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SOLUBLE GLASS 
 
 AND 
 
 ALL ITS APPLICATIONS. 
 
 CONTAINING 
 
 DIRECTIONS FOR RENDERING WOOD AND TIMBER FIRE 
 AND DRY ROT PROOF, SILICIFYING STONES, MORTARS, 
 CONCRETE AND HYDRAULIC LIME, WHITE WASHES, 
 PAINTS AND CEMENTS, AND HOVTTO PROTECT 
 WOODEN SHINGLES, PAVEMENTS, RAIL- 
 ROAD SLEEPERS, &c.. &c. 
 
 By Dr. LEWIS FEUCHTWANGEE, 
 
 CHEMIST AND MINERALOGIST. 
 
 NEW YOKK : 
 
 PUBLISHED BY L. & J. W. FEUCHTWANGEE, 
 No. 55 Cedar Street. 
 1873. 
 
INDEX. 
 
 SOLUBLE GLASS. . . . . j 
 
 The Uses of Soluble Glass (Liquid Silex). 
 Silicate of Soda, Silicate of Potash, Silicate 
 of Soda and Potash combined, . . // 
 ON MORTARS AND CEMENTS, . 21 
 Common Mo^da.r, . . . . ,28 
 
 Hydraulic Ceinent^ , . . . , 2g 
 The Silicate Hydraulic Cement in the pre- 
 servation of Wall-damp^ . . » 30 
 Damp Walls a7td Cellars, . . • 
 Mamfacture of Portland Cement, . . 
 Hydraulic Mortar from American Lime- 
 stone, . . . . , . ,42 
 
 German Hydraulic Cement, , . .46 
 The Uses of Hydratdic Cement, . , 50 
 SILICA TE PAINTING, ^ . . 57 
 Stereo-chrome for Easel Painthig, . . 60 
 SILICIFICATION OF WOOD, . . 62 
 Wooden Roof Shingles, . . . ,66 
 Decay of Wood and Processes for Preserv- 
 ing it, , . . . . . . ^7 
 
 Timber Rot and Seasoning, , , » 70 
 
Index, 
 
 Wooden Roof Shingles, . . . '74 
 Street Pavements, . , . . '75 
 Various Systems Adapted for 'Roadway 
 Pavements, . . . . . • 7<^ 
 
 The Fiske Co7icrete Pavement^ , . • 7/ 
 The Nicolsoii Pavement, . . . • 7^ 
 The Stafford Pavement, . . . - . 7p 
 
 CEMENTS: 
 The Most Durable Aquarium Cement, . 8i 
 The Soluble Glass as Manure for Grape- 
 
 viites, 82 
 The Soluble Glass as a Substitute for Glue, 8j 
 Sohible Glass Application for vario7is Ce- 
 ments, • . . . . . . • ^5 
 
 An Impermeable Cement Resisting Steain, 86 
 Hard Ce7nent, . . . . . ,86 
 
 Cement for Closing Cracks in Stoves, , 8/ 
 Ce7nent for a Cistern, , , , • ^7 
 A Strong Cement for Iron, , , ,88 
 Iron Ceinent for Water and Gas Pipes and 
 Castings, . . . . ,. ,88 
 
 Colored Cements, , , . . ,88 
 Coating for Outside Walls, , . ,8^ 
 Preservation of Sto7tes from Green Coating, 8g 
 
PREFACE 
 
 TO THE PRESENT TREATISE. 
 
 The objects of this condensed volume and tlie 
 causes which induced the author for its issue, 
 are the following : 
 
 I. The two last Treatises of 1870 and 1871, 
 giving a detailed description of the manufacture 
 and uses of Soluble Glass, are this day entirely 
 exhausted, not having been stereotyped, there 
 is not one copy left. 
 
 II. The programme of both previous editions, 
 the first containing additional treatises " On the 
 functions of Carbonic Acid and origin of Lime- 
 stone," and the last consisting in three practical 
 treatises "On Soluble Glass, on Glass Making, 
 and Guide on Soap Making,'' were deemed as 
 exceeding the main object, and more advisable 
 of touching solely on the application of Soluble 
 Glass. 
 
iv PREFACE. 
 
 III. The great improvement lately accom- 
 plished by the author in producing a neutral 
 
 silicate which could answer all the purposes of 
 painting, pasting, varnishing and soap making, 
 
 without any efflorescence of the alkali, is the 
 
 main object of this publication. 
 
 lY. The price of the former editions was, by 
 
 many applicants, considered too expensive, 
 
 while the present edition can be supplied at a 
 
 moderate price. 
 
 Respectfully submitted by the author, 
 
 Lewis Feuchtwanger. 
 
SOLUBLE GLASS. 
 
 It is also called liquid quartz, water glass or alka- 
 line silicate, consisting essentially of silex and either 
 potash or soda, or both together, heated to fusion, 
 and it is therefore a silicate; it is likewise the main 
 comj)osition of all kinds of glass ; a silicate of potash 
 and lime is the Bohemian ; a silicate of soda and 
 lime is the English crown or spread glass ; if there is 
 oxide of lead, such as litharge, or red lead, is added 
 to the mixture of silex and alkalies and heated to con- 
 tinued fusion, we obtain thereby a flint glass, crystal 
 glass or strass ; the latter is the paste used in mock jew- 
 elry. According to the quantity of alkali employed in 
 this mixture the product is made soluble or insoluble. 
 
 THE SOLUBLE GLASS has, of late, become para- 
 mount in the arts, as many trades cannot dispense with 
 it in their pursuits, and more so since the great confla- 
 gration of the City of Chicago, which took place on the 
 9th and 10th of October, 1871, whereby one-fifth of it 
 was laid waste and destroyed ; all the public buildings, 
 churches, court-house, the principal business houses, 
 and many wooden-roofed houses inhabited by poor 
 people. This disaster has aroused in the minds of 
 many men, and journalists in particular, the question 
 whether or not such a catastrophe, by resorting to 
 
4 
 
 APPLICATION OF SOLUBLE GLASS. 
 
 more precautions in the construction of buildings could 
 not be, in future, either entirely avoided, or conflagra- 
 tions of any magnitude be stayed in the sudden pro- 
 gress of the fiery element. Well-informed men have 
 so expressed their belief in letters to the Author, that 
 the steeples of high buildings caught from the sparks 
 flying in all directions from the contagion, and could 
 with ease have been saved by a judicious management. 
 The editor of the Scientific American of November 
 11th makes the following pertinent remarks in his 
 leader respecting the great fire, which we copy here 
 with alacrity, for they coincide entirely with the 
 Author's ideas, and they inspire the hope that all the 
 newspapers in United States may take due notice of 
 such valuable hints thrown out, and copy them in 
 their own local papers, so that all readers may profit 
 thereby, and follow out such precautions which this 
 journal recommends, and whereby, at trifling expense 
 and trouble, millions of dollars worth of property can 
 be saved to owners and insurance companies. 
 
 He speaks of suitable building material in the fol- 
 lowing article : 
 
 " Recent events have turned the attention of 
 thoughtful people to a consideration of the question of 
 building material for large towns. It no longer ap- 
 pears proper to permit indiscriminate constructions, 
 where the safety of a whole community may be en- 
 dangered. We have, in large cities, superintendents 
 of buildings, but they generally confine their attention 
 to the question of security against falling, and not to 
 the character of the building material, excepting in so 
 far as wooden structures may be prohibited in certain 
 
APPLICATION OF SOLUBLE GLASS. 
 
 5 
 
 districts. There would now appear to be cogent 
 reasons why commissioners should be appointed to 
 secure greater precautions than the mere question of 
 wood and iron. A mixed commission, composed of 
 builders, arcliitects, underwriters, firemen and scienti- 
 fic experts, could be appointed to study the whole 
 subject and report thereon to the government. The 
 commission could very properly decide upon the sur- 
 vey of streets, and the width, the kind of pavement 
 and flagging to be used. They could lay down water 
 pipes and establish hydrants at suitable distances, 
 and see to proper arrangements for extinguishing any 
 fires that might arise ; but the most important duty 
 to be assigned to them would be the control of build- 
 ing material in certain sections of the city. 
 
 " By insisting upon the construction of a row of 
 buildings, up and down and across town, as nearly 
 fireproof as it is possible to make them, a wall, imper- 
 vious to fire, and constituting a barrier impassable to 
 any ordinary conflagration, would arrest the flames 
 and save whole sections of the city. A street, built up 
 entirely of fireproof buildings, would be a novelty ; * 
 but in the light of recent events it would appear to 
 offer great protection, and it may be worth while to 
 designate what streets shall be of this character, and 
 then insist upon a compliance with the prescribed 
 style of building. Having adopted some such plan as 
 this, the commission would have to study tiie kind of 
 building material best adapted to city structures, 
 combining security and durability with reasonable 
 economy. This opens up the whole question of the 
 compaft'ative value, for building purposes, of wood, iron 
 
6 
 
 APPLICATION^ OF SOLUBLE GLASS. 
 
 and stone. They tried wood in Chicago, without 
 having treated any of the material with the numerous 
 agents that have been recommended to render it in- 
 combustible ; and the sad consequences of this neglect 
 ought to serve as a warning to all other cities. If the 
 wood had been saturated with soluble glass, it could 
 not have been set on fire. Silicate of soda, or soluble 
 glass, can be obtained in sufficiently large quantities, 
 and at such reasonable rates, as to admit of the pre- 
 paration of the shingles, clapboards, and all exposed 
 portions of frame buildings. Any such precaution as 
 this has the double advantage of protecting against 
 fire, and securing against decay ; and, in the long run, 
 would be found to be the greatest economy. 
 
 " If people will insist upon constructing frame build- 
 ings in large towns, they ought to be compelled to 
 render them essentially fireproof by the above chemi- 
 cal mixture. So many experiments have been tried 
 with soluble glass, that the security it affords against 
 fire and decay may be considered as fully determined. 
 Wood thus prepared will char and smolder, but will 
 not burst into flame ; and hence there could be no 
 scattering of cinders or blowing about of firebrands. 
 
 " In reference to the use of iron for houses, the facts 
 that it is employed to a large extent, and that we are 
 constantly acquiring greater skill in its manipulation 
 and management, are sufficient proof of its practica- 
 bility. In Chicago, however, this material proved 
 unavailing, for the reason that the wooden structures 
 made a fire hotter far than a blast furnace constructed 
 to melt pig iron. No iron could stand such a heat, 
 and it melted down like wax. This was not the fault 
 
APPLICATION OF SOLUBLE GLASS. 
 
 7 
 
 of the iron, but caused by tlie neglect to prepare the 
 wood against such an emergency ; and no one will be 
 likely to condemn iron structures on account of their 
 failure in Chicago. 
 
 " A third building material is stone, and this may be 
 divided into native and artificial. There are a good 
 many varieties of stone suitable for building purposes ; 
 but the cost of quarrying, transportation and working, 
 is so great in this country as almost to shut this mate- 
 rial out of competition. This objection does not apply 
 to artificial stone. The lime and sand required to 
 make artificial stone can be found nearly everywhere. 
 They can be mixed by simple machinery, and require 
 no labor to cut them into shape ; but the plastic mate- 
 rial can be run into any kind of a mold, where it dries 
 in a few hours, and one layer after another can be 
 carried up in marvellously short time. 
 
 " For rapidity of construction, for durability, for 
 security against fire, for warmth and ventilation, for 
 dryness and health, for economy, for architectural 
 effects, there is nothing like artificial stone ; and we 
 look upon this material as the most suitable for cities, 
 and as probably destined to supersede all other. It 
 only needs the popular dissemination of information 
 on the subject to occasion a demand for artificial 
 stone ; and as soon as such a demand is created, tliis 
 material can be furnished in any quantity in all parts 
 of the country ; and we shall have it for our cellars 
 and our ice houses, our sewers, cisterns, wells, water 
 pipes, paths, roads, schools, churches, dwelling houses 
 and stores, in a way that will make us wonder how we 
 ever performed the slow and tedious labor of hewing 
 
8 
 
 APPLICATION OF SOLUBLE GLASS. 
 
 out stones or laying up brick, when we could have 
 formed a whole house at one casting — as Krupp pours 
 the melted steel into moulds, and produces a cannon 
 of any size." 
 
 It is generally known that the Author was the first 
 to introduce the soluble glass in the United States, 
 and has devoted much time in experimenting with it ; 
 and he has succeeded, after many fruitless trials, to 
 create a demand in many branches of industry. 
 From the extensive list of patents issued in Europe 
 and the United States, he has collected all informa- 
 tion, along with that obtained from the scientific and 
 practical journals, and experimenters will find in this 
 Treatise the various uses and applications. Kuhl- 
 mann's Pamphlet, the Mining and Engineering Jour- 
 nal, the Transactions of the American Institute, the 
 Manufacturer and Builder, Scientific American, the 
 Annual of Scientific Discovery, have all furnished ma- 
 terial for this Treatise. 
 
 Many interesting topics, such as the origin of salt- 
 petre, the nitrate of soda, and the manufacture of blanc 
 fix, had to be related, and will, no doubt, interest the 
 general reader. 
 
 Particular attention has been bestowed upon the 
 formation of hydraulic cements and. artificial stone, 
 for the reason that more inquiries and experiments 
 are performed in this branch than in any other of do-, 
 mestic economy. The natural stones, such as the 
 brown stone, sandstone, limestone, and brick building, 
 will, sooner or later, after an exposure to the atmos- 
 pheric elements, and rain and frost, become decom- 
 posed ; cracks and fissures Avill then produce the de- 
 
APPLICATION OF SOLUBLE GLASS. 
 
 9 
 
 terioration, ^vhile coated with the sohible glass and 
 mixing the mortar with the same and impregnating 
 the bricks, much is gained for their preservation. 
 
 It is somewhat remarkable, that long before this 
 the art of making artificial stone has not been brought 
 to perfection. Yet, if we may judge from the great 
 and increasing variety of processes, patented and 
 otherwise, which now press their claims upon public 
 notice, the time is ripe for the introduction of any 
 process which can demonstrate practically its capacity 
 to fulfill the requirements of the case. Every oppor- 
 tunity has been afforded us to examine and test 
 specimens of artificial stone, and we have met with 
 many kinds, which have very little merit. Some, how- 
 ever, are really good stones, and, as such, must, in our 
 opinion, come largely into use. 
 
 The silicification of railroad sleepers, wooden rails 
 and blocks for pavement is in importance next to the 
 preparation of artificial stone. The comparison of 
 the wooden and iron rails has also been clearly stated 
 here, and the future will, no doubt, bring to light 
 many facts here stated, but not yet put to practice. 
 The advantages of the wooden block pavement are 
 numerous, and if properly laid, will withstand long 
 years of the hardest kind of travel ; and there are but 
 two important points in the wooden pavement to be 
 observed, which are a firm and even foundation, and 
 the good silicification of the foundation planks and 
 blocks. 
 
 The reason why the Author has devoted so much 
 space upon hydraulic limes, mortars, paints, white- 
 washes, and the preparation for guarding timber 
 
10 
 
 APPLICATION OF SOLUBLE GLASS. 
 
 against dry rot and conflagration, is solely to prove 
 and make it plausible that the application of soluble 
 glass possesses great advantages, and may, with very 
 little expense, give additional safeguards. 
 
 Siemens recommends for the production of a white 
 stouQ, to work up the fine silex with so much liquid 
 soluble glass so as to form a plastic mass, say from 
 3-4 parts of the sand may be required, similar to pot- 
 ter's clay, and adding, at the same time, a small 
 quantity of chalk and fine clay, whereby the mass be- 
 comes more uniform and compact. Prepared in this 
 manner, objects moulded or pressed from the mass 
 must be exposed to the air for some time. 
 
 For monuments, millstones and other building ma- 
 terial, he uses 1 part liquid silica to 2 parts fine sand 
 and 12 parts coarse sand, which mass, formed into the 
 desired sizes or objects, after being dried long enough 
 in the air, are left in a heated room of 75° for several 
 days, and even to the boiling point of water ; they 
 become so hard, after a lapse of four to six days, that 
 they never crack or fall to pieces. It is also recom- 
 mended to expose the mass to the pressure of a hy- 
 draulic press before exposing to the air. For obtain- 
 ing a cement — roofing and wall body — it is advisable 
 to add the chloride of calcium to the mass, and thereby 
 the excess of alkali is absorbed. 
 
 The mass so formed may be steeped in a solution 
 of chloride of calcium, or chloride of iron, before ex- 
 posing to the atmosphere. In all these cases the silica 
 ought to be employed very concentrated, even in jelly 
 form. 
 
 The uses of the soluble glass are here condensed in 
 
APPLICATION OF SOLUBLE GLASS. 
 
 11 
 
 a short sketch, intended as a circular to those desirous 
 of obtaining some information : 
 
 " THE USES OF ^SOLUBLE GLASS (LIQUID SILEX) SILICATE 
 OE SODA, SILICATE OF POTASH, SILICATE OF SODA 
 AND POTASH (COMBINED). 
 
 " Liquid silica is now employed in the arts for many 
 useful purposes, and particularly for preser-v;jing stone 
 buildings from decomposition ; for preparing an arti- 
 ficial stone, and thereby reducing the price of build- 
 ing, and making a composition more ornamental. Its 
 introduction for architecture is but of recent da-te, and 
 the true and proper method of application not yet on 
 an infallible base ; but the subject is of so vast impor- 
 tance, that experiments are continually going on for 
 making a perfect stone from its original ingredients. 
 
 " The cause of gradual decomposition of building 
 stone is attributed to the expansion and contraction 
 of water absorbed, as well as to the chemical action 
 of carbonic acid of the atmosphere, which abstracts 
 portions of the gases from the silicates, and liberating 
 thereby silica. Many places in Europe, churches and 
 other public buildings, have been refinished by the 
 silicate, such as the Louvre and Notre Dame Cathe- 
 dral in Paris, the Houses of Parliament in London, 
 and in other cities. Still, its general application has 
 met with many failures. It was found that rain coun- 
 teracted the effect before the alkali has had time to 
 take up a sufficient quantity of carbonic acid from the 
 
 * lu the year 1882 Dr. F. prep ired a qu'mlity of soluble y:las3 for the 
 U. S. Governmeut to prei<e; ve the caunon etin« and bocub-Bhella from 
 ru8t or oxydiition at tho Navy Yaid ia Biooklyn, to the fullent satisfaotiou 
 of the late ConimodOi'e Perry. 
 
12 
 
 APPLICATION OP SOLUBLE GLASS. 
 
 atmosphere and to liberate the insoluble silicate ; the 
 coating will produce cracks, and a gradual disintegra- 
 tion of the surface or compound is caused thereby. 
 Numerous remedies were suggested to counteract this 
 evil — the ghloride of calcium, oxychloride of magne- 
 sium, the bittern of salines, and hydrofluoric acid. 
 At present a concrete stone Of considerable hardness 
 and durability is now prepared by means of greater 
 pressure and proper manipulation, the main object 
 being to neutralize and extract the alkali, and to form 
 a solid chemical compound by a second application of 
 of a weak wash of chloride of calcium or magnesium. 
 The object is now fully achieved. 
 
 " Another important application of the soluble glass 
 is to render wood non-inflammable, and to stop any 
 communication of the fire, and at the same time 
 proof against water and damp. The wood, timber or 
 other substances, after being boiled for several hours 
 in the soluble glass, then exposed in tanks, contain- 
 ing solution of lime water and solutions of chloride 
 of calcium, are hereb}^ petrified. 
 
 "Railroad sleepers, cross-ties, house, ship and 
 bridge timber, will also be silicified by this process. 
 Telegraph poles become more durable and better non- 
 conductors of electricity. The lining of barrels for 
 oil and other liquids, the coating of tanks, tubs and 
 cisterns, flour barrels, to prevent the flour getting 
 must}^, is very easy and effectually done by the projDer 
 and judicious use of liquid silica. 
 
 " Soluble glass may be mixed with paper pulp,' or 
 che;ip vegetable and animal fibre, and serve for th( 
 manufacture _of a variety of useful articles, such as 
 
APPLICATION OF SOLUBLE GLASS. 
 
 13 
 
 boxes, trunks, soles for boots and shoes, patterns, 
 moulds and handles. Invaluable and of the highest 
 usefulness, the soluble glass can be employed in fire-proof 
 paints, cements, varnishes, etc.^ for ivhich purposes the 
 daily demands are sufficient proofs. 
 
 " The dentists make use of the sihca for mending 
 their plaster moulds, or in case of an accident to the 
 east of a set of teeth. Valuable documents are made 
 fireproof, and parchment board, slates and marbles 
 are cemented together, and cracks and crevices 
 filled up. 
 
 " The wool growers apply the silicate of soda and 
 potash to the greatest advantage for cleansing or de- 
 greasing the fleece wool and make it soft. 
 
 " The waste of wool or cotton used in the locomo- 
 tive engines to sustain the lubricating materials, may 
 be cleaned and made new by the aid of soluble glass. 
 
 " A hard and ornamental cement, which can be 
 moulded like plaster of Paris, is obtained from the 
 mixture of silicate of soda and ground dolomite or 
 magnesian limestone, which may be used both natural 
 and calcined in equal quantities, and before the mass 
 is dry, the bittern, (chloride of magnesium) from the 
 salines is added, which will harden it at once. A 
 good cellar and roofing cement is made by adding to 
 this mass three parts of white sand. 
 
 " The silicate is also used for penetrating fire-brick 
 and clay, in order to make them more fire-proof, and 
 also used for cementing the walls ; for producing a 
 durable putty in iron castings, such as furnaces, heat- 
 ers, stoves, etc., and also for mending air holes. 
 Boiler makers can produce a very durable lining by 
 
14 
 
 APPLICATION OF SOLUBLE GLASS. 
 
 making a cement of silicate witli asbestos and man- 
 ganese finely ground ; it renders boilers and other 
 metallic vessels perfectly fire-proof, and the best fire 
 and anti-rust paint for iron, steel and brass. There 
 are a great many more useful applications in which 
 the silicate may be used." 
 
 The alkaline silicates, as have been here described, 
 have a bright future for their application : the genius 
 of the nineteenth century cannot fail to accomplish 
 the perfecting the work begun fifty years ago, and to 
 this moment still liable to faults. Ere long we will 
 be enabled to produce an artificial stone which shall 
 excel nature ; we will be able to produce a perfect 
 silification of wood and other organic matter ; we 
 will challenge the atmosphere and other chemical 
 productions to do their best for forming a decomposi- 
 tion of these materials obtained by the new acquired 
 skill to resist their action. The labors of Fuchs, Lie- 
 big, Kuhlmann, Yicat, Fremy, Guerin and Eansome 
 have fairly begun their work, and in ten years more 
 the ship builder, carpenter, mason, painter, the rail- 
 road contractor, and the mechanic in general, will 
 consider this valuable substance indispensable. 
 
 The author has, many j^ears ago, in the course of 
 his experiments, succeeded in preparing an artificial 
 stone in the following manner : — Fluorspar, finely 
 ground, is mixed with the powdered soluble glass, 2 
 parts of the first to 1 part of the latter, the mixture 
 made into a thin paste by the concentrated liquid 
 soluble glass, and then as much finely powdered shell 
 limestone, or magnesian limestone added, until the 
 
APPLICATION OF SOLUBLE GLASS. 15 
 
 mass becomes thick enough to form into moulds or 
 blocks, whichever may be desired ; after an exposure 
 of three to four days to the atmosphere, are treated 
 by a weak solution of chloride of calcium, (2 pounds 
 dry chloride to the gallon of hot water) this liquid 
 will soon be absorbed by the stone ; it is then exposed 
 again to the atmosphere for a week ; a dilute hydro- 
 fluoric acid is then applied with a sponge, and again 
 exposed to the atmosphere ; after a lapse of a week 
 the stone is as hard as a natural stone, and not liable 
 to crack or to disintegrate. 
 
 This composition is much easier prepared, and in- 
 stead of common lime chalk may be substituted, and 
 the result is still more favorable. Instead of the entire 
 quantity of lime, coarse sand may be partially added, 
 and, after the stones are moulded, are exposed to 
 hydraulic pressure, and then exposed to the air, pre- 
 vious to which the chloride of calcium has to be thrown 
 over it. The price of hydro-fluoric acid, as is used for 
 this purpose, costs about 25 cents per pound, and this 
 sufiices for ten square feet. 
 
 Furthermore, it may be remarked that exposing the 
 stone so prepared may be subjected to a high tem- 
 perature or not ; it may be left to the operator to 
 decide whether it will improve the stone by *tiiis mani- 
 pulation. 
 
 For the sandstone imitation, when 1 part liquid 
 soluble glass is to be mixed with 2 parts powdered 
 soluble glass, and 15 parts of sand is added, it is 
 necessary to expose the mass to great pressure, but 
 requires not the addition of calcium, while exposuf e to 
 great heat is indispensable. 
 
16 
 
 APPLICATION OF SOLUBLE GLASS. 
 
 An artificial stone may be also obtained by the use 
 of the alkaline silicates with common chalk, which, by 
 mixing even cold with the liquid silica, is at once con- 
 verted into silicate of lime and carbonate of soda, or 
 potash ; this composition, when exposed to the air, 
 becomes in a few days hard enough, so as to resemble 
 a hydraulic lime, to adhere, when wetted again, like a 
 cement, which may be used for restoring cracks and 
 crevices in marble works and monuments. 
 
 The silicification of chalk has led to numerous ex- 
 periments, and resulted in the production of artificial 
 stone, in the formation of hydraulic lime, hydraulic 
 mortar, and the various cements. The first successful 
 result of the treatment of chalk with the silicate solu- 
 tion has shown that the hardening of the chalk 
 extended to the depth of four inches, which not alone 
 was produced from the decomposition of the silicate 
 by the carbonate of lime (chalk), but also by the car- 
 bonic acid of the atmosphere. If two balls of chalk 
 of equal size and quality are silicified at the same time, 
 and one of them is exposed to the atmosphere, the 
 other kept under a bell glass, where the carbonic acid 
 of the atmosphere is withdrawn, the first will acquire 
 more hardness than the other, which proves that the 
 silicification has assumed a hydrate of silico — carbonate 
 of lime — which loses by degrees its water of crystalliza- 
 tion, and forming a precipitate of silica, contributing 
 mainly to the hardening of the stone. 
 
 A hydraulic lime may be obtained by the mixture of 
 a fat or rich limestone combined with soluble glass in 
 a dry state, say 10 parts silicate to 100 parts of air 
 lime, both fine powder, which proves plainly the theory 
 
It 
 
 APPLICATION OF SOLUBLE GLASS. 17 
 
 of the part which the silicates play in the production 
 of the native limestone, the artificial' hydraulic lime, 
 mortar, cements, and the application of all silicates for 
 the purposes of building, production of artificial stones, 
 and the conversion of organic into inorganic materials, 
 as we shall show hereafter. 
 
 Wood, paper, linen and straw, when covered with 
 several coats of soluble glass, are no longer inflam- 
 mable, but simply char when exposed to fire. It also 
 prevents the decay and rotting of wood, and keeps 
 out worms. Beer barrels, butter firkins and milk tubs 
 can be easily kept clean when painted with soluble 
 glass, and the same is true of vessels designed to hold 
 sugars, syrups, wines, petroleum, etc. The most im- 
 portant use of soluble glass is its application to sur- 
 faces of stone and mortar. For this purpose it. is 
 necessary to impregnate the surface with a solution 
 composed of one part 33 degrees and three parts rain 
 water. 
 
 Mortar and porous limestones react upon the solu- 
 ble glass, producing carbonate of lime, hydrate of 
 lime, and, ultimately, silicate of lime, which thus pre- 
 sents an impervious, vitreous surface, capable of 
 resisting the action of moisture and the atmosphere, 
 and is in a proper state for fresco-painting, in mineral 
 colors. Organic colors are apt to be destroyed by 
 the alkali of the soluble glass, and hence, for fresco- 
 painting, mineral paints are alone available. A 
 second coating of paint, rubbed up with soluble glass, 
 is iisually sufficieni for all practical purposes, and a 
 wall thus treated can be washed with soap and Avater, 
 and kept thoroughly clean. A plain, white color is 
 
18 APrLTCA-TTON OF SOLUBLE GLASS. 
 
 obtained by mixing clialk with soluble glass. Zihv, 
 white, and silicate of soda set so rapidly, that it is 
 necessary to add $ to ^ its weight of precipitated 
 sulphate of baryta before applying the color. Baryta, 
 white and soluble glass also afford a good, fast color. 
 Fluor-spar, with pulverized glass and soluble glass, 
 also gives an exceedingly solid mass. The pigments 
 that have been found by experience to serve the best 
 purpose are chromate of zinc, sulphate of cadmium, 
 blue and green ultramarine, Schweinfurth green, ox- 
 ide of chromium, cinnabar, etc. Prussian blue and 
 colors prepared from it, and chromate of lead, will 
 not answer, as they are destroyed by the alkali, the 
 same as organic colors. It is well known that the 
 fresco-painting in the capitol at Washington, in the 
 new museums in Berlin and Munich, are done with 
 water-glass, and that the success in their use is com- 
 plete. 
 
 Soluble glass, with or without colors, adheres 
 closely to such metals as iron, zinc and brass, and 
 protects them from the influences of the air and 
 water. It has been found that when stoves are 
 painted with a mixture of soluble glass and black ox- 
 ide of manganese, a species of flux is produced by , 
 the heat which does not scale off, but thoroughly pro- 
 tects the iron from any corroding action. Plate glass, 
 when coated with the soluble silicate, becomes opaque, 
 and when baryta is mixed with the liquid quartz, it 
 assumes a fine, white appearance. If the glass be 
 heated it becomes enameled, lilfe porcelain ; and 
 fixed colors, such as ultramarine and oxide of chro- 
 nium, open up an extensive application for soluble 
 
APPLICATION OF SOLUBLE GLASS. 19 
 
 glass for transparencies, cliurch windows, etc. The 
 manufacture of artificial building stone by means of 
 soluble glass has been conducted in Germany and 
 England on an extensive scale. In Vienna barracks of 
 an enormous size have been constructed of such arti- 
 ficial stone ; and the tower of the Cathedral in that 
 city was put into thorough repair in the only way 
 that was possible, considering the great height of the 
 tower and the extent to which it had fallen to decay. 
 
 When ground chalk or marble is stirred into a 
 paste with soluble glass, the mass becomes so hard 
 that it can be employed for building purposes, or for 
 the restoration of decayed stone structures. 
 
 Marble and dolomite immersed in a solution of 
 soluble glass, and the operation repeated a number 
 of times, take up an appreciable quantity of silica, 
 and become so hard that they are capable of taking a 
 fine polish. Attempts to employ such stones for 
 lithography have been made, but not altogether with 
 success. Artificial stone can be prepared as follows : 
 
 Well washed and gently heated sand is stirred into 
 a warm solution of soluble glass until a proper con- 
 sistence has been reached for pouring it into a mould. 
 After it has set it is removed from the frame, which 
 ought to have been previously oiled, and is left to dry 
 in an airy place. To avoid too great a consumption 
 of water glass, a stone or brick can be put in the cen- 
 tre of the mould. It is also possible to stir in peb- 
 bles and to use earthly colors in imitation of marble 
 and conglomerate. Such artificial material becomes 
 very hard, and is adapted to pavements, hearths and 
 •building purposes. 
 
20 APPLICATION OF SOLUBLE GLASS. 
 
 Soluble glass can be used in the manufacture of 
 paper hangings, for printing on paper and woven 
 fabrics, for attaching gold and silver powder to any 
 kind of object. 
 
 Hydraulic lime can be prepared by mixing in fine 
 powder 10 to 12 parts by weight of dry soluble glass 
 and 100 parts of lime — this affords a ready way of 
 preparing a hydraulic cement from ordinary lime, 
 which is always available. 
 
 One of the earliest and best known uses of soluble 
 glass is a cement for glass, porcelain and metals. 
 It is put up in small packages for this purpose, and 
 sold on the corners of streets under various names. 
 Pieces of glass or porcelain cemented in this way will 
 break more readily in places which were whole, than 
 where they were repaired. The solution ought to be 
 quite concentrated when employed for this purpose. 
 The fragments to be repaired must be heated to the 
 boiling point of water, and both surfaces be then 
 moistened with the cement and pressed closely to- 
 gether, and held in position by a strong cord, and 
 left to dry in a warm place. By mixing sulphate of 
 magnesia or calcined magnesia and soluble glass, a 
 cement can be formed that can be cast into moulds, 
 and very generally be substituted for meerschaum. 
 
 Wood and timber and other porous substances, 
 after being boiled for several hours in soluble glass, 
 then exposed in tanks containing lime water or chlo- 
 ride of calcium, and left to dry, become higlily vitri- 
 fied and incombustible. Railroad ties, ships' timber, 
 house and bridge beams, have been treated in this 
 manner with entire success. 
 
ON MORTAR AND CEMENTS. 
 
 21 
 
 The silicate is also used for penetrating fire brick 
 arid clay, and for cementing the walls of furnaces. 
 
 When stirred up with chloride of calcium and used 
 for luting down the covers of crucibles, it answers an 
 excellent purpose. 
 
 ON MOKTAR AND CEMENTS. 
 
 " The earliest architectural constructions to fasten 
 together the bricks or stones of which buildings are 
 made were of various kinds ; the most common is 
 called mortar. It is obtained by first calcining crude 
 hmestone in a kiln, and converting it into quicklime, 
 by depriving it of its carbonic acid. After calcining, 
 the resulting qiiickiime is of a whitish or grayish pow- 
 dery and cracked substance, which, on the application 
 of water, absorbs a certain quantity with the evolution 
 of much heat, and crumbles into a fine powder. This 
 powder further moistened, made into a thin paste 
 with water, and mixed with two or three times its own 
 weight of sharp sand, is called mortar. Slaked lime, 
 or hydrate of lime, as moistened quicklime is called, 
 absorbs carbonic acid from the air, and in time mor- 
 tar is reconverted into limestone ; but the operation 
 goes on under peculiar conditions, and the result is 
 also peculiar ; for a film of silicate of lime is formed 
 round each grain of sand, and thus the whole mass 
 and the stones, between which it is placed, become in 
 time more compact than the particles of limestone. 
 
 " As, however, there are different kinds of limestone, 
 more or less impure, the result will be limes of very 
 
22 
 
 ON MORTAR AND CEMENTS. 
 
 different qualities and properties. These require 
 special treatment to obtain from them the best results. 
 The purest carbonate of lime, such as marble, or 
 chalk, make what is called a rich lime, setting firmly 
 only in dry air, while the very impure carbonates, in 
 which clay is largely mixed with the hmestone, result 
 in the production of hydraulic limes, which set more 
 or less rapidly in moist air or even under water. 
 Some of the impure limestones are used in the manu- 
 facture of cements by the admixture of definite pro- 
 portions of foreign ingredients. Sometimes, by the 
 admixture of certain substances (as puzzuolana) with 
 the rich limes, instead of sand, hydraulic limes are 
 produced. There are few subjects connected with the 
 apphcation of geology that are more important, than 
 the determination of the material that should be used 
 and the treatment adopted in various countries in the 
 manufacture of cements, mortars and stuccoes. 
 
 " Commencing with nearly pure carbonates of lime, 
 it is not difiicult to trace the changes that take place 
 in their conversion into cements; a layer of such 
 mortar, not too thick, placed between bricks or stone, 
 which are themselves absorbent, and kept in dry air. 
 dries gradually and holds together such substances 
 with extraordinary tenacity. But this is a work of 
 years, and sometimes even centuries must run out 
 before the extreme of hardness is attained ! It is not 
 unusual to find imperfectly hardened mortars in very 
 old constructions. The mortar that fastened together 
 the bricks in the old Eoman walls is now almost 
 everywhere so far hardened that a fracture takes place 
 in the brick rather than in the cement. 
 
ON MORTAR AND CEMENTS. 
 
 23 
 
 " Limestone is widely distributed, and almost every 
 variety, however impure, can be burnt into lime. In 
 the manufacture of good common mortar to set in 
 the air, pure limestones and those of fair ordinary 
 quality are available ; but in using them, attention 
 must be given their composition and even texture ; 
 thus, the hardest limestones and marbles make the 
 fattest lime, but each variety yields a lime of difierent 
 quality, distinct in color, in weight, in the greediness 
 with which it absorbs water, and in its ultimate hard- 
 ness. The method of calcination also varies, but the 
 general result is that, after burning the limestone, the 
 resulting quicklime is lighter than the original stone, 
 and differs from it essentially. 
 
 The word hydraulic, as applied to lime, means only 
 that it possesses the property of setting, or becoming 
 solid, in moist air or under water. 
 
 " Eich limes are obtained from the purest and 
 hardest limestones. When slaked, they increase to 
 double their volume ; if employed alone, they remain 
 unaltered even for years, and they are soluble in pure 
 water. Limestones which contain from 1 to 6 per cent, 
 of foreign substances, such as silica, alumina, magne- 
 sia, etc., yield rich limes ; but such as contain from 15 
 to 30 per cent., are poor limes ; they increase in bulk, 
 but little on slaking, do not set under water, and are 
 soluble, like the rich limes, except that they leave a 
 residuum. The fossiliferous limestones make bad 
 mortar, as the slaking is irregular ; limestones contain- 
 ing much silica swell in setting, and may dislocate the 
 masonry executed with them. Where alumina is in 
 excess, the lime is apt to shrink and crack. Where 
 
24 
 
 ON MORTAR AND CEMENTS. 
 
 carbonate of magnesia is combined wifcli carbonate of 
 lime, as in the magnesian limestones, the original bulk 
 is retained. For ordinary purposes, moderately pure 
 limestones, with a mixture of foreign substances, is a 
 moderately pure limestone. Hydraulic limes are of 
 great value in construction, and are extremely inter- 
 esting, and are either obtained naturally from the 
 burning of certain varieties of calcareous rock, or are 
 manufactured artificially by mixing limestones with 
 the requisite foreign ingredients ; such are the Roman 
 cement, Portland cement, Parker's and Rosendale 
 cements. The Portland cement is largely manufac- 
 tured at the mouth of the Thames from a mixed river 
 mud, while Roman cement is formed from the nodules 
 found in the cliffs near Harv/ich, all owing their quality 
 to argillaceous admixture. Limestone, containing 
 from 15 to 25 per cent, of a silicate of alumina, will 
 burn into a good hydraulic lime. It is also quite, 
 certain that the oxide of iron and carbonate of masf- 
 nesia exercise a great influence in rendering limes mora 
 hydraulic. All materials intended for the manufac-. 
 ture of cements require to be burnt carefulty, and 
 ground down to a fine powder, and the best cement is 
 the lightest. When these cements are intended for 
 the production of an artificial stone, from ten to twelve 
 times the weight of broken pebbles are added, and 
 form also an excellent concrete. A stone made from 
 these cements just described, Avill bear a strain varj-ing 
 from 20-60 pounds to the square inch. 
 
 "The plaster cement is obtained from the gypsum, 
 or sulphate of lime, abundant in England, France, and 
 the United States ; is treate i lilie common limestone 
 
ON MORTATl AND CEMENTS. 
 
 25 
 
 for a cement. The calcining of gypsum does not in- 
 volve its decomposition, but the water of solidification 
 being driven off by the calcination, leaves only a soft 
 white powder called plaster of Paris ; when this is 
 again united with water, the latter is absorbed, and 
 the mass becomes first, plastic, and then solid; but it 
 cannot be brought back to its original condition as a 
 crystalline mineral, but it is converted into various 
 substances used as a cement, such as Keenes cement, 
 if alum is added to the fine powdered plaster ; parian 
 cement, if borax is used ; Martin's cement, if pearl 
 ashes are employed. Stucco is a very useful material 
 for ornaments for in and out-door work, is nothing else 
 but a plaster of Paris, finely ground, and a weak glue 
 added before mixing it with water. 
 
 " One of the richest kinds of hydraulic lime may be 
 obtained from volcanic minerals mixed with limes ; 
 such material is the Puzzuolana, found near Naples, 
 as well as other substances found in large quantities 
 in the neighborhood of extinct volcanic districts, as in 
 France and on the Rhine ; and which, according to its 
 chemical analysis, consists of 44 per cent, of silica, 15 
 per cent, alumina, 87 per cent, lime, 4 per cent, mag- 
 nesia, and 12 per cent, oxide of iron ; combined with 
 lime instead of sand, have the property of rendering 
 even the richest limes hydraulic, and fit for use for 
 every description of works executed in the sea or 
 in the fresh water; they have been used from thn'e 
 immemorial v^^ith great success, arid may be mixed 
 either with fat or hydraulic limes and silicate of soda 
 to form a plastic mass, and assist in the setting of the 
 lime. 
 
26 
 
 ON MORTAR AND CEMENTS. 
 
 " In many cases the chemical composition of an 
 argillaceous limestone is not only the condition which 
 determines the quality of the cement ; the reaction of 
 the lime upon the clay must take place at the highest 
 temperature. Indeed, this excessive heat produces 
 the hydraulic elements of the cement in the basic 
 conditions which the setting in the water requires, 
 and which, by melting the aluminate of lime, gives it 
 all its activit3\ 
 
 *' The Roman or hydraulic cement mostly contains, 
 also, magnesia and iron ; whether of any essential 
 benefit or not, has not been fairly tested. It is cer- 
 tain that neither of these substances exercise a per- 
 nicious influence, for the reason that dolomite, a 
 magnesian limestone found in great abundance in 
 this country, offers a fine mineral when calcined with 
 any marls, so abundant along our coast. In produces 
 an excellent hydraulic cement. 
 
 " The analysis of the hydraulic lime from Rondout, 
 on the North River, gives in one hundred parts : 
 
 Carbonic a:' id 35 
 
 Magnesia 12 
 
 ■ ' • 10 
 
 Lime 26 
 
 Silica 15 
 
 Iron 
 
 " Sand or quartz, wdiicli by itself is unfit for a mor- 
 tar, when calcined wdth lime, becomes very suitable 
 for a hydraulic cement or artificial stone, for it forms 
 a silicate of lime. More than thirty years ago, I en- 
 tertained the idea of preserving timber by the infiltra- 
 tion of silicate of lime into the cells of planks, 
 timber, and through the double chemical affinity of 
 silicate of soda and sulphate of lime. The experi- 
 
ON MORTAR AND CEMENTS. 
 
 27 
 
 ments I made then, in the Brooklyn Navy Yard, with 
 pier piles and wooden vats, were very satisfactory. 
 
 " For water-proofing cellars and buildings, not 
 alone the best hj^draulic, but other cements have of 
 late years been introduced in this city ; for instance, 
 the asphalt cement, which is very extensively em- 
 ployed in the foundation of buildings. Having made, 
 myself, many experiments, for a number of years 
 past, in order to introduce the silica cement, or the 
 soluble glass in combination with alkaline earths as a 
 base, and met with varied success, I beg to offer here 
 a sample of a cement which consists of silicate of 
 lime combined with manganese and fluorspar, or 
 fluoride of calcium, which becomes very hard, and 
 which, I think, will, after some improvement in the 
 preparation, be found highly useful in keeping dry 
 walls and cellars. I have mixed equal quantities of 
 manganese, limestone, fluorspar, and dry soluble 
 glass, and make the whole mass plastic by the liquid 
 soluble glass, and apply it while soft ; after the lapse 
 of a few hours it becomes very hard. 
 
 " Among the great variety of cements in which 
 silica is the active principle, the two following are 
 very useful : 
 
 " 1. A mortar, to be made as hard as any cement, 
 and which does not crack in setting, and even of great 
 usefulness as hydraulic cement under water, is ob- 
 tained by mixing finely slaked lime with fine sand 
 (the angular grains are always preferable to the 
 round grains for producing a good mortar,) — by mix- 
 ing the sand thus prepared with finely powdered 
 quicklime, and stir the mixture thoroughly. During 
 
28 
 
 ON MORTAR AND CEMENTS. 
 
 tli6 process tlie mass heats, and may then be em- 
 ployed as a mortar, to which has to be added to one- 
 eighth of the mass the hquid sihcate of soda. 
 
 " One part of good slaked Hme was used with three 
 parts of sand, and to this was added three-fourths of 
 its weight of finely powdered quicklime ; the mortar 
 containing one-eighth of the liquid silicate of soda 
 was then used as a foundation wall, and in four days 
 had become so hard that a piece of sharp iron would 
 not attack it ; and in two months afterwards it had 
 become as hard as the stones of the wall. 
 
 " 2. A thin coating of slaked lime made into paste 
 with water or whitewash is put at once on the stone, 
 and before becoming quite dry apply the silicate so- 
 lution over the paste, by which means the mass be- 
 comes completely insoluble ; a petrification takes 
 place if applied to vegetable substances, decomposi- 
 tion is prevented, porous building stone and brick are 
 protected against air and damp. 
 
 " Common Mortar. 
 
 " Limestone, an impure carbonate of lime, when 
 exposed to a red heat, loses carbonic acid gas, and 
 the oxide of calcium or lime remains. This process 
 of burning lime, as it is called, is accelerated by the 
 presence of moisture in the stone, or by the introduc- 
 tion of a small quantity of steam into the lime kiln. 
 The hydrate of lime reacts with considerable power 
 on siliceous comj^ounds, bat the action only takes 
 place at the surfaces, and unless the lime is used in 
 very thin layers, between smooth stones, it still re- 
 
ON MORTAR AND CEMENTS. 
 
 29 
 
 tains, in the centre of the layer, its own soft and 
 friable condition. 
 
 " In order to make the hydrate of lime effective as 
 a cement, it is mixed with sand, one of the most 
 abundant of natural compounds, now regarded as 
 consisting of two atoms of oxygen and one of silicon. 
 Equal parts of fine and coarse sand are said to be 
 better than either quality used separately with lime. 
 Mortar designed for exterior or surface work is gene- 
 rally made with fine sand. When lime is compara- 
 tively free from impurities, and crumbles to a fine 
 powder on being slaked, it is called fat lime, and will 
 require about six times its own weight of sand, or, if 
 estimated by bulk, one cubic foot of semi-fluid lime 
 and w^ater, called the milk of lime, will require about 
 three or four cubic feet of sand. This mortar is very 
 effective as a cement when well dried or set, but if it 
 is placed in water, the lime is gradually dissolved and 
 the mass is disintegrated. 
 
 " Hydraulic Cement. 
 
 " For all permanent structures under water it is, 
 therefore, essential to use a material called hydraulic 
 cement, which is a mixture of lime with other oxides 
 possessing the valuable quality of hardening until 
 it has the solidity and permanency of the masses of 
 rock bound together by it. The varieties of limestone 
 from which hydraulic cement is made, when burned, 
 yield a lime that is very slowlv slaked. All that is 
 required is to add water until it attains the consist- 
 ency of dough ; it will then harden and become con- 
 crete. These hydraulic limes may be made artificially 
 
30 
 
 ON MORTAR AND CEMENTS. 
 
 by mixing with impure slaked lime a quantity of 
 burnt clay in the proper proportions. The celebrated 
 Roman cement is a porous volcanic rock found at 
 Pazzuoli, near Naples, and called there puzzuolana. 
 It consists of silicate of alumina, soda and lime. 
 This substance is pulverized and mixed with common 
 Hme." 
 
 The S1LICA.TE Hydraulic Cement in the Prevention 
 OF Wall-Damp. 
 
 In laying the foundation of any building, the mat- 
 ter of particular consideration should be the thorough 
 drainage of the site, and next to that complete pre- 
 vention of wall-damp, that is, the rising of moisture 
 by capillary attraction or otherwise, in the heart of 
 the brick or stone work, the particulars of which have 
 been lately described in the Manufacturer and Dtdlder^s 
 Journal, to which the author had added the silicifica- 
 tion of the bricks and plaster. It states that wher- 
 ever brickwork comes in contact with the earth, or 
 even with adjacent walls which may happen to be 
 damp, there the infection is certain to take, and there 
 is no easy cure for it, if once it makes an entrance. 
 
 The readiest remedy in all cases is a layer of fine 
 concrete, which may bo thinly coated on the top with 
 asphaltum laid on hot. This done all around the top 
 of the walls, external and internal, the piers and every 
 piece of brickwork, that in any manner has connec- 
 tion with the ground, then the bricks, which ought to 
 be specially pi'epared before calcination with a sili- 
 cate solution, should be heated over charcoal furnaces 
 and dipped in the asphaltum before being laid. It is 
 
ON MORTAR AND CEMENTS. 
 
 31 
 
 evident that a preventive course could thus be formed 
 above ground at a trifling expense, wholly impervious 
 to wall-damp, at the same time giving a base to the 
 superstructure of a quality very far superior to any 
 now in use. Coating the outside face of the wall with 
 water-proof silicated cement, as has been before 
 noticed, is the only safeguard against capillary attrac- 
 tion from below, and excluding the external air which 
 might let the artificial heat of the rooms to attract the 
 enemy of wall-damp. It is known that common brick 
 will absorb one-fifth of its weight of water, and where 
 the storm drives the rain continually against the face 
 of a wall for a sufficient time to permit the interior 
 heat to attract it, the inside of the wall must, of ne- 
 cessit}^, be damp, and the papering become mouldy, 
 as well as the ceiling, will next be rotton. This cause 
 of wall-damp is one that cannot be too carefully 
 guarded against, as it is one to which may be referred 
 the early decay of many residences, as well as the in- 
 ception of these pulmonary symptoms which so surely 
 steal away the health and ultimately the life of many 
 a victim. 
 
 The mortar to be used in the foundation and the 
 wall ought to be very well prepared, so as to possess 
 all the h3^draulic properties and silicification, and 
 caution should be taken in not using sea sand, which 
 will certainly create the damp by absorbing all the 
 water in the atmosphere, this being the chemical effect 
 of its saline property. 
 
 Tbe surface of the walls of the" rooms must be well 
 attended to ; the plaster of Paris, which is generally 
 employed, ought to be properly silicified, so as to 
 
32 
 
 ox MOHTAPt AND CEMENTS. 
 
 prevent tlie absoi^ption of the natural damp of tlie 
 atmosphere created in uninhabited and unheated 
 rooms. 
 
 It is preferable to paint rooms than to paper them, 
 for the white lead and linseed oil, with some man- 
 ganese to facilitate the drying, becomes hard after a 
 short time, and assists the fresh plaster wall in pre- 
 venting the admission of the moisture, as the fourth 
 coating of white lead is applied with equal portions of 
 oil and spirits of turpentine, which has the property 
 of being very volatile, will evaporate entirely, leaving 
 the surface of the paint of a very compact and hard 
 ■nature, and rendering the plaster incapable of absorp- 
 tion. 
 
 Damp Walls and Cellars. 
 
 The application of silicates for preventing the pene- 
 tration of rain or moisture in houses, whereby the 
 wails are absorbing the same, and render the paper- 
 • hangings or delicate paint unfit, so as to destroy their 
 appearance, has been amply and satisfactorily proved. 
 The silicates of soda and potash, or either of them, are 
 mixed with pure white lead or zinc, and applied soon 
 after upon the walls, which will dry immediately. 
 
 The presence of damp in walls arises from three 
 causes : either from the porous condition of the mate- 
 rials of which they are built, allowing the penetration 
 of damp from without ; from the existence of salts in 
 the mortar, bricks or stone, which absorb and give out 
 moisture, according' to the changes of tlie weather, or 
 from damp foundations. The first only can be reme- 
 died by the application of external coatings, the second 
 
ON MORTAR AND CEMENTS. 
 
 33 
 
 by battening the walls, and tlie last by removing the 
 adjacent earth from the foundations. 
 
 As has already been stated, a single application of 
 a paint formed with lead or zinc has proved very suc- 
 cessfal. The second application is the silicate solution 
 with china clay, or pure alumina, which' has the advan- 
 tage of not drying so quick as that with lead or zinc. 
 In all cases the paints must be put on uniformly, so 
 that the whole wall surface should be completely 
 covered with the solid coat ; and in order to effect this, 
 a rough stucco surface, from two to three coats, may 
 be required. It is found also useful to apply the 
 second coat thinner than the first. 
 
 The mixture of liquid silicate of soda with clay and 
 that of whiting, or washed carbonate of lime, may 
 probably be the most reliable for keeping out damp 
 from walls as well as cellars. 
 
 On applying the lead or zinc as the first coat, either 
 of them or both, it may be done in the following 
 manner : 
 
 Mix them with a little water and lay them on the 
 stone ; they will dry very soon ; apply then the silicate 
 solution by means of a syringe. If the application is 
 to be made on stone which shows some decay, it is 
 necessary to remove first the same ; apply then the 
 aluminous silicate of soda (by an equal mixture of 
 liquid silicate with fine white clay), and then apply 
 the carbonate lime and silicate wash with an ordinary 
 paint brush, stippling it so as to give it the appearance 
 of the granulated surface of the stone. When dry, it 
 will adhere sufficiently to allow of other washes of 
 silicates being brushed on it. 
 
ON MORTAR AND CEMENTS. 
 
 The conditions necessary for success are : 
 
 1. The wall should be coated with a porous mate- 
 rial, such as lime or Portland cement. 
 
 2. The coating must be perfect. A wall which has 
 been once painted is altogether unfit for any applica- 
 tion of siliceous washes, for the reason that it is not 
 absorbent enough. 
 
 The best ground for any siliceous work is lime and 
 sand. In new buildings it would be better to use lime 
 and sand at once, and then to cover it with lime and 
 silicate of alumina and soda. The precipitated sul- 
 phate of baryta may safely be applied in thie silicate 
 of soda for all the above purposes, and it will produce 
 a good coating and a fine paint. 
 
 Manufacture of Portland Cement. 
 
 Portland cement was introduced to public notice 
 under a patent by an Englishman, nearly fifty years 
 ago, and a partial monopoly in its production has been 
 kept up, inasmuch as inexhaustible beds of the raw 
 material from which it is made, and an abundant sup- 
 ply of fuel necessary for their economical manufacture, 
 is at hand. It is strange that under these conditions 
 French engineers should have obtained the start of 
 their professional confreres, and that they should have 
 been the first to demonstrate by experiments, and 
 subsequently by the erection of magnificent harbor 
 works on their seaboard, the valuable properties of this 
 excellent constructive material. We may date the ex- 
 tensive employment of Portland cement in England 
 from the commencement of the metropolitan main- 
 drainage works. During the last fifteen 3'ears the 
 
ON MOETAR AND CEMENTS. 
 
 35 
 
 matiufacture of Portland cement has gone on steadily 
 increasing, until at the present day we find that little 
 short of 400,000 tons per annum are made in the 
 county of Kent — the centre of cement manufacture — 
 irrespective of the productions of many minor factories 
 in difierent parts of the country. 
 
 The chemistry of the setting of Portland cement is 
 by no means so well understood as it ought to be. 
 There is no doubt, however, that, like the hydrauhc 
 lime and natural cements, it is, chemically speaking, 
 a double silicate of lime and alumina ; silicic acid is 
 generated by the hydration of the cement, and forms 
 insoluble salts with the lime and alumina bases. It is 
 a curious fact that Portland cement hardens more 
 rapidly when salt water is employed. According to 
 Schweitzer, 1,000 grains of sea-water in the English 
 Channel contains 27,060 grains of chloride of sodium ; 
 soluble silica has a known preference for alkaline 
 bases, and it is not improbable, when the cement is 
 hydrated with sea- water, that the chloride of sodium 
 is decomposed, the silicic acid of the cement combin- 
 ing with the sodium and oxygen of the water, and 
 forming thereby a silicate of soda, or a species of crude 
 glass. 
 
 Portland cement is of two classes, which, for the sake 
 of distinction, may be termed " Engineers' " cement 
 and "Plasterers'" cement. The former is the more 
 costly ; it is usually described by manufacturers as 
 " best heavy tested ;" it weighs from 112 pounds to 
 120 pounds to the bushel, is slow setting, and of great 
 strength ; the latter is a light cement, qnick setting, 
 and of inferior strength Avhen compared with the other. 
 
36 
 
 GN MORTAR AND CEMENTS. 
 
 It must be understood that our remarks apply exclu- 
 sively to " Engineers' " cement. 
 
 Portland cement is made from clialk and alluvial 
 clay ; the factories on the banks of the Thames use 
 white chalk, those on the Medway gray chalk ; the 
 latter is probably preferable, inasmuch as it contains 
 large quantities of silicious matter. Mr. Read, in his 
 treatise on " Portland Cement," says that " the pre- 
 sent and safest proportions, provided both chalk and 
 clay are selected free from sand, are four parts of 
 chalk from the Medway, (gray,) or three parts of 
 Thames, (white, with one of clay by measure." These 
 materials are placed in mills of simple construction, 
 each having a circular pan, 6 feet in diameter and 2 
 feet deep, in which two " edge runners," 4 feet 6 
 inches in diameter, are kept continually going ; a con- 
 stant stream of water flows into the pan, and as the 
 " edge runners " revolve, the chalk and clay are thor- 
 oughly ground, and, being thus converted into a fluid 
 state, they filter, through a band of fine brass wire 
 gauze fixed to the side of the pan, and flow through 
 wooden " launders " into tanks or settling reservoirs. 
 One wash -mill v.'ill feed four tanks, each of which" is 
 about 100 feet long, 40 feet broad, and 4 feet deep. 
 When one of these has been filled in the manner just 
 described, the same process is applied to the others 
 in succession. About three weeks after the tanks are 
 filled, the whole of the materials will be precipitated, 
 the clear water being drained off in the meantime 
 through a small weir in the brick side of the tank ; 
 the residuum is a plastic mixture of the consistenc\ 
 of " putty," and not much unlike it in color. The 
 
ON MOETAR AND CEMENTS. 
 
 37 
 
 next process is to convey this precipitate from the 
 tank 'to the " drying floors," over which it is spread 
 in a layer about 6 inches thick ; each floor is 40 feet 
 by 30 feet ; it consists of an outer skin of boiler 
 plates, sufficiently hot to effect the rapid desiccation 
 of the water from the superincumbent layer, a pro- 
 cess generally accomplished in about twelve hours. 
 The materials having thus been thoroughly dried, are 
 ready for conveyance to the kilns. The "charge" 
 consists of alternate layers of coke and raw mate- 
 rials, the burning generally occupying thirty-six 
 hours. When the contents of the kiln become suffi- 
 ciently cool, the " clinkers," or cement stones — for the 
 mixture has now assumed that form — are drawn and 
 removed to a floor where the larger pieces are bro- 
 ken, and the whole of the burnt materials are then 
 conveyed to the hoppers of the grinding mills, where, 
 passing under rapidly-revolving horizontal burr- 
 stones, they are ground into an almost impalpable 
 powder. The cement issues from the mill at a tem- 
 perature of about 160 degrees, and the now manu- 
 factured material is wheeled away, and placed in a 
 layer from 2 feet to 3 feet thick over the floor of a 
 cool shed ; it is subsequently packed in casks or sacks 
 for conveyance from the works. The essential condi- 
 tions for the manufacture of good Portland cement 
 are : 1. The chalk and clay should be thoroughly 
 mixed in the wash-mills, and the fluid materials de- 
 livered by " launders " over tlie enfire area of the 
 settling tanks. 2. The contents of the kilns ought to 
 be burnt equally throughout. 3. The burnt mate- 
 rials should be ground very fine. 4. After coming 
 
38 
 
 ON MORTAR AND CEMENTS. 
 
 from the mill tlie cement should be spread over the 
 floor of a shed, and allowed to remain there for at 
 least a fortnight previously to being packed in casks 
 or sacks. 
 
 The strength of Portland cement increases as its 
 specific gravity increases ; the tensile tests are usu- 
 ally made with briquettes, the standard size for the 
 neck being 1\ in. by IJ in. ; and it must be under- 
 stood that all experiments referred to have reference 
 to the weight necessary to sever 2| square inches of 
 neat cement. 
 
 It appears from Mr. Grant's valuable paper, read 
 before the Institution of Civil Engineers in December, 
 1865, that Portlond cement gains from 20 to 30 per 
 cent, in strength by setting under water ; it is usual, 
 therefore, to place the best briquettes in water, after 
 gaging, and allow them to remain there until they are 
 to be tested. The following table has been compiled 
 from a recent series of experiments^ ; it shows the 
 average tensile strength of Portland cement as com- 
 pared with the natural cements ; the test blocks were 
 of standard size of 2| square- inches, and placed in 
 water, as before described : 
 
 
 Weight per 
 bushel. 
 
 1 
 
 Breaking weight 
 two days old. 
 
 Breaking w6-ght 
 lour days old. 
 
 - §2 
 o o 
 
 % ^ 
 
 it 
 a 
 
 
 lbs. 
 
 lbs. 
 
 lbs. 
 
 lbs. 
 
 
 119 
 
 598 
 
 914 
 
 1.024 
 
 
 76 
 
 200 
 
 240 
 
 280 
 
 
 09 
 
 280 
 
 313 
 
 313 
 
 Cement do Zumaya, (Spanish. ) 
 
 84 
 
 306 
 
 
 403 
 
ON MORTAR AND CEMENTS. 
 
 39 
 
 Portland cement now forms an important item in 
 the list of our manufactures ; but even now its valua- 
 ble properties are not ^s fully appreciated as they 
 deserve to be. It should present a fine and homoge- 
 neous powder ; it should set firmly and quickly, when 
 used in works exposed to the surf, filling up joints in 
 water works, etc., otherwise too rapid setting is not 
 desirable. It should neither contract nor expand ; it 
 ought to assume a uniform, bright, gray-stone color, 
 free from brown spots ; it should possess great ce- 
 menting properties, adhere strongly to the stone, and 
 bear a high addition of sand. Finally, it ought to be 
 free from adulterations, while the ton should have the 
 generally adopted weight of 200 kilogrammes. It is 
 to be recommended, under all circumstances, and 
 even if the cement has been procured from well- 
 known manufacturers, to weigh it on delivery, and to 
 keep an accurate account of it. It is very often the 
 case that the weight is considerably below 200 kilo- 
 grammes, due either to the frequent use of the same 
 barrel, which almost inevitably .gets smaller, or to 
 bad packing, which produces incompactness ; or to 
 unpacking it in smaller barrels, which is often done 
 by second or third hand dealers. 
 
 A difference of ten or twenty kilogrammes per ton, 
 which often occurs away from the centres of trade, 
 ought certainly to be taken into consideration, if oc- 
 curring in larger quantities. 
 
 In order to examine cements for their fineness and 
 uninformity of mixture, it is only necessary to pass 
 samples or different barrels through sieves of twenty 
 meshes per centimetre. 
 
40 
 
 ON MORTAR AND CEMENTS. 
 
 There should, properly speaking, reraain nothing on 
 the sieve, and under all circumstances, preference 
 must V)e given to the cement which most nearly fulfills 
 these conditions ; for the finer and more uniformly 
 the cement is diyided, the more promptly and simul- 
 taneously will the chemical reactions take place, the 
 more perfect its combining and cementing properties, 
 and the less fear is to be entertained about a dura- 
 bility of the mass after it has once properly set. The 
 most common adulterations are inferior or spoiled 
 cement, slags, ashes, clay and sand. They are most 
 easily discovered by constant shaking of a sample 
 with an abundant amount of water, after which it is 
 allowed to settle in a high, narrow vessel. The 
 cement to be examined is to be put in the glass filled 
 two-thirds full of water, after which it must be shaken 
 at once, or the cement will cake together and stick to 
 the vessel. Ashes and clay deposit on top, on ac- 
 count of their smaller specific gravity, and the water 
 in this case genera,lly looks turbid. The upper por- 
 tion of the sediment generally fails then to harden at 
 * all, but exhibits a distinctly different color from the 
 rest of the mass. A close examination of it will then 
 usually disclose the nature of the adulteration. 
 
 When made into paste, with sufiicient water to pro- 
 duce a mortar which slides smoothly from the trowel, 
 pure cement should not set in less than twenty or 
 thirty minutes. 
 
 Yet the view that the most quickly-setting cement 
 is the best, is found to be quite generally disseminated. 
 We read, for instance, in a book on this subject of re- 
 cent date : " Excellent cements, such as the Portland 
 
ON MORTAR AND CEMENTS. 
 
 41 
 
 cement, Eoman cement, and others, if immersed in 
 water, harden in a few minutes, wliile inferior cements 
 only attain after a few hours such a degree of hard- 
 ness that they will not take an imjDression b} the 
 fingers." 
 
 This view is not quite correct, for it can be proven 
 that rapidly-hardening cements will, under otherwise 
 equal circumstances, never attain such a degree of 
 solidity and strength as slowly-setting ones. They 
 will, therefore, not bare the same amount of sand. 
 
 Rapidly-setting cements ought, therefore, to be 
 avoided when possible, and only used in filling up 
 cracks in water works, or for similar purposes : firstly, 
 because they fail to attain the same degree of solidity 
 and power of resistance as the slowly-setting ones; 
 secondly, because they can only be worked with diffi- 
 culty in small quantities, and only giving the best re- 
 sult of which they are capable, when the mason is 
 exceedingly prompt and skillful ; thirdly, because* they 
 accomplish much less than they really should by 
 being worked in a careless manner, besides causing 
 considerable dela}^ 
 
 For, if the hardening process has once begun in the 
 mortar -box, the most assiduous working up of the so- 
 lidifying mass will not (especially if more water is 
 added) entirely remedy the evil. 
 
 By employing slow-binding cements, these draw- 
 backs are in a great measure avoided. Portland ce- 
 ment, which, if mixed with the necessary amount of 
 water, say from thirty to forty per cent, in weight, and 
 if not setting in less than twenty minutes, will 
 scarcely increase in temperature ; quickly -hardening 
 
42 
 
 ON MORTAR AND CEMENTS. 
 
 cement, however, will get Lot in consequence of the 
 rapid chemical action which takes place. Still, there 
 exist also limits in regard to slow-setting. If it sets 
 too slowly, it remains resistless, and is pressed out of 
 the joints, for which reason the continuation of the 
 work will be prevented until the mass is sufficiently 
 hardened. 
 
 If once set under water, the cement should continu- 
 ally get harder without changing its volume, cracking, 
 or perhaps even falling to pieces. The cement should 
 completely fill the mould in which it has been pre- 
 pared as thick paste ; it should not suifer any contrac- 
 tion by the evaporation of water added in surplus. 
 On the other hand, there should be no increase of vol- 
 ume by swelling. 
 
 Hydraulic Mortar from American Limestone. 
 
 These limestones contain mostly lime, silica, alu- 
 mina, oxide of iron and magnesia, which form the 
 proper materials for the preparation of mortars ; they 
 will withstand the action of water and moisture better 
 in proportion, as the quantity of silica, alumina and 
 magnesia is larger ; they contain 40 per cent, carbon- 
 ate of lime, 30 per cent, carbonate of magnesia, and 
 20 per cent, silica, the balance is alumina and oxide 
 of iron, and they form a good mortar and a good 
 building material ; but when the magnesia is too pre- 
 valent, will deteriorate it for building purposes, it 
 being too friable. The dolomite, Avhich is also called 
 bitterspar, a magnesian limestone, is a double carbon- 
 ate of lime and magnesia, and abundant in the United 
 States, is a granular limestone, and a hardness of 3. 5, 
 
ON MORTAIl AND CEMENTS. 
 
 43 
 
 a spec. gr. of 3.1, and consisting of 70 per cent, lime 
 and nearly 40 per cent, of magnesia and some oxide of 
 iron and manganese ; is unfit by itself as a building 
 material, having a great tendency to crumble into 
 small fragments, and forms likewise an inferior 
 material for burning and converting it into cement, 
 because it lacks the silica indispensable for this pur- 
 lose. By an addition of an alkaline silicate, either 
 the silicate of potash or soda, and an addition of some 
 alumina, will, after burning, produce a good hydraulic 
 cement, particularly in such localities where no good 
 native hydraulic limestone is found. Not alone 
 France and Germany are particularly rich in deposits 
 of hydraulic lime, and in the United States likewise, 
 but these in our neighborhood may be particularly 
 mentioned at Rondout, on the western shore of the 
 Hudson River, 100 miles distant from New-York. 
 The quarrying in those subterranean rocks for 
 hydraulic cement, and also common limestone is car- 
 ried on in that region, along a large extent of the 
 valley of the Rosedale River ; through this valley the 
 Hudson and Delaware Canal is constructed, which 
 brings the coal from the Lackawanna valley at Car- 
 bondale directly to to the Hudson River. This coal 
 being a very pure anthracite, is admirably adapted 
 for use in the limestone and cement furnaces situated 
 at the junction of this canal with the Hudson River. 
 
 In burning hydraulic limestone, not only the car- 
 bonic acid and water of hydration are drawn off, as is 
 the case with common limestone, but after the lime 
 and magnesia have parted with their carbonic acid, at 
 the high temperature of the furnace, they act on the 
 
ON MOHTAR AND CEMENTS. 
 
 silica and alumina, as it were, like two powerful bases, 
 and a silicate of lime and magnesia, as also silicate oi 
 alumina and aluminate of lime, are formed. Tlie ex- 
 act chemical reaction during the burning process is, 
 however, as yet not well understood, and undoubtedly 
 varies in different limestones, according to their 
 chemical constitution, which latter appears also to 
 vary considerably, but without affecting materially 
 their useful properties. 
 
 In regard to the theoretical causes of the hardening 
 process, which takes place under water, it may be re- 
 marked that this curious and interesting phenomenon, 
 being of an entirely chemical nature, has largely 
 drawn towards itself the attention of eminent chemists, 
 who have attempted to explain it in accordance with 
 well known chemical laws. All hydraulic limestones 
 may, by the ordinary method of analysis, be decom- 
 posed into two component parts ; the one consisting 
 of the carbonates of the earth, such as lime, magnesia, 
 etc., which, like ordinary limestones, jdeld a fat lime ; 
 the other, a silicate, or rather a mixture of the sili- 
 cates of alumina, magnesia, lime, and sometimes po- 
 tassa, as we find in the felspar, which is a silicate of 
 alumina and potash, and a greater or less excess of 
 free silica ; the latter constituent is, therefore, simply a 
 kind of clay. The reaction during the burning pro- 
 cess has been already alluded to. Now, when freshly 
 burnt cement is mixed with water, the excess of caus- 
 tic lime as well as the compound into which the 
 silicious clay has been converted during the burning, 
 react upon one another in such a manner, that a solid' 
 stone-like silicate is produced in the humid way, the 
 
ON MOHTAR AND CEMENTS. 
 
 45 
 
 water has a double action ; dry substances, such as 
 lime and silicate of alumina, do not act one upon 
 another, unless the solvent power of water is brought 
 into play so as to bring them into close contact ; the 
 water transfers continually the lime it dissolves to the 
 siHca. The absolute necessity of keeping such mor- 
 tar under water, in order to have it harden, is thus 
 explained. Another action of the water is this : it 
 enters into a state of hydration in the silicate of lime 
 as soon as formed. It must also be observed, that the 
 molecular condition of the silica is of the utmost im- 
 portance in this process. Fine sand will not combine 
 with lime, when the latter is dissolved in water that is 
 in a form known under the name of limewater ; but 
 silica, precipitated from a soluble glass solution by 
 means of an acid, which produces the gelatinous form 
 of silica, will at once combine with the lime in lime- 
 water and form a siHca of lime. The silica in the 
 hydraulic mortar is also in a state, not like fine sand, 
 but chemically combined and dissolved in the mass, 
 and therefore ready to combine with the lime in lime- 
 water. Next in importance to silica is the magnesia, 
 which renders the lime hydraulic, which, according to 
 Fuchs, has been proved that lime and magnesia, well 
 mixed will harden under water to a certain extent 
 without the addition of silica ; for we have in Ger- 
 many a hydraulic lime containing only 4 per cent. 
 When silica is found to the extent of 52 per cent,, the 
 point of saturation is reached, and such limestone is 
 no more hydraulic. Alumina and iron may be en- 
 tirely absent, although the foi'mer is always present in 
 the best kinds of hydraulic mortars, of which that of 
 
46 
 
 ON MORTAE AND CEMENTS. 
 
 Eondout, usuaflly called Eosedale cement, and with 
 tlie employment of which the Croton Water Works of 
 New -York City were built, is the best on this conti- 
 nent. 
 
 It is confidently to be hoped, that by the proper ap- 
 plication of alkaline, silicates will contribute much to 
 the manufacture of an artificial hydraulic cement. 
 
 Gekman Hydraulic Cement. 
 
 This material, artificially prepared, is in great use, 
 and is of very peculiar composition ; unquestionably 
 it is intended to form a silicate-aluminate of lime, or, 
 in other words, an argillaceous silicate, but the admix- 
 ture, such as charcoal and iron filings, cannot be ex- 
 plained, but the base being obtained by the produc- 
 tion of an alkaline silicate, bespeaks for it a useful 
 vehicle as a cement. 
 
 It is prepared with 25 parts common clay, 60 parts 
 lime, 10 parts magnesian limestone, 10 parts iron fil- 
 ings, and 10 parts of black oxide of manganese ; these 
 materials, in very fine powders, are made plastic by 
 the liquid silicate of soda, at once applied as a ce- 
 ment or mortar, but it will not set at once, six hours 
 being required for the mass to harden. 
 
 Stinde proposes the silicate as a very useful cement, 
 by mixing equal parts of oxide of manganese and 
 oxide of zinc, and making them into a thinish paste 
 with the silicate of soda, which paste, quickly applied, 
 sets very rapidly ; and by mixing the hydrauhc lime 
 to this composition, it is a cement which will resist 
 permanently also the action of water and heat. 
 
ON MORTAR AND CEMENTS. 
 
 47 
 
 "Cement and Mortar of the Ancients. 
 
 We all know how entlmsiastic some are in tlieir 
 praises of those ancient structures which have resisted 
 for ages the ravages of time. They imagine that they 
 are at liberty to draw conclusions which are not the 
 most favorable to the architecture of the present time. 
 Although they may be in a measure correct, it can- 
 not be denied that such critics are too partial in their 
 admiration for things ancient as opposed to things 
 modern. We frequently hear the remark that some 
 of the Eoman mortars have endured for eighteen cen- 
 turies the vicissitudes, of time, while many buildings 
 of now-a-days present, in a very brief period, the sign 
 of quick decay ; but they forget that these ancient 
 buildings constitute an exceedingly small fraction of 
 the enormous number of those erected during many 
 centuries in- Egypt, Greece, Rome and her provinces. 
 They do not consider that thousands of temples, pal- 
 aces, and private dwellings have been entirely de- 
 stroyed. And what answer can they assign to the 
 fact that the very complaints they indulge in were 
 even more frequent then than now ? Pliny asserts 
 that the reason of the falling in of many buildings in 
 Rome was to be attributed to the fact of the bad 
 quality of the mortar. 
 
 " Still more important than this argument is that 
 of Yitruvius, the architect of Augustus. He has left 
 a work on Roman architecture in which we find noth- 
 ing that entitles us to place the architects of antiquity 
 above those of the present time. Again, it has not 
 been taken into account that a great part of the ex- 
 traordinary strength of antique architecture is more 
 
48 
 
 ON MORTAR AND CEMENTS. 
 
 the effect of time than the mechanical skill of the 
 builder, or the virtues of his cements, as we propose 
 to show hereafter. Pliny and Yitruvius both explain, 
 to the best of their knowledge, what kind of materials 
 the builders selected for their cements, and how they 
 were prepared. The. process was identical with the 
 modern modus operandi. It is true that the old Ro- 
 mans were particularly careful in the selection of ma- 
 terials for their mortar, as well as in its preparation. 
 They were aware that they must calcine the lime- 
 stone, and mix it with sand, in order to apply it ; but 
 did not possess any correct idea of the change which 
 limestone undergoes in the process of calcination, nor 
 of that which is the cause of the cohesive quality of 
 mortar. 
 
 " Many centuries elapsed before these facts were 
 understood and explained. Black, in 1757, started 
 the explanatory theory by the discovery of carbonic 
 acid. A few years previous to this, Marggraf, the 
 discoverer of sugar in beets, found the elements of 
 gypsum, which was already employed by the Komans ; 
 and, in 1768, Lavoisier demonstrated the causes of the 
 hardening of burnt gypsum when it is mixed with 
 water. 
 
 [ " The ancients, therefore, put their practical know- 
 ledge to the best possible account. As they were de- 
 ficient in chemical knowledge, • they were guided only 
 by what observation taught them. Their chief care 
 was centred in the exterior. In the selection of lime- 
 stone, the color decided. The white ones were con- 
 sidered best, and the colored ones were seldom used. 
 Those taken from the interior of the earth were pre- 
 
ON MORTAR AND CEMENTS. 
 
 49 
 
 ferred to the stones wliicli were met with upon the 
 shores of rivers. A law provided that the Hme must 
 have been slaked three years before it could be used. 
 The same also prescribed the quantity of sand which 
 must be mixed with the lime, mentioning also that 
 crushed cherts imparted a greater strength to the 
 mortar. Its preparation was, as, it were, a state af- 
 fair, the censors watching carefully over it. In spite 
 of all this, it often happened, as Pliny states, that 
 they did not attain the object in view. 
 
 " But in the advance of chemical science, the fact 
 has been established that a mortar can be prepared 
 that, in the course of one or two years, will be as 
 strong and durable as Roman mortar after the lapse 
 of two thousand years. The builders of the ancients 
 were not farther advanced than those of the middle 
 ages. The wall's of the Bastile, for instance, were so 
 strong that they had to be blasted away. This had 
 likewise to be done in the removal of the remnants of 
 a bridge at Agen, built about the year 1200 ; and the 
 mortar of a bridge erected at Calhours in 1400 was 
 even found to be considerably stronger than that of 
 the antique theatre of the same city. 
 
 " The Bomans were also acquainted with hydraulic 
 cement. The merit of this knowledge is, however, 
 considerably lessened, when we consider that the same 
 is found in the volcanic districts of Southern Italy. A 
 mere accidental observation, the same being, perhaps^ 
 mixed with sand instead of lime, may have led to its 
 application. Says Yitruvius : ' There exists a kind oi 
 dust which produces strange things ; it is found near 
 Baja and the Vesuvius. When mixed with lime, it 
 
50 
 
 ON MORTAR AND CEMENTS. 
 
 forms a mortar wliicli not only imparts great strength 
 to buildings, but also to water-works.' 
 
 " The natural cement in question is a volcanic 
 pumice-stone, like breccia, which is still found in the 
 I .environs of Naples. At a less remote period of time, 
 when the Eomans invaded the valleys of the Lower 
 Bhine, they easily recognized the volcanic nature of 
 the Brolil Yalley. Here, as well as amid the surround- 
 ings of the beautiful Laacher Lake, which lies like a 
 jewel set in the midst of the long-extinct Hhenish 
 volcanoes, they discovered another natural cement — 
 the trass — in such considerable quantities, that the 
 quarries which were opened at that time are still in 
 existence. The use of hydraulic cement in ancient 
 times could, therefore, have been only a limited one, 
 as it w^as found only at the two places mentioned. 
 Its artificial preparation was not understood. The 
 solution of this problem was reversed for the investi- 
 gating minds of the present progressive century." 
 
 " The Uses of Hydraulic Cement. 
 
 " It is justly esteemed far superior to metal for the 
 lining of cisterns, the water-proofiDg of cellar bot- 
 toms, and similar purposes. A few directions for its 
 preparation and use may not be out of place. To 
 make water-proof work, it must be borne in mind 
 that common lime must not be used at all ; for on com- 
 mon lime, water or moisture has an effect just the 
 opposite to that which it has on the water lime, ren- 
 dering it soft and quite friable when dried ; whilst on 
 the water lime the well-known effect is to make it 
 
ON MORTAIl AND CEMENTS. 
 
 51 
 
 perfectly hard. No mixture of these two varieties of 
 Kme can, therefore, be made under water. But, 
 although they do not act well together even under 
 ground, they serve well in dry places, such as build- 
 ings whose walls are of extra thickness ; and if proper 
 care be taken, they will conjointly form a ver^^ com- 
 pact and powerful cement. The fact that water Kme 
 shrinks when wet, while common lime, in the same 
 state, swells, at once points out the manner of treat- 
 ment to be pursued in uniting the two thoroughly. 
 Thus, it is necessary to ascertain the percentage of 
 shrinking of the one and increase in the other, as 
 nearly as possible, before the proportion of one to the 
 other can be determined, A\dtli a view to their inti- 
 mate combination. Such experiments are the more 
 necessary when we consider the great difference 
 which exists in the quality of both kinds of lime in 
 various localities. The simplest and most effectual 
 mode of testing water lime is to put several portions 
 of different makes into small bags of flannel, and 
 throw them into a basin of water. After three min- 
 utes' immersion, take them all out at once, and 
 squeeze each in the hand. Then take off each bag, 
 and that which is best is firmest, and when thrown 
 naked into the water again, loses least of its outer 
 cast. If none of them will bear uncovering at three 
 minutes, try four, five minutes, but this latter should 
 be the longest test. The test for common lime is, on 
 the contrary, the bursting open and evolving of caloric 
 in a greater or less degree ; and the consequent action 
 of the water will show, by its bubbles, the power of 
 the lime. 
 
52 
 
 ON MORTAR AND CEMENTS. 
 
 " It is the percentage of claj contained in any 
 specimen of lime that determines the solidifying pro- 
 perty of the cement made from it. The best hydraulic 
 lime contains silex, lime and -magnesia, or alumina. 
 Its solidification is attributable to the formation ' of 
 silicate of alumina and lime, or of magnesia and 
 lime, which combines with water, and produces a hy- 
 drate excessively hard and insoluble in water. The 
 hardening of hydraulic lime may, then, be compared 
 to that of calcined plaster, which also combines with 
 water to form a solid hydrate ; which calcined plaster, 
 from the large quantities of it manufactured near 
 that city, is commonly known as Plaster of Paris. A 
 limestone containing thirty per cent, of clay makes a 
 quick-setting cement ; and we have in the United 
 States the Kosedale and the Belleville cements, hav- 
 ing forty and fifty per cent. They become exceed- 
 ingly hard when plunged in water for from two to 
 three minutes. Both these cements, especially the 
 former, have been used extensively by our engineers. 
 
 " Inferiority in the quality of hydrauHc lime may 
 be produced by the want of proper care during its 
 manufacture, the stone being calcined at too high a 
 temperature ; the double silicate in such case becom- 
 ing a sort of frit J which does not hydrate in contact 
 with water. 
 
 "As hydraulic lime is expensive according to the 
 distance of its transportation, we will here give the 
 method of making an artificial hydraulic lime, accord- 
 ing to the highly successful experiments of M. Yicat, 
 a celebrated French engineer, and the author of a 
 much esteemed work on hydraulic cement, who first 
 
ON MORTAR AND CEMENTS. 
 
 53 
 
 showed the method to be adopted in its formation 
 It is prepared by stirring into water a mixture of one 
 part of clay and four parts of chalk ; these materials 
 should be mixed by a vertical wheel turning in a cir- 
 cular trough, and made to flow out into a large 
 receiver. A deposit soon takes place, which is formed 
 into small bricks, which, after being dried in the air, 
 are moderately calcined. Hydraulic lime thus pre- 
 pared enlarges about two- thirds in volume when 
 placed in water. Like the natural hydraulic lime, it 
 can be completely dissolved by acids. This invention 
 of artificial hydraulic lime has rendered Vicat deserv- 
 edly famous, as it has been in use for many years in 
 the public works throughout France, and was even 
 employed in the hydraulic masonry of the St. Martin 
 Canal. That it can be made in this country, there is 
 no doubt, as the argillaceous or potter's clay required 
 is to be found almost everywhere. 
 
 The new cement which M. Sorel proposed to the 
 French Academy consists in the application of basic 
 hydrated oxychloride of magnesium, may unquestion- 
 ably be improved by means of a silicated hydraulic 
 lime and the bittern of the salines, which is a chlo- 
 ride of magnesium in a concentrated condition. 
 
 Many important facts have come to light by the 
 investigations made on hydraulic limes and artificial 
 stones, which prove that a considerable qua itity of 
 })otash is contained in the natural hydraulic and other 
 cements ; the origin of which is attributed to the 
 decomposition of the alkaline silicates by the lime, 
 and this may be proved by the formation of saltpetre 
 or nitrate of potash in the efiiorescences of walls and 
 
54 
 
 ON MORTAR AND CEMENTS. 
 
 earths in caves, called an eremacausis of substances 
 which contain nitrogen, and form, therefore, ammo- 
 nia, and in contact with porous substances undergo 
 an oxydation and conversion into nitric acid, and at 
 once is combined with the alkalies contained in the 
 native lime occurring in the older formations, and was 
 separated, under certain circumstances, from the al- 
 kaline silicates found in those limestones — nitrate of 
 potash the result. In general terms, nitre, or nitrate 
 of potash, which is found in crusts on the surface of 
 the earth, on walls and rocks, and in caves, is found 
 in those localities in certain soils of Spain, Egjp^t, 
 Persia and East Indies, especially in hot weather 
 succeeding rains ; it is also manufactured from soils 
 where other nitrates (nitrate of lime or nitrate of 
 soda) form in a similar manner, and beds called nitra- 
 ries are arranged for this purpose in many countries. 
 Hefuse animal matter also, putrified in calcareous 
 soils, gives rise to nitrate of lime, as we find it so fre- 
 quently in cow and horse stables, and is then con- 
 verted into nitrate of potash ; old plaster walls, when 
 lixiviated, afford about 5 per cent, of nitre. It is 
 known that nitre requires for its formation dry air and 
 long periods without rain ; the potash comes mainly 
 from the debris of felspathic and lime rocks in the 
 soil, or in the cements, if they have been used for 
 building walls, and the oxydation of the nitrogen of 
 the air is promoted by organic matters, hence the 
 nitre is generally associated with azotized decomposed 
 organic substances. A nitre crust from the vicinity 
 of Constantine, Algeria, afforded Boussingault 85 per 
 cent, nitrate of potash, with some nitrate of lime, 
 
ON MORTAR AND CEMENTS. 
 
 55 
 
 soda and magnesia. In the Mammoth Cave of Ken- 
 tucky, where the nitre is found scattered through the 
 loose earth in great abundance, and was utilized dur- 
 ing the war of 1812, also in the Mississippi Valley, 
 in Missouri, many caves have yielded the nitre which 
 was of great use to the Secessionists of the late war, 
 when Tennessee, along the limestone slopes and in 
 the gorges of the Cumberland table land, produced a 
 large amount of saltpetre. 
 
 The nitrate of soda, formed in a similar manner 
 like that of nitrate of potash, but more particularly 
 is found in the dry pampas of Chili, where it is found 
 at a height of 3,300 feet above the sea, contains beds 
 of several feet in thickness, along with gypsum, com- 
 mon sail, glauber salt, and the remains of recent 
 shells, indicating the former presence of the sea. 
 
 Respecting the cement which is formed by the 
 moist way, it is a fact that when chalk is brought in 
 contact with solutions of alkaline silicates, an ex- 
 change of the acids of both salts takes place, one 
 part of the chalk is converted into silicate of lime, 
 and the corresponding quantity of potash in carbon- 
 ate of potash ; this explains the true artificial stone, 
 which has become, on exposure to the atmosphere, so 
 hard, that, if the mixture contains a sufficient quan- 
 tity of a silicate, possesses the property to adhere 
 firmly to such bodies where it has been applied, the 
 materials so formed with the silicate of potash or 
 soda are analogous to cements without burning, and 
 may be used for restoring monuments, etc. In the 
 silicification of artificial stones, the affinity of lime to 
 the silica contained in the soluble glass is manifest, 
 
56 
 
 ON MORTAK AND CEMENTS. 
 
 and shows the effect of the alkahne silicates on lime- 
 stones ; and how the influence of the atmosphere in 
 the hardening of silicates or artificial limes is brought 
 to bear through the atmospheric carbonic acid by the 
 separation of one part of silica in the silicates, and 
 how the other parts of the silicates, when in close 
 contact with a sufficient quantity of carbonate of 
 lime, a lime silicate is formed. 
 
 This acquired knowledge has produced numerous 
 applications in industry ; it has proved that, by arti- 
 ficial impregnation of mineral substances into the 
 interior of porous substances, organic as well as 
 inorganic matters are preserved or silicified. The 
 silicificiition of fine sandstone is easily effected by the 
 mixture of 1 part of liquid silica, and 2 parts of fine 
 sand, with the addition of a small quantity of chalk 
 and whits clay, all of which are wrought into a paste, 
 and then formed into desired objects and exposed to 
 the atmosphere for some time, and the finishing pro- 
 cess continued^ by means of hj^draulic pressure and 
 heating in hot chambers, the particulars of which 
 have been indicated in a former chapter. It has been 
 ascertained that always, if any salt insoluble in water 
 is brought in contact with the solution of a salt which 
 forms with the acid of the base of the insoluble salt 
 a less soluble substance, an exchange takes place, 
 which, although but partial sometimes, produces the 
 formation of double salts. This discovery led to a 
 direct application that white lead, chromate of lead, 
 chromate of lime, and the majority of the carbonated 
 metallic salts, are suitable for silicification. 
 
SILICATE PAINTING. 
 
 57 
 
 SILICATE PAINTING. 
 
 . Wood may be painted by covering it first witli a 
 chalk ground, which must be thick enough to allow a 
 polishing with pumice ; to chalk, glue or a little sili- 
 cate solution may be added, as a binding material. 
 Another difficulty occurs after the first has been over- 
 come, in the oozing out of the carbonate of potash in 
 damp weather, until the whole salt has been expelled, 
 and many experiments have failed, and hydrochlorate 
 of ammonia was first proposed in a weak solution, and 
 an absolute insolubility of the color was thereby ob- 
 tained, but chlorate of potash remained in this opera- 
 tion, which destroys the gloss of the colors if not at 
 once removed by repeated washing ; forced to resort 
 to those few chemical agents, apt to fix the potash, 
 which should enter as insoluble combinations in the 
 color without destroying them, the perchloric and 
 hydrofluoric acids were resorted to. It is well known, 
 that by washing with hydrofluoric acid the density of 
 the colors is much increased, and it was thought, 
 therefore, safe to use it, particularly in painting on 
 glass, but only as a very weak solution. Hydrofluoric 
 acid possesses the most remarkable property to dis- 
 solve most oxides when in a concentrated state. The 
 application of the weak solution of hydrofluoric acid, 
 either for fixing the potash in painting and in silicifi- 
 cation of limestone, was mainly c^ilculated for such 
 case where a silicate has been used witli an excess of 
 potash ; and in hardening of soft an-l porous lime- 
 stones be a partial conversion into a lime silicate, it 
 was found very expedient for fixing the potash, and 
 
58 
 
 SILICATE PAINTING. 
 
 making sure the insolubility to moisten, at first with 
 a weak, and then strong solution of the hydrofluoric 
 acid, the stones when the potash oozed out. The 
 acid, however, penetrates the stone and produces an 
 insoluble compound ; in other words, it fixes the 
 soluble potash, and produces an insoluble compound. 
 Through this discovery hydrofluoric acid was found a 
 Very useful application in the fluosilicated lime. * 
 
 If brought in contact with lime, hydrofluoric acid is 
 capable of dissolving it considerably without produc- 
 ing an immediate precipitate of calcium, or a separa- 
 tion of the silica ; but at a certain state of saturation 
 any addition of lime decomposes entirely the hydro- 
 fluoric acid, and so much that not a trace of these 
 bodies can be discovered in the fluid. The same re- 
 sults are obtained by the carbonate of lime, instead 
 of the caustic lime, and that silicium and fluor are 
 produced in the limestone, which hardens but slowly, 
 and it is therefore simply a fluorsihcon that produces 
 the hardening of the lime. The effect of the hydro- 
 fluoric acid on gypsum is also produced in both mix- 
 ing, the surface of the gypsum is considerably har- 
 dened. If, however, the acid is used in excess, the 
 gypsum is covered with raised pustules, which owe 
 their existence to the formation of bisulphate of lime, 
 because sulphuric acid does not act as well as the car- 
 bonic acid in the treatment of limestone ; a fluor-cal- 
 cium, mixed with soluble glass, may be used as a 
 paint, or paste, or a cement, or any coating of other 
 substances, and becomes so hard and weatherproof 
 that neither soda nor potash will detach from the 
 combination, and will remain drv. 
 
SILICATE PAINTING. 
 
 69 
 
 Painting on Metals, Glass and Porcelain. 
 Silica painting adheres strongly on metals, provided 
 
 care is taken to keep the substances some time from 
 the contact with water. The most durable paint is 
 produced on zinc, also on porcelain and glass ; the 
 colors assume a semi -transparency if painted on glass, 
 and no doubt afford much inducement for its use. 
 The sulphate of baryta, artificially prepared, combined 
 with silicate, applied to glass, makes a milliy white 
 appearance, and is very beautiful, as it incoporates 
 very intimately with the silica, so that after the lapse 
 of a few days the paint cannot be removed even with 
 warm water. If this glass is exposed to high heat, 
 (6^ Wedgewood), a fine white enamel is formed on the 
 surface, which will compare well with the oxide of tin, 
 and is much cheaper. Ultramarine, oxide of chrome, 
 if converted into enamels, form a prolific source for 
 the new art of painting. It is not quite necessary 
 that a chemical combination should be produced in 
 all these colors, if they only adhere strongly and pro- 
 duce the silicated cement, which has become hard by 
 its fine division and easy admission of air. 
 
 Emery, sesquioxide of iron and peroxide of man- 
 ganese, if finely powdered and prepared with a con- 
 centrated solution of .soluable glass, produce cements 
 of extraordinary hardness, resisting the effect of heat 
 completely, and become perfectly insoluble in water. 
 
 For the production of an indestructible ink, soluble 
 glass has been used and obtained by mixing finely 
 burnt lampblack with the liquid soluble glass. Bra- 
 connot's ink is prepared by decomposing leather in 
 caustic potash, and adding to the black mass the 
 
60 
 
 SILICATE PAINTING. 
 
 liquid soluble glass. A decoction of cochineal mixed 
 with the liquid soluble glass, produces a red ink, re- 
 sisting completely the action of chlorine and all other 
 acids. 
 
 Stereo-chromic for Easel Painting. 
 
 The basis for this class of painting may be made 
 from plates of burnt porous clay ; it is first impreg- 
 nated sufficiently with liquid soda glass. These plates 
 may be three-fourths of an inch thick ; after one or 
 two applications they become as hard as any stone 
 ware ; they are very suitable for painting ground. 
 The Uthographic stone makes a good base for easel 
 painting ; a thin coating of liquid glass mortar will 
 produce a good base, and it maybe first moistened 
 with phosphoric acid, which assists much to absorb 
 the colors with the liquid glass, and to make them 
 fast. 
 
 The colors to be used for this class of painting 
 ought not to be chosen which decomposes the liqtiid 
 glass, such as contain strong acids, nor those from 
 organic substances. Burnt oxides are better than 
 raw oxides, vermihon becomes brown, and at last 
 black ; cobalt blue becomes clearer with the liquid, 
 and the yellow ochre becomes darker. 
 
 All colors ought to be properly prepared to make 
 them fit for the silica painting, such as the great 
 variety of oxides ; many of which may be suitable, 
 also chrome red, ultramarine, umber, baryta white, 
 cadmium yellow, and many more, purposely made by 
 some chemists, not containing free acid, which enter 
 into a decomposing chemical combination. 
 
SILICATE PAINTING. 
 
 61 
 
 The permanent white, or artificial sulphate of baryta, 
 is said to be the -proper material for a white paint„ It 
 is obtained from the native minerals, heavy spar or 
 sulphur of baryta, and witherite or carbonate of baryta, 
 The manufacture of the new paint is effected by the 
 reduction of the native sulphate to a chloride of 
 barium, or dissolving the native witherite in hydro- 
 chloric acid, and then adding either sulphuric acid or 
 glaubersalt. The artificial sulphate of baryta is found 
 in a condition of extreme fineness and purity, possess- 
 ing a fine lustre, and susceptible for producing a fine 
 white paint, which is the best substitute for white lead 
 and zinc white, is not subject to tarnish or become 
 brown in parlors, like white lead, which is attacked by 
 hydrosulphuric acid, and forms, when combined" with 
 the liquid glass, a slow but intimate combination, and 
 is likewise used under the name of blancfix for card- 
 makers, paper-stainers, and paper collar manufac- 
 turers to a very large extent. It may also be considered 
 in point of importance, if compared with that of white 
 lead, not having a dilatory effect upon health as the 
 latter. If mixed with the soluble glass, it obviates the 
 odious smell of linseed oil and spirits of turpentine. 
 If it is mixed with dexterine, starch, or other binding 
 material in connection with the liquid silicate of soda, 
 its applications may be multiplied to any extent. 
 
 The artificial sulphate of baryta is largely manufac- 
 tured on the continent of Europe ; in the United 
 States it has so far been manufactured in New- York 
 by a few chemical establishments for card-makers, But 
 not yet for the purpose of substituting it to white lead. 
 
62 
 
 SILICIFICATION OF WOOD. 
 
 SILICIFICATION OF WOOD. 
 
 Wood, and all other organic combustible substances, 
 may, to a great extent, be preserved against that great 
 element, the fire, by the proper application of the 
 liquid silicates. Still it requires much skill, experience 
 and proper management to subdue this wonderful 
 element when brought to its full power. There are 
 many instances on record to prove either a full, or at 
 least partial success in arresting the progress of a 
 conflagration by the impregnation or coating of com- 
 bustible bodies with many substances, such as possess 
 incombustibility, whether liquids, gases, or materials 
 which possess the properties of generating gases, that 
 will withdraw or suffocate the surrounding atmosphere, 
 such as the oxygen gas, and thereby arrest the progress 
 of the flames. Many chemical agents have been from 
 time to time proposed to effect this object ; such as 
 salt, chloride of lime, and, latterly, carbonic acid in its 
 gaseous and liquid form, and many metallic salts have 
 proved but a partial success in the prevention of decay 
 or dry rot of wood. The soluble glass is one of the 
 first materials which have been successfully employed 
 in arresting conflagration, and as far as 1823 this 
 material was recommended in the construction of the 
 Munich Theatre, where 465,000 square feet of timber 
 surface were treated witli a coating of the liquid 
 soluble glass, and in 1830-31 and '32 the author per- 
 formed many experiments in the Brooklyn Navy Yard, 
 partially as a protecting agent against fire, as also 
 against decay of the woody fibre. Small square blocks 
 of wood, after having been impregnated with the solu- 
 
SILICIFICATION OF WOOD. 
 
 63 
 
 ble glass, and sailcloth, writing paper, parchment, etc., 
 were exposed iof some time to the flame of a gas lamp. 
 After the lapse of an hour, all these substances were 
 found to be charred, but not consumed. It is proved 
 that the liquid soluble glass produces a perfect adher- 
 ing, permanent covering, which, when properly laid 
 on, suffers no damage from the atmosphere. For 
 coating the wood, etc., a pure solution of the liquid 
 glass is required, otherwise it will peel ofl, and it is 
 best not to use it first in a concentrated state, as it 
 will not be able to penetrate into the pores, whereby 
 the atmosphere must be expelled, and even five or six 
 applications may be made in intervals of twenty-four 
 hours. Although this process renders good services, 
 it may be improved by the addition of other pulverized 
 substances, wherein the soluble glass acts as the bind- 
 ing material, the coating assumes a better body, is 
 stronger and more permanent, and if exposed to the 
 fire, a crust is formed ; such, for instance, are bone 
 dust, clay and chalk mixed together, a lead glass, etc. ; 
 common cla^^, one-tenth of the quantity of silicate of 
 soda, was successfully used with the liquid glass in the 
 Munich Theatre. If applied on linen or other organic 
 textur3S, the mere coating or dipping is not sufficient, , 
 but a surface between rollers must be resorted to, in 
 order to produce a full absorption with the pores ; 
 these stuffs may then be rolled up, but not folded. 
 
 Building timber, rail-road sleepers, and other similar 
 materials, have been treated in the manner just de- 
 scribed, and were protected fully against fire and dry 
 rot. 
 
 The author proposed a combination of the liquid 
 
64 
 
 SILICIFICATION OF WOOD. 
 
 glass with tlie following substances, intended as de- 
 composing agents by chemical affinity, and producing 
 in the cells of the vegetable fibre the various mineral 
 and metallic salts which are altogether insoluble in 
 water, alkalies and acids, and he extended his experi- 
 ments on the uses of lime, chalk, gypsum, .copperas, 
 etc. His process of treating ship timber, sleepers, 
 cross-ties, roofing shingles, and other wood blocks, 
 was the following : 
 
 1. The materials to be treated were put in steam 
 boilers and exposed for four hours to a pressure of hot 
 steam (or 300^ F.), then withdrawn from the kettles 
 and dried. Alkalies and acids, such as hydrochloric, 
 have been since recommended for the purpose of ab- 
 stracting color and albumen existing in the cells of the 
 woody fibres, which, however, is accomplished by 
 steaming. 
 
 2. In a solution of silicate of soda, while hot, the 
 materials to be treated are thrown, and kept there for 
 twenty-four hours, which will give ample time for the 
 liquid to enter into the open cells while hot. 
 
 d. A large vat, containing either lime water, solution 
 of copperas, or blue vitriol, white vitriol or gypsum, 
 finely powdered and thrown into hot water, or finely- 
 powdered chalk of 1 pound to 10 gallons of water ; the 
 proportion of metallic salts is but one-quarter jDound 
 to the gallon of water. The woods are kept in the 
 vats for another day, and then taken out, dried and 
 ready for use. 
 
 Coal tar, and the other products of dry distillation 
 from tar and peat, have been recommended by Krieg 
 as far back as 1858, under the name of Creosote-car- 
 
SILICIFICATION OF WOOD. 
 
 65 
 
 bolic acid, which was then considered a waste product 
 and in its raw state having a specific gravity of 1.02 
 to 1.058, and yielded from 20 to 30 per cent, of the 
 tar ; it was well known to possess the property of pro- 
 protecting wood against decay. 
 
 This chemist combined with the impregnation of 
 wood, etc., the soluble glass and the creosote-car- 
 botic acid, for the reason that the latter precipitates 
 the soluble silica as an insoluble substance while it is 
 soluble in an alkaline lye. He proposed to expose 
 the woods for three-quarters of an hour to a tempera- 
 ture of SOO'^ F., and then drying them thoroughly. 
 
 The woods thus prepared showed an increased 
 weight of 6 per cent., and a lacquered surface, while 
 in the inside the pores were filled with an insoluble 
 precipitated silica. 
 
 For effecting a still more perfect success is to fix 
 the creosote on the woody fibre from the alkaline so- 
 lution, by diluted sulphuric acid, or by a solution of 
 copperas, (sulphate of iron,) whereby the sulphate 
 of soda thus obtained may either be washed out, or 
 oozed out, the creosote-carbolic acid combines 
 stronger with the woody fibre, and the impregnated 
 woods may be considered safely protected against fire 
 or rot. 
 
 This process just described, deserves the serious at- 
 tention of the various companies established for the 
 last five years in the preservation of wood by carbolic 
 acid, tar, etc., by combining the soluble glass with 
 their process, as we have described. 
 
 Since the introduction of railroads, not quite fifty 
 years, many men have been engaged in chemical ex- 
 
66 
 
 SILICIFICATION OF WOOD. 
 
 periments upon the cross-ties and sleepers, which, 
 after being laid down for a few years, undergo the de- 
 cay or rot, and have to be renewed, which causes 
 great expense to the companies. Kyan, Burnett, 
 Laboucherieand many other chemists in all countries 
 where this evil existed, proposed remedies ; the sub- 
 limate, chloride of zinc, p3Tolignite of iron, all had 
 their advantages ; of late, borax, alum, rosin, carbolic 
 acid have been introduced. 
 
 Wooden Eoof Shingles. 
 
 One of the most valuable applications of the soluble 
 glass may be recommended for .shingles and wooden 
 roofs of farm-houses in the country and near rail- 
 roads, where the sparks of the locomotives have fre- 
 quently caused conflagrations and destruction of pro- 
 perty. 
 
 The operation is quite simple, and the expense but- 
 trifling ; the process has already been described, but 
 it may be still more simplified in the following 
 manner : 
 
 After the steaming of the shingles in boilers or in 
 tanks, where steam of 250 to 350^ is led into them, 
 they are dried and thrown into a weak solution of 
 liquid silica, standing about 25^ B., in which they are 
 left for twenty-four hours, when they are taken out 
 and exposed to the air. Before they are quite dry, a 
 weak solution of chloride of calcium is thrown over 
 them or sprinkled over them with a broom. When 
 quite dry they are fit for use. They will not burn 
 nor be ignited with the sparks ; if exposed to a direct 
 
SILICIFICATION OF WOOD. 
 
 67 
 
 fire, will not light in a surrounding fire. An intense 
 heat of long duration may char them on the surface ; 
 they are, however, quite safe from any inflammation. 
 
 Decay of Wood and Pbocesses for Preserving it. 
 
 According to the experiments which were made by 
 De Saussure, in the beginning of this century, it 
 would seem that the decay of woody fibre was exclu- 
 sively caused by the action of air and water. On ex- 
 posing moist wood to the action of oxygen gas, he 
 found that, for every volume of oxygen absorbed by 
 the wood, one volume of carbonic acid was disengaged. 
 It is now conceded that it is the hydrogen of the fibre 
 which is oxj^dized at the expense of the oxygen of the 
 atmosphere, while the carbolic acid is solely formed 
 from the elements of the wood, or that the process is 
 simply a separation of a portion of the carbon of the 
 wood by direct oxydation ; and it would seem, from 
 the experiment mentioned, that the first and only 
 cause of the deca^^ of vegetable tissue must be ascribed 
 to the affinity of oxygen for the elements of the latter. 
 
 Such cases of slow, decomposition have indeed also 
 been distinguished by the name eremacausis, a term 
 composed of two Greek words, and meaning to burn 
 by degrees. 
 
 The above explanation, however, scarcely holds 
 good in all cases ; it is now known that, in dry air, 
 woody fibre may be preserved without decaying for 
 thousands of years ; and, under water, in certain con- 
 ditions, it appears to be equally durable. One must, 
 therefore, look for some other cause to explain the 
 transformation of woody fibre. Such a one presents 
 
68 
 
 BILICIFICATION OF WOOD. 
 
 itself in the fact that, when wood is exposed for some 
 weeks to running water, or if it is boiled in water and 
 afterwards dried until the original weight is restored, 
 it is rendered thereby considerably more durable. 
 
 The cause of the transformation in question must, 
 therefore, be sought in a substance which is removed 
 by the dissolving action of water in the experiment 
 mentioned. By further investigation, this substance 
 is found to consist of the albumen of the sap, which , 
 is distributed throughout the cellular tissue. Like 
 the animal albumen, as the white of eggs, which it 
 closely resembles both in properties and composition, 
 the vegetable albumen is exceedingly liable to decom- 
 position. In this state it acts like a ferment, induc- 
 ing the decay of other bodies, according to the 
 physical law propounded in another application by 
 Laplace and Berthollet, namely, that a molecule set 
 in motion by any power can impart its own motion to 
 another molecule with which it may come in contact. 
 
 Among the bodies most prone to decomposition is 
 the sugary element, which is first dissolved. Then 
 the growth of fungi generally begins, and the putre- 
 faction proceeds step by step. It may, therefore, be 
 considered that the spontaneous decomposition of the 
 vegetable albumen is the primary cause of the decay 
 of wood. It is, indeed, found that those kinds of 
 wood which contain the smallest quantity of albu- 
 minous matter and amylum are the most durable. 
 Especially is this the case with a certain tree of the 
 acacia tribe, the locust and the cedar, which resist 
 decomposition in situations where all other kinds of 
 wood soon decay. 
 
SILICIFICATION OF WOOD. 
 
 69 
 
 In order, tlien, to find out whether a certain kind 
 of wood is especially fitted for building purposes, the 
 quantity of albumen present in the fibre should be 
 ascertained by analysis. M. Payen recommends, for 
 this pui7)ose, to digest the wood in a dilute solution 
 of caustic alkali — this soda, or potash — which has no 
 action on the woody fibre, but only dissolves the albu- 
 men. Hence the quantity of the latter may be esti* 
 mated by washing, drying and weighing the wood 
 after the experiment has been made. 
 
 The capability of wood to sustain the strain to 
 which it must necessarily be exposed, especially when 
 moying over it at high velocities, has been satisfacto- 
 rily proved by the experience of the Great Western 
 and other railwajs, where continuous longitudinal 
 sleepers of wood have been employed, and experience 
 has shown that the solidity of the road is much 
 greater than when the iron rails were attached either 
 to stone blocks or transverse wooden sleepers. In 
 proof that wooden rails cut from beech will bear the 
 wear and tear of trains passing over it, it is well 
 known that be^ch logs have proven to last eighteen 
 to twenty years when working in gear with an iron 
 wheel. The rails on the Yauxhall line were prepared 
 by Payne's patented process for preventing dry rot 
 and decay of timber. Scotch fir, if subjected to pres- 
 sure, will crush at ten tons, while beech (the wood re- 
 commended for railways) will bear a pressure of 
 eighty-two tons before it begins to yield. 
 
 Experience ha-^ing confirmed the" capability of 
 Scotch fir to withstand the traffic of twelve engines 
 per day for seven hours, without any visible wear, it 
 
70 
 
 SILICIFICATION OF WOOD. 
 
 would be difficult to say how long the rails cut from 
 beech, sustaining eighty-two tons pressure, would last. 
 Some of the impediments with which railroads have 
 to contend are the undulations of the country, and 
 the necessity of diverging from a right line in order 
 to obtain the traffic of important towns. These ob- 
 stacles can only be overcome by an outlay of capital, 
 in making the required excavations and embankments, 
 or by the oftentimes ruinous system of tunneling ; 
 and after all, inclines of greater or less radients are 
 unavoidable, and prevent the line working economi- 
 cally. Curves on iron rail-roads are highly prejudi- 
 cial, especially if the radius be small, as the wear and 
 tear become proportionately increased. 
 
 Timber Eot and Seasoning. 
 
 It is generally supposed that the rotting of timber 
 is merely induced by the action of the oxygen of the 
 aii\ From analysis made of sound and decayed oak, 
 it has been shown that for every two equivalents of 
 hydrogen oxydized by the air, one equivalent of car- 
 bonic acid had separated. It may therefore be in- 
 ferred that the decay or rot of timber does not arise 
 from fermentation, but is rather a chemical process. 
 Others admit that microscopical parasites of vegeta- 
 ble nature play an important part in the decay of 
 wood ; but consider the presence of albuminous mat- 
 ter in the sap as necessary, which, according to them, 
 must also be first in a state of decomposition before 
 it allows the growth of those organisms. In order to 
 throw light upon this most important subject, we pro- 
 
SlLCCmCATION OF WOOD. 
 
 71 
 
 pose first to tabulate a number of well obseryed facts. 
 Sound timber, when immersed in.%water, without ac- 
 cess of air. will withstand decay for almost an 
 unlimited time. This is proved by the piles upon 
 which the dwelHngs on the Canaries rest, which were 
 erected in the time of the Conquest in 1402, they 
 being just as sound now as if they had been freshly 
 felled. Eoots of trees that have been submerged in 
 marshes are rarely found decomposed. This is stated 
 to be the case with the utensils discovered in the lake 
 dwellings of Switzerland, Bavaria and Lombardy, 
 which must be at least ten thousand years old. Har- 
 tig also describes a cypress stem with over three 
 thousand rings, representing the same number of 
 years, which, though submerged, had only partially 
 turned into brown coal. 
 
 The German botanist, Schacht, in all instances of 
 decayed timber, has met with fungi and lichens. The 
 destruction of timber by decay, after the same has 
 been hewn, must, therefore, be considered as being 
 produced by similar causes which brought on the dis- 
 ease of the vine, potato, mulberry trees, and other cul- 
 tivated plants, which make the years 1845, '48, '53, '57 
 and others forever painful to the memory. 
 
 That the juice should be in a state of decomposition 
 before being capable of generating those organisms 
 seems doubtful, since this has not been found the case 
 in other and well studied modes of fermentation. The 
 morel, a species of mushroom, will also attack per- 
 fectly sound wood. Hand in hand with the spread of 
 the fungi continues the decomposition of the ligneous 
 tissue. Access to moisture and air, as also a certain 
 
72 
 
 SILICIFICATION OF WOOD. 
 
 degree of heat, are necessary. In regard to the air 
 fungi require oxygen for their generation. When aii^- 
 dried, steamed, or chemically treated and afterward 
 dried, wood commences to rot, it is a sign that moist- 
 ure has again penetrated ; for it is scarcely to be ad- 
 mitted, that in all these cases the sap had been entirely 
 removed. Timber decomposes the easier the more 
 sap it contains ; and if green trees are hewn when the 
 vessels are overflowing with juice, one may look with 
 certainty for diminished durability of the timber. 
 Timber is not always the more durable the more dense 
 it is, but rather when the even fineness of the grain 
 continues to the pith of the stem. 
 
 The Koman historian, Pliny, considers the resin- 
 ifer ous woods as the most durable. Indeed, nature 
 shows that this is frequently the case. The resinifer- 
 ous red and white pines of Oregon and California are 
 considered first-class ship timber, so much so that en- 
 tire vessels have been constructed from the denser 
 qualities. The yellow or long-leaved pine, in dry sit- 
 uations, is extremely durable, and is preferred to oak 
 of any kind, where a lighter, yet solid wood, is re- 
 quired. The white or northern pine, which grows 
 abundantly in every northern State of the Union, from 
 Maine to Minnesota, reaching often to an altitude of 
 one hundred and eighty feet, with a diameter of six 
 feet or more, is said to retain its properties as long as 
 the very best description of oak. 
 
 The proportion in which the w^oody fibre and water 
 are to each other is very different. It varies accord- 
 ing to the degree of dryness and the nature of the 
 
SIUCIFICATION OF WOOD. 
 
 73 
 
 wood itself. According to Scliubler and NeuiBfer, we 
 Lave for" newlj-felled woods the following table : 
 
 "WOOD. WATER. 
 
 Hornbeam , 1 8 . 6 per cent. 
 
 Willow 26.0 
 
 Sycamore 27.0 
 
 Ash 28.7 
 
 Birch 30.8 
 
 Oak 34.7 
 
 Pedich Oak 35 4 
 
 White Fir 37.1 
 
 Pine 39.7 
 
 Ked Beech 39.7 
 
 Alder .41.6 
 
 Asp 43 7 
 
 Elm 44.5 
 
 • Red Fir 45 .2 
 
 Lime Tree s 47.1 
 
 Italian Poplar , 48.2 
 
 Larch 48.6 
 
 White Poplar 50.6 
 
 Black Poplar 51.8 
 
 The amount of water in wood, after one year's dry- 
 ing in the air, ranges from 20 to 25 per cent., and when 
 perfectly air-dry, as it is called, it still holds from 10 
 to 15 per eent. 
 
 The specific weight of newly-felled timber ranges 
 from 0.85 to 1.05 ; that of air-dried timber from 0.45 
 to 0.75. The weight of one cubic foot of newly-cut 
 native timber would thus range from 50 to 65 pounds, 
 while that of seasoned wood would vary from 28 to 47 
 pounds. The total expulsion of moisture by means of 
 air-drying, according to the experiments of Rumford, 
 takes place only at 280^ Fahrenheit. But even if thus 
 completely dried, and then exposed again to the 
 atmosphere, it absorbs nearly five per cent, of water 
 during the first three days, and continues to absorb 
 until it contains from fourteen to sixteen per cent., 
 
74 
 
 SILICIFICATION OF WOOD. 
 
 after which it becomes very hygroscopic, losing or ab- 
 sorbing water according to the state of the atmosphere. 
 
 The drying of lumber in confined rooms by means 
 of hot air, or steam and air alternately, is now largely 
 practiced, and the more on account of the economy of 
 the method than on account of its yielding a superior 
 product. In some cases, the wood, before being ex- 
 posed to artificial heat, is subjected to a longitudinal 
 pressure, in order to rupture the cells in which the 
 moisture^ is confined, to the end that it may escape 
 more freely upon the application of heat. It is claimed 
 that the wood is thus rendered more valuable for nearly 
 all the purposes for which it is used, but particularly 
 for the hubs, spokes, and panels of carriages, etc. 
 
 Wooden Eoof Shingles. 
 
 One of the most valuable applications of the soluble 
 glass may be recommended for shingles and wooden 
 roofs of farm-houses in the country, and near rail- 
 roads, where the sparks of the locomotives have 
 frequently caused conflagrations and destruction of 
 property. 
 
 The operation is quite simple, and the expense but 
 trifling. The process has already been described, but 
 it may be still more simplified in the following manner : 
 
 After the steaming of the shingles in boilers or in 
 tanks, where steam of 300 to 350^ is led into them for 
 several honrs, they are dried and thrown into a weak 
 solution of liquid silica, standing about 25^ B., from 
 which they are taken out and exposed to the air before 
 they are quite dry ; a weak solution of chloride of cal- 
 cium is thrown over them or sprinkled over them with 
 
SILICIFICATION OF WOOD. 
 
 75 
 
 a broom ; when quite dry, they are fit for use. They 
 will not burn nor be lighted by the sparks if exposed 
 to a direct fire — will not light in a surrounding fire. 
 An intense heat of long duration may char them on 
 the surface ; they are, however, quite safe against any 
 inflammation. 
 
 Street Pavements. 
 
 As a rule, competent engineers express doubts as to 
 the merits of the Nicolson, and of wooden pavements 
 of all patterns. 
 
 In the Nicolson structure, the road-bed is of sharp, 
 clean sand, of the proper thickness. A basis is then 
 made by laying common boards, dipped in hot coal- 
 tar, lengthwise on stringers of like material, laid from 
 curb to curb. The blocks forming the superstructure 
 are of Southern hard pine, three by four, and are set 
 on end in rows, crosswise of the street — the blocks, 
 before setting, being dipped to half their length in a 
 bath of coal-tar. Between the rows of blocks inter- 
 vene pickets of thin board set on edge, and leaving an 
 opening between the rows of blocks of an inch or 
 nearly in depth. This opening is filled with clean 
 screened gravel, rammed down with a paver's ham- 
 mer, and an iron blade made for the purpose, and the 
 surface is covered with hot coal-tar. The gutter exhibits 
 its lowest point half a foot from the curb. The whole 
 surface is covered with coal-tar sufficiently boiled to 
 be tough and fibrous, but not brittle, upon which is 
 sprinkled a layer of fine gravel and common sand. 
 The Staffard pavement differs from the Nicolson, in 
 the laying of large blocks prepared after the Seely 
 
78 
 
 SILICIFICATION OF WOOD. 
 
 patent, resting upon stringers, which in their turn may 
 be supported by any specified road-bed. Provided 
 the road-bed is sufficiently secure, say of strong con- 
 crete, and the upper deposit is made sufficiently com- 
 plete, the Stafford Pavement cannot but compare 
 favorably with other wooden pavements, and, for sim- 
 plicity, is quite superior to the Nicolson. 
 
 Various Systems Adopted for Eoadway Pavements. 
 
 A great variety of systems have been adopted for 
 roadway pavements. The most convenient classifica- 
 tion of ^them is into gravel compositions, broken 
 stone, plank, wooden block, cobble stone or pebble 
 stone block and iron block pavements and tramways. 
 The first attempts at pavements generally commence 
 with the use of gravel. Roads thus made possess the 
 advantages of cheapness of material and construction. 
 In the Central Park, where there are probably the 
 most perfect roads in this country, they have shown 
 better endurance than those made on the MacAdam 
 plan. Gravel roads, when properly constructed and 
 maintained, are comparatively smooth and noiseless, 
 besides afi"ording excellent foothold for horses. The 
 great objections to them are that they cannot be kept 
 firm enough to afford easy draught for heavy traffic ; 
 that they lack, in a high degree, permanence, and are 
 constantly requiring repairs ; that they are difficult to 
 keep clean and to drain properly ; the rapidly grind- 
 ing and crushing to powder tending greatly to cause 
 dust in dry weather and mud in wet weather ; and, 
 lastly, that the best construction yet attained has 
 failed to prevent them from washing into gullies. 
 
SILICIFICATION OF WOOD. 
 
 77 
 
 Under the head pf second composition pavements, 
 may properly be included pavements formed by the 
 combinations of several materials, such as the famous 
 asphalte pavement of Paris, concrete, beton, gutta 
 percha, slag, cinder, and other pavements ; also those 
 formed according to the experiments of M'Neil, partly 
 of broken stone and partly of pieces of cast metal, laid 
 on a sub-pavement of rubble stone. The asphalte 
 pavement of Paris, so often recommended in news- 
 paper articles, is really quite an imperfect pavement. 
 It is generally formed on a foundation of Mac- 
 Adamized road. Powdered asphalte is placed on the 
 foundation, and stamped with hot rammers until it is 
 very hard, and has a thickness of one or two inches. 
 It is very pleasant and smooth to ride over, but re- 
 requires most constant watching and repairing. It is 
 slippery in wet weather, and excessively so at a freez- 
 ing temperature. 
 
 The Fiske Conorete Pavement. 
 
 ' This pavement is composed of seventy per cent, in 
 bulk of broken stone, coal or gravel, clean coal or 
 iron cinders, not over three inches in any dimensions. 
 These are passed over a screen with meshes one quar- 
 ter inch square. The coarser portion is then coated 
 by mixing with tar, warm or cold, and then spread 
 on the road-bed and heavily rolled until a depth of 
 four inches is attained. The finer portion is then 
 mixed with clean sharp sand, warmed, and then 
 thoroughly mixed with tar, to which has been added 
 rosin, carbojapanis or pitch. This is placed on the 
 first layer of coarse material, and rolled until a depth 
 
78 
 
 SILICIPICATION OF WOOD. 
 
 of two inches is attained ; after which the surface is 
 covered with an excess of clean sharp sand, and again 
 rolled. 
 
 The Nicolson Pavement. 
 
 We now come to the subject of wooden pavements. 
 The first general attempt to use wooden blocks for 
 pavements took place some thirty years ago, both in 
 this country and Europe. They are generally made 
 in the form of hexagonal prisms of hard wood, laid 
 directly on sand or earth. Leading off in the list of 
 wooden pavements adopted in this city is the Nicol- 
 son pavement. In laying this pavement, the street is 
 first prepared by a sufficient covering of sand, which 
 is brought to the proper crown with a straight edge 
 made for that purpose. This surface is then covered 
 with common round inch boards, laid lengthwise with 
 the line of the street. The ends of these boards rest 
 on stringers of the same material laid from curb to 
 curb. 
 
 Both sides of these boards are covered with hot 
 coal-tar. The blocks are of Southern pine, three 
 inches "wide and six inches deep, and are set on end 
 in rows cro*sswise of the street. Before setting, the 
 blocks are dipped to half their height in hot coal-tar. 
 Between each row of blocks, and at their base, pickets 
 one inch thick and three inches wide are nailed on 
 edge. The opening thus formed between the rows is 
 filled with clean screened gravel, rammed with a 
 paver's rammer, an iron blade made for that purpose 
 and then colored with hot coal-tar. The whole of 
 the upper surface of the pavement, when laid, is 
 
SILrCIFICATION OF WOOD. 
 
 79 
 
 covered with hot coal tar, boiled to a consistency 
 which, when cold, is to be tough, fibrous and not 
 brittle, and then covered with fine gravel and common 
 sand. After the top. gravel has become packed on 
 the surface and in the grooves, the street is swept. 
 
 The Staffoed Pavement 
 
 is only another imitation of the great original Nicol- 
 son. The blocks are dressed to a uniform thickness, 
 grooved in the middle with a double dovetail, two 
 and one-half by three-fourth inches, each side of the 
 block beveled at one end, and running to an edge so 
 as to form a groove on the upper surface. 
 
 General Directions for The Protection of Eail- 
 EoAD Sleepers, Cross Ties, Frame Houses, Tele- 
 graph Poles, Timber, Staves, Shingles, Laths, 
 Tanks, Tubs, Casks, Barrels, (Petroleum, Naptha, 
 Spirits Turpentine Alcohol, Linseed Oil,) Cisterns 
 AND Every Description of Wood, against Fire, Dry 
 EoT AND Leakage. 
 
 The seasoning or initiatory preparation of the lum- 
 ber, so as to destroy the organic or nitrogenized mat- 
 ters enclosed in all the cells of vegetable matters, are 
 dissolved and washed out of it ; or, in other words, 
 the removal of all the albumen, sap and coloring mat- 
 ter, is effected by exposing from four to six hours to 
 boiling water, containing about one per cent, of soda 
 ash in solution. They are then withdrawn and dried 
 in hot rooms, and then thrown into tanks containing 
 the tar and carbolic acid water, and left for a few 
 hours, then dried again and thrown into a hot solution 
 of silicate of soda, standing 20 ^ B., in which they are 
 
80 
 
 SILICIFICATION OF WOOD. 
 
 left for ten or twelve Lours. When removed from 
 here a weak hmewash is apphed with a brush or 
 sponge, consisting of 10 lbs. slaked lime to 40 gallons 
 of water, when likewise thej are removed to a dry or 
 hot air ; after that a weak wash of chloride of calcium 
 is thrown or brushed over them when nearly dry. 
 The process is then finished, and the articles so pre- 
 pared will resist the elements as above stated. They 
 increase in weight by this process aboat 6 per cent. 
 After this treatment, they assume upon the 'first dry- 
 ing a glazed appearance, and the pores are filled with 
 insoluble silicas precipitated by the action of the tar 
 liquor upon the alkali of the silicate of soda. Barrels 
 which have been treated may be rendered perfectly 
 impervious, by filliug up the chimes (the inside of 
 those barrels having been treated with the silicate of 
 soda and chloride of calcium) with a thin silicated 
 cement applied on the interstices. No air nor any 
 liquid will then have any effect ; the ligliest liquid 
 may then be kept in those prepared barrels without 
 escapihg ; flour, butter, lard, and many other perisha- 
 ble substances may be kept for a length of time in 
 barrels so prepared. Spirits of turpentime, linseed 
 oil, alcohol, and other spirituous liquors, may safely 
 be transported and kept for a length of time, -without 
 evaporation or loss in the contents of the barrels. 
 Telegraph poles, which are from twenty to thirty feet 
 long, require a different treatment for their seasoning 
 before they undergo the silicification. They are 
 steeped first in the tar carbolic liquid, in holes dug in 
 the ground with tanks built in the same, and left ia 
 there for several days ; then taken out, and under- 
 
CEMENTS. 
 
 81 
 
 going the otlier process of silicate of soda, lime wash 
 and chloride of calcium, as described, will render them 
 proof against fire and dry rot. 
 
 CEMENTS. 
 TiiE Most Adhesive Lubricator. 
 
 Black lead, 6 lbs., are mixed with 3 lbs. slaked 
 lime ; 8 lbs. sulphate of baryta are mixed with 7 lbs. 
 of linseed oil ; the whole mass is well mixed together 
 to a uniform consistency, and the entire mass made 
 more plastic with concentrated solution of silicate of 
 soda. This cement may be used for numerous pur- 
 poses, where hardness and adhesiveness are the de- 
 sired objects, uniting at the same time steam and 
 hot water. For locomotives, engines and machinery 
 it is prepared from a mixture of silicate of soda 
 liquid, at 25^ B., added to a fine plumbago, talc 
 asbestos in equal quantities, so as to retain the thin 
 plastic condition, and capable of dropping it on the 
 journals in very small portions. 
 
 The CHEAPEST WHITEWASH, which is very durable for 
 indoor and outdoor work, is pi-epared by the follow- 
 ing composition : To 1 lb. slaked lime and 1 lb. sul- 
 phate baryta, add 1 pint of silicate of soda and 1 
 pailful of hot water ; stir the materials well to,Gjether, 
 and use it at once. If the color is intended for a 
 yellow wash, add a quarter of a lb. chrome yellow ; 
 if for a blue wash, use instead of the latter a quarter 
 of a lb. ultramarine, (worth six cents;) and if the 
 
82 
 
 CEMENTS. 
 
 paint is intended to coat iron railing, stoves, steam- 
 boat chimneys, and to obtain a brown or black fire- 
 proof paint, add half a lb. of manganite, an oxide of 
 manganese, or the pyrolusite, which is the black or 
 gray peroxide of manganese. 
 
 The white-wash or yellow-wash just quoted is ex- 
 tremely durable and cheap for wooden fences along 
 railroad tracks, canal boats, farm houses and other 
 wooden structures. 
 
 The Most Durable Aquarium Cement. 
 
 Tlie materials of a water-resisting composition are 
 prepared by mixing finely powdered dry silicate of 
 soda, powdered chalk, and fine sand in equal quan- 
 tities, made plastic mth the liquid silicate, and applied 
 at the joints, and worked over with fluid chloride of 
 calcium, and when quite dry let some weak hydroflu- 
 oric acid pass over the cemented joints. This cement 
 will be permanently impervious to water, and will not 
 crack. The same composition is quite suitable for 
 breweries, malt houses, linings for water tanks, and 
 cellars into which water flows. 
 
 The author considers it advisable to show, also, the 
 advantages of concrete, by quoting Tail's system, ap- 
 plied in Paris, and the description of the concrete 
 bridge at London, and will state, that the addition of 
 silicate of soda to the concrete wdll undoubtedly en- 
 sure a great saving. 
 
 The material consists of one part of Portland ce- 
 ment to eight parts of coarse gravel. The cement 
 and gravel are first well mixed together in a dry state, 
 
CEMENTS. 
 
 83 
 
 and when this is done it is damped by means of a 
 large watering pot, containing some hot silicate of 
 soda, and again mixed by a pronged drag, such as is 
 used for dragging dung out of a cart, until the entire 
 heap has been wetted and mixed together. It is then 
 put in iron or zinc pails and poured into the frame, 
 where it is levelled by men stationed for the purpose. 
 In order to save concrete, large lumps of stones or 
 brickbats are put into the centre of the wall, and cov- 
 ered over and about with concrete. Frost does not 
 affect the concrete after it has once set, which, with 
 good cement, will be in about live or six hours. Nor 
 do heavy rains appear to injure it .in the slightest de- 
 gree, though they may chance to fall ere the concrete 
 has hardened. The walls can be made straight and 
 even as it is possible for walls to be, and the corners 
 as sharp and neat as if they had been formed of the 
 most carefully dressed stone. 
 
 The Soluble Glass as Manure foe Grapevines. 
 
 By putting the dry silicate of soda at the roots of 
 grapevines, with or without the addition of phosphate 
 of lime, has, by experiments, proved of immense 
 benefit to the thriving of the vines to a proper thick- 
 ness, and the grapes of uncommon size. 
 
 The Soluble Glass a Substitute for Glue. 
 
 It has proved quite useful in applying the liquid 
 glass for glueing wood and paper together, instead of 
 the common glue, and it is sold in the trade as mu- 
 cilage, and applied on pasteboard instead of emery 
 
84 
 
 CEMENTB. 
 
 or corundum paper, and used by cabinet-makers and 
 other mechanics for polishing. As a paste for book- 
 binders instead of giue, starch or dexterine, it has 
 proved quite useful. Earthenware may be kept more 
 durable by lining them with a weak solution. It is 
 likewise used on leather, provided the same is not ex- 
 posed to much bending. 
 
 The glazing or enamelwg of culinary vessels, made 
 either for iron or stone ware, the soluble glass is use- 
 fully applied in the following manner : 
 
 The silicate solution of soda and potash is mixed 
 with thick lime water ; to 100 parts of the silicate add 
 1 part of lime water, made from 1 part caustic lime 
 to 6 parts of water. The mixture is then evaporated 
 to dryness and reduced to fine powder. By dipping 
 first the objects to be glazed in the liquid silica, the 
 powder is then sifted over them ; when dry, the 
 operation is repeated again ; when dry, the coating 
 becomes so hard that it cannot be rubbed off by the 
 hands ; they are then treated hke other ware by 
 putting them in a furnace, requiring, however, not a 
 very great heat. 
 
 A similar process is to prepare a mass from 100 
 parts powdered quartz, 80 parts pure potash, 10 parts 
 saltpetre, and 20 parts slaked lime, which mixture 
 is made into a thin paste with the liquid silicate, and 
 then burnt. Tha glazing is very durable, and resists 
 both vegetable and mineral acids like common glass. 
 It requires no great skill to execute the operation, 
 and the expense to prepare such a glazing is but a 
 trifle. 
 
CEMENTS. 
 
 85 
 
 Soluble Glass Application roPt Various Cements. 
 
 Forcelain, Glass and Bletals are fastened together 
 when broken, either by the hquid or gelatinous siH- 
 cate by the following method : Heat the object to be 
 fastened together to that of boiling water, and apply 
 the soluble glass on both sides of the fracture, press 
 them together and leave them in a warm place for a 
 fortnight, when they will be fit for use. Flourspar 
 finely ground, black oxide of manganese, oxide of iron 
 (crocus) finely powdered soluble glass, and many 
 more refractory substances are suitable articles to mix 
 with the liquid silica for the various cements in use. 
 . A cement for fastening iron in stone, glass or wood is 
 recommended, consisting in 1 part prepared chalk, 1 
 part marble dust, and made plastic with the liquid 
 silica, or 1 part powdered soluble glass, 2 parts pow- 
 dered flourspar, made into a paste with the liquid 
 silica, and this is for pasting labels on glass bottles. 
 
 Fireproof Cement is composed of the various oxides 
 of iron, and formed into a paste with the liquid 
 silica. 
 
 The Ilarhle Cement is composed of carbonate of 
 lime, carbonate of magnesia and silica with oxide of 
 iron, and made into a thin liquid and applied to the 
 stone, which, on drying, is permanently fastened to 
 the surface, and protects it from smoke, dust and 
 atmospheric agents. 
 
 Common and fire brick acquire great strength if the 
 silicate of soda has been employed in the manufacture, 
 and become indestructible ; they are then particularly 
 
86 
 
 CEMENTS. 
 
 fifc for baker's ovens, wall and well foundations and 
 furnace beds. 
 
 Glazed Paper for apothecaries' use, may likewise 
 be prepared with the soluble glass. 
 
 Metallic Cement is formed of a mixture of equal 
 parts of oxide of zinc, peroxide of manganese and 
 litharge, and made up with liquid silica and marble 
 dust, and applied between the metals to be cemented. 
 
 An Impermeable Cement Kesisting Steam. 
 
 It is prepared by mixing six parts finely powdered 
 black lead, 3 parts slaked lime, and 8 parts of Plaster 
 of Paris, made into consistency by the liquid silica. 
 
 Zinc Cement, for stopping cracks in metallic appa- 
 ratus and other materials, is made by mixing equal 
 weights of zinc white and finely powdered soluble 
 glass with a solution of chloride of zinc of the den- 
 sity of 126 ; it sets rapidly and resists th^ action of 
 most agents. The simple mixture of oxide of zinc 
 with a solution of the chloride of zinc, has also been 
 recommended. 
 
 Hard Cement. 
 
 It consists in mixing 5 parts powdered clay, 2 parts 
 iron fihng, and 1 part of black oxide of manganese, 
 and J part borax, made into paste with liquid sihca ; 
 when dry is very hard, and withstands water. Also, 
 a mixture oi manganese and zinc luhite with Plaster of 
 Paris forms a very hard cement, and has great ad- 
 hesive capacity. 
 
 Brain and gas pipes, for conducting to sewers and 
 houses, may be made as permanent as iron pipes by 
 
CEMENTS. 
 
 87 
 
 using a hard cement, consisting of hydraulic hme, 
 clay and sand, mixed with fine powdered fluorspar and 
 soluble glass, all made plastic by the liquid silica ; 
 this mass, when dry and burnt, will resist a pressure 
 of 600 pounds to the square inch, while iron pipes, 
 burst under a pressure of 400 pounds to the square 
 inch. 
 
 Cement for CLOsiNa Cracks in Stoves. 
 
 It is prepared by mixing finely pulverized iron, such 
 as can be procured at the druggists, with liquid 
 water glass, to a thick paste, and then coating the 
 cracks with it. The hotter the fire, the more does 
 the cement melt with its metallic ingredients, and 
 the more completely will the crack become closed. 
 
 Cement for a Cistern. 
 
 Ta'ke 10 parts of Plaster of Paris, 
 2 " Glauber Salts. 
 • 4 " Clay. 
 4 " Slaked Lime. 
 
 Made in a plastic cement with the liquid silicate of 
 soda, and, before it hardens, add liquid chloride of 
 calcium. 
 
 For sweetening the water in cisterns, which is found 
 to be hard, may be made soft by one gallon of silicate 
 of soda in the cistern, and repeat the operation once a 
 month. 
 
 Tlie best iron cement is composed of calcined plaster 
 and iron filings, from each 10 parts, 4 parts oxide 
 manganese, 2 parts slaked lime; made plastic with the 
 liquid siHcate of soda. 
 
88 
 
 CEMENTS. 
 
 A Sthong Cement for Iron. 
 
 To 4-5 parts claj, dry and. powdered, 2 parts iron 
 filings, 1 part manganese, J part salt. J- part borax, in 
 a paste made with soluble glass, or equal parts zinc 
 white and manganese, made to a paste, must be used 
 immediately. 
 
 Iron Cement for Water and Gas Pipes and Castings. 
 
 It is obtained from 60 parts cast iron turnings, 
 mixed with 2 parts of sal ammonia, 1 part fluor sulphur, 
 and 1 part lime cement ; the whole made plastic by the 
 liquid glass just before using it, to mend holes of what- 
 ever description in iron pipes or iron castings ; it be- 
 comes soon very hard, and every crevice is filled. 
 
 Colored Cements. 
 
 To a solution of silicate of soda»of 1.298, add, while 
 stirring, first pulverized and previously washed lixivia- 
 ted chalk, so as to form a thick mass, to which are 
 added, for coloring purposes, the following substances : 
 
 For black, sulphuret of antimony. 
 
 Gray, iron filings. 
 
 Gray white, zinc dust. 
 
 Bright green, carbonate of copper. 
 
 Blue, orange and red, cobalt, vermilion and carmine. 
 
 This cement hardens in six to eight hours, and bears 
 polishing like marble. 
 
 Coating for Outside Walls. 
 
 The following coating for rough brick walls is used 
 by the United States Government for painting light- 
 houses, and it effectually prevents moisture from strik- 
 
CEMENTS. 
 
 89 
 
 ing tlirougli : Take of fresli Eosendale cement tliree 
 parts, and of clean, fine sand one part ; mix with soluble 
 glass thoroughly. This gives a gray or granite color, 
 dark or light, according to the color of the cement. 
 If brick color is desired, add enough Venetian red to 
 the mixture to produce the c6lor. If a very light color 
 'is desired, lime may be used with the cement and sand. 
 Care must be taken to have all the ingredients well 
 mixed together. In applying the wash, the wall must 
 be wet with clean fresh water ; then follow immediately 
 with the cement wash. This prevents the bricks from 
 absorbing the water from the wash too rapidly, and 
 gives time for the cement to set. The wash must be 
 well stirred during the application. The mixture is to 
 be made as thick as can be applied conveniently with 
 a whitewash brush. It is admirably suited for brick- 
 work, fences, etc., but it cannot be used to advantage 
 over paint or whitewash. 
 
 PHESEKYATION OF StoNES FROM GrEEN CoATING. 
 
 The decay of granite, marble, limestones, sandstones, 
 and all natural building stones, is the combined effect 
 of various causes, and among these is a very minute 
 lichen, the Lepra antiquitalis, which is one of the 
 worst enemies of stone, and its action is to such 
 an extent that, for instance, the beautiful maj-ble 
 sculptures of the well-known Pare de Versailles 
 will, unless proper measures be taken for siaj^- 
 ing the process of decay, be unsightly and ugly 
 masses of dirt, and quite irretrievably lost, as works 
 of art, within the next 50 years. Various places and 
 instances are cited of the application of oxide of 
 
90 
 
 CEMENTS. 
 
 copper and its salts, whicli places are open to inspec- 
 tion ; and the length of time which has elapsed since 
 such application, seems to warrant the conclusion 
 that these compounds act as preservatives of stone. 
 In reference to granite, the author states that this 
 stone is also, according to the experience of Egj^ptian 
 engineers, far more readily affected by a moist climate 
 than one would be led to believe. The obelisk of 
 Luxur, brought from Upper Egypt to Paris, has be- 
 come blanched and full of small cracks during the 
 40 years it has stood on the Place de la Concorde ; 
 although 40 centuries had not perceptibly affected it 
 as long as it was in Egypt. Granite in a moist 
 climate becomes the seat of a minute cryptogamic 
 plant, which greatly aids its destruction ; and it is, 
 moreover, a well-known fact, that the disintegration 
 of this stone, which is composed of three separate 
 minerals, (quartz, mica, and felspar), depends very 
 greatly upon the thorough and intimate mixture, as 
 well as the chemical composition, of thesa three in- 
 gredients, each of which, in a separate state, more 
 easily withstands the influence of the weather. 
 
 The most refractory cement is formed from silica^ 
 asbestos^ plumbago and soapstone. These materials, 
 mixed in certain proportions and made plastic by 
 the liquid silica, form a most valuable cement for 
 locomotive journals and other lubricating purposes, 
 for lining of steam boilers as well as coating, for 
 filling up airholes in iron castinge. By the addition 
 of peroxide of manganese, it may be much improved, 
 and serve as a permanent paint, which is fire and 
 water proof. 
 
SPECIAL NOTICE 
 
 To Bail lioad Companies, Superintendents, and blaster 
 Mechaivica. 
 
 Rail Road Sleepers, Cross Ties, 
 
 SHINGLE EOOFS, 
 STATION HOUSES, BBIDGES, dc, 
 
 PROTECTED AGAINST 
 
 The Sparks of Locomotives, Direct Fire, and 
 Dry Rot. 
 
 THE MANUFACTUEEKS OF THE IMPRO\'ED 
 SOLUBLE GLASS OR SILICATE OF SODA, 
 
 Beg to call the attention of those interested in the 
 construction of railroads that they are prepared to 
 furnish all quantities of the liquid, either for impreg- 
 nating or covering materials used in the construction 
 of railroads, with full directions for the entire suc- 
 cess of painting the sheds, fences, and outposts on 
 the line of railroads, thereby preventing, very fre- 
 quently conflagrations and the loss of valuable pro- 
 perty. 
 
 For hardening mortars, cements, artificial stone, 
 common brick so as to resist a greater degree of heat 
 and exposure to dampness. 
 
 The soluble glass is invaluable, and proved be- 
 yond contradiction, that if wood is saturated with it 
 by a very simple process, say shingles, clapboards, 
 sleepers, or ties on the canvas as a covering of rail- 
 road cars, a double advantage is achieved ; the pro- 
 tection against fire and the security against decay ; 
 
92 
 
 SPECIAL NOTICE. 
 
 it may cliar or smotliei, if exposed to a great confla- 
 gration, but it will never burst into flames, no scatter- 
 ing of cinders, or blowing about of firebrand. The 
 application is quite simple, and the price extremely 
 reasonable. 
 
 Directions for use : — In a tank, containing about 
 120 gallons boiling water, put a barrel of soluble 
 glass, containing about 40 gallons ; the various rail- 
 road materials to be treated are thrown in and kept 
 for two or three hours ; they are taken out and ex- 
 posed for an hour to the air, and then are painted 
 with a whitewash brush of the whiting, 2 lbs. to 1 
 gallon water, or a paint of white zinc may be applied 
 when the wood is perfectly dry. 
 
 For further particulars and contracts apply to the 
 original manufacturers, 
 
 L. & J. W. FEUCHTWANGEE, 
 
 Manufacturing Chemists and Drug Importers, 
 
 55 CEDAR STBEET, NEW YOIIK. 
 
 Special Notice to Soap, Trunk, Pasteboard, Band- 
 box and other Manufacturers of Paper or Paints and 
 Paper Hangings. The improved soluble glass is par- 
 ticularly recommended to the above trades, as being 
 superior to glue, starch or flour paste ; it does not 
 crust, and is very economical. 
 
8^ -^5:15 ^3