (57.25 cubic feet) = 1621.085 " British Imperial Measures. Gill = 0.141983 litre. Pint Q gallon) = 0.567932 Quart (i gallon) = 1.135864 " Imperial gallon (277.2738 cub. in.) = 4.54345797 litres. Peck (2 gallons) = 9.0869159 " Bushel (8 gallons) = 36.347664 " Sack (3 bushels) Quarter (8 bushels) Chaldron (12 sacks) Milligramme Centigramme Decigramme Gramme Decagramme u Hectogramme Kilogramme (( Myriagramme = 1.09043 = 2.907813 = 13.08516 hectolitre, hectolitres. Weights. 0.015438395 troy grain. 0.15438395 1.5438395 15.438395 0.643 0.0321633 0.0352889 154.38395 5.64 3.21633 3.52889 2.6803 2.205486 26.803 22.05486 Quintal metrique = Tonne = lOO 1000 " grains, pennyweight, oz. troy, oz. avoirdupois, troy grains, drachms avoirdupois, oz. troy, oz. avoirdupois, lbs. troy, lbs. avoirdupois, lbs. troy, lbs. avoirdupois, kilog. = 220.5486 lbs. avoirdupois, kilog. = 2205.486 " 550 VALUES OF FRENCH AND ENGLISH Diflferent authors give the following values for the gramme : — Gramme = 15.44402 troy grains. " = 15.44242 " « = 15.4402 « == 15.433159 " « = 15.43234874 « AVOIRDUPOIS. Long ton = 20 cwt. = 2240 lbs. = 1015.649 kilogrammes. Short ton (2000 lbs.) = 906.8296 " Hundred weight (112 lbs.) = 50.78245 " Quarter (28 lbs.) == 12.6956144 " Pound = 16 oz. = 7000 grs. = 453.4148 grammes. Ounce = 16 dr'ms. = 437.5 grs. = 28.3375 " Drachm = 27.344 grains = 1.77108 gramme. TROY (precious metals). Pound = 12 oz. = 5760 grs. Ounce = 20 dwt. = 480 grs. Pennyweight = 24 grs. Grain = 373.096 grammes. = 31.0913 « = 1.55457 gramme. = 0.064773 " APOTHECARIES' (pharmacy). Ounce = 8 drachms = 480 grs. = 31.0913 gramme. Drachm = 3 scruples = 60 grs. = 3.8869 " Scruple =• 20 grs. = 1.29546 gramme. CARAT WEIGHT FOR DIAMONDS. 1 carat = 4 carat grains = 64 carat parts, " = 3.2 troy grains. " = 3.273 " « = 0.207264 gramme « =0.212 « = 0.205 " Great diversity in value. 8 WEIGHTS AND MEASURES, ETC. 551 Proposed Symbols for Abbreviations. M — myria — 10000 Mm Mg Ml K— kilo — 1000 Km Kg Kl H — hecto — 100 Hm Hg HI Ha D — deca — 10 Dm Dg Dl Da Unit — 1 metre — m gramme — g litre— 1 are — a d — deci — 0.1 dm dg dl da c — centi — 0.01 cm eg cl ca m — milli — 0.001 mm mg ml Km — Kilometre. HI = Hectolitre. eg = centigramme, c. cm = Jra^ = cubic centimetre, dm^ = sq. dm = square deci- metre. Kgm = Kilogrammetre. Kg° = Kilogramme degree. Celsius or Ccnti^rjido. T" fi h r G n li c i t . — 15° + 5° — 12° — 10 + 14 — 8 — 5 + 23 — 4 melting + 32 ice + 5 + 41 + 4 4- 10 + 50 + 8 + 15 + 59 + 12 + 20 + 68 + 16 + 25 + 77 + 86 + 20 + 30 + 24 + 35 + 95 + 28 -f 40 +104 + 32 + 45 + 113 + 36 + 50 +122 + 40 + 55 + 131 + 44 4- 60 +140 4- 48 4- 65 +149 + 52 4- 70 +158 + 56 + 75 +167 + 60 4- 80 +176 + 64 4- 85 +185 + 68 4- 90 +194 + 72 -f 95 +203 + 76 +100 boiling +212 water +80 4-200 ^ +300 +392 +160 +572 +240 +400 +752 +320 +500 +932 +400 552 VALUES OF FRENCH AND ENGLISH 1° C. X 1° C. X C. == 1' = 1° Ft. = 1° R. 1° Ft. X t 1° Ft. X f == 1 = 1° C. R. R. X f R. X f =1^ Ft. C. English. Calorie (French) = unit of heat = kilogramme degree It 13 the quantity of heat necessary to raise 1° C. the tempera- ture of 1 kilogramme of distilled water. Kilogrammetre = Kgra = the power necessary to raise 1 kilo- gramme, 1 metre high, in one second. It is equal to J-^ of a French horse power. An English horse power = 550 foot pounds^ while a French horse power = 542.7 foot pounds. Ready-made Calculations. No. of units. Inches to centimetres. Feet to metres. Yards to metres. Miles to Kilometres. Millimetres to inches. 1 2.53995 0.3047945 0.91438348 1.6093 0.03937079 2 5.0799 0.6095890 1.82876696 3.2186 0.07874158 3 7.6199 0.9143835 2.74315044 4.8279 0.11811237 4 10.1598 1.2197680 3.65753392 6.4373 0.15748316 5 12.G998 1.5239724 4.57191740 8.0466 0.19685395 6 15.2397 1.8287669 5.48630088 9.6559 0.23622474 7 17.7797 2.1335614 6.40068436 11.2652 0.27559553 8 20.3196 2.4383559 7.31506784 12.8745 0.31496632 9 22.8596 2.7431504 8.22945132 14.4838 0.35433711 10 25.3995 3.0479450 9.14383480 16.0930 0.39370790 No. Centimetres Metres to Metres to Kilometres Square incbe.. of to inches. feet. yards. to miles. to s^quare units. centimetrec 1 0.3937079 3.2808992 1.093633 0.6213824 6.45136 2 0.7874158 6.5617984 2.187266 1.2427648 12.90272 3 1.1811237 9.8426976 3.280899 1.8641472 19.35408 4 1.5748316 13 1235968 4.374532 2.4855296 25.80544 5 1.9685395 16.4044960 5.468165 3.1089120 32.25680 6 2.3622474 19.6853952 6.561798 3.7282944 38.70816 7 2.7559553 22.9662944 7.655431 4.3496768 45.15952 8 3.1496632 26.2471936 8.749064 4.9710592 51.61088 9 3.5433711 29.5280928 9.842697 5.5924416 58.06224 10 3.9370790 32.8089'.i20 10.936330 6.2138240 64.51360 10 WEIGHTS AND MEASUEES, ETC. 553 No Squai'c feet to Scj, yfirds to Acres to Srj, mptrps of' sq. metres. sq. metres. hectares. centimetres to sq. feet. units. to sq. inches. 1 0.0929 0.836097 0.404671 0.155 10.7643 2 0.1858 1.672194 0.809342 0.310 21.5286 3 0.2787 2.508291 1.204013 0.465 32.2929 4 0.3716 3.344388 1.618684 0.620 43.0572 5 0.4645 4.180485 2.023355 0.775 53.8215 6 0.5574 5.016582 2.428026 0.930 64.5858 7 0.6503 5.852679 2.832697 1.085 75.3501 8 0.7432 6.688776 3.237368 1.240 86.1144 9 0.8361 7.524873 3.642039 1.395 96.8787 10 0.9290 8.360970 4.046710 1.550 107.6430 No. Square metres Hectares Cubic inches Cubic feet to Cubic yards of to sq. yards. to acres. to cubic cubic metres. to cubic units. centimetres. metres. 1 1.196033 2.471143 16.3855 0.02831 0.76451 2 2.392066 4.9422S6 32.7710 0.05662 1.52902 3 3.588099 7.413429 49.1565 0.08494 2.29354 4 4.784132 9.884572 65.5420 0.11325 3.05805 5 5.980165 12.355715 81.9275 0.14157 3.82257 6 7.176198 14.826858 98.3130 0.16988 4.58708 7 8.3722.31 17.298001 114.6985 0.19819 5.:^5159 8 9.568264 19.769144 131.0840 0.22651 6.11611 9 10.764297 22.240287 147.4695 0.25482 6.88062 10 11.960330 24.711430 163.8550 0.28315 7.64513 No. ^ Cubic Litres to 1 Hectolitres to Cubic metres Cubic metres of centimetres to cubic inches. cubic feet. to cubic feet. to cubic units. cubic inches. yards. 1 0.06102 61.02705 3.5317 35.31659 1.30802 2 0.12205 122.05410 7.0634 70.63318 2.61604 3 0.18308 183.08115 10.5951 105.94977 3.92406 4 0.24411 244.10820 14.1268 141.26636 5.23208 5 0.30514 305.13525 17.6585 176.58295 6.54010 6 0.36617 366.16230 21.1902 211.89954 7.84812 7 0.42720 427.18935 24.7219 247.21613 9.15614 8 0.48823 488.21640 28.2536 282.53272 10.46416 9 0.54926 549.24345 31.7853 317.84931 11.77218 10 1 0.61027 610.27050 35.3166 353.16590 13,08020 11 551 FKENCH AND ENGLISH WEIGHTS, ETC. No. Grains Ounces avoir. Ounces troy Pounds avoir. Pounds troy of to grammes. to grammes. to grammes. to to units. kilogrammes, kilogrammes. 1 0.064773 28.3375 31.0913 0.4534148 0.373096 2 0.129546 56.6750 62.1826 0.9068296 0.746192 3 0.194319 85.0125 93.2739 1.3602444 1.119288 4 0.259092 113.3500 124.3652 1.8136592 1.492384 5 0.323865 141.6871 155.4565 2.2670740 1.865480 6 0.388638 170.0250 186.5478 2.7204888 2.238576 7 0.453411 198.3625 217.6391 3.1739036 2.611672 8 0.518184 226.7000 248.7304 3.6273184 2.984768 9 0.582957 255.0375 279.8217 4.0807332 3.357864 10 0.647730 283.3750 310.9130 4.5341480 3.730960 Pounds per No. Long tons to square inch to Grammes to Grammes to Grammes to of tonnes of 1000 kilogrammes grains. ounces avoir. ounces troy. units. kilog. per square centimetre. 1 1.015649 0.0702774 15.438395 0.0352889 0.0321633 2 2.031298 0.1405548 30.876790 0.0705778 0.0643266 3 3.046947 0.2108322 46.315185 0.1058667 0.0964899 4 4.062596 0.2811096 61.753580 0.1411556 0.1286532 5 5.078245 0.3513870 77.191975 0.1764445 0.1608165 6 6.093894 0.4216644 92.630370 0.2117384 0.1929798 7 7.109543 0.4919418 108.068765 0.2470223 0.2251431 8 8.125192 0.5622192 123.507160 0.2823112 0.2573064 9 9.140841 0.6324966 138.945555 0.3176001 0.2894697 10 10.156490 0.7027740 154.383950 0.3528890 0.3216330 No. of units. Kilogrammes to pounds avoirdupois. Kilogrammes to pounds troy. Metric tonnes of 1000 kilog to iong tons of 2240 pounds. Kilog. per square milli- metre to pounds per square inch. Kilog. per square centi- metre to pounds per square inch. 1 2.205486 2.6803 0.9845919 1422.52 14.22526 2 4.410972 5.3606 1.9691838 2845.05 28.45052 3 6.616458 8.0409 2.9537757 4267.57 42.67578 4 8.821944 10.7212 3.9383676 5690.10 56.90104 5 11.027430 13.4015 4.9229595 7112.63 71.12630 6 13.232916 16.0818 ?.9(75514 8535.15 85.35156 7 15.438402 18.7621 6.8921433 9957.68 99.57682 8 17.643888 21.4424 7.8767352 11380.20 113.80208 9 19.849374 24.1227 8.861.3271 12802.73 128.02734 10 22.054860 26.8030 9.8459190 14225.26 142.25260 13 HYDROMETERS AND THERMOMETERS. 555 HYDROMETERS AND THERMOMETERS. An areometer is a convenient glass instrument for measuring the densit}^ or specific gravity of fluids. Areometer and hydrometer are synonymous terms, the first being derived from the Greek words apatoj, rare^ and /wsrpov, measure; and the latter from i^Sup, water, and /ustpov, measure ; hence the same instrument is fre- quently denominated both hydrometer and areometer. This appa- ratus is often referred to throughout this work; for instance, in speaking of alcohol, or lye, their strength is stated as being of so many degrees (17° or 36°) Baume, that is, its force or value is of that specific gravity, corresponding with the degree to which the hydrometer sinks in either the alcohol or alkaline solution. But, for those liquids lighter or rarer than water, viz., alcohol, ethers, etc., the scale is graduated differently than for the heavier or more dense, examples of which are the acids, saline solutions, syrups, and the like. There are several kinds of hydrometers; but that called Baume's is the most used, and to this our remarks are applied. They are blown out of a piece of slender glass tubing, and of the form shown by Figs. 171 and 172; A being tlie stem containing the Fig. 171. Fig. 172. graduated paper scale, B the bulb portion, and D the small globes containing mercury or shot, serving as ballast to maintain the instrument in an upright position, when it is placed in a liquid. The graduation is accomplished by plunging it into distilled water of 58° F., and weighting the globe with shot or mercury, until the instrument sinks to the line a, which is its zero point. This zero point thus determined is to be marked accurately upon 13 556 HYDROMETERS AND THERMOMETERS the glass or its accompanying paper scale, and the instrument again plunged into ninety parts of distilled water, holding in solu- tion ten parts of previously dried chloride of sodium or common salt. The point to which it sinks in this liquid, say for instance, is then also marked carefully upon the scale, and rated as ten compared with its zero point. The interval between these two points is then spaced olf into ten equal divisions, according to which the remainder of the tube is graduated so that each degree is intended to represent a density corresponding to one per cent, of the salt. The above mode of graduating refers to the hydrometer for liquids denser than water, but that for the liquids rarer than water is a little different from the preceding in form, and necessarily has a modified scale, which is graduated as is shown by Fig. 172. The instrument should be sufficiently heavy in ballast to sink in a saline solution of ten parts of dried chloride of sodium in ninety parts distilled water to the bottom of .its stem a, to be marked as the zero of the scale. Now, when it is again placed in distilled water alone, it floats or sinks to a point somewhere about 6, which is to be the ten degree mark. The rest of the stem is then to be accurately divided into as many ten degree intervals as its length will permit, and each subdivision into ten uniform smaller degrees or intervals. As it would be troublesome, and with many impracticable, to estimate the specific gravities of their liquids in a sci- Fig. 173. entific way, these little instruments are a great con- venience, for by taking out a portion of the fluid to be tested, and placing it in a glass cylinder, Fig. 173, its degree Baurae may be ascertained by noting the point to which a hydrometer sinks therein, and afterwards its specific gravity, by comparing that with its corre- sponding degree in the table. For instance, suppose the h3"drometer sinks in alcohol to 35°, then its specific gravity is 0.8538, and this agiiin can be translated into its absolute spirit strength by comparison with any accurately calculated alcohol tables. So, also, if a hydrometer for liquids denser than water sinks in lye to 26°, it denotes that the lye, as will be seen by refer- ence to Tiinnermann's tables (pages 259 and 261), has a specific gravity of 1.2268. The presence of foreign 14 HYDROMETERS AND THERMOMETERS. 557 matters will cause the hydrometer to give a false indication, and it is, therefore, necessary, when lyes contain impurities, to follow the directions given under Alkalimetry, to ascertain their amount of caustic alkali. When the lye is nearly pure, they answer satis- factorily ; and, indeed, under all circumstances, they serve very well for noting a progressive increase or diminution in the strength of lyes or other liquids. The temperature of the liquid should be 58° to 60° F., at the moment of testing it. Thermometers. — The thermometer is an instrument made of glass exclusivel}^, when intended for practical purposes. Fig. IH shows one with the scale of Fahreidieit, graduated on the glass, so that, when having been dipped in liquids, it ma}^ be easily cleansed. It derives its name from two Greek words, gfpiwoj, vmrm^ and |Wfrpo^, measure^ and is, as its title indicates, a measurer of the variation of temperature in bodies. The principle upon which it is constructed, "is the change of volume which takes place in bodies, when their temperature undergoes an alteration, or, in other words, upon their exi)ansion." As it is necessary, in the construction of thermometers, that the material used to measure the change of tem- perature shall be of uniform expansion, and with a very distant interval between its freezing and boiling point, as fulfilling these requisites better than any other body, metallic mercur}^ is generally used. There are several different theruiometrical scales, all con- structed upon the same principle, but varying in their graduation ; the boiling and freezing points of each, though corresponding in fact, being rei)resented by different numbers. The Fahrenheit scale is most used in this country; that of Celsius, called the Centigrade, in France and the Continent generally, except Spain and German3', where Reaumur's scale is prefei-red. The relation between the three scales is shown 1)3^ Fig. 175. The Fahrenheit scale is most convenient, because of the lesser value of its divisions. In the graduation of the scale, it is onl}^ necessary to have two fixed determinate temperatures, and for these the boiling and freezing points of water are universall}' chosen. The scales can be extended be3'ond either of these points, by continuing the 15 558 HYDROMETERS AND THERMOMETERS. graduation. Those degrees below zero or 0° have the minus ( — ) prefixed, to distinguish them from those above; thus, 55° F. means fifty-five degrees above zero, Fahrenheit's scale, and — 9° C, nii?e Fig. 175. degrees below zero. Centigrade scale. The thermometers for general use very seldom, however, extend either way beyond the boiling and freezing points of water, but for manufacturers' use they are graduated sometimes to 400° or 600°. Centigrade and Fahrenheit — In the Fahrenheit thermometer the number 0° on the scale corresponds to the temperature of a mixture of salt and ice — tlie greatest degree of cold that could be artificially produced when the thermometer was oriijinally intro- duced ; 32° (freezing point) corresponds to the temperature of melting ice; and 212° to the temperature of pure boiling water — in both cases, under the ordinary atmospheric pressure of 14.7 pounds per square inch. Each division of the (this) thermometer represents 1° Fah., and between 32° and 212° there are 180°. In the Cent, thermometer, used universally in scientific investigations, 1° corresponds to melting ice, and 100° to boiling water. From the freezing to the boiling point there are 100°. The accompanying table shows the relation of the Centigrade and Fahrenheit thermometer scales, 5° C. being equal to 9° F., because the interval between the freezing and boiling points of water is divided into 100 and 180 equal parts, and these numbers 16 HYDROMETERS AND THERMOMETERS. 559 are respectively multiples of, or 20 times 5 and 9. If the super- fluous 32° on the F. side were disposed of, the mutual translation of the scales would be simple, since the two units are to each other inversely as the number of them in any given range. To reduce F. above melting ice to terms of C, 32^ must first be subtracted from the given F. temperature, then multiply the re- mainder by f ; the product will be the C. term for the given tem- perature; and conversely divide C. by f and add 32 to translate C. into F.; to prove the work, read the terms across the diagram in the table. Below melting ice, the same rules as given above apply, except that where 32 is added above, it should be subtracted here, and vice versa. In the columns at the right hand of each diagram in this table, are found the approximate steam pressures per square inch, due to the adjoining indications of temperature. Tiie pressure is expressed in pounds and in atmospheres. The high pressures are obtained from the several authors who have deduced and tabulated them from experiments and formulas of Regnault and others ; and being hypothetical, accuracy is not claimed for them. 17 5(30 HYDROMETERS AND THERMOMETERS. COMPARISON OF CENTIGRADE AND FAHRENHEIT SCALES, AND APPROX- IMATE STEAM PRESSURE IN POUNDS AND ATMOSPHERES PER SQUARE INCH DUE TO THE TEMPERATURE. Thermometer. Steam. Non-condensing Engine. Fahr. 500 491 482 473 464 455 446 437 428 419 410 401 392 383 374 365. 356 347 338 329 320 311 302 293 284 |275 266 257 248 239 230 221 Pres. per gauge, lbs. 665 610 560 515 472 430 390 354 321 290 262 235 211 188 167 148 131 115 100 85 73 63 55 45 37 30 25 19 14 10 6 3 Total Press. Lbs. 680 625 575 530 487 445 405 369 336 305 277 250 226 203 182 163 146 130 115 100 88 78 70 60 52 45 40 34 29 25 21 18 Atmos. 46. 42. 39. 36. 33. 30. 27.5 25. 23. 20.7 18.8 17. 15.3 13.8 12.4 11.1 9.9 8 7, 6.8 6. 5. 4. 4.1 3.5 3 2. 2 1.9 1.6 1.4 1.2 Thermometer. Centi. 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 — 51 —10 —15 ~£0 —25 —30 — 35 -40 —45 Fahr. 1212 203 |l94 185 L76 167 o o 1149 o o 1140 I 131 1 122 113 il04 95 86 77 68 59 50 41 32 23 14 5 — 4 —13 —22 —31 —40 -49 Steam. Condensing Engine. Press, per gauge. Back Press. Vacuum, effective Lbs. Atmos. 1. 14.7 Gauge. H 12i 15f m 20^ 22 24 25 26 26i 27f 28| 29 Lbs.* 4.7 6.2 7.7 9.1 10.2 11. 11.9 12.4 12.9 13.3 13.6 13.8 13.9 12. 10. 8.5 7. 5.6 4.5 3.7 2.8 2.3 1.8 1.4 1.1 .9 .8 0.85 0.7 0.6 0.5 0.4 0.3 0.2 0.2 0.1 * To be added to the pressure indicated by steam gauge to get total pressure on piston. M. T. Mines of Brittany. 500 It., . . . 59 F. Hydrochloric Ether boils, 52 F. Max. density of water, f^^Q' Melting Ice, . 32F. =0C. Blood freezes, , . £5 F. Castor Oil freezes, . 21 F. Spirits of turpentine freezes. Brandy freezes, 14 F. -7F. Mercury freezes, . —40 F. Sulphuric Acid (1.641) freezes, . . —45 F. Greatest artificial cold, . -166 to -220 F. Absolute cold, ( —450.4 F. •■)— 213. C. 18 AMMONIACAL PROCESS FOR SODA ASH. 561 Note. — Soda Ash by the Ammoniacal Soda Process, Much at- tention has been attracted to a very pure soda obtained by this process, which was really not perfected in a practical way until 1878. This process is the only one that has successfully competed with that of Leblanc, and consists of the conversion of ammonium carbonate and sodium chloride (common salt) into sodium bicarbo- nate and ammonium chloride. The equation is — NaCl + (NHJ HCO3 = NH^Cl + NaHC03. The latter two salts are easily separated, as sodium bicarbonate is ver}^ slightly soluble in a solution of sal ammoniac and separates in the form of crystals. Of course the ammonium carbonate must always be regenerated. Mr. Hemming obtained a patent in England in 1838 for this process, and it attracted much attention in France, Germany, and Austria, and was tried in numerous places, and became the subject of many patents in each country, but it seems that it is due to the untiring perseverance of Mr. Ernest Solvay, of Belgium, that the process has been practically carried out to a paying enterprise. He has several patents in both England and Germany, and the last is as late as 18tt, and since then several other chemists have made some slight improvements upon his methods. Soda, made by this process, is now an article of commerce, and is much used by the soap manufacturers of Europe, and by a few in this country, and seems to have given entire satisfaction, as it should, as it is much more free from admixture of other salts, and consequently must produce a better soap with less labor than the sodas by the old processes. In appearance it differs very much from the ordinary crj'stallized carbonate of soda, being in the state of amorphous lumps of various sizes combined with some powder. We add this note to call the attention of the alkali as well as the soap manufacturer to this valuable soda. 36 INDEX. Acid, normal liquor, 365, 368, 369 Adamantine candles, 532 Adulteration of attar of roses, 450, 451 of black poppy oil, 141 of castor oil, 142 of cocoa-nut oil, 142 of herapseed oil, 141 of linseed oil, 141 of neat's-foot oil, 142 of oil of sweet almonds, 140 of oleic acid, 142 of olive oil, 140 of palm oil, 142 of rapeseed oil, 141 of sesame oil, 141 of the fatty bodies, 140-151 of volatile oils. 443 Agricultural soap, 389 Aigues-Mortes, soda of, 43 Alkali and soap trades, history of, 19- 25 Alkali in soaps, determination of, 352- 357 Alkali, manufacture of, in Germany, 22, 23 normal, 184, 185 trade of England, 22 Alkalies, 26-68 carbonated, 337, 338 for toilet soaps, 401 importance of a knowledge of con- stituents, 166 nitric acid required for mixed, 189, 190 of commerce, never pure, 166, 248 pulpliuretted, 338 Alkalimetric test of lyes, 255 Alkalimetry, 166-192 Alkalimetry, bases of, 179-184 Alkaline liquor, normal, 365, 369, 370 Alkalumino-silicic soap, 333 Almond, bitter, oil of, 444-446 grain soap, 296 Almond oil, 97, 98, 108 shaving cream, 426 Altenburge's rosin soap, 383 Alum for filling soft soaps, 319 soap, 419 Ambergris, 453, 455 soap, 412 Ambrosial shaving cream, 426 soap, 412 American measures, 549 potash, red, 35-37 Ammonia, 60 action on oils, 74 Ammoniacal process for soda ash, 561 Ammoniated soap, 388 Analyses of soaps, table of, 363 Analysis of lime, 194 of soaps, 351-379 volumetric, 167, 1 68 Anhydrous carbonate of soda 193 potash, table of specific gravity and hydrometric degrees, 259 soda, table of specific gravity and hydrometric degree, 361 Animal fats, 75-97 Apothecaries' and imperial measures, relative value of, 545 measure in apothecaries' weight, value of, 546 in avoirdupois weight, value of, 546 weight, 545, 550 in apothecaries' measure, value of, 546 Apparatus for boiling soap by sur- charged steam, 219-221 Apple-seed, oil of, 98 Application of soaps, 195, 196 Aqueous solutions of soaps, 365, 366, 367. 368 Artificial grain soap, 320, 321 light from the flame of a caudle, principles of, 460 564 INDEX. Artificial — salted eoda, 52-54 wax-candles, 5:^2, 538 Ashes and potash in different vegeta- bles, table of, 30 boiling with, 312, 313 from tnrtar, 37 in different parts of the same plant, 30 in vegetables, 29 leaching or washing, 34, 3o Ash-fat, 96 pan, 205 Ashley's moulding machine,. 513 Assajs of oils, 143-147 Attar of rose, 449, 451 adulteration of, 450, 451 Avocado oil, 1 1 1 Avoirdupois weight, 545, 550 in apothecaries' measure, value of, 54G Balsam, Peruvian, 454 B^imhuk butter, 104 Barilla, mixed, 44 salted, 44 Barring machine, Van Haagan's, 239 Bases, neutralized by norm;il nitric acid, 181-184 of alkalimetry, 179-184 Basins of brick or stone, 205 Bassia oil, 107 Baum^ hydrometer, 167, 655 Beech, oil of, 98 Beechnut oil, 97, 115, 116 Beef marrow soap, 420 tallow for candles, 458 Beeswax, 125, 484, 485 bleaching, 485 melting point of, 125 Beet-root molasses, potash from, 38, 39 Belgian soft soap, 388 Belgium, iMarseilles soap made in, 275 Belladonna seeds, oil of, 124 Belmont sperm candles, 532 wax candles, 532 Bennett & Gibbs's process, 347-350 Ben oil, 97, 110 Benzine for dissolvitig fats, 132 Benzoic acid soap, 419 Benzoin soap, 412 Bergaraot, oil of, 443, 444 Bertagnani on the detection of adulte- ration of oil of bitter almond, 444 Berzelius, 19 Bicuyda wax, 126 Bisam, or musk, 453 Bitter almonds, oil of, 444-446 Black poppy oil, adulteration of, 141 Bleaching of palm oil, 101-104 soap, 296, 384 stearic acid, 518 Bogardus's eccentric mill, 229 Boilers, 206 Boiling, melting, and freezing points of different substances, 560 of soft soap, 317, 318 pans or caldrons, 224, 225 soap by surcharged steam, 219- 221 in France, 200. 201 toilet soaps by, 392-399 with wood ashes, 312 Bole Armenian, for marbling soap, 272 Bone fat, 92, 93 soda soap made with, 92 soft soap of, 92 soap, 334, 335 Bones, falsification of wax with, 150 for making soaps, manipulation of with muriatic acid, 335 treatment of, to obtain the fat, 92 of, with caustic lye, 335 Boomer & Boschet's elbow presses, 467-469 Borax soap, 305 powder, 387 soft soap, 386 toilet soap, 419 Bordhardt's herb soap, 420 Bougies, large, for churches, 526 l)0uquet soap, 410 Braconnet, researches of, on fatty bod- ies, 458 Bran soap, 384, 419 British Imperial Measures, 549 Bromine soap, 419 Buchner's method to determine the value of sebacic acid in soap, 359 Buchner's table of the soap and glyce- rine furnished by fats, 359 Burette, the, 168-172 Butter, 90, 91 Butter, cocoa, 123-124 Butter, composition of, 91 Butter, Goa, 124 of nutmegs, 122 composition of, 122 proportions of the injmediate prin- ciples of, 91 substance yielded by, when washed in warm water, 91 Cabbage-seed, oil of, 98 Caesium, 60 oxides of, 156 Cailletet, process of analysis, 365-370 Caking machines, 241, 242, 428-430 INDEX. 565 Calcination of soda, 50 Calculations of weights and measures ready made, 552-554 Cameliua oil, 97, 98, 116 Camphor ice soap, 419 Camp's moulding wheel, 518, 514 Canada snakeroot, oil of, 452 Candle-flame, description of, 4r)0-4(j2 Candle manufacture, a scientific indus- try, 459 to burn on water, 536 Candles, advantages of, for illumina- tion, 457 • by steam, 520-522 composite and patent, 532-530 decorated and colored, 587-542 dipped, 494-500 Gay-Lussac and Chevreul patents, 458 history of, 457 manufactures of, 457-542 materials for, 457 for, and their preparation, 463-487 moulded, 501-527 moulding, stearic acid, 517, 518 polishing and finishing of, 528-581 principles of light from the tt ime of, 4G0 stearine, 51 5-517 tallow, early manufncture of, 457 Capacity, measures of, 548 Carapa oil, 124 Carat weight, 550 Caraway seed oil, 447 Carbadinic musk, 453 Carbolic soap, 418 Carbonate of lime, 180 of potash, 89, 41 and carbonate of soda, table of mixture of, 189, 19i) to change into caustic alkali, 249 of soda and carbonate of potash, mixture of, 189, 190 crystallized, 55-57 for filling soft so;ips, 819 for rosin soaps, 304 refined, 54, 55 to change into caustic soda, 250 Carbonated alkalies, 337, 388 Carbonates of alkali never pure, 249 of soda, table of, 198 Carbonic acid, to remove from lyes, 248 Carnalite, 28 Carnauba wax, 126, 485 Carny, 46, 47 Cashmere soap, perfume for, 442 Cassia oil, 452 Castile soap, 274-276 formulas for, 273, 274 from cotton-seed oil, 296-300 white, 281 Cast-iron kettles, 212, 213 Castor oil, 97, 98, 113 adulteration of, 142 soap, 419 Cauldrons or boiling pans, 224, 225 Caustic lime never pure, 249 lyes of soda, 248 potash, Liebig's experiments on, 251 lye, 248 salts of soda, 57-59 soda, analysis of, 58 for rosin soap, 304 from cryolite, 60 table of specific gravity, and per cent, of, 59 solution of crystals of soda, 396 Cellars, 205, 207 Celsius or Centigrade thermometer, 551 , 557-560 Centigrade orCelsius thermometer, 551, 557-560 Centrifugal mill for tallow, 470 Cerophatie bougies, 532 Chamby, apparatus of, for extracting tallow, 77 Chemical equivalents applicable to soap, 152-155 Chevreul and De Milly, importance of their researches upon the indus- try of candles, 4()0 and Scheele, researches of, on fatty bodies, 69 importance of his discoveries, 28 on composition of butter, 91 on the eff'ects of saponification on fats, 156 patent for candles, 458 researches of on fatty bodies, 458 theory of saponification of, 17 Chimney, 206 Chimney, general, 204 Chinese wax, 485 Churches, bougies for, 526 Cierges for churches, 524 CinnamoJi, oil of, 452 Cisterns in masonry, 205, 207 Civet, 454 tincture of, 454 Clay for filling soft soaps, 819 Clear boiling, 269 boiling or coction, 277, 278 Cloves, oil of, 448 Cocoa butter, 97, 123, 124 566 INDEX. Cocoa-nut kernels, oil in, 105 oil, 24, 97, 105-107 action of, in saponification, lOH adulteration of, 142 for candles, 459 for rosin soaps, 286 for toilet soaps, 392. 897 has property of making soaps capable of retaining water, 304 in soaps, salt which they will bear, 325 odor of, 106 power to absorb water, 325 soap by cold process, 303 soaps, common, 326 the peculiar acids of, 70 white soap from, 398, 399 oils, melting points of, 105 Cochineal tincture. 177-179 Coction, 277, 278, 394, 395 Cod-liver oil, 95-97 oil, composition of, 96 Coffee's siphon, 228 Cold, absolute, 560 cream soap, 409 greatest artificial, 560 process, for toilet soaps, 392 toilet soaps by, 400-408 soaps, 302 lyes for, 304 mechanical aid in, 302 Coleseed oil, 97, 98, 109 Cologne, fat lost in tlie soap consumed in, 139 • Colophony, action of train oil on, 96 or rosin, 126-129 Coloration taken by different oils, 146, 147 Colored candles, tapers, etc., 537-542 Coloring toilet soaps, 439 for toilet soaps, 404 soaps, 428 Colors for candles, 537, 538 for coloring candles, which desir- able and which objectionable, 537, 538 Colza oil, 116 Combustion of plants in furnaces for potash, 33, 34 Commercial red oil, 117-121 Common cocoa-nut oil soaps, 326 filled rosin soaps, 326 Composite and patent candles, 532-536 Composition candles, 533 of commercial potashes, 39, 40 Consistency of soap affected by the melting points of the fats, 163 to give to soap, 280 Continuous wick machine, 512, 513 Coops, melting, for tallow, 81 Copper soap, 156 Cornmeal soap. 419 Cotton-seed oil, 97, 98, 111-113, 296- 300 castile soap from, 296-300 extraction of. 111 for toilet soaps, 392 saponified, 297 Country soap, 385 Crackling soap, 334 Cream shaving, 424 Creme d'Ambrosie, 426 Creasote soap, 419 CrotOD-oil soap, 419 Crown soap, Etiglish, first quality, 323 second quality, 323 Crutching machines, 243-246 Cryolite, 60 caustic soda from, 60 Ciystallized carbonate of soda, 55-57 Ci ystals of soda, 55-57 caustic solutions of, 396 Cucumber soap, 415 Culinary salt, use of, for separation, 267, 268 Curd or grain soaps, 266-284 soap, 281-284 tallow soap, 309-313 Cutter, Ralston's, 243 (Jutting of the pan, 283, 310, 311 of wicks, machines for, 490, 491 operation, 238 table for soaps, 430, 431 Cylinders for mixing in alkalimetry, 176 Dalton's table of contents of soda in lye, 261, 262 of potash contents of lye, 259, 260 D'Arcet, method of extracting tallow, 75 methods, 341-346 on the extraction of potash from the ashes of horse-chestnuts, 29 Davis's alkaluraino-silicic soap, 333 Decalcomanie, 539 Decorated and colored candles, tapers, night lights, etc., 537-542 candles, 538-540 base of, 539 Decoration of candles, styles for, 539, 540 Deiss, application of sulphuret of carbon to otfall fats by, 131 Deite, Dr., formula for transparent soap, 305 INDEX. 567 De Milly, manufacture of stearine by, 459 De Milly's process of saponification by lime, 477, 478 by sulphuric acid, 479 Detergent, 17 Determination of amount of alkali in soaps, 352-859 of soap as to admixtures, 302 of the amount of sebacic acid and rosin in soap, 857, 359-3G1 Diaphanous candles, 533 Dipped candles, 494-500 apparatus for making symme- trical, 495 wicks for, 494 Dipping of candles, machines for, 495- 497 Disinfectant soap, 419 Distilling apparatus for use of sur- charged steam. 481 Domestic soft soap, 386 Dresden palm soap, 383 Drying oils, 71 room, 207, 208 manner of using, 210 temperature of, 208 with warm air, 208-21 1 soap in rooms heated by stoves. 209 Dry melting of tallow, 81 Dubrunfault, M., process for extracting potash from beet-root molasses, 38 saponification by, 479 Dumas, 46 Dunn's silicic soap, 381, 332 Dyeing, soaps for, 195 Earth-nut oil, 98 Eccentric mill, Bogardus', 229 Edinburgh wheel for candles, 408, 499 Egg yolk soap, 419 Egypt, natron of, 44, 45 Elaidic acid, 486 Elaidin soap, 288-296 - soft soap, 321, 322 Elain soaps from oleic acid, 119 Elaine, what it is, 70 Elder-flower soap, 411 perfumes for, 442 Emollient properties of brown Windsor soap, what due to, 406 Empatage, 276 England, alkali, trade of, 22 candles used in, 460 soap manufacture in, 21, 22 English crown soap, first quality, 323 Epicea seeds, oil of, 98 Erasive soap, 385 Essences for perfuming toilet soaps, 440 Essential oils for perfuming, 44(), 443- 455 Establishment of a soap factory, 197- 247 Estimation of soda in lyes of potash, 185-193 Extempore soaps, 400 and other soaps, 301-313 Extraction of potash, 32-41 Euphorbium, oil of, 98 % Fabrication of artificial soda, history of, 45-48 of soaps, 248-336 Factory at St. Quen, France, 199-202 building, 203 establishment of a soap, 197-249 Fahrenheit thermometer, 551, 557-560 Falsification of lard, 148 of tallows, 149 of waxes, 150, 151 Faraday, process of saponification, 480 Fat, bone. 92, 93 Fuller's utilization of, 132-139 glue, 92, 98, 94 horse, 93 in pyroligneous aeid, 71 kitchen, 94 lost in the soaps consumed in Co- logne, 139 oils, 71 or oil, none used alone, which nuikes a faultless sojip, 262 wool, utilization of, 182-139 Fats and lyes, proportions of, 263-266 and oils, 68-124 advantages in mixing, 262, 268 decomposition of, 68 ethers of glycerine, 157 impurities in, 262 of vegetable origin, 97-124 used in the manufacture of soaps, 69 benzine for dissolving, 132 chiefly used for candles, 458 decomposition of, 72 of by lime, 472-477 decomposed when distilled, 72 dissolved by sulphuret of carhon, 182 expand in increase of temperature, 71 found in animals and vegetables, great variety of, 74, 75 in chloroform, 71 in ether, 71 668 INDEX. Fats- influence of sulphuric acid on, 73 in heated alcohol, 71 in sulphuret of carbon, 71 in volatile oil, 71 lime in, 92, 93 liquid or oils, when they become solid, 69 of animal origin, 75-97 off"al, yield of by means of sul- phuret of carbon, 131, 182 phosphorescent in the dark, 72 saponification of,^by means of car- bonated alkalies, 337, 838 by sulphuretted alkali, 338 solid, when they become liquid, 69 specific lubricity of, 71 gravity of, 71 vegetable and animal, composition of, 70 ■waste of, in cloth factories, 132 what soluble in, 7 1 Fatty acids, behavior of, when conibined with alkaline bases, 27 acids, 27 report on, 480, 481 bodies, adulteration of, 140-150 importance of in industries, 69 rags, treatment of, by sulphuret of carbon, 132 Fecula, falsification of wax with, 151 Fennel, oil of, 446 Fetid vapors of tallow, destroying, 78- 86 Fig soap, 320, 387 Filled rosin soaps, common, 326 soaps, 325-336 formulas for, 335, 386 Filling, applicable to certain soaps, 326 in toilet soaps, 401 or grinding of soap, 271, 272 Finishing and polishing of candles, 528- 531 soap cakes, 438, 439 soaps, 428 Fireplnce, 204-206 Fish oils, 95 Fitted soap, 201 Fitting, 279, 281, 395 D'Arcet's views on, 842 olein soap, 292-294 Fixed oils, 98 Flame, cause of shape of, 460 of a candle, description of, 460- 462 Flasks, measure for alkalimetry, 175, 176 Floating soaps, 421 Flour, falsification of wax with, 151 Foundation of kettles, 207 Frames for dipping candles, 500 of brick and cement, 205 of iron, 231, 233 of masonry, 230, 231 of wood, 207, 233-236 soap, 230-236 soap, German, 235 Whittakei's soap, 232, 283 France, candles used in, 460 establishment of the soap industry in, 20 soap statistics of, 24 Frangipanni soap, 411 Frankfort black, for marbling soap, 272 Freezing, melting, and boiling points of difl'ererit substatices, 560 French and English weights and meas- ures, relative values of, 547-^54 apparatus for moulding, 521 scouring soap, 385 soap factories, 199-208 toilet soaps, names of, 417 weights, 549 Fucus maritimus, 43 Fuller's fat, utilization of, 132-139 Fulling, soaps for, 195 Furnace for candles, 498 Furnaces for heating kettles, 213-215 Gaduin, 96 Galam butter, 104, 121 Gallipoli oil, 107, 108 Gaultheria or wintergreen oil, 446, 447 GayLussac, 19 analysis of soda by, 42 base of for alkalimetry. 179 patent for candles, 458 Germany, manufacture of alkali in, 22 soap manufacture in, 22 statistics of, 24 Gentele, formula for soft soaps with soda, 315, 316 Geranium oil, 447 Glass soap, soluble, 327 for filling soft soaps, 320 Glue fat, 92, 93. 94 Gljcerides, 69, 70 Glycerine, 69, 157, 486, 487 cocoanut oil soap, 427 drawing off", 473 furnished by fats, 359 Milly's process for production, 1 62 production and great value of, 103 separation of, 472 soap, 405 liquid, 424 perfumes for, 441 INDEX. 569 Glycerine — soap, transparent, 428 Tilghman's process for production of, 162 Glyceryl-oxide, 70 absorbed by acids, 73 Goa butter, 124 Gold soap, 156 Gontard's soap factory at St. Quen, 199-202 Gossage, on the use of soluble glass in soaps, 164 process for silicated soaps, 327 Gourd, oil of, 98 Grained soft soap, 320 Grain or curd soaps, 266-284 soap, artificial, 320,321 soaps, marbling, 201 Grape-seed oil, 124 -stone, oil of, 98 Grate, 204 Grease for toilet soap, 390, 392 oil wngon, treatment of with sul- phuric acid, .132 utilization of old wheel, 131 Greases for fine toilet soaps, 400 Great Britain, soap statistics of, 24 Greaves or crackling soap, 334 treating of, for making soap, 334 Greenland, cryolite of, 6') Green soft soap, 323, 324 Grinding apparatus, 229 or fitting of soap, 271, 272 Grodhaus and Fink, investigations on the extraction of tallow without of- fense, 78 Ground-nut oil, 97, 109, 110 Guppy's process for silicic soap, 332, 333 Guyton de Morveau, 46 Half-boiled or Swiss soap«, 30i)-309 soaps, 301 Swiss soaps, 400, 407 Half-palm soap, formulas for, 393 Hand soap press, 431 Hard soaps, 266-284 from potash lye, 162, 309 tallow for chandlers, 73, 74 Hazel-nut oil, 97, 98, 117 Heating manufactory by steam, 206- 21 1 of kettles by fire, 213-215 by steam, 215-224 Heintz on composition of butter, 91 on the composition of spermaceti, 484 Heliotrope soap, 411 Hempseed oil, 97, 98, 114, 115 adulteration of, 141 Hempseed oil — composition of, 114 soft soaps from, 319 Herb soap, 420 Hersey's patent rotary soap-pump, 236-238 patent steam press, 432 Honey soap, 405 perfumes for, 440 Hood for catching the offensive gases from tallow, 465 Hops, Spanish oil of, 451 Horse-chestnut, oil of, 98 fat, 93 Hubert's apparatus for boiling soap by surcharged steam, 219-221 Hungary, natron of, 45 Hydrate of lime, necessary to make caustic alkali, 248 of soda, 193 Hydraulic press, 475 Hydrometer of Baum^. 167 Hydrometers and thermometers, 555- 560 Illipe oil, 107 Imperial measure, 545 in apothecaries'%nd avoirdu- pois weights, value of, 546 Implements, minor, 246, 247 Impurities in fats and oils, 262 Iodine soap, 419 Irish-moss soap, 419 Iron, frames of, 231-233 kettles, 212, 213 red, for marbling soaps, 201 vats, 207, 227 Jacket crutching machine, 245, 246 Morfit's steam, 221-224 St. John's steam, 221, 222 Japan wax, 485 Jassamine, oil of, 447, 448 Jonquille soap, 413 Juenneman's process for changing oleic into palmitic acid, 119-121 Kalkothar for marbling soaps, 201 Kalucz, Hungary potasli from the salt- rocks in, 2» Keton, 480 Kettles, 204, 207, 211 cast and sheet-iron, 212, 213 heating by steam, 215-224 of by fire, 213-215 masonry, 21 1 used at Marseilles, 211, 212 used in France, Belgium, and England, 212 570 INDEX. King's foot-power press, 432 Kitchen fat, 94 Knapp on the efficacy of the globular state, 840 Kocin, 106 composition of, 106 Kraft, Prof. T., reports on sebacic or fatty acids, 480, 481 Kurten's table of composition and pro- duct of soaps by cold process, 408 Labor saving soap, 385 Lard, 86-90 falsification of, 148 for candles, 459 rendering of, by steam, Wilson's process, 88-90 Laurel oil, 97, 123 Lavender, oil of, 448 Lavoisier, 19 Leaching or washing of ashes, 34, 35 Lead-lined vats, 227 Leblanc, 45, 47, 48 discovery of process for making soda from salt, 21 Lefevre, method of extracting tallow, 77 Leleivre, 19 • Lemon, oil of, 446 seeds, oil of, 98 soap, 410 Length, measures of, 547 Lettuce soap, 415 Leubel's candle machine, 506, 507 Liebig's experiments on caustic potash and soda, 251 experiments on caustic alkali, 251 Light, artificial, from the flame of can- dle, principles of, 460 Lilly soap, 415 Lime, 61-63 analysis of, 194 for the removal of carbonic acid from lyes, 248 hydrated, 61 impure, 63 in fats, 92, 93 in preparation of lyes, 62 keeping of for use, 63 milk of, 61 qtialities of, 61 quantity of hydrate of, necessary to make caustic alkali, 248 saponification by, 472-477 slacked, 61 soap, 156 tests of, 63 Lime — to be applied in proportion to the contents of potash and soda to pure carbonate of alkali, tables of, 250, 251 water, 62 Limette, oil of, 448 Linden seeds, oil of, 98 Linseed oil, 97, 98, 117 adulteration of, 141 Lipyloxide, 70 Liquation, 344 Liquid fats or oils, when they become solid, 69 glj'cerine soap, 424 Liquefaction, 395, 396 D'Arcet's views on, 342 Litmus, tincture of, 177, 178 Little pan soaps, 301 Liverpool poor man's soap, 335 London soap powder, 387 Lubricating soap, 386 Lye, Dalton's table of soda in, 261, 262 for hard soaps, 266-271 for toilet soaps, 402 for treatment of bones, 385 potash from wood ashes, 253, 254 to separate from soap, 310 used at soap factory at St. Quen, France, 200 vats, 225, 226 Marseilles, 227 Lyes, Dalton's table of contents, 259, 260 for cold soaps, 801 for elaidin soft soaps, 321 for olein soap, 290-292 for saponification of rosin, 804 importance of maintaining a pro- per proportion of materials in, 251 importance of preparation of, 248 of potash, estimation of soda in, 185-193 preparation of, 248 preservation of, 254 specific gravity and hydrometrio test of,' 258 testing the strength of, 255 Mace, oil of, 122 Machinery and appliances for manipu- lation of soaps, 428 iMacquer, 46 Magnesia soap, 156 Malabar tallow, 124 Malherbe, 40 INDEX. 571 Manipulation of soap, 428-442 Manufactory of soap, heated by steam, 206-211 Marbled or Marseilles soap, 266 Marbling, D'Arcet's views on, 343-346 imperfect, 273 of grain soaps, 201 of soap, 272 soap, sub-lye used in, 273 Margaric, 71 Margarine, 71 Margarinic acid, melting and boiling points of, 481 Marine soap, 388 Marjoram, oil of, 451 Marseilles, establi-liment of sonp in- dustry in, 20 fabrication of artificial soda at, 48 kettles used at, 211, 212 lye vats, 227 soap, 266, 274-276 factory at St. Qnen, 199-202 soap, formulas for, 273, 274 from cotton-seed oil, 296-298 statistics of, 24 Marsh-mallow soap, 405 Masonry, frames of, 280, 231 kettles, 211 vats, 205 Materials for candles and their prepa- ration, 463-487 used in the manufacture of sonp, 26-129 Maujot, researches of, on fatty bodies, 458 Measures, American, 549 British imperial, 549 of capacity, 548 of length, 547 superficial, 548 Mechanical aid in making cold soaps, 302 stirrer, 302 Medicated soaps, 409-419 soft soap, 388 tar soap, 418 Melsen's process of saponification, 480 Melting and freezing and boiling points of ditferent substances, 560 Mercurial soap, 419 Mercury soap, 156 Metherie, de la, 46 Metric system. Congressional report on, 543, 544 Metric system of weights and measures, 543-554 Mill, Bogardus's eccentric, 229 centrifugal, for tallow, 470 for grinding alkalies, 229 Millefleur soap, 413 Mills, soap, 435 Milly's process for production of gly- cerine, 162 Miscellaneous useful soaps, 383-388 Mixed barilla, 44 Mohr, base of, for alkalimetry, 179 Molasse.y, potash from, 38, 39 Montigny, 46 Morfit's steam jacket, 221-224 Morgan's moulding machine, 508-512 Morrhua oil, 96 Mottled castile soap from cotton-seed oil, 298 Moulded candles, 501-527 Moulding candles by hand, 503, 504 by steam, French apparatus for, 520-522 by machinery, 504-527 machine, Ashley's, 513 of candles, when first made, 458 paraffine candles, 522 spermacetic candles, 523, 524 stearic acid candles, 517,518 by hand, 518-520 wax candles, 525 wheel. Camp's, 513-^515 Moulds for candles, 501, 502 for candles, improved, 535, 536 for stearic-acid candles, 518 Mouries, process of, 339-341 Mousseleine soap, 415 Muddiness, cause of, in soft soaps, 318 in soft soaps, 321 Muriatic acid for dissolving bones, 335 Musk or Bisam, 453 tincture of, 455 Windsor soap, 417 Muspratt, manufacture of artificial soda by, 21 Mustard-seed oil, 116 white, oil of, 98 Mutton tallow for candles, 458 Myrtle wax, 126, 485 Naples soap or shaving cream, 426 Narbonne, soda of, 42 Natron, 41, 42, 44, 45 Neat's-foot oil, 94 adulteration of 142 Needle for threading, 501, 503 Neroli or orange-flower oil, 449 Neutral fats, decomposition of, by super-heated steam, 162 New soaps by new methods, 337-350 Night lights or tapers, 542 Nitric acid, action of, on oils, 74 normal, quantities that will neu- tralize bases, 182 572 INDEX. Nitric acid — required for mixed alk;»lie9,189,190 Normal acid liquor, 865-369 alkali, 184,-185 alkaline liquor, 865, 369. 370 nitric acid, quantities which will neutralize bases, 182 Nutmeg, analysis of, 122 butter of, 122 Nutmegs, oil of, 452 Nut oil, 97, 98, 115 Nymph floating soap, 421 Oatmeal soap, 419 Ocuba wax, 126, 485 Offal fats, yield of, by means of sul- phuret of carbon, 131, 132 recovery of, 130-139 Offenbach's palm soap, H83 Oil, almond, 97, 98, 109 avocado, 111 beechnut, 97, 115, 1 16 ben, 97, 110 camelina, 97, 98, 116 carapa, 1 24 caraway seed, 447 cassia, 452 castor, 97, 98, 113 cocoanut, 105-1U7 coleseed, 97, 98, 109 colza, 116 cotton-seed, 97, 98, 111-113, 296- 300 for Marseilles soaps, 275 gallipoli, 107, 108 geranium, 447 grape-seed, 124 ground-nut, 97, 109, 110 hazel-nut, 97, 98, 117 hemp-seed, 97, 98, 114, 1 15 linseed, 97, 98, 117 morrhua, 96 mustard-seed, 116 neat's-foot, 94 nut, 97, 98, 115 of belladonna seed, 124 uf bergamot, 443. 444 of bitter almonds, 444-416 of Canada snakeroot, 452 of cinnamon, 452 of cloves, 448 of fennel, 446 of gaultheria or wintergreen o"l, 446,447 of jassamine, 447, 448 of laurel, 97, 123 of lavender, 448 of lemon, 446 of limette, 448 Oil— of mace, 122 of marjoram, 451 of nutmegs, 452 of patchouly, 419 of pimento, 452 of Portugal, 449 of rosemary, 452 of roses, 449-451 of sassafras, 451 of sweet almonds, adulteration of, 140 of thyme, 451 of tobacco seeds, 124 of valerian, 443 of vitivert, 452 olive, 98, 99 or fat, none used alone, which makes the faultless soap, 2(j2 palm, 99-104 palm kernel, 104 poppy seed, 97, 98, 113, 114 raja, 96 rapeseed, 97, 98, 109 sesame, 108, 109 sunflower, 97, 111 Oils and fats, 68-124 advantage in mixing, 262, 263 decomposition of, 68 impurities in, 262 of vegetable origin, 97-124 used in the manufacture of soaps, 69 assays of, 148-147 coloration of, 143, 144 coloration of, taken by different, 146, 147 fish, 95 fixed, 98 or liquid fats, when tliey become solid, 69 physical properties of, 98 sebacic acid, from sediment of, 131 train, 95 volatile, 443-455 volatile, specific gravities of, 442- 453 yielded by vegetables, quantities of, 97, 98 Old brown Windsor soap, 406 Oleabutyric acid, 91 Oleic acid, 117-121 adulteration of, 142 characteristics of, 118 glyceryl oxide, 71 in the fabrication of soap, 119 recovery of, 480 reduced by Chevreul, 458 soap, 288-296 INDEX. 573 Oleic acid — with hydrate of potash, dissolved into palmitic and acetic acids, 119 Olein, 117-121 acid, in vegetable oils, 71 constitution of, 157 or stearic glycei'yl oxide, 70 quantity obtained from oleic acid, 295 soap, 288-296 what it is, 70 Oleines, 70 Oleophane, 424 Olive oil, 97-99 adulteration of, 140 discoloration of, by heat, 143 soaps will bear no salt, 325 white soap, from composition of, 280 Onoporde acanthe, oil of, 98 Orange-flower oil, 449 Orange soap, 411 Orleans, Duke of, 47 Ox-gall soaps, for scouring woollens, 384 Palmitic acid from palm oil, melting and boiling points, 480, 481 Palmitic acid or margaric acid, 71 Palmitin, 70, 157 Pnlmitin or margarine, 71 Palm-kernel oil, 104 Palm oil, 24, 99-104 adulteration of, 142 bleaching of, 101 color of, in soap, 101 composition of, 101 consumption of, 100 consumption of, in England, 100 extraction of, 100 for candles, 459 free acids in, 101 melting points of, 101 soap, hardness and brittleness of, to correct, 284 soaps, salt which they will bear, 325 the peculiar acid of, 70 Palm-tree wax, 125 Palm soap, 284, 285 Dresden, 383 half, 393 for stock, 397 formulae for, 285 Offenbach's, 383 Swiss, 306, 307 Paraffine, addition of stearic acid to, 483 Paraffine — addition to stearic acid, for can- dles, 458 bleaching of, 483 candles, 522 moulding, 522 discovery of, 458 melting points of, 483-522 production and uses of, 482, 483 scale, 482 soap, 419 Paris, manufacture of candles at, 457 Taste for Marseilles soap, 266 Paste, homogeneity of, 295 Pasting, 276, 394 Patchouly, oil of, 449 Patent candles, 582-536 Payen, 47 Pearl soap powder, 387 Pela wax, 485 Pelouze, method of saponification by sulphuretted alkalies, 338 Pentadecyl acid, melting and - boiling points of, 481 Perfume for Cashmere soap, 442 Perfumes for elder flower soap, 442 for glycerine soaps, 441 for honey soap, 440 for rose soap, 441, 442 for toilet soaps, 403-427 for white Windsor soap, 441 Perfuming soaps, materials for, 443- 455 steam for finishing soap cakes, 438 toilet soaps, 440-442 Permanganate of potash, for whitening tallow, 470 Perutz's fine soda-grain soap, 320 improvement of Mege Mouries' process, 341 Perutz, on the success of Mege Mou- ries, 341 1 Perutz's table of anhydrous potash, 259 of anhydrous soda, 2b 1 Peruvian balsam, 454 Petroleum soap, 419 Pimento, oil of, 452 Pine-tree oil, 97 Pipes to draw off lyes from kettles, 207 Pipette, the, 172-174 Pitch, falsification of, wax with, 150 Pitch tree oil, 97 Plant of a soap factory, 197-247 Plants, combustion of in furnaces, for potash, 33, 34 Plaster of Paris, detection of, in lard, 148 Plotting machines, 436-438 hydraulic, 437, 4ii8 574 INDEX. Plum seeds, oil of, 98 Polishing and finishing of candles, 528- 631 soap cakes, 488, 480 machines for candles, 529-581 Poncein soap, 884 Poole & Hunt's iron frames, 282 Poor man's soap, 385 Poppy oil, adulteration of, 141 seed oil, 97, 98, 113, 114 Portugal, oil of, 449 Potash, 26, 27-41 a small quantity in vegetables which grow on the sea-shore, 28 and soda, determination of rela- tive quantities of, in soaps, 855 mixtures of, in soaps, 376-879 proportions of, for soft soaps, 316, 817 anhydrous, 259 carbonate of, 89, 41 to change into caustic alkali, 249 caustic, Liebig's experiments, 251 contents of lyes, Dalton's table of, 259, 260 extraction of, 82-41 fictitious, 36 from beet-root molasses, 88, 89 from the salt rocks in Kalucz, Hungary, 28 from the salt rocks in Strassfort, Prussia, 28 from vegetables which grow inland, 29 in carbonate of potash, 191, 192 in different vegetables, table of, 30 in hydrate potash, 191, 192 in the younger parts of plants, 29 in vegetables, 28 lye from wood ashes, preparing, 253, 254 lye, hard soap from, 162, 309 lyes, estimation of soda in, 185-198 manufacture of, in Russia and the United States, 28 purification of, 40, 41 red American, 35-37 soap to transform into soda soap by the use of salt, 310 soft toilet soaps of, 424 sources of, 28 table of lime to be applied in pro- portion to contents of pure car- bonate, 250 Potashes, table of the composition of the principal commercial, 39, 40 the most esteemed, 39 Potassium, 26 Powder soap, 887 Powdered soap, 421 Preservation of lyes, 254 Press, hand, for soap, 431 Hersey's patent steam soap, 482 soap, King's foot-power, 432 Presses, elbow, 467-469 for extracting fats from greases, 466-469 Price & Co., London candle factory of, 460 Process of Mege Mouries, 389-341 Proctor on production of wintergreen oil, 446 Properties, physical, of oils, 88 Proportions of fats and lyes, 263-266 Purification of potash, 40, 41 Purifying and whitening tallow, 470 the grease for toilet soap, 890-392 Putrid waters, utilization of, 180 Qualitative assays of oils, 144-147 Quartz soap, 384 Radish-seed, oil of, 98 Rags, fatty, treatment by sulphuret of carbon, 132 Raja oil, 96 Ralston's cutter, 243 Ram to mould soap, 207 Rapeseed oil, 97, 98, 109 adulteration of, 141 residue, utilization of, 131 Reaumur, thermometer, 551, 557-560 Recovery of offal fats, 180-139 of refuse fats and greases, 130-189 Red American potash, 85-87 oil, commercial, 117-121 Refuse fats and greases, recovery of, 180-189 Refined carbonate of soda, 54-55 Relargage, 277 Remelter, Whittaker's, 881,882 Remelting of soap, 880-382 Rendering and purifying the grease for toilet soaps, 890-392 lard by steam, 88-90 tallow, without offence, Vohl's pro- cess, 84-86 Residues of rapeseed oil, utilization, 181 Residuum of distilled fat, 181 Resinous grain soap, 287, 288 Resins, falsification of wax with, 150 Rose floating soap, 421 leaf soap, 415 shaving cream, 426 soap, 403, 404 INDEX. 575 Rose soap — perfumes for, 441, 442 Windsor soap, 416 Rosemary, oil of, 452 Roses, attar of, 449-451 oil of, 449-451 Rosin, abietic acids in, 128 action of train oil on, 96 and fat, saponification of, 304 for filling soft soaps, 319 for removal of touch from sub-lye, 283 in elaidin soaps, 322 in soap, 285 in soap-making, 129 in soaps, determination of, 357 makes soaps soft and pasty, 304 or colophony, 126-129 percentage applied to fats, 304 saponification of, 304 Sutherland's method for testing in soap, 360 Swiss soap, 368 the acids in affinities for alkalies,! 64 uses of, 129 uses of, in soaps, 164 Rosin soap, 129, 285-289 Altenburge's, 383 by cold process, 304 formula for, 286 separation from salt, 283 transparent, 305 Rosin soaps, common, filled, 326 English, 286-287 large number of, 304 Rosins, preparation of, in the United States, 285 Rubinium, 60 Rubidium, oxides of, 156 Rutschman's hydraulic soap plotter, 437, 438 power soap-mill, 435 rotary soap-plotter, 430,437 stripping machine, 434, 485 Saint John's steam jacket, 221, 222 Quen, France, soap factory at, 199-202 Salicor, 42 Salicornia annua, 42 Europoea, 42 Salicylic soap, 419 Salin, 32 Salmo-phymallus, fat of, 96 Salsola soda, 42, 43 Salt, 67, 68 a solution of, filling soft soaps, 319 action of, on lye, 268 Salt— and sulphate of copper, dissolved by the fats, 74 the use of, in making soap, 310, 311 Salted barilla, 44 soda, artificial, 52-54 Salting out, 310 Salts, efi^ect of, in separating soap from its lyes, 161 in vegetables, 28 of soda, caustic, 57, 59 soluble and insoluble, in diflFerent plants, 31 soluble, composition of, from cer- tain vegetables, 31, 32 Sfind soap, 334 Saponification, 156-165 by lime, 472-477 by lime, water, and pressure, 472 by sulphuric acid and distillation, 472, 478, 479 by water and distillation, 472, 479, 480 by water under high pressure, 472, 480, 481 D'Arcefs practice, 341 views on, 342 eflFect of, on fats, 156 of fats by means of carbonated alkalies, 337, 338 of fiits by sulphuretted alkalies, 338 of lime, De Milly's process, 477, 478 of rosin, 304 of rosin and fat, 304 theory of, 17 to test, 473 Sapophane, 424 Sassafras, oil of, 451 Savon a la marechale, 414 a la violette de Parme, 414 de muguet, 415 hygienique, 414 Savonettes, 427 Sawdust for filtering oil, treatment of, 131, 132 Scales and weights in alkalimetry, 177 Scheele, 19 Scouring balls, 384 soap, French, 385 tablets, 385 Sea-weeds, soda from, 43 Seal oil, 95 Sebacic acid in soap, Buckner's method to determine, 359 Sebacic acids, congealing points of, 3.')8 in soaps, determination of, 357, 359 676 INDEX. Sebacic or f:itty acids, Kraft's report on, 480, 481 Sebacylic acid, 486 high fusion point of, 486 Separation, 277, 394 Sesame oil, 108, 109 adulteration of, 1 41 soda soap from, 109 uses of, 109 Sesamum oil, 97, 98 Shaker soft soap, 386 Sharks' livers, oil of, 96 Shaving compounds, 421 cream, almoml, 426 ambrosial, 426 by boiling, 426 or Naples soap, 426 rose, 426 creams, 424 soaps in tablets, 420 Shea butter, 104, 121 Sheet-iron vats, 207 Sieve, drum, 229, 230 Silica, preparation of, for soaps, 332 Silicated and other filled soaps, 325- 336 Silicated soaps, 327 Silicic soap, 331, 332 Guppy's process for, 332, 333 Silver soap. 156 Siphon, 228 Slabber, the champion, 242, 243 Slabbing and barring machine, Van Haagen, 239 Smell of melting tallow, correcting of, 80 Snakeroot, oil of, 452 Soap, 156 a test of civilization, 17 almond-grain, 296 analysis, 351-379 and alkali trades, history of, 19-25 balls. 427 bleaching, 296 boiling by surcharged steam, 219, 220 in France, 200, 201 bone, 334, 335 borax, 305 caking making machine, 428-430 castile, 274-276 formulas for, 273, 274 from cotton seed oil, 296-300 cocoanut-oil, by cold process, 303 consistency of, effected by the melting points of the fats, 163 crown, second quality, 323 crutching machine, 243-246 curd, 281-284 Soap — decomposition of, 473 determination of, as to admixtures, 362 elaidin, 288-296 English crown, first quality, 323 essences, 422 factories, French, 199-208 factory at St. Quen, 199-202 building for, 198 establishment of, 197-247 location of, 197 plant of, 197-247 fig, 320 fitted, 201 frame, Whittaker, 232, 238 frames, 230-236 gold, 156 grain, artificial, 320, 321 grained soft, 320 Greaves or crackling, 334 green soft, 323, 324 grinding or filling, 271, 272 Guppy's process for silicic, 332, 333 bard, from potash lye, 309 industry, establishment of, in Mar- seilles, 20 insoluble in strong lyes, 161 lime, 156 Liverpool poormau's, 335 magnesia, 156 manufacture, importance of the art, 17 in England, 21, 22 in Germany, 22 marbled or Marseilles, 266 marbling of, 272 Marseilles, formulas for, 273, 274 materials used in manufacture of, 26-129 mercury, 156 mills, 435 olein, 288-296 olive oil, composition of, 280 palm, 284, 285 poncein, 334 press, Mersey's patent, 432 pump, Hersey's rotary, 236-238 purest in commerce, 275 quartz, 334 remelting of, 380-382 resinous grain, 287, 288 rosin, 285-287 by cold process, 304 sand, 334 silver, 156 slabber, 242, 243 soft, elaidin, 321,322 INDEX. 577 Soap — soluble glass, 327 statistics of various countries, 24 stripping of, 434 substitutes for, 25 Swiss olein, 308 palm, 306, 307 rosin, 308 white wax, 307 yellow, 307 tallow, 281-284 by cold process, 303 curd (grained), 309-313 tin, 166 transparent rosin, 305 turpentine, 287, 288 wax, 296 what it is, 17, 156 when first made, 20 yellow, 285-287 zinc, 156 Soaps, acid salts, 196 action of in washing, 195 and candles, manufacture of true chemical industries, 18 and glycerine furnished by fats, Buchner's table of, 359 application of, 195, 196 by boiling, 248-256 by cold process, composition and product of, 408 by steam pressure, 346-350 chemical equivalents applicable to, 152-155 cold, 302 common cocoanut oil, 326 common filled rosin, 326 curd or grain, 266-284 elain, from oleic acid, 119 extempore, 301, 400 fabrication of, 248-336 for dyeing, 195 for wool-washing and fulling, 195 hard, 266-284 from potash lye, 162 importance of making good, honest, 18 made with potash and soda, 26 manipulation of, 428-442 manufacture of, in United States, 18, 23 marbling grain, 201 not entirely soluble in cold water, 164 of oleic acid and rosin, sapouime- try of, 375, 376 of solid and liquid fatty acid, sa- ponimetry of, 370-375 of weak stock, 163 37 Soaps — silicated, 327 silicated and other filled, 325-336 soda, 266-284 soft, 314-324 soft, cause of thickness in, 318 soft with soda, Gentele's formula for, 315, 316 solid, 266-284 soluble glass in, 164 Swiss or half-boiled, 306-309 table of analyses, 363 toilet, 195, 389-427 useful, 383-388 valuation of, 364, 365 white soft, 322 with potash, always soft, and re- tain their glycerine, 161 Soda, 26, 41-60 and potash, proportions of, for soft soaps, 316, 317 determination of relative quan- tities of, in soaps, 355 anhydrous, table of specific gravity and hydrometric degree, 261 artificial, 41 expense of manufacturing in France, 52 history of the fabrication of, 45-48 salted, 52-54 ash, by the ammoniacal process, 561 calcination of, 50 carbonate of, for filling soft soaps, 319 for rosin soaps, 304 to change into caustic soda, 250 carbonates of, 42 caustic, from cryolite, 60 caustic lyes of, 248 caustic salts of, 57-59 chemically pure, composition of, 42 crystals of, 55-57 English caustic, analysis of, 58 fabrication of artificial at Mar- seilles, 48 fabrication of crude, 48 from salt, discovered by Leblanc, 21 from sea-weeds, 43 grain soap, Perutz's, 320 hydrate of, table of, 193 in lye, Dalton's table of, 261, 262 • in lyes of potash, estimation of, i: 185-193 in vegetables which grow on the seashore, 29 678 INDEX. Soda — manufacture of artificial, by Mus- pratt, 21 of Aigues-Mortes, 43 of Alicante, 43 of Carthagena, 43 of Malaga, 43 of Narbonne, 42 refined carbonate of, 54 salsola, 42, 43 Boap, made with bone fat, 92 soaps, 266-284 sulphate of, 48-52 table of, 193 table of anhydrous of, 193 table of crystallized carbonate of, 193 table of lime to be applied in pro- portion to contents of pure car- bonate, 251 Sodas, natural, 42 Spanish, 43, 44 Sodium, 26 Soft soap, a good appearance of, 314 Belgian, 388 boiling of, 317, 318 borax, 386 cause of dulness of, 314 domestic, 386 elaidin, 321, 322 grained, 320 green, 323, 324 Shaker, 386 Soft soaps, 314-324 cause of thickening in, 318 filling, 319 from oleic acid, 119 judging of in making, 318 to give a greenish color to, 319 use of caustic soda in, 315 what they are, 314 white, 322 Soft toilet soap, white, 424, 425 Soft toilet soaps of potash, 424 Solid fats, when they become liquid, 69 soaps, 266-284 Soluble glass for filling soft soaps, 320 in soap, 164 soap, 317 Solvay, Ernst, process for soda ash, 561 Sophistication of soaps, materials used for, 325 Soutfrice & Co., offal utilized by, 130 South America, natron of, 45 Spanish sodas, 43, 44 Sperm candles, Belmont, 532 Spermaceti, 483, 484 candles, 458, 523 machine for cutting, 484 soap, 420 tendency to crystallize, 484 what composed of, 484 Star candles, 532 Starch, falsification of wax with, 151 for filling soft soaps, 319 Statistics of soaps of various countries, 24 Steam, advantage of the system, 207 decomposition of neutral fats by, 162 heating of kettles by, 215-224 jacket, Morfit's, 221-224 St. John's, 221,222 manufactory of soap heated by, 206-211 perfuming for finishing soap cakes, 438 press, Hersey's patent, 432 pressure in pounds and atmo- spheres, 560 pressure, soaps by, 346-350 series, 216-218 Stearic acid, addition to paraffine, 483 and stearine, the base of most cau- dles, 454 bleaching, 518 candles, moulding, 517, 518 crystallization of, to remedy, 517 for candles, 471 Stearic acid industry, great importance of, 459, 460 preparation of, 471 Stearic glyceryl, oxide, or oleine, 70 Stearine and stearic acid the base for most candles, 459 candles, 515-517 constitution of, 157 manufacture of, by De Milly, 459 what it is, 70 Stearines, 70 Stein, charcoal coves for disinfecting, 80 investigations of on the extracting of tallow, without offence, 78 on disinfecting the odorous pro- ducts in rendering, 78-81 Stirrer, mechanical, 302 Stirring olein soap in the frames, 294- 296 Stockhardt's table of the congealing points of sebacic fields, 358 Stock soap, palm, 397 Store-rooms, 205 Stoves, use of, in drying-rooms, 209 Strassfurt, Prussia, potash from the salt rocks of, 28 INDEX. 579 strength of lyes, testing, 255 Stripping machines, Rutschman's, 434, 435 of soap, 434 Strunz's soap crutching machine, 243, 244 Sub-lye, touch of, to remove, 283 Suinter, manufacture of, 133 Sulphate of soda, 48-52 Sulphur, falsification of yellow wax , by, 150 Sulphur soap, 418 Sulphuric acid, saponification of fats by, 478, 479 Sulphuret of carbon, to dissolve fats, 132 treatment of ofi'al fats by, 131, 132 Sulphuretted alkalies, 338 Sunflower-seed oil, 97, 111 oil of, 98 Superficial measures, 548 Superfine soaps, 412 Superheated steam, use of, for heating, 216, 217 Surcharged steam, boiling soap by, 219-221 Sutherland's method for testing the rosin in soap, 360 Swiss olein soap, 308 or half-boiled soaps, 306-309 palm soap, 306, 307 rosin soap, 308-310 soap, 308 white wax soap, 307 yellow soap, 307 Symbols proposed for weights, 551 Table of the quantities of ashes and potash in different vegetables, 30 Tablets, scouring, 385 shaving soaps, 420 Tallow bleaching, 470, 471 candles, early manufacture of, 457 how first made, 458 centrifugal mill for, 470 curd soap, 309-313 hood for catching the ofi^ensive gas from, 465 machines for cutting, 463, 464 Malabar, 124 of virola, 123 preparation of, for candles, 463 Price's process for melting, 86 rendering, 463 by open fire, 463 by steam, 463 saponification of, by De Milly's process, 477, 478 Tallow- soap, 281-284 by cold process, 303 soaps, will bear no salt, 325 to extract, 75-76 to obtain hai-d, for chandlers, 73, 74 vegetable, 121 Vohl's process for removing, with- out oflFence, 84-86 wax adulterated with, 151 Tallows, 75-86 falsifications of, 149 melting and refining, by steam, 505 vegetable, 485 Tannin soap, 419 Tapers, 540-542 Tar soap, medicated, 418 Tartar, ashes from, 37 Taulet, apparatus of, for extracting tallow, 77 Temperature of dryiqg-room, 208 Thermometers, 551, 555, 557-560 Thickness in soft soap, cause of, 318 Thyme, oil of, 451 Thymol soap, 419 Tilghman's apparatus for decomposition of neutral fats, 162 process of saponification, 480 Tin soap, 156 Tincture of ambergris, 455 of civet, 454 of cochineal, 177-179 of litmus, 177, 178 of musk, 455 Tobacco seeds, oil of, 124 Toilet soaps, 195, 389-427 by boiling, 392-399 by the cold process, 400-408 coloring, 439 made by cold process, 392 names of French, 417 perfuming, 440-442 Tooth soap, 418 Torsk livers, oil of, 96 Touch of sub-lye, to remove, 283 soaps adjusted upon a, 326 Toy candles, 538 Train oils, 95 for soap, 95 purifying, 95 Transparent glycerine soap, 423 soap by the cold process, 422-125 simple method for cheaper, 423 old method, 423 soft soaps, 424 rosin soaps, 305 toilet soap, 422-424 580 INDEX. Trays of tin plate, 474 Tripoli, natron of, 45 Troy weight, 550 Tiianermann's table of anhydrous pot ash, 259 soda, 261 Turnip-seed, oil of, 98 Turpentine, 128 investigations of Laurent, 128 of Maly on, 128 of Unverdorben on, 128 soap, 287, 288, 419 United States, manufacture of soap in, 18, 22 soap statistics of, 24 Useful soaps, miscellaneous, 383-388 Valerian, oil of, 443 Valuation of soaps, 364, 365 Van Haagan's slabbing and barring ma- chine, 239 Vanilla soap, 416 Varnish for decorated candles, 539 Vat, lead lined, 227 Vats, iron, 227 large masonry, 205 lye, 225, 226 sheet iron, 207 Vegetable fatty bodies employed in making soap, 97 oils and fats, 97-124 for candles, 459 oleine acid in, 71 refuse, purification of, 130 tallow, 121 waxes and tallow, 485 Vegetables, potash in, 28 quantities of oils yielded by, 97, 98 salts in, 28 table of potash and ashes in, 30 Venice, manufacture of candles at, 457 Ventilation in drying-room, 209 Vesiculos habens, 43 Violet soap, 416 Windsor soap, 417 Virola, tallow of, 123 Vitibert, oil of, 452 Vohl's apparatus for removing tallow, 463 Vohl's process for rendering tallow without otfense, 84-86 Volatile oils, adulteration in, 443 and other materials tor per- fuming soaps, 443-455 testing, 443-455 Volumetric analysis, 167, 1G8 Washing, action of soaps in, 195 Warm air, drying-room with, 208-211 Water, 64-67 absorbed by soaps, 325 and distillation, saponification of fats by. 479, 480 Fleck test of, 64-67 for a soap factory, 199, 202 importance of, in a factory, 207 in manufacture of soap, 64 proportion of, absorbed by soaps, 325 to make caustic potash and soda, 251, 252 Waters, soap-maker's, 310 Watson's process for purifying and whitening tallow, 470 Watts' method for bleaching tallow, 470 Wax candles, 524 artificial, 532, 533 Belmont, 532 how first made, 458 Carnauba, 126, 485 Chinese, 485 Japan, 485 myrtle, 126, 485 ocuba, 126, 485 of bicuyda, 126 or bleaching soap, 384 palm tree, 125 pela, 485 soap, 296, 419 Swiss white, 307 tapers, 540 machine for making, 540, 542 white, 125 yellow, 125 Waxes, 125, 126, 484, 485 falsification of, 150, 151 vegetable, 485 Weights and measures, 543-554 relative value in distilled water, 546 French, 549 Whale oil, 95 soap, 387 Wheel, Edinburgh, 498, 499 White Castile soap, 281 Marseilles soap, 274-276 soap, by the cold process, 402, 403 from cocoanut oil, 398, 399 from olive oil, composition of, 280 soft soap, 424, 425 soaps, 322 Windsor soap, 404 perfumes for, 441 Whitening tallow, 470 INDEX. 581 Whittaker's patent soap frame, 232, 233 remelter, 381, 382 Wick machine, continuous, 512, 513 Wicks and their preparation, 488-493 apparatus for soaking and cutting, 492, 493 for dipped candles, 494 for stearic acid candles, 517 machines for cutting, 490, 491 plaiting and gimping of, 493 Windsor soap, 404 musk, 417 old brown, 406 rose, 416 violet, 417 white, 404 perfumes for, 441 Wilson, George, saponification by, of fats by water and distillation, 479, 480 Wilson's process, rendering lard by steam, 88-90 Wine measure, U. S., 545 Wiutergreen oil, 446-447 Woad, oil of, 98 Wood ashes, boiling with, 312, 313 potash lye from, 253, 254 Wood, frames of, 233-236 Wool, fat train, 136 utilization of, 132-139 washing, soaps for, 195 Woollens, ox-gall soap for scouring, 384 Yarns, mode of designating the fine- ness of, 489, 490 Yellow ochre, falsification of yellow wax with, loO silicic soap, 331, 332 soap, 285-287, 404 Swiss soap, 307 Zinc soap, 156 CATALOGUE OF PRACTICAL 5 SCIENTIFIC BOORS PUBLISHED BY HENRY CAREY BAIRD KO., INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS. 810 WAmUT STEEET, PHILADELPHIA. Jl^* Any of the Books comprised in this Catalogue will be sent free of postage at the printed prices to any address in the World. 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INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 810 Walnut Street, Philadelphia. 4®" Any of the Books comprised in this Catabgne will he sent by mail, free of postage, to any address in the world, at the publication prices, 4®=- A Descriptive Catalogue, 96 pages, 8vo., will he sent free and free of postage, to any one in any part of the world, who will furnish his address, 4®* Where not otherwise stated, all of the Books in this Catalogue are bound in muslin, AMATEUR MECHANICS' WORKSHOP: A treatise containing plain and concise directions for the manipula- tion of Wood and Metals, including Casting, Forging, Brazing, Soldering and Carpentry. By the author of the " Lathe and Its Uses." Third edition. Illustrated. 8vo. . . . ^3.00 ANDRES.— A Practical Treatise on the Fabrication of Volatile and Fat Varnishes, Lacquers, Siccatives and Sealing Waxes. From the German of Erwin Andres, Manufacturer of Varnishes and Lacquers. 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With over One Hundred Illustrations. i2mo. ^^2.50 BOOTH. — Marble Worker's Manual : Containing Practical Information respecting Marbles in general, their Cutting, Working and Polishing ; Veneering of Marble ; Mosaics ; Composition and Use of Artificial Marble, Stuccos, Cements, Receipts, Secrets, etc., etc. Translated from the French by M. L. Booth. With an Appendix concerning American Marbles. i2mo., cloth $1.50 BOOTH and MORFIT.— The Encyclopaedia of Chemistry, Practical and Theoretical : Embracing its application to the Arts, Metallurgy, Mineralogy, Geology, Medicine and Pharmacy. By James C. Booth, Melter and Refiner in the United States Mint, Professor of Applied Chem- istry in the Franklin Institute, etc., assisted by Campbell Morfit, author of " Chemical Manipulations," etc. Seventh Edition. Com- plete in one volume, royal 8vo., 978 pages, with numerous wood-cuts and other illustrations ....... ^5.00 BRAMWELL.— The Wool Carder's Vade-Mecum : A Complete Manual of the Art of Carding Textile Fabrics. By W. C. Bramwell. Third Edition, revised and enlarged. Illustrated, pp. 400. l2mo ^^2.50 BRANNT.— The Techno-Chemical Receipt Book : Containing several thousand Receipts comprising the latest and most useful discoveries in Chemical Technology and Industry. Edited from the German of Drs. E. Winckler, Heintze and Mierzinski, with additions by W. T. Brannt. [In preparation.) BROWN. — Five Hundred and Seven Mechanical Movements: Embracing all those which are most important in Dynamics, Hy- draulics, Hydrostatics, Pneumatics, Steam-Engines, Mill and other Gearing, Presses, Horology and Miscellaneous Machinery; and in- cluding many movements never before published, and several of which have only recently come into use. By Henry T. 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To which are added Practical Directions for Distilling, from the French of Th. Fling, Brewer and Distiller. i2mo • • • $^-SO BYRNE. — Hand-Book for the Artisan, Mechanic, and Engi- neer : Comprising the Grinding and Sharpening of Cutting Tools, Abrasive Processes, Lapidary Work, Gem and Glass Engraving, Varnishing and Lackering, Apparatus, Materials and Processes for Grinding and HENRY CAREY BAIRD & CO.'S CATALOGUE. Polishing, etc. By Oliver Byrne. Illustrated by 185 wood en- gravings. 8vo. ^5.00 BYRNE.— Pocket-Book for Railroad and Civil Engineers : Containing New, Exact and Concise Methods for Laying out Railroad Curves, Switches, Frog Angles and Crossings ; the Staking out of work; Levelling; the Calculation of Cuttings; Embankments; Earth- work, etc. By Oliver Byrne. i8mo., full bound, pocket-book form ^1-75 BYRNE.— The Practical Metal-Worker's Assistant: Comprising Metallurgic Chemistry; the Arts of Working all Metals and Alloys; Forging of Iron and Steel; Hardening and Tempering ; Melting and Mixing; Casting and Founding ; Works in Sheet Metal; the Processes Dependent on the Ductility of the Metals; Soldering; and the most Improved Processes and Tools employed by Metal- W^orkers. With the Application of the Art of Electro-Metallurgy to Manufacturing Processes; collected from Original Sources, and from the works of Holtzapffel, Bergeron, Leupold, Plumier, Napier, Scoffern, Clay, Fairbairn and others. By Oliver Byrne, A new, revised and improved edition, to which is added an Appendix, con- taining The Manufacture of Russian Sheet-Iron, By John Percy, M. D., F, R. S, The Manufacture of Malleable Iron Castings, and Improvements in Bessemer Steel. By A. A. Fesquet, Chemist and Engineer. With over Six Hundred Engravings, Illustrating every Branch of the Subject. 8vo ^7-00 BYRNE.— The Practical Model Calculator: For the Engineer, Mechanic, Manufacturer of Engine Work, Naval Architect, Miner and Millwright. By Oliver Byrne. 8vo., nearly 600 pages ^4.50 CABINET MAKER'S ALBUM OF FURNITURE: Comprising a Collection of Designs for various Styles of Furniture. Illustrated by Forty-eight Large and Beautifully Engraved Plates. Oblong, 8vo ^3.50 CALLINGHAM.— Sign Writing and Glass Embossing: A Complete Practical Illustrated Manual of the Art. 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With a portrait. 8vo., cloth . . 75 CAREY.— The Works of Henry C. Carey : Harmony of Interests : Agricultural, Manufacturing and Commer- cial. 8vo. ^i-5o Manual of Social Science. Condensed from Carey's " Principles of Social Science." By KatE McKean. I vol. l2mo. . ^2.25 Miscellaneous Works. With a Portrait. 2 vols. 8vo. ^6.00 Past, Present and Future. Svo ^^2.50 Principles of Social Science. 3 volumes, Svo. . . ^10.00 The Slave-Trade, Domestic and Foreign; Why it Exists, and How it may be Extinguished (1853). 8vo. . . . ^2.00 The Unity of Law : As Exhibited in the Relations of Physical, Social, Mental and Moral Science (1872). Svo. . . ^3.50 CLARK. — Tramways, their Construction and Working : Embracing a Comprehensive History of the System. With an ex- haustive analysis of the various modes of traction, including horse- power, steam, heated water and compressed air; a description of the varieties of Rolling stock, and ample details of cost and working ex- penses. By D. 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Illus- trated by 176 engravings. 581 pages, 8vo. . . . ^7.50 CRISTIANI.— Perfumery and Kindred Arts: A Comprehensive Treatise on Perfumery, containing a History of Perfumes from the remotest ages to the present time. A complete detailed description of the various Materials and Apparatus used in the Perfumer's Art, v^^ith thorough Practical Instruction and careful Formulae, and advice for the fabrication of all known preparations of the day, including Essences, Tinctures, Extracts, Spirits, Waters, Vinegars, Pomades, Powders, Paints, Oils, Emulsions, Cosmetics, Infusions, Pastilles, Tooth Powders and Washes, Cachous, Hair Dyes, Sachets, Essential Oils, Flavoring Extracts, etc. ; and full details for making and manipulating Fancy Toilet Soaps, Shaving Creams, etc., by new and improved methods. 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Large 4to. . ^2.50 DAVIDSON.— A Practical Manual of House Painting, Grain- ing, Marbling, and Sign- Writing : Containing full information on the processes of House Painting in i HENRY CAREY BAIRD & CO.'S CATALOGUE, Oil and 'Distemper, the Formation of Letters and Practice of Sign- Writing, the Principles of Decorative Art, a Course of Elementary Drawing for House Painters, Writers, etc., and a Collection of Useful Receipts. With nine colored illustrations of Woods and Marbles, and numerous wood engravings. By Ellis A. Davidson. i2mo. $300 DAVIES. — A Treatise on Metalliferous Minerals and Mining: By D. C. Davies, F. G. S., Mining Engineer, Examiner of Mines, Quarries and Collieries. Illustrated by 148 engravings of Geological Formations, Mining Operations and Machinery, drawn from the practice of all parts of the world. 2d Edition, i2mo., 450 pages ^5.00 DAVIES. — A Treatise on Slate and Slate Quarrying: Scientific, Practical and Commercial. By D. C. Davies, F. G. 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Edited with Notes, by Robert Mallet, F. R. S., F. S. G., M. I. C. E., etc. American Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. Fesquet, Chemist and Engineer. i2mo. . . . ^2.50 DUNCAN.— Practical Surveyor's Guide: Containing the necessary information to make any person of com- mon capacity, a finished land surveyor without the aid of a teacher. By Andrew Duncan. Illustrated, i2mo. . . . ^1.25 DUPLAIS. — A Treatise on the Manufacture and Distillation of Alcoholic Liquors : Comprising Accurate and Complete Details in Regard to Alcohol from Wine, Molasses, Beets, Grain, Rice, Potatoes, Sorghum, Aspho- del, Fruits, etc. ; with the Distillation and Rectification of Brandy, Whiskey, Rum, Gin, Swiss Absinthe, etc., the Preparation of Aro- matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., the HENRY CAREY BAIRD & CO^S CATALOGUE. n Ageing of Brandy and the improvement of Spirits, with Copious Directions and Tables for Testing and Reducing Spirituous Liquors, etc., etc. Translated and Edited from the French of MM. DuPLAis, Aine et Jeune. By M. McKennie, M. D. To which are added the United States Internal Revenue Regulations for the Assessment and Collection of Taxes on Distilled Spirits. Illustrated by fourteen folding plates and several wood engravings-. 743 pp. 8vo. $10 00 DUSSAUCE.— A General Treatise on the Manufacture of Every Description of Soap : Comprising the Chemistry of the Art, with Remarks on Alkalies, Saponifiable Fatty Bodies, the apparatus necessary in a Soap Factory, Practical Instructions in the manufacture of the various kinds of Soap, the assay of Soaps, etc., etc. By Prof. H. Dussauce, Chemist. Illustrated. 8vo ^25 00 DUSSAUCE.— A General Treatise on the Manufacture of Vinegar: Theoretical and Practical. Comprising the various Methods, by the Slow and the Quick Processes, with Alcohol, Wine, Grain, Malt, Cider, Molasses, and Beets ; as well as the Fabrication of Wood Vinegar, etc., etc. By Prof. H. Dussauce. 8vo. . ^5 00 DUSSAUCE.— A New and Complete Treatise on the Arts of Tanning, Currying, and Leather Dressing : Comprising all the Discoveries and Improvements made in France, Great Britain, and the United States. Edited from Notes and Documents of Messrs. Sallerou, Grouvelle, Duval, Dessables, Labar- raque, Payen, Rene, De Fontenelle, Malapeyre, etc., etc. By Prof. H. Dussauce, Chemist. Illustrated by 212 wood engravings. 8vo. $25 00 DUSSAUCE.— Practical Treatise on the Fabrication of Matches, Gun Cotton, and Fulminating Powder. By Professor H. Dussauce. i2mo. . . . . $3 00 DYER AND COLOR-MAKER'S COMPANION: Containing upwards of two hundred Receipts for making Colors, on the most approved principles, for all the various styles and fabrics now in existence ; with the Scouring Process, and plain Directions for Preparing, Washing-ofF, and Finishing the Goods. i2mo. $i 25 EASTON.— A Practical Treatise on Street or Horse-Power Railways : By Alexander Easton, C. E. Illustrated by 23 plates. 8vo. ^3 00 EDWARDS.— A Catechism of the Marine Steam-Engine, For the use of Engineers, Firemen, and Mechanics. A Practical Work for Practical Men. By Emory Edwards, Mechanical Engi- neer. Illustrated by sixty-three Engravings, including examples of the most modern Engines. Third edition, thoroughly revised, with much additional matter. 1 2 mo. 414 pages . . . ^2 00 EDWARDS. — Modern American Locomotive Engines, Their Design, Construction and Management. By Emory Edwards. Illustrated i2mo 12 HENRY CAREY BAIRD & CO.'S CATALOGUE. EDWARDS. — Modern American Marine Engines, Boilers, and Screw Propellers, Their Design and Construction. Showing the Present Practice of the most Eminent Engineers and Marine Engine Builders in the United States. Ilhistrated by 30 large and elaborate plates. 4to. ^5.00 EDWARDS.— The Practical Steam Engineer's Guide In the Design, Construction, and Management of American Stationary, Portable, and Steam Fire-Engines, Steam Pumps, Boilers, Injectors, Governors, Indicators, Pistons and Rings, Safety Valves and Steam Gauges. For the use of Engineers, Firemen, and Steam Users. By Emory Edwards. Illustrated by 119 engravings. 420 pages. l2mo $2 50 ELDER. — Conversations on the Principal Subjects of Political Economy. By Dr. William Elder. 8vo ^2 50 ELDER.— Questions of the Day, Economic and Social. By Dr. William Elder, 8vo. . go ELDER.— Memoir of Henry C. Carey. By Dr. William Elder. 8vo. cloth 75 ERNL — Mineralogy Simplified. Easy Methods of Determining and Classifying Minerals, including Ores, by means of the Blowpipe, and by Humid Chemical Analysis, based on Professor von Kobell's Tables for the Determination of Minerals, with an Introduction to Modern Chemistry. By Henry Erni, A.m., M.D., Professor of Chemistry. Second Edition, rewritten, enlarged and improved. i2mo. (7« presj.) FITCH.— Bessemer Steel, Ores and Methods, New Facts and Statistics Relating to the Types of Machinery in Use, the Methods in Vogue, Cost and Class of Labor employed, and the Character and Availability of the Ores utilized in the Manufacture of Bessemer Steel in Europe and in the United States; together with opinions and excerpts from various accepted authorities. Compiled and arranged by Thomas W. Fitch. 8vo. . ^3 00 FLEMING.— Narrow Gauge Railways in America. A Sketch of their Rise, Progress, and Success. Valuable Statistics as to Grades, Curves, Weight of Rail, Locomotives, Cars, etc. By Howard Fleming. Illustrated, 8vo ^150 FORSYTH.— Book of Designs for Headstones, Mural, and other Monuments : Containing 78 Designs. By James Forsyth. With an Introduction by Charles Boutell, M. A. 4 to., cloth . . . $S FRANKEL— HUTTER.— A Practical Treatise on the Manu- facture of Starch, Glucose, Starch- Sugar, and Dextrine : Based on the German of Ladislaus Von Wagner, Professor in the Royal Technical High School, Buda-Pest, Hungary, and other authorities. By Julius Frankel, Graduate of the Polytechnic School of Hanover. Edited by Robert Hutter, Chemist, Practical Manufacturer of Starch-Sugar, Proprietor of the Philadelphia Starch- HENRY CAREY BAIRD & CO.'S CATALOGUE. Sugar Works. Illustrated by 58 engravings, covering every branch of the subject, including examples of the most recent and best Ameri- can machinery. 8vo., 344 pp. ..... ^3.50 FRAZIER. — Modern Processes in the Metallurgy of Iron and Steel : By B. W. Frazier, Professor of Mining and Metallurgy in Lehigh University, Bethlehem, Pa. Elaborately Illustrated. (/« prepar- ation.) GEE. — The Practical Gold Worker : Or, the Goldsmith's and Jeweller's Instructor in the Art of Alloying, Melting, Reducing, Coloring, Collecting, and Refining; the Processes of Manipulation, Recovery of Waste, Chemical and Physical Proper- ties of Gold, with a New System of Mixing its Alloys, Solders, Enamels, and other Useful Rules and Recipes. By George E. Gee. i2mo $1.75 GEE.— The Silversmith's Handbook : Containing full instructions for the Alloying and Working of Silver, including the different modes of Refining and Melting the Metal ; its Solders ; the Preparation of Imitation Alloys ; Methods of Manipula- tion ; Prevention of Waste; Instructions for Improving and Finishing the Surface of the Work ; together with other Useful Information and Memoranda. By George E. Gee, Jeweller. Illustrated. i2mo. ^1-75 GOTHIC ALBUM FOR CABINET-MAKERS: Designs for Gothic Furniture. Twenty-three plates. Oblong ^2.00 GREGORY.— Mathematics for Practical Men : Adapted to the Pursuits of Surveyors, Architects, Mechanics, and Civil Engineers. By Olinthus Gregory. 8vo., plates . ^3.00 GRIER.— Rural Hydraulics : A Practical Treatise on Rural Household Water Supply. Giving a full description of Springs and Wells, of Pumps and Hydraulic Ram, with Instructions in Cistern Building, Laying of Pipes, etc. By W. W. Grier. Illustrated 8vo. ...... 75 GRIMSHAW.— Modern Milling: Being the substance of two addresses delivered by request, at the Franklin Institute, Philadelphia, January 19th and January 27th, 1881. By Robert Grimshaw, Ph. D. Edited from the Phono- graphic Reports. With 28 Illustrations. 8vo. . . ^i.oo GRIMSHAW.— Saws : The History, Development, Action, Classification, and Comparison of Saws of all kinds. With Copious Appendices. Giving the details of Manufacture, Filing, Setting, Gumming, etc. Care and Use of Saws; Tables of Gauges; Capacities of Saw-Mills; List of Saw- Patents, and other valuable information. By Robert Grimshaw. Second and greatly enlarged edition, with Supplejuent, and 354 Illus- trations. Quarto ........ ^4.00 GRIMSHAW. — A Supplement to Grimshaw on Saws : Containing additional practical matter, more especially relating to the HENRY CAREY BAIRD & CO.'S CATALOGUE. P'orms of Saw-Teeth, for special material and conditions, and to the Behavior of Saws under particular conditions. 120 Illustrations. By Robert Grimshaw. Quarto $2.00 GRISWOLD. — Railroad Engineer's Pocket Companion for the Field : Comprising Rules for Calculating Deflection Distances and Angles, Tangential Distances and Angles, and all Necessary Tables for En- gineers; also the Art of Levelling from Preliminary Survey to the Construction of Railroads, intended Expressly for the Young En- gineer, together with Numerous Valuable Rules and Examples. By W. Gris-wold. lamo., tucks $^-7S GRUNER.— Studies of Blast Furnace Phenomena: By M. L. Gruner, President of the General Council of Mines of France, and lately Professor of Metallurgy at the Ecole des Mines. Translated, with the author's sanction, with an Appendix, by L. D. B. Gordon, F, R. S. E., F. G. S. 8vo. . . . ^2.50 GUETTIER.— Metallic Alloys: Being a Practical Guide to their Chemical and Physical Properties, their Prejxiration, Composition, and Uses. Translated from the F'rench of A. Guettier, Engineer and Director of Founderies, author of " La Fouderie en France," etc., etc. By A. A. Fesquet, Chemist and Engineer. l2mo. ..... $3-00 HASERICK.— The Secrets of the Art of Dyeing Wool, Cotton, and Linen, Including Bleaching and Coloring Wool and Cotton Hosiery and Random Yarns. A Treatise based on Economy and Practice. By E. C. Haserick. Illustrated by 323 Dyed Patterns of the Yarns or Fabrics. 8vo, ........ ^25.00 HATS AND FELTING: A Practical Treatise on their Manufacture. By a Practical Hatter. Illustrated by Drawings of Machinery, etc. 8vo. . . ^1.25 HEINZERLING.— Elements of the Fabrication of Leather, with Special Regard to the Latest Improvements in this Branch of Industry. A Manual for Tanners, Technologists, Etc. By Dr. Chris- tian Heinzerling. Translated from the German by William T. Brannt, Graduate of the Royal Agricultural College of Eldena, Prussia; With additions by an American Editor. Illustrated by numerous Engravings. Svo. (/« preparation.) 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Embracing Rules and Directions for Estimates, Items of Cost, Nomenclature, Tal)les of Brackets, Modillions, Den- tals, Trusses, Stop-Blocks, Frieze Pieces, etc. Architect's Specifica- tion, Tables of Tin-Roofing, Galvanized Iron, etc., etc. To which is added the Exemplar of Architectural Sheet-Metal Work, containing details of the Centennial Buildings, and other important Sheet-Metal Work, Designs and Prices of Architectural Ornaments, as manufac- .tured for the Trade by the Kittredge Cornice and Ornament Com- HENRY CAREY BAIRD & CO.'S CATALOGUE. 17 pany, and a Catalogue of Cornices, Window-Caps, Mouldings, etc., as manufactured by the Kittredge Cornice and Ornament Company. The whole supplemented by a full Index and Table of Contents. By A. O. Kittredge. 8vo., 565 pages .... ^5.00 LANDRIN.— A Treatise on Steel: Comprising its Theory, Metallurgy, Properties, Practical Working, and Use. By M. H. C. Landrin, Jr., Civil Engineer. Translated from the French, with Notes, by A. A. 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Fifth edition, revised, with extensive additions. l2mo. . . . ^2.25 LEROUX.— A Practical Treatise on the Manufacture of Worsteds and Carded Yarns : Comprising Practical Mechanics, with Rules and Calculations applied to Spinning; Sorting, Cleaning, and Scouring Wools; the English and French Methods of Combing, Drawing, and Spinning Worsteds, and Manufacturing Carded Yarns. Translated from the French of Charles Leroux, Mechanical Engineer and Superintendent of a Spinning-Mill, by Horatio Paine, M. D., and A. A. Fesquet, Chemist and Engineer. Illustrated by twelve large Plates. To which is added an Appendix, containing Extracts from the Reports of the International Jury, and of the Artisans selected by the Committee appointed by the Council of the Society of Arts, London, on Woolen and Worsted Machinery and Fabrics, as exhibited in the Paris Uni- versal Exposition, 1867. 8vo. ..... ^S-oo LEFFEL. — The Construction of Mill-Dams : Comprising also the Building of Race and Reservoir Embankments and Head-Gates, the Measurement of Streams, Gauging of Water Supply, etc. By James Leffel & Co. Illustrated by 58 engravings. 8vo. ^2.50 LESLIE.— Complete Cookery: Directions for Cookery in its Various Branches. By Miss Leslie. Sixtieth thousand. Thoroughly revised, with the addition of New Receipts. In i2mo., cloth $i-50 2 i8 HENRY CAREY BAIRD & CO.'S CATALOGUE. 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Second American Edition, to which are added General Instructions for the use of Aniline Colors. 8vo. 343 pages ^5.00 LUKIN. — Amongst Machines: Embracing Descriptions of the various Mechanical Appliances used in the Manufacture of Wood, Metal, and other Substances. i2mo. ^1-75 LUKIN.— The Boy Engineers: What They Did, and How They Did It. With 30 plates. l8mo. ^1-75 LUKIN.— The Young Mechanic c Practical Carpentry. Containing Directions for the Use of all kinds of Tools, and for Construction of Steam- Engines and Mechanical Models, including the Art of Turning in Wood and Metal. By John LuKiN, Author of "The Lathe and Its Uses," etc. Illustrated. l2mo ^1.75 MAIN and BROWN.— Questions on Subjects Connected with the Marine Steam-Engine : And Examination Papers; with Hints for their Solution. By Thomas J. Main, Professor of Mathemadcs, Royal Naval College, and Thomas Brown, Chief Engineer, R. N. i2mo., cloth . ^1.50 MAIN and BROWN. — The Indicator and Dynamometer: With their Practical Applications to the Steam-Engine. By Thomas J. Main, M. A. F. R., Ass't S. Professor Royal Naval College, Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer R. N., attached to the R. N. College. Illustrated. 8vo. . ^1.50 MAIN and BROWN.— The Marine Steam-Engine. By Thomas J. Main, F. R. Ass't S. Mathematical Professor at the Royal Naval College, Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer R. N. Attached to the Royal Naval College. With numerous illustrations. 8vo. . . . ^5.00 MARTIN.— Screw-Cutting Tables, for the Use of Mechanical Engineers : Showing the Proper Arrangement of Wheels for Cutting the Threads of Screws of any Required Pitch; with a Table for Making the Uni- versal Gas-Pipe Thread and Taps. By W. A. Martin, Engineer. 8vo 50 HENRY CAREY BAIRD & CO.'S CATALOGUE. MICHELL.— Mine Drainage: Being a Complete and Practical Treatise on Direct-Acting Under- ground Steam Pumping Machinery. With a Description of a large number of the best known Engines, their General Utility and the Special Sphere of their Action, the Mode of their Application, and their Merits compared with other Pumping Machinery. By Stephen MiCHELL. Illustrated by 137 engravings. 8vq., 277 pages . ^6.00 MOLESWORTH.— Pocket-Book of Useful Formulae and Memoranda for Civil and Mechanical Engineers. By Guilford L. Molesworth, Member of the Institution of Civil Engineers, Chief Resident Engineer of the Ceylon Railway. Full- bound in Pocket-book form ...... ^i.oo MOORE.— The Universal Assistant and the Complete Me- chanic : Containing over one million Industrial Facts, Calculations, Receipts, Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., in every occupation, from the Household to the Manufactory. By R. Moore. Illustrated by 500 Engravings. i2mo. . ^2,50 MORRIS. — Easy Rules for the Measurement of Earthworks : By means of the Prismoidal Formula. Illustrated with Numerous Wood-Cuts, Problems, and Examples, and concluded by an Exten- sive Table for finding the Solidity in cubic yards from Mean Areas. The whole being adapted for convenient use by Engineers, Surveyors, Contractors, and others needing Correct Measurements of Earthwork. By Elwood Morris, C. E. 8vo ;^i.50 MORTON. — The System of Calculating Diameter, Circumfer- ence, Area, and Squaring the Circle : Together with Interest and Miscellaneous Tables, and other informa- tion. By James Morton. Second Edition, enlarged, with the Metric System. i2mo. ....... ^i.oo NAPIER.— Manual of Electro-Metallurgy: Including the Application of the Art to Manufacturing Processes, By James Napier. Fourth American, from the Fourth London edition, revised and enlarged. Illustrated by engravings. 8vo. ^1.50 NAPIER. — A System of Chemistry Applied to Dyeing. By James Napier, F. C. S. A New and Thoroughly Revised Edi- tion. Completely brought up to the present state of the Science, including the Chemistry of Coal Tar Colors, by A. A. Fesquet, Chemist and Engineer. With an Appendix on Dyeing and Calico Printing, as shown at the Universal Exposition, Paris, 1867. Illus- trated. 8vo, 422 pages ^5-oo NEVILLE.— Hydraulic Tables, Coefficients, and Formulae, for finding the Discharge of Water from Orifices, Notches, Weirs, Pipes, and Rivers: Third Edition, with Additions, consisting of New Formulas for the Discharge from Tidal and Flood Sluices and Siphons ; general infor- mation on Rainfall, Catchment-Basins, Drainage, Sewerage, Water Supply for Towns and Mill Power. By John Neville, C. E. M. R. HENRY CAREY BAIRD & CO.'S CATALOGUE. I. A. ; Fellow of the Royal Geological Society of Ireland. Thick I2mo ^350 NEWBERY.— Gleanings from Ornamental Art of every style : Drawn from Examples in the British, South Kensington, Indian, Crystal Palace, and other Museums, the Exhibitions of 1851 and 1862, and the best English and Foreign works. In a series of 100 exquisitely drawn Plates, containing many hundred examples. By Robert Newbery. 410. $12.50 NICHOLLS. —The Theoretical and Practical Boiler-Maker and Engineer's Reference Book: • Containing a variety of Useful Information for Employers of Labor, Foremen and Working Boiler-Makers, Iron, Copper, and Tinsmiths, Draughtsmen, Engineers, the General Steam-using Public, and for the Use of Science Schools and Classes. By Samuel NicholLS. Illus- trated by sixteen plates, i2mo. . . . . . $2.50 NICHOLSON.— A Manual of the Art of Bookbinding : Containing full instructions in the different Branches of Forwarding, Gilding, and Finishing. Also, the Art of Marbling Book-edges and Paper. By James B. Nicholson. 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Principally designed for explorers and those interested in Mines. By Oliver North. Illustrated. i2mo. . ^2.50 NYSTROM.— A New Treatise on Elements of Mechanics : Establishing Strict Precision in the Meaning of Dynamical Terms : accompanied with an Appendix on Duodenal Arithmetic and Me- trology. By John W. Nystrom, C. E. Illustrated. Svo. ;^2.oo^ NYSTROM.— On Technological Education and the Construc- tion of Ships and Screw Propellers : For Naval and Marine Engineers. By John W. Nystrom, late HENRY CAREY BAIRD & CO.'S CATALOGUE. Acting Chief Engineer, U. S, N. Second edition, revised, with addi- tional matter. Illustrated by seven engravings. i2mo. , ^1.50 O'NEILL. — A Dictionary of Dyeing and Calico Printing: Containing a brief account of all the Substances and Processes in use in the Art of Dyeing and Printing Textile Fabrics ; with Practical Receipts and Scientific Information. By Charles O'Neill, Analy- tical Chemist. To which is added an Essay on Coal Tar Colors and their application to Dyeing and Calico Printing. By A. A. Fesquet, Cheniist and Engineer. With an appendix on Dyeing and Calico Printing, as shown at the Universal Exposition, Paris, 1867. 8vo., 491 pages ^5.00 ORTON. — Underground Treasures: How and Where to Find Them. A Key for the Ready Determination of all the Useful Minerals within the United Slates. By James Orton, A.m., Late Professor of Natural History in Vassar College, N. Y.; Cor. Mem. of the Academy of Natural Sciences, Philadelphia, and of the Lyceum of Natural History, New York ; author of the Andes and the Amazon," etc. A New Edition, with Additions. Illustrated ......... ^^1.50 OSBORN.— The Metallurgy of Iron and Steel: Theoretical and Practical in all its Branches; with special reference to American Materials and Processes. By H. S. OsBORN, LL. D., Professor of Mining and Metallurgy in Lafayette College, Easton, Pennsylvania. Illustrated by numerous large folding plates and wood-engravings. Svo. ...... ^25.00 OVERMAN.— The Manufacture of Steel : Containing the Practice and Principles of Working and Making Steel. A Handbook for Blacksmiths and Workers in Steel and Iron, Wagon Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hard- ware, of Steel and Iron, and for Men of Science and Art. By Frederick Overman, Mining Engineer, Author of the " Manu- facture of Iron," etc. A new, enlarged, and revised Edition. By A. A. Fesquet, Chemist and Engineer. i2mo. . . ^1.50 OVERMAN.— The Moulder's and Founder's Pocket Guide : A Treatise on Moulding and Founding in Green-sand, Dry-sand, Loam, and Cement; the Moulding of Machine Frames, Mill-gear, Hollow- ware, Ornaments, Trinkets, Bells, and Statues; Description of Moulds for Iron, Bronze, Brass, and other Metals; Plaster of Paris, Sulphur, Wax, etc. ; the Construction of Melting Furnaces, the Melting and Founding of Metals ; the Composition of Alloys and their Nature, etc., etc. By Frederick Overman, M, E, A new Edition, to which is added a Supplement on Statuary and Ornamental Moulding, Ordnance, Malleable Iron Castings, etc. By A. A. Fesquet, Chem- ist and Engineer. Illustrated by 44 encrravinirs. i2mo. . ^^2.00 PAINTER, GILDER, AND VARNISHER'S COMPANION : Containing Rules and Regulations in everything relating to the Arts of Painting, Gilding, Varnishing, Glass-Staining, Graining, Marbling, Sign-Wriimg, Gilding on Glass, and Coach Painting and Varnishing; 22 HENRY CAREY BAIRD & CO.'S CATALOGUE. Tests for the Detection of Adulterations in Oils, Colors, etc. ; and a Statement of the Diseases to which Painters are peculiarly liable, with the Simplest and Best R-emedies. Sixteenth Edition. Revised, with an Appendix. Containing Colors and Coloring — Theoretical ai\G Practical. Comprising descriptions of a great variety of Additional Pigments, their Qualities and Uses, to which are added, Dryers, and* Modes and Operations of Painting, etc. Together with Chevreui's Principles of Harmony and Contrast of Colors. l2mo. Cloth $1.50 PALLETT.— The Miller's, Millwright's, and Engineer's Guide. By Henry Pallett. Illustrated. i2mo. . . . ^3.00 PEARSE. — A Concise History of the Iron Manufacture of the American Colonies up to the Revolution, and of Pennsyl- vania until the present time. By John B. Pearse. Illustrated i2mo. . . . ^2.00 PERCY. — The Manufacture of Russian Sheet-Iron. By John Percy", M. D., F. R. S., Lecturer on Metallurgy at the Royal School of Mines, and to The Advance Class of Artillery Officers at the Royal Artillery Institution, Woolwich; Author of " Metallurgy." With Illustrations. 8vo., paper . . 50 cts, PERKINS.— Gas and Ventilation : Practical Treatise on Gas and Ventilation. With Special Relation to Illuminating, Heating, and Cooking by Gas. Including Scientific Helps to Engineer-students and others. With Illustrated Diagrams. By E. E. 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Proteaux. From the French, by Horatio Paine, A, B., M. D. To which is added the Manufacture of Paper from Wood, by Henry T. Brown. Illustrated by six plates. 8vo. . $12.50 PROCTOR.— A Pocket-Book of Useful Tables and Formulae for Marine Engineers. By Frank Proctor. Second Edition, Revised and Enlarged. Full bound pocket-book form ...... $1.50 HENRY CAREY BAIRD & CO.'S CATALOGUE. 23 REGNAULT.— Elements of Chemistry. By M. V. Regnault. Translated from the French by T. Forrest Betton, M. D., and edited, with Notes, by James C. Booth, Melter and Refiner U. S. Mint, and William L. Faber. Metallurgist and Mining Engineer. Illustrated by nearly 700 wood engravings. Com- prising nearly 1,500 pages. In two volumes, 8vo., cloth . ^7.50 ROPER. — A Catechism of High-Pressure, or Non-Condensing Steam-Engines : Including the Modelling, Constructing, and Management of Steam- » Engines and Steam Boilers. With valuable illustrations. By Ste- phen Roper, Engineer. Sixteenth edition, revised and enlarged. i8mo., tucks, gilt edge ^2.00 ROPER.— Engineer's Handy-Book: Containing a full Explanation of the Steam-Engine Indicator, and its Use and Advantages to Engineers and wSteam Users. With Formulae for Estimating the Power of all Classes of Steam-Engines; also, Facts, Figures, Questions, and Tables for Engineers who wish to qualify themselves for the United States Navy, the Revenue Service, the Mercantile Marine, or to take charge of the Better Class of Sta- tionary Steam-Engines. Sixth edition. i6mo., 690 pages, tucks, gilt edge $3.50 ROPER. — Hand-Book of Land and Marine Engines : Including the Modelling, Construction, Running, and Management of Land and Marine Engines and Boilers. With illustrations. By Stephen Roper, Engineer. Sixth edition. i2mo., tucks, gilt edge. ^3-50 ROPER.— Hand-Book of the Locomotive : Including the Construction of Engines and Boilers, and the Construc- tion, Management, and Running of Locomotives. By Stephen Roper. Eleventh edition. i8mo., tucks, gilt edge . ^2.50 ROPER.— Hand-Book of Modern Steam Fire-Engines. With illustrations. By STEPHEN RoPER, Engineer. Fourth edition, i2mo., tucks, gilt edge ....... ^3-50 ROPER. — Questions and Answers for Engineers. This little book contains all the Que^^tions that Engineers will be asked when undergoing an Examination for the purpose of procuring Licenses, and they are so plain that any Engineer or Fireman of or- dinary intelligence may commit them to memory in a short time. By Stephen Roper, Engineer. Third edition . . . $3.00 ROPER.— Use and Abuse of the Steam Boiler. By Stephen Roper, Engineer. Eighth edition, with illustrations. l8mo., tucks, gilt edge ....... $2.00 ROSE.— The Complete Practical Machinist : Embracing Lathe-Work, Vise- Work, Drills and Drilling, Taps and Dies, Hardening and Tempering, the Making and Use of Tools, Tool Grinding, Marking Out Work, etc. By JosHUA Rose, Author of " The Pattern-maker's Assistant" and "The Slide Valve." Illustrated by 196 engravings. Eighth edition, revised and enlarged by the addition of much new matter. I2mc., 441 pages . . . ^^2.50 24 HENRY CAREY BAIRD & CO.'S CATALOGUE. ROSE,— Mechanical Drawing Self-Taught: Comprising Instructions in the Selection and Preparation of Drawing Instruments, Elementary Instruction in Practical Mechanical Draw- ing, together with Examples in Simple Geometry and Elementary Mechanism, including Screw Threads, Gear Wheels, Mechanical Mo- tions, Engines and Boilers. By JosHUA Rose, M. E., Author of " The Complete Practical Machinist," " The Pattern-maker's Assist- ant," " The Slide-valve." Illustrated by 330 engravings. 8vo., 313 pages $4.00 ROSE.— The Slide-Valve Practically Explained : « Embracing simple and complete Practical Demonstrations of the operation of each element in a Slide-valve Movement, and illustrating the effects of Variations in their Proportions by examples carefully selected from the most recent and successful practice. By Joshua Rose, M. E., Author of " The Complete Practical Machinist," " The Pattern-maker's Assistant," etc. Illustrated by 35 engravings ^i.oo ROSELEUR. — Galvanoplastic Manipulations : A Practical Guide for the Gold and Silver Electroplater, and the Galvanoplastic Operator. By Alfred Roseleur, Chemist, Professor of the Galvanoplastic Art, Gold and Silver Electroplater. Edited from the fourth French edition, with the addition of much new and original American matter, bringing it up to the best practice of the present day. By William H. Wahl, Ph. D., Secretary of the Franklin Institute. Illustrated by about 200 engravings. (/« press.) SHAW.— Civil Architecture : Being a Complete Theoretical and Practical System of Building, con- taining the Fundamental Principles of the Art. By Edward Shaw, Architect. To which is added a Treatise on Gothic Architecture, etc. By Thomas W. Silloway and George M. Harding, Architects. The whole illustrated by 102 quarto plates finely engraved on copper. 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With a Portrait, and a Biographical Sketch. 8vo. . . ^3.00 STOKES.— The Cabinet-Maker and Upholsterer's Companion : Comprising the Art of Drawing, as applicable to Cabinet Work; Veneering, Inlaying, and Buhl- Work ; the Art of Dyeing and Stain- ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker- ing, Japanning, and Varnishing; to make French Polish, Glues. Cements, and Compositions; with numerous Receipts, useful to work- men generally. By J, Stokes. Illustrated. A New Edition, with an Appendix upon French Polishing, Staining, Imitating, Varnishing, etc., etc. i2mo ^1.25 26 HENRY CAREY BAIRD & CO.'S CATALOGUE. STRENGTH AND OTHER PROPERTIES OF METALS: Reports of Experiments on the Strength and other Properties of Metals for Cannon. With a Description of the Machines for Testing Metals, and of the Classification of Cannon in service. By Officers of the Ordnance Department, U. S. Army. By authority of the Secre- tary of War. Illustrated by 25 large steel plates. Quarto . ^10.00 SULLIVAN.— Protection to Native Industry. By Sir Edward Sullivan, Baronet, author of " Ten Chapters on Social Reforms." 8vo. ....... $1.50 SYME. — Outlines of an Industrial Science. By David Syme. i2mo. . . . . . . $2.00 TABLES SHOWING THE WEIGHT OF ROUND, SQUARE, AND FLAT BAR IRON, STEEL, ETC., By Measurement. Cloth ...... 63 TAYLOR.— Statistics of Coal : Including Mineral Bituminous Substances employed in Arts and Manufactures; with their Geographical, Geological, and Commercial Distribution and Amount of Production and Consumption on the American Continent. With Incidental Statistics of the Iron Manu- facture. By R. C. Taylor. Second edition, revised by S. S. Halde- man. Illustrated by five Maps and many wood engravings. 8vo., cloth ^lO.OD TEMPLETON.— The Practical Examinator on Steam and the Steam-Engine : With Instructive References relative thereto, arranged for the Use of Engineers, Students, and others. 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Illustrated by 140 engravings. 8vo. 815 pages ......... ^10.00 THOMAS.— The Modern Practice of Photography. By R. W. Thomas, F. C. S. 8vo. .... 75 THOMPSON.— Political Economy. With Especial Reference to the Industrial History of Nations. By Robert E. Thompson, M. A., Professor of Social Science in the University of Pennsylvania. i2mo. .... ^1.50 HENRY CAREY BAIRD & CO.'S CATALOGUE. 27 TURNER'S (THE) COMPANION: Containing Instructions in Concentric, Elliptic, and Eccentric Turn- ing ; also various Plates of Chucks, Tools, and Instruments ; and Directions for using the Eccentric Cutter, Drill, Vertical Cutter, and Circular Rest; with Patterns and Instructions for working them. i2mo , ' « ^1-25 TURNING : Specimens of Fancy Turning Executed on the Hand or Foot-Lathe : With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting Frame. By an Amateur. Illustrated by 30 exquisite Photographs. 4to. .......... ^3.00 URBIN— BRULL.— A Practical Guide for Puddling Iron and Steel. By Ed. 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Including a History of the Beet Sugar Industry in Europe, Varieties of the Sugar Beet, Examination, Soils, Tillage, Seeds and Sowing, Yield and Cost of Cultivation, Harvesting, Transportation, Conserva- tion, Feeding Qualities of the Beet and of the Pulp, etc. By Lewis S. Ware, C. E., M. E. Illustrated by ninety engravings. 8vo. ^4.00 WARN.— The Sheet-Metal Worker's Instructor: P'or Zinc, SheetTron, Copper, and Tin-Piate Workers, etc. Contain- ing a selection of Geometrical Problems ; also. Practical and Simple Rules for Describing the various Patterns required in the different branches of the above Trades. By Reuben H. Warn, Practical Tin-Plate Worker, To which is added an Appendix, containing Instructions for Boiler-Making, Mensuration of Surfaces and Solids, Rules for Calculating the Weights of different Figures of Iron and Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty- two Plates and thirty-seven Wood Engravings. 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In one volume, i2mo ......... ^2.50 RIFFAULT, VERGNAUD, and TOUSSAINT.— A Practical Treatise on the Manufacture of Colors for Painting : Comprising the Origni, Definition, and Classification of Colors; the Treatment of the Raw Materials ; the best Formulae and the Newest Processes for the Preparation of every description of Pigment, and the Necessary Apparatus and Directions for its Use ; Dryers ; the Testing, Application, and Qualities of Paints, etc., etc. By MM. RiFFAULT, Vergnaud, and ToussAiNT. Revised and Edited by M. ¥. Malepeyre. Translated from the French, by A. A. Fesquet, Chemist and Engineer. Illustrated by Eighty engravings. In one vol., Svo., 659 pages ....... ^7.50 THOMSON.— Freight Charges Calculator: By Andrew Thomson, Freight Agent. 24mo. . . ^1.25 This useful little volume comprises Tables for the Calculation of Freight at all prices per 100 \hs. from one cent to one dollar. WIGHTWICK.— Hints to Young Architects: Comprising Advice to those who, while yet at school, are destined to the Profession; to such as, having passed their pupilage, are about to travel ; and to those who, having completed their education, are about to practise. Together with a Model Specification involving a great variety of instructive and suggestive matter. By George WiGHTWiCK, Architect. A new edition, revised and considerably enlarged; comprising Treatises on the Principles of Construction and Design. By G. HusKissoN Guillaume, Architect. Numerous Illustrations. One vol. i2mo ^2.00 GETTY CENTER LIBRARY 3 3125 00835 8331