Chapter XIII (2)

Reduce the rosin to small pieces, run down in a pot, add the other ingredient, and stir until mixed and syrupy, then run out into tins. It is used for cementing the bristles in the stocks, also for string binding on sash tools, etc.

_Cement for electrical apparatus._ Mix together 1 lb. of beeswax added to 5 lbs. of rosin, 1 lb. of red ochre, and 2 tablespoonfuls of plaster of Paris. It will make an excellent composition for electrical apparatus.

A cheaper composition for cementing voltaic plates into wooden troughs is made with 6 lbs. of plaster of Paris and ¼ pint of linseed oil. The ochre and the plaster of Paris should be well dried and added to the other ingredients when these are in a melted state.

_Jewelers’ cement._ Dissolve over the water-bath 25 parts of fish glue in a small quantity of strong spirits of wine, add 2 parts of gum ammoniac; separately dissolve 1 part of mastic in 5 of spirits of wine. Mix the two solutions and keep them in well-stoppered bottles.

_American cement for jewelers._ Soak 4 ozs. of isinglass in 2 lbs. of water for 24 hours, then evaporate in the water-bath; to 1 lb. add 1 lb. of rectified spirits of wine, and strain. Then mix in a solution of 2 ozs. of mastic and 1 oz. of gum ammoniac in 16 ozs. of rectified spirit.

_Cement for celluloid._ Shellac 2 ozs., spirits of camphor 2, 90 per cent. alcohol 6 to 8.

_Stratena._ This well-known household cement is said to be prepared as follows: Dissolve 12 parts of white glue in 16 of acetic acid, and then add this solution to one of 2 parts gelatine in 16 of water. After mixing add 2 parts shellac varnish.

_Cement for cloth._ Gutta-percha 16 parts, rubber 4, pitch 2, shellac 1, linseed oil 2 pints. Dissolve the whole by heat, stirring constantly.

HOW TO USE CEMENTS.

It is unquestionably true that quite as much depends upon the manner in which a cement is applied, as upon the cement itself. The best cement that was ever compounded would prove entirely worthless improperly applied. In the foregoing a number of cements have been given which answer every reasonable demand when properly prepared and properly used. Good common glue will unite two pieces of wood so firmly that the fibres will part from each other rather than from the cementing material; two pieces of glass can be so joined that they will part anywhere rather than on the line of union; glass can be united to metal, metal to metal, stone to stone, and all so strongly that the joint will certainly not be the weakest part of the resulting mass. What are the rules to be observed in effecting these results?

The first point that demands attention is to bring the cement itself into intimate contact with the surface to be united. If glue is employed, the surface should be made so warm that the melted glue will not be chilled before it has time to effect a thorough adhesion. The same is more eminently true in regard to cements that are used in a fused state, such as mixtures of resins, shellac, and similar materials. These matters will not adhere to any substance unless the latter has been heated to nearly or quite the fusing point of the cement used. This fact was quite familiar to those who used sealing-wax in the olden days of seals. When the seal was used, in succession, rapidly so as to become heated, the sealing-wax stuck to it with a firmness that was annoying, so much so that the impression was generally destroyed, from the simple fact that the sealing-wax would rather part in its own substance than at the point of adhesion to the seal. Sealing-wax or ordinary so-called electric cement is a very good agent for uniting metal to glass or stone, provided the masses to be united are made so hot as to fuse the cement; but if the cement is applied to them while they are cold, it will not stick at all. This fact is well known to those itinerant venders of cement for uniting earthenware. By heating two pieces of delf so that they will fuse shellac, they are able to smear them with a little of this gum and join them so that they will rather break at any other part than along the line of union. But although people see the operation constantly performed and buy liberally of the cement, it will be found that in nine cases out of ten, the cement proves worthless in the hands of the purchasers, simply because they do not know how to use it. They are afraid to heat a delicate glass or porcelain vessel to a sufficient degree, and they are apt to use too much of the material, and the result is a failure.

The great obstacles to the junction of any two surfaces are air and dirt. The former is universally present, while the latter is due to accident or carelessness. All surfaces are covered with a thin adhering layer of air, which it is difficult to remove, and which, although it may at first sight seem improbable, bears a relation to the outer surface of most bodies different from that maintained by the air a few lines away. The reality of the existence of this adhering layer of air is well known to all who are familiar with electrotype manipulation. It is also seen in the case of highly polished metals which may be immersed in water without becoming wet. Unless this adhering layer of air is displaced, the cement cannot adhere to the surface to which it is applied because it cannot come in contact with it. The most efficient agent in displacing this air is heat. Metals warmed to a point a little above 203° F. become instantly and completely wet when immersed in water. Hence, for cements that are used in a fused condition, heat is the most efficient means of bringing them in contact with the surfaces to which they are to be applied. Another very important point is to use as little cement as possible. When the surfaces are separated by a large mass of cement we have to depend upon the strength of the cement itself and not upon its adhesion to the surfaces which it is used to join; and, in general, cements are comparatively brittle.

The cement forced out of the joint by pressing the surfaces together should be removed while the cement is in a fused state or liquid. This can generally be effected by wiping the surplus off, while after solidification a certain amount of force has to be used which may frequently break the joint.

Oil cements, which generally solidify slowly, have the advantage of being water-proof. In cementing with oil cements, coat the surfaces to be joined with linseed oil, or, still better, boiled linseed oil, but in working with resinous cements apply oil of turpentine, spirit of wine, or a fluid which will readily dissolve the cementing constituent of the cement.

For cleansing the surfaces from grease and dirt place the articles in strong lye and rinse off in clean water without touching the surfaces with the hands. For painted porcelain articles which cannot be placed in lye, it is recommended to brush the surfaces several times with carbon disulphide.

PASTES AND MUCILAGES.

_Preparation of paste._ Ordinary paste is prepared either from flour or starch, and according to the raw material used in its preparation, may, therefore, be divided into starch and flour paste.

Starch is an indispensable constituent of certain parts of plants, and plays an important part in the nutrition of the plant. It is chiefly manufactured from potatoes, Indian corn and grain. Examined under the microscope, it is seen to be composed of small granules consisting of layers placed one above the other.

_Starch paste._ In stirring starch with water to a thin paste and gradually heating it, it will be observed that at a temperature between 140° and 158° F. a peculiar change takes place; the thin milk-white liquid becomes transparent, opalizes, and at the same time becomes thickly fluid, in short, the starch is converted into paste. During this process the separate layers of the starch granules become detached somewhat in the same manner as an opening bud, whereby they absorb water, and the peculiar mass, called paste, is formed. That paste is not a solution is easily proved by the fact that on attempting to filter starch-paste only water drains off, while the starch remains upon the filter and gradually dries to a horny mass.

Paste left to itself soon decomposes, especially during the hot season of the year; it becomes sour through the formation of lactic acid, butyric acid, acetic acid, and other substances, and loses its adhesive power.

In preparing paste, the following rules must be especially observed: Divide the starch in water by constant stirring so as to form a homogeneous, rather thinly liquid fluid, and then add boiling water in small portions, stirring constantly. The conversion of the starch into paste is recognized by the thickening of the entire mass and the appearance of opalescence, when it is only necessary to add the required quantity of water to give the paste the desired consistency.

If white lumps are observed, it is an indication that the starch has not been thoroughly mixed with the water, and that certain portions of it have remained dry. Paste containing such lumps cannot be applied with any degree of uniformity, and besides it possesses less adhesive power. Nothing can be done to remedy the evil except diluting the paste with a considerable quantity of water and boiling, with constant stirring, until the mass is perfectly homogenous.

Starch paste prepared in a proper manner possesses great adhesive power, and, when applied in a thin layer, dries to an almost colorless coating. Pure starch paste is used for many purposes. It serves not only for pasting paper, wall paper, etc., but also for sizing tissues, such as paper-muslin, linen, etc., in order to give them lustre, body, and, under certain circumstances, greater weight. To increase the weight of linen, white lead or heavy spar is frequently mixed with the starch.

_Flour paste._ The principal constituent of flour, besides starch, is gluten. It is obtained in a pure state by tying flour in a linen bag and kneading it under water so long as the latter is rendered turbid by particles of starch. The gluten remaining in the bag is a light-brown, very tenacious mass, drawing threads between the fingers, and, as regards its chemical properties, is closely allied to albumen and caseine. Gluten, like the last-mentioned substances, shows a tendency to form combinations with lime which gradually solidify, and it can therefore be used for preparing cements. Like albumen and caseine, it speedily putrefies if exposed to the air in a moist state, and in decomposing forms products which have a very unpleasant odor.

Flour paste is prepared in precisely the same manner as starch paste, but while the latter is white, flour paste, even if prepared from the best wheat flour, has always a yellow-brown color. As regards adhesive power it is superior to starch paste, but is less durable.

There are many means to prevent the spoiling of paste. With paste once dry and kept so, there is no danger of spoiling, but if it is alternately exposed to dampness and dryness, as for instance with wall-paper hung on walls not entirely dry, decomposition will unavoidably take place, and the wall paper will become spotted and fall off the wall.

Provided either starch or flour paste is protected against drying in, it can be kept unchanged for a long time by the addition of a small quantity of carbolic acid.

For hanging wall-paper an addition of alum is, generally speaking, more suitable than carbolic acid.

In hanging wall-paper the wall is generally first sized with glue water. By the alum coming in contact with glue an insoluble leather-like combination is formed, which not only resists decomposition, but by far surpasses ordinary paste as regards adhesive power, so that when the paper is to be removed from the wall it has to be scraped and torn off in small pieces, while that hung without previous sizing of the wall is readily removed in large pieces.

But alum cannot be used for preserving a glue solution, as it would cause it to coagulate to a flaky mass. Carbolic acid is, on the other hand, an excellent means for the purpose, but to prevent its characteristic empyreumatic odor from making itself too sensibly felt, no more than about one two-thousandth of the weight of the glue solution should be added.

_Shoemakers’ paste._ In addition to being cheap, no other paste adheres as well to leather as the so-called shoemakers’ paste. With it leather can be secured not only to leather, but also to woven materials, paper, etc. Though its preparation is very simple, it is connected with some disagreeable features consisting chiefly in the development of a truly terrible stench.

The paste is prepared by stirring crushed barley with hot water to a thick paste and adding small portions of hot water, so that the temperature of the mass is kept at between 86° to 104° F. In a few days the mass commences to develop gas, which shows at first no odor, but soon the development of gas becomes stronger and an acid odor is perceptible, which in a short time is replaced by a terrific stench which, as before mentioned, affects the olfactory organs in a most unpleasant manner.

In consequence of the acid and putrid fermentation the pasty mass gradually loses its granular condition, and is finally converted into a homogeneous, thickly fluid mass of a brown color, which draws threads between the fingers, and possesses great adhesive power. When this is the case, decomposition, which otherwise would go on until nothing remained but a watery and acid fluid, is interrupted by lowering the temperature of the paste by ladling it from the vat or by adding a small quantity of carbolic acid.

To render the stench developed during the fermentation of the paste innoxious, the vat in which it is prepared should be provided with a well-fitting cover, in which is fitted a stovepipe passing into a chimney connected with a kitchen range or furnace, in which a fire is frequently burnt.

By kneading shoemaker’s paste together with indifferent substances it can be used as a cement for various purposes. The substances best adapted for the purpose are burnt lime slaked to a powder, whiting, zinc white, pipe clay, ochre, etc.

_Gum arabic._ This gum is an exudation from certain tropical species of acacia, and consists essentially of arabine, which has the composition C_{12}H_{11}O_{11}. The best gum arabic is that in the form of very pale-yellow, brittle pieces; golden-yellow to brownish pieces are not valued as highly, though they give a solution of considerable adhesive power.

Gum arabic dissolves in water, but not in alcohol, and therefore can not be employed for cements in the preparation of which solutions of resins in spirit of wine are to be used.

There are other products of vegetable life, which are also in commerce, called gums, but dissolve partly in spirit of wine. To this class belongs the gum ammoniac mentioned in some receipts for cements. As it is rather expensive, it is seldom used by itself as a cement.

_Dextrine_ is extensively used in place of gum arabic in printing wall-papers, for stiffening and glazing cards and paper, for thickening the colors of calico printers, in making mucilages, etc. It is prepared by heating starch previously moistened with nitric acid in an oven, and can also be produced by heating paste with malt extract or very dilute sulphuric acid. There is a current anecdote which attributes the discovery of dextrine to a conflagration at a starch factory where one of the workmen who assisted in quenching the fire observed the gummy properties of the water which had been thrown over the torrefied starch.

Commercial dextrine forms pale-yellow to dark-brown masses. These masses dissolve readily in water, and form solutions which, as regards adhesive power, compare favorably with those prepared from gum arabic. The mucilage is prepared by simply stirring the pulverized dextrine with water to a thickly-fluid liquid.

To preserve mucilage unchanged for any length of time, and to prevent the disagreeable formation of mould upon its surface, it is recommended to dissolve some salicylic acid in the water to be used for preparing the mucilage.

Dextrine is usually prepared on a large scale by moistening 10 parts of starch with 3 parts of water acidulated with 1/100 part of nitric acid. The mixture is allowed to dry, and is then spread upon trays in layers about three-quarters of an inch deep in an oven, where it is heated for about one hour to 239° F. Sometimes large drums revolving over a fire are used, or, in order to keep up a uniform temperature, the starch is placed in a copper cylinder suspended in a vessel with oil which is heated to 356° F. The object of the addition of nitric acid is to allow the starch to be converted into dextrine at a temperature which would be inadequate to effect the transformation of starch alone.

Dextrine is also frequently prepared by allowing germinated barley or malt to act upon starch. Heat 350 to 400 parts of water to about 77° F., and after adding 5 to 10 parts of dry malt, raise the temperature to 140° F. Then add 100 parts of starch, and after mixing the whole thoroughly together, raise the temperature to about 158° F. for twenty minutes. The mass, which appears at first milky and sticky, will gradually become as liquid as water by the conversion of the starch into gum through the action of the malt. To prevent the conversion of the gum into sugar by the diastase of the malt, the fluid must be quickly brought to the boiling-point, and, after cooling, filtered and evaporated to the consistency of syrup. In cooling, the mass gelatinizes to a jelly, which after drying is hard and brittle.

According to Blumenthal’s method, a drum which can be hermetically closed, is filled two-thirds full with dry starch flour by means of a funnel. A stirring apparatus is then set in motion, and the acid which is contained in a graduated cylinder is sprayed into the drum by means of a special contrivance.

In a drum 5 feet long and 3¼ feet in diameter, 220 lbs. of potato starch can be uniformly mixed in 5 minutes with about 9 ozs. of nitric acid of 40° B., and the drum emptied by opening the slide. Starch thus treated may be brought into the oven without previous drying.

Heuzé gives the following method: Four and a half pounds of nitric acid of 1.4 specific gravity together with 300 quarts of water are mixed with 2,200 lbs. of starch, and boiled to form a mass which, when exposed to the air becomes dry. It is sometimes effected at 177° F., but it becomes a paste at 212° to 230° F. The starch changes into dextrine in an hour or an hour and a half at the most; it is white and soluble in water.

_Tragacanth, or gum tragacanth_, exudes from _Astragalus verus_, a tree indigenous to Asia. The term gum is a misnomer, as tragacanth does not actually dissolve in water nor in spirit of wine, but merely swells up in water to a soft gelatinous mass. Tragacanth consists of irregular pieces of a pure white to yellowish color. It is chiefly used for confectioner’s purposes, though sometimes as a paste for fancy articles. This variety of gum is found, together with arabine, in the gum which exudes from cherry, plum, almond, and apricot trees, and gives the mucilaginous character to the watery decoctions prepared from certain seeds, such as linseed and quince-seed, and from the root of marshmallow.

PASTES AND MUCILAGES FOR SPECIAL PURPOSES.

_Starch paste._ Corn starch 8 ozs., cold water ½ pint, boiling water 1 gallon.

Beat up the starch in the cold water until reduced to a creamy consistence, then pour the mixture into the boiling water and stir briskly until the white, semi-opaque mass, becomes transparent. Should it fail to do so, place it over the fire, and boil until the desired result is obtained, stirring constantly.

_Flour paste._ Wheat flour 4 lbs., cold water 2 quarts, alum 2 ozs., hot water ½ pint, boiling water 2 gallons.

Work the wheat flour into a batter free from lumps with the cold water. Dissolve the alum in the hot water. Then stir the batter into the boiling water, and if necessary, continue boiling until the paste thickens into a semi-transparent mucilage, after which stir in the alum solution. This makes a very fine paste for wall-paper.

_Strong adhesive paste._ Rye flour 2 lbs., cold water 1 quart, boiling water 3 quarts, pulverized rosin 1 oz.

Make the flour into a batter with the cold water, free from lumps, and pour into the boiling water. Boil, if necessary, and while hot stir in the pulverized rosin, a little at a time. This paste is very strong, and will fasten heavy wall-paper or thin leather. If too thick, thin with hot water. Never thin paste with cold water.

_Paste that will not sour._ Allow 4 parts by weight of glue to soften in 15 parts of cold water for some hours, and then heat moderately till the solution becomes quite clear; then add, while stirring, 65 parts of boiling water. In another vessel stir up 30 parts of starch paste with 20 parts of cold water, so that a thin, milky fluid without lumps is obtained. Into this pour the boiling glue solution, stirring constantly, and keep the whole at the boiling temperature. After cooling, add 5 to 10 drops of carbolic acid to the paste. Preserve the paste in closed bottles to prevent evaporation of the water. It will thus keep good for years.

_Venetian paste._ White or fish glue 4 ozs., cold water ½ pint, Venice turpentine 2 fluid ozs., rye flour 1 lb., cold water 1 pint, boiling water 2 quarts.

Soak the 4 ozs. of glue in the cold water for 4 hours. Dissolve over a water-bath, and while hot stir in the Venice turpentine. Make up the rye flour into a batter free from lumps with the pint of water, and pour the latter into the boiling water. Stir briskly, and finally add the glue solution. This makes a very strong paste, and it will adhere to a painted surface, owing to the Venice turpentine in its composition.

_Label paste._ A good paste for attaching labels to bottles may be made by soaking glue in strong vinegar, then heat to boiling and add flour. This is very adhesive, and will not decompose when kept in wide-mouthed bottles.

_Elastic or pliable paste._ Starch 4 ozs., white dextrine 2 ozs., cold water 10 fluid ozs., borax 1 oz., glycerine 3 fluid ozs., boiling water 2 quarts.

Beat the starch and dextrine into paste with the cold water. Dissolve the borax in the boiling water, then add the glycerine, and pour the starch and dextrine mixture into the borax solution. Stir until it becomes translucent. This paste will not crack, and, being very pliable, is suitable for paper, cloth, leather and other material where flexibility is required.

_Mucilage for labels._ Macerate 5 parts of good glue in 20 parts of water for 24 hours, and to the liquid add 9 parts of rock candy, and 3 parts of gum arabic. The mixture may be brushed upon paper while lukewarm. It keeps well, does not stick together and adheres firmly to bottles.

_Mucilage._ A strong aqueous solution of dextrine forms a most adhesive and cheap mucilage. Dilute alcohol is usually employed as the solvent where the mucilage is to be used for gumming envelopes, postage stamps, etc., and in order to facilitate the drying, acetic acid is added to increase the mobility of the fluid. The strong aqueous solution is more adhesive than that prepared with alcohol, for the reason that it contains a greater proportion of dextrine.

To prepare this add an excess of dextrine to boiling water, stir for a minute or two, allow to cool and settle, and strain the liquid through a cloth. The addition of a little powdered sugar increases the glossiness of the dried gum. The sugar should be dissolved in the water before the dextrine is added.

_According to another formula_, dextrine is mixed with hot water until a syrupy liquid is obtained. Then add a few drops of oil of cloves, and cool for use.

_Another formula is as follows_: Dextrine 120 parts, powdered alum 6, sugar 30, carbolic acid 1, water 300. Mix gradually the dextrine, alum and sugar with the water, boil to effect solution, and when cold, add the carbolic acid.

The solubility of dextrine may be enhanced by the addition of a calcium salt readily soluble in water, the resulting mixture dissolving with ease in cold water. Calcium nitrate has proved especially suitable for the purpose. By pouring 1 quart of water over a mixture of 18 ozs. of dextrine and 7 ozs. of calcium nitrate, a mass of great adhesive power is immediately obtained.

_Mucilage for postage stamps._ Dextrine 2 parts, acetic acid 1, water 5, alcohol 1. Mix all together.

_Caseine mucilage._ Take the curd of skim milk, wash it thoroughly, and dissolve it to saturation in a cold concentrated solution of borax.

_Tragacanth mucilage._ Powdered tragacanth 2 drachms, glycerine 12 drachms, water enough to make 20 ozs.

Put the tragacanth in a mortar with the glycerine, and then add the water. This will produce at once a mucilage of excellent quality.

_Adhesive paste._ Steep 4 ozs. of ordinary gelatine in 16 ozs. of water until it becomes soft, then dissolve it by the heat of a water bath, and while still hot pour into a mixture of 2 lbs. of good flour paste and 1 part of water. Heat the whole to boiling and when thickened remove from the fire. While cooling add 6 drachms of silicate of soda and stir the mixture with a wooden spatula. This preparation will keep good for an indefinite period, and is very adhesive. The addition of 2 drachms of oil of cloves is an improvement.

_Fluid pastes._ I. Gum arabic 10 lbs., sugar 2 lbs., nitric acid 1¾ ozs., water as required.

Dissolve the gum and sugar in the water, then add the acid and heat to the boiling-point. The resulting paste is liquid, does not mould, and dries to a transparent layer upon paper. It is especially suitable for flaps of envelopes, fine bookbinders’ work, etc.

II. Potato starch 10 lbs., water 5 quarts, nitric acid 8 ozs.

Mix the acid and water and pour it on the starch in an earthenware basin, put the latter in a warm place, and allow it to remain 24 hours, with occasional stirring. Then boil it until it becomes thickly-fluid and very transparent. If necessary it should be diluted with water and filtered through a cloth.

_Sugar and lime paste._ Dissolve 12 parts of white sugar in 36 of water. Heat the solution to the boiling-point and add 3 parts of slaked lime. Allow the liquid to stand in a covered vessel for several days, stirring frequently and, when settled, pour off the supernatant thick fluid from the excess of lime.

The paste thus obtained has all the properties of gum arabic solution and dries to a lustrous mass.

_Liquid sugar and lime paste._ Allow 3 parts of glue to swell in 10 to 15 parts of the foregoing paste. Heat the mixture to the boiling-point. The paste thus obtained does not congeal on cooling and possesses considerable adhesive power.

By reason of its caustic properties, due to the content of lime, this paste should not be used for pasting colored materials.

_Pastes for paper and fine fancy articles._ I. Dissolve, with the assistance of heat, 100 parts of gilder’s glue in 200 of water, and add a solution of 2 parts of bleached shellac in 10 of alcohol.

II. Dissolve, with the assistance of heat, 50 parts of dextrine in 50 of water, stir solutions 1 and 2 together, strain through a cloth into a flat prismatic mould, and allow it to congeal. For use, melt a piece of corresponding size, and dilute the liquid, if necessary, with water.

_Albumen paste._ This is a misnomer, as it contains no albumen. It is partly decayed gluten from flour, washed with water and then heated to 60° or 68° F., when it ferments and becomes partly fluid. It is then dried at 77° to 86° F., and is claimed to keep any length of time in a dry place. Dissolved in twice its weight of water it can be used as a paste for all purposes.

_Glycerine paste._ Dissolve 2 ozs. of gum arabic and 4 drachms of glycerine in 6 ozs. of boiling water. This is a good paste for office use.

_Paste for fixing labels on machines._ Make a paste of rye flour and glue and add to every pound thereof ½ oz. each of boiled linseed oil and turpentine. This paste resists damp and thus prevents printed labels from falling off metallic surfaces.

_Paste for mounting maps._ Stiff rye flour paste is best for this purpose.

_Paste for fastening paper on tin-foil._ Make a paste by dissolving rye flour in solution of caustic soda; dilute with water, stirring all the time. Add to this paste a few drops of Venice turpentine for each ½ lb. of flour.

_Paste for paper bags._ Add to 3 parts of starch 24 to 30 parts of cold water. Stir together to a homogeneous mass of about the thickness of syrup. Pour over this, stirring constantly, boiling water until the paste is of the required consistency. Stir until nearly cold. Take a portion of the paste and add to it 6 to 15 per cent. liquefied Venice turpentine; rub together until a kind of emulsion is formed, then mix the whole together and work thoroughly.

_Caseine mucilage for photographer’s use._ Separate the caseine from milk by means of a little tartaric acid, and treat the caseine while still warm with a solution of 6 parts of borax to 100 parts water, and warm gently while stirring which will cause the caseine to be dissolved. Of the borax solution enough should be used to leave only a little undissolved caseine behind.

_Paste for scrap-books._ Rice starch 1 oz., gelatine 3 drachms, water ½ pint.

Heat, stirring constantly, until the milky fluid becomes thick and gluey. When the paste is nearly thick put in a bottle closely corked. It is well to add a few drops of oil of cloves to each bottle.

_Paste for skins._ Pour enough boiling water over 1 lb. of rye flour in a basin to make a stiff paste, almost as stiff as ordinary dough for puddings. Stir and beat up well with a stick for three or four minutes, then cover up and let it stand for two days before using, when it will be much softer and stick better. Spread thinly and evenly on the back of the skin with a stiff brush or pad. It will stick firmly and not crack.

_Strong mucilage_ capable of fastening wood or china and glass together is made of 3½ ozs. of strong gum arabic solution, to which a solution of 30 grains of sulphate of aluminium dissolved in ⅔ oz. of water is added.

_Dextrine mucilage._ I. Dissolve with the assistance of heat 60 parts of borax in 420 parts of water, add 480 parts of pale yellow dextrine and 50 parts of glucose, and heat carefully, stirring constantly until solution is complete, replacing the water lost by evaporation. Strain through flannel.

The resulting mucilage is quite clear, has great adhesive power, and dries very quickly. In heating the mixture, great care should be exercised not to exceed a temperature of 194° F. and not to heat too long, otherwise the product readily becomes brown and brittle.

II. Dextrine 120 parts, powdered alum 6, sugar 30, carbolic acid 1, distilled water 300. Gradually mix the dextrine, alum and sugar with the water, effect solution by boiling and when the solution is cold, add the carbolic acid.

_Paste for joining leather to pasteboard._ Dissolve 50 parts of strong glue with a little water at a gentle heat, then add a small quantity of Venice turpentine, and next a thick paste made with 100 parts of starch in water. Apply quickly when cold.

_Another formula_ for a similar paste is as follows: Rye whisky 2 pints, water 1 pint, powdered starch 4¼ ozs., good glue 1¼ ozs., Venice turpentine 1¼ ozs. Mix the whisky and water together, then stir in the starch and make a thick paste. Separately dissolve the glue in an equal weight of water, and mix the Venice turpentine therein, mix thoroughly, and then compound this mixture with the thick paste by constantly stirring until all is well incorporated.

_Paste for attaching labels to polished nickel._ Dissolve 400 parts by weight of dextrine in 600 parts of water, and add 20 parts of glycerine and 10 parts of glucose. Heat the mixture to 194° F.

_Another formula_ is as follows: Mix 400 parts by weight of dextrine with water, and add 200 parts of water together with 20 parts of glucose and 10 parts of aluminium sulphate.

_Mucilage for attaching labels to tin._ I. Shellac 8 parts, borax 4 parts, water 60 parts. Boil until the shellac is dissolved.

II. To 2 parts of dammar varnish add 8 parts of tragacanth mucilage.

III. An excellent mucilage for the purpose consists of starch paste to which a small quantity of Venice turpentine has been added.

IV. Make a paste of corrosive sublimate 2½ parts, wheat flour 200, absinthe 100, tansy 50, water 3000. This mucilage is useful for vessels kept in a damp place.

_Mucilage for office use._ Gum arabic 100 parts, aluminium sulphate 6 parts, glycerine 10, dilute acetic acid 20, distilled water 140. Dissolve, in a wide-mouthed glass bottle, the gum arabic in cold distilled water, stirring frequently. Let the solution stand 2 or 3 days, then add the glycerine, later on the dilute acetic acid and finally the aluminium sulphate. Strain through a hair sieve, allow to clarify, and decant from the sediment.

_Glycerine paste for office use._ Dissolve 4 ozs. of gum arabic and 8 drachms of glycerine in 12 ozs. of boiling water.

_Clean and durable paste._ Dissolve 5 ozs. of gum arabic in 4 quarts of warm water, and thicken to a paste with wheat flour. Then add a solution of alum and sugar of lead, 3 ozs. of each in water. Heat the mixture and stir it until it is about to boil, and then cool it. If too thick, add gum solution.

_Banknote or mouth glue._ Dissolve by the aid of heat a fine quality of glue or gelatine with about a quarter or one-third of its weight of brown sugar, in as small a quantity of water as possible. Then when perfectly liquid cast the mixture into thin cakes on a flat surface very slightly oiled, and when cold cut up into pieces of convenient size. When required for use moisten one end. A piece of this glue kept in the desk will be found very convenient for many purposes.

_Paste for cardboard._ Dissolve 3½ ozs. of best French glue in 6½ ozs. of water by soaking and heating. Then add a solution of ½ drachm of shellac in 3½ drachms of alcohol and stir as long as the solution is warm. Next dissolve 2 drachms of dextrine in 1¾ ozs. of alcohol and 14 drachms of water, stir, and place the vessel in warm water until solution is complete. Mix this solution with that of the glue, and pour the whole into a suitable vessel, in which it may solidify. When wanted for use cut off a small piece and liquefy it by warming.

_Paste for attaching cloth or leather to table tops._ Wheat flour 1 lb., powdered rosin 2 tablespoonfuls, powdered alum 1 tablespoonful. Heat and stir to a stiff consistency.

_Caseine mucilage._ Separate the caseine from milk with a little tartaric acid, and treat the caseine while still warm with a solution of 6 parts borax to 100 parts water and warm gently while stirring, which will cause the caseine to be dissolved. Of the borax solution enough should be used to leave only a little undissolved caseine behind.

_Very adhesive paste which may be used for wood and parchment._ Gum arabic 60 parts, fine wheat starch 45, sugar 15. Dissolve the gum in as much water as is required for boiling the quantity of paste to be made. Then add the starch and sugar and boil it in a vessel suspended in boiling water until the mixture is clear and has the consistency of liquid tar. Keep in a well-closed vessel protected from mould by the addition of a few drops of oil of cloves.

_Paste for pads._ Glue 4 parts by weight, glycerine 2, linseed oil ½, sugar 4, aniline dye sufficient to color. Soften the glue by soaking in cold water, then dissolve together with the sugar in the glycerine by the aid of heat over the water-bath, then add the dye and stir in the oil. Use the paste hot.

_Paste for fastening paper on tin-foil._ Make a paste by dissolving rye flour in a solution of caustic soda; dilute with water, stirring constantly. Add to this paste a few drops of Venice turpentine for each ½ lb. flour used. This paste adheres to all kinds of metal, tin-foil, glass, etc.

_Paste for attaching labels to glass, porcelain, and metal._ Gum arabic 15 parts, pulverized tragacanth 7½, glycerin 45, thymol 0.3, alcohol 3¾, water 120. Dissolve the gum arabic in 15 parts of water and triturate the tragacanth with 30 parts of water. Mix the two fluids and strain. Then add the glycerine and finally the thymol dissolved in the alcohol.

_Preparation of arabol-gum._ Mix intimately 44 lbs. of wheat starch with 176 lbs. of water. Bring the mass into a water-bath, mix it with a solution of 4.4 lbs. of oxalic acid in 44 lbs. of water and heat for four hours at 194° F., stirring frequently. The conversion of the starch is as a rule effected during this time, but should such not be the case, continue heating, constantly replacing the evaporated water, until the mass is clear and liquid. While still hot, neutralize the mass with marble dust, allow to settle, filter, and evaporate the clear solution in a water-bath to a solid gum containing about 15 per cent. of water.

_Preparation of an adhesive substance from desaccharized beet-root slices_ (German patent 96316 f. G. Eichelbaum). The insoluble metarabin contained in the slices is converted into soluble arabin by treating the slices under pressure with hot aqueous sulphurous acid or with aqueous solutions of the bisulphites of the alkalies or alkaline earths.

According to a later patent (German patent 121422 f. Fabrik Bettenhausen Marquart and Schulz), the insoluble metarabin is converted into soluble arabin by heating the desaccharized beet-root slices with phosphoric acid and water. According to a supplement to this patent (122048), conversion is effected by heating the slices with aqueous solutions of organic acids and phenols, or the acid salts of oxalic, tartaric or phosphoric acids.

INDEX.

Acid calcium phosphate, 120

—— —— —— crystallization of, 125, 126

—— —— —— formation of, 121-124

—— sodium sulphate, use of, in drying glue, 72, 73

Acidity, determination of, in glue, 205, 206

Acids, dilute, effect of, on glue solution, 7

Adamson, Wm., method of, for removing hydrocarbons from substances
which have been treated therewith, 84-86

—— —— method of, for treating substances with hydro carbon vapor for
the purpose of extracting oils, fats, etc., 79-82

—— —— method of, for treating substances with liquid hydrocarbons for
the purpose of extracting oils, fats, etc., 82-84

—— —— and Simonis, Chas. F. A., apparatus of, for extracting bones
with benzine, 76-79

Adhesive paste, 264

Adulterations of glue, determination of, 214, 215

Agar-Agar, 12, 201, 202

Air-bladders, 16, 41

—— bleaching glue in the, 141

—— drying the cakes of glue in the, 64

Alabaster, 244

—— cement for, 242

Albumen paste, 265, 266

—— —— use of, for clarifying glue liquor, 54

Alum cement, 228

—— —— effect of, on glue solution, 7

—— —— use of, for clarifying glue liquor, 54

—— —— —— —— preserving paste, 257

Amber, resinous cement for, 229

American cement for jewelers, 252

American glue, analysis of, 207

Ammonium sulphate, use of, in drying glue, 72, 73

Animal charcoal, bleaching glue with, 142

—— —— bones for the manufacture of, 107

—— —— carbonization of bones for, 108-112

—— —— decolorizing glue liquor with, 55

—— —— manufacture of, 112, 113

—— —— yield of, 113

—— skin, constitution of, 17, 18

Antiseptics for the preservation of glue-stock, 30

Arabin, conversion of metarabin into, 271

Arabol-gum, preparation of, 270

Ash, burning bones to, 117-119

Bacteriology, use of gelatine in, 194

Banknote glue, 269

Barium chloride, effect of, on glue solution, 7

Basic calcium phosphate, 120

Beet-root slices, desaccharized, preparation of an adhesive
substance from, 270, 271

Belgian retort-furnace for the carbonization of bones, 109-112

Benzine, extracting fat from bones with, 76-92

Billiard balls, compound for, 155, 156

Bleaching glue, methods of, 141-145

—— —— stock, 55, 56

Blood, fresh, use of, for clarifying glue liquor, 54

Blumenthal’s method of preparing dextrine, 260, 261

Boiler for glue boiling, 44

Boiling bones, 74, 75

—— —— duration of, 45

—— —— or cooking glue, 44-52

Bone ash, composition of, 119

—— —— conversion of, into a coarse powder, 119

—— —— decomposition of, by sulphuric acid, 119-125

—— —— kiln for, 117-119

—— —— preparation of, 117-119

—— —— yield of, 119

—— cartilage, composition of, 32

—— cement for, 230

—— crusher, 36

—— gelatine, 170-180

—— —— modern process of preparing, 179, 180

—— -glue, manufacture of, 74-116

—— meal, glue and fat, simultaneous utilization of bones for, 104-113

—— -mill, Crosskill, 36

—— raw materials, 16

—— size, 159, 160

Bones, absorption of sulphurous acid by, 92

—— Adamson and Simonis’ apparatus for extracting, 76-79

—— and cartilages, 31-39

—— apparatus for extracting the fat from, with benzine, 76-94

—— Belgian retort-furnace for the carbonization of, 109-112

—— boiling of, 74, 75

—— burning of, to ash, 117-119

—— buying of, 32

—— carbonization of, 108-112

—— constitution of, 32

—— crushed, sorting of, 36, 37

—— crushing or grinding of, 33-36

—— extraction of, 76-94

—— —— —— phosphates from, 115

—— fatty matters in, 32

—— for the manufacture of animal charcoal, 107

—— honey-combed, 39

—— Leuner’s apparatus for extracting, 90-92

—— lime bath for, 37

—— products obtained in the distillation of, 112

—— Seltsam’s apparatus for extracting, 84-86

—— —— apparatus for extracting, improved by Th. Richter, 88-90

—— simultaneous utilization of, for fat, bone-meal and glue, 104-113

—— —— utilization of, for fat, glue and calcium phosphate, 113-116

—— sorting of, 32, 33, 104, 105

—— sulphurous acid for extracting, 92-94

—— treatment of, with high pressure steam, 105-107

—— utilization of the liquor obtained in the treatment of, with
hydrochloric acid, 125-127

—— value of, 32

—— waste of, from the preparation of tinned provisions, 19

Bookbinder’s glue, 12

—— size, 160

Book isinglass, 197

Boric acid, preservation of glue-stock with, 30

Bottles, cracked, cement for, 240, 241

Bouillon tablets, 12

Brazilian isinglass, 199, 200

Briers, D. J., process for the preparation of bone gelatine
employed by, 171-179

Brochette, 43

Brushmaker’s cement, 251

Bullock’s feet, 18

—— hide, waste of, 18

—— leather, 30

Burning bones to ash, 117-119

Cakes, cutting glue into, 57-64

—— drying the, 64-73

—— machines for cutting the jelly into, 60-64

—— shape of, 57, 58

—— tools for cutting the jelly into, 59

Calcium chloride, 116

—— metaphosphate, 120, 127

—— phosphate, 115

—— —— fat and glue, simultaneous utilization of bones for, 113-116

Calf leather, 30

—— skin waste, 18

Calves’ feet, 30

—— heads, 18, 30

Carbolic acid, preservation of glue-stock with, 29

—— —— use of, for preserving paste, 257, 258

Carbon disulphide, use of, for extracting bones, 76

Cardboard, paste for, 269

Cartilage, 1

—— conversion of, into glue, 94-104

—— drying of, 114

—— preservation of, 114

—— treatment of, with high-pressure steam, 98

—— yield of glue from, 115

Cartilages and bones, 31-39

Caseine cement which can be kept for a long time, 239

—— cements, 237-240

—— mucilage, 264

—— —— for photographer’s use, 266

—— ordinary technical, preparation of, 238, 239

—— pure, preparation of, 237, 238

Castings, cement for filling in defects in, 246

Cattle, pieces of hide from the lower parts of the limbs of, 30

Cayenne isinglass, 199, 200

Cellular tissue, 1

Celluloid, cement for, 252

Cement resisting acids, 248

—— —— —— very high temperatures, 248

Cements, caseine, 237-240

—— chemical nature of, 219

—— classification of, 218-223

—— for chemical apparatus, 247-249

—— —— —— —— special purposes, 249-252

—— glue and starch, 222, 223

—— glycerine, 242

—— gypsum, 244, 245

—— how to use, 252-255

—— iron, 245-247

—— lime, 223, 243, 244

—— oil, 219, 220, 224-229

—— pastes and mucilages, preparation of, 224-271

—— resinous, 220, 221, 229-233

—— resisting high temperatures, 246

—— rubber and gutta-percha, 222, 233-237

—— water glass, 240-242

Chalk, 243

Charcoal, animal, bleaching glue with, 142

—— —— bones for the manufacture of, 107

—— —— carbonization of bones for, 108-112

—— —— manufacture of, 112, 113

—— —— yield of, 113

—— mixing calcium phosphate with, 124

Chemical apparatus, cements for, 247-249

Chinese isinglass, 201, 202

Chlorbarium, soaking hides in, 20

Chloride of lime, bleaching glue-stock with, 55

Chlorine, bleaching glue with, 141

Chondrin, chemical composition of, 5, 6

—— conversion of, into glutin, 6

—— formation of, 3

—— properties of, 5

—— pure, preparation of, 5

Chrome glue, 153

Clarifying glue liquor, 52-56

—— —— —— apparatus for, 98

—— —— —— vats, 53

Clay crucibles, cracked, cement for, 243

Clearness of glue, definition of, 53

Clock faces, white enameled, cement for, 230

Cloth, cement for, 252

—— paste for attaching, to table tops, 269

Colle franche, 43

Cologne glue, 148

Color mixtures, glue for, 11

—— of glue, definition of, 53

Colored gelatine, 181, 182

Coloring glue, 156

—— matters for gelatine, 181, 182

—— substances, removal of, from glue liquor, 54-56

Combs, hard rubber, cement for, 236

Common salt, effect of, on glue solution, 7

Constitution of glue, 3-6

Conversion of cartilage into glue, 94-104

Cooking, duration of, 44

—— or boiling glue, 44-52

Cooling boxes, 100

—— glue liquor, 100

Corium, 1, 17

Court-plaster, 12, 184, 185

Cox, J. and G., process for the manufacture of gelatine patented
by, 166, 167

Crockery, cement for, 236, 237

Crosskill bone mill, 36

Crucibles, cement for, 243

Crude glue, definition of, 3

—— —— preparation of, 43

Culinary purposes, glue for, 12-14

Dark steam glue, 152

Devoulx, cutting apparatus invented by, 62-64

Dextrine mucilage, 267

—— —— preparation of, 259-261

Diamond cement, 229

Distillation of crude phosphorus, 133-135

—— —— phosphorus, 127-132

Drying, acceleration of, 72, 73

—— cakes of glue, 64-73

—— galleries, 68-71

—— house, modern, 71, 72

Drying room, 65

—— —— regulating the temperature of the, 67, 68

East India isinglass, 199

Elastic cement, 234

—— gutta-percha cement, 236

—— masses, glue for, 14

—— paste, 263

Electric furnace for the manufacture of phosphorus, 138-140

Electrical apparatus, cement for, 251, 252

Emery paper, use of glue in the manufacture of, 12

Epidermis, 17

Epsom salt, behavior of glue solution towards, 7

—— —— use of, in drying glue, 72, 73

Evaporating pan, open, 98-100

—— pans, 124

Evaporators, spiral, 100, 101

Extraction of bones, 76-94

Fabrics, water-proofing of, 161-163

Fancy articles, fine, paste for, 265

Fans, gelatine veneers for, 15

Fat, bone meal and glue, simultaneous utilization of bones
for, 104-113

—— extraction of, with benzine, 76-92

—— —— —— hydrocarbon vapors, 79-82

—— —— —— liquid hydrocarbons, 82-84

—— glue and calcium phosphate, simultaneous utilization of
bones for, 113-116

Fertilizers, utilization of liquors for, 116

Fining, gelatine for, 182

Fish bladders, 1

—— —— glue, 202-204

—— —— —— points to be observed in the manufacture of, 41, 42

—— —— —— raw materials for, 41, 42

—— scales, 16, 42

—— —— preparation of glue from, 203

Fleck’s kiln for burning bones, 118, 119

—— process of accelerating the drying of glue, 72, 73

Flour paste, 256-258, 261, 262

Fluid pastes, 264, 265

Foils, gelatine, 15, 185, 186

Formaldehyde, preservation of glue-stock with, 29, 30

Forming or moulding the glue, 56-64

Formo-gelatine, 193, 194

French mastic, 227

—— putty, 225

Friedberg’s apparatus for clarifying glue liquor, 98

—- —— —— conversion of cartilage into glue, 94-97

Furnace, electric, for the manufacture of phosphorus, 138-140

Galley furnace, 128, 129

Galvanized iron-wire netting, 66

Gelatin, pure, preparation of, 4

Gelatine and glycerine, compound of, 12

—— and products prepared from it, manufacture of, 165-195

—— artificial silk from, 195

—— capsules, 14, 184

—— colored, 181, 182

—— constitution of, 165

—— Cox’s process for the manufacture of, 166, 167

—— foils, 15, 185, 186

—— for fining purposes, 182

—— for photographic printing and photographic purposes in
general, 183, 184

—— Jullion and Pirie’s process for the preparation of, 38

—— Nelson’s process for the manufacture of, 166

—— preparation of, from ordinary glue, 182, 183

—— substitute for, 203, 204

—— Swinborne’s improved patented process for the preparation of, 167

—— testing of, 205-217

—— veneers, 15, 186-193

—— yielding tissues, 1

German isinglass, 200

Gilder’s glue, 150

Glass, cement for, 230, 233, 239, 241, 243, 245

—— —— for attaching metal letters to, 249

—— —— —— —— —— to metal, 251

—— mastic cement for, 232

—— oil cement for, 228

—— paper, use of glue in the manufacture of, 12

—— paste for attaching labels to, 270

—— plates, gelatinizing liquors upon, 58, 59

—— upon glass, cement for, 230

—— —— metal, cement for, 230

Glauber’s salt, use of, in drying glue, 72, 73

Gloves, waste from the manufacture of, 43

Glue, acceleration of the drying of, 72, 73

—— addition of mineral substances to, 149

—— American, analysis of, 207

—— and starch cements, 222, 223

—— as a binding agent, 11

—— —— —— joining medium, 10, 11

—— banknote or mouth, 269

—— boiler, Terne’s, 51, 52

—— boiling, boiler for, 44

—— —— convenient apparatus for, 46, 47

—— —— in open jacketed pans, 49, 50

—— —— or cooking, 44-52

—— —— with steam, boiler for, 47-49

—— chemical composition of, 8

—— chrome, 153

—— clearness of, 53

—— Cologne, 148

—— color of, 53

—— coloring of, 156

—— constitution of, 3-6

—— conversion of cartilage into, 94-104

—— cooking, process of, 51

—— crude, definition of, 3

—— —— preparation of, 43

—— cutting the, into cakes, 57-64

—— deduction of the quality of, from indirect properties, 207, 208

—— determination of acidity in, 205, 206

—— —— of adulterations of, 214, 215

—— —— of glutin in, 206, 207

—— —— of moisture in, 205

—— different varieties of, and their preparation, 146-164

—— drying cakes of, 64-73

—— —— room for, 65

—— factory, location of a, 21

—— —— manner of carrying on the work in a, 26-30

—— fat and bone-meal, simultaneous utilization of bones for, 104-113

—— for attaching leather to metal, 153

—— —— culinary and medicinal purposes, 12-14

—— —— elastic masses and as a partial substitute for rubber, 14

—— —— fancy articles, 14, 15

Glue joints in leather driving belts, 163

—— —— —— leather, paper, etc., 153, 154

—— —— —— parchment paper in making sausage skins, 154, 155

—— formation of, 6

—— from various materials, external characteristics of, 6, 7

—— gilder’s, 150

—— holding power of, 147, 148

—— how to make and use, 147

—— in animal organism, 2

—— —— sizing, 12

—— inferior qualities of, 12

—— joiner’s, 146

—— Kissling’s results in testing, 215

—— liquid, 151, 152

—— liquor, apparatus for clarifying, 98

—— —— clarifying the, 52-56

—— —— concentration of, 50

—— —— cooling of, 100

—— —— decolorizing of, with animal charcoal, 55

—— —— instrument for measuring the percentage of glue in, 103

—— measuring the percentage of, in glue liquor, 103, 104

—— methods of bleaching, 141-145

—— moulding or forming of, 56-64

—— nature of, 1-9

—— nets for drying, 66, 67

—— ordinary, preparation of gelatine from, 182, 183

—— parchment, 150

—— Paris, 150, 151

—— patent, 150

—— practical testing of, 215-217

—— principal substances employed as raw material for, 16

—— properties of, and its behavior towards other substances, 6-9

—— raw materials and their preparation for the manufacture of, 16-38

—— results obtained by comparative experiments in testing, 209, 210

—— Russian, 149, 150

—— size, 150

—— solution, behavior of, towards salts, 7, 8

—— steam, 152

—— stock, bleaching of, 55, 56

—— —— dry-limed, 19

—— —— dry, uncured, or salted, 19

—— —— green-limed, 19