Chapter III: Front Matter (3)

«Knockenplombe.»—If 1 part of thymol be mixed with 2 parts of iodoform we obtain a substance that retains its fluidity down to 72° C. (161.6° F.). If the temperature be carried down to 60° C. (140° F.) it suddenly becomes solid and hard. If, in its liquid condition, this substance be mixed intimately with an equal quantity of calcined bone, it forms a cement that can be molded or kneaded into any shape, that, at the temperature of the body (98° F.), becomes as hard as stone, a fact that suggests many useful purposes to which the mixture may be put.

«Cement for General Use.»—Take gum arabic, 100 parts, by weight; starch, 75 {32} parts by weight; white sugar, 21 parts, by weight; camphor, 4 parts, by weight. Dissolve the gum arabic in a little water. On the other hand, dissolve the starch also in some water. When this is done add the sugar and the camphor and put in a water bath. Boil until a paste is formed, which must be rather thin, because it will thicken on cooling.

«Strong Cement.»—Pour over well-washed and cleaned casein 12 1/2 parts of boiled linseed oil and the same amount of castor oil, put on the fire and bring to a boil; stir actively and add a small amount of a saturated aqueous solution of alum; remove from the fire and set aside. After standing a while a milky-looking fluid will separate at the bottom and rise to the top. This should be poured off and to the residue add 120 parts of rock-candy syrup and 6 parts of dextrine.

«Syndeticon.»—I.—Slake 100 parts of burnt lime with 50 parts of water, pour off the supernatant water; next, dissolve 60 parts of lump sugar in 160 parts of water, add to the solution 15 parts of the slaked lime, heat to 70° or 80° C. (158° to 176° F.), and set aside, shaking frequently. Finally dissolve 50 to 60 parts of genuine Cologne glue in 250 parts of the clear solution.

II.—A solution of 10 parts gum arabic and 30 parts of sugar in 100 parts of soda water glass.

III.—A hot solution of 50 parts of Cologne glue in 60 parts of a 20-per-cent aqueous calcium-chloride solution.

IV.—A solution of 50 parts of Cologne glue in 60 parts of acetic acid.

V.—Soak isinglass (fish bladder) in acetic acid of 70 per cent until it swells up, then rub it up, adding a little water during the process.

«“Shio Liao.”»—Under this name the Chinese manufacture an excellent cement which takes the place of glue, and with which gypsum, marble, porcelain, stone, and stoneware can be cemented. It consists of the following parts (by weight): Slaked powdered lime, 54 parts; powdered alum, 6 parts; and fresh, well-strained blood, 40 parts. These materials are stirred thoroughly until an intimately bound mass of the consistency of a more or less stiff salve is obtained. In paste form this mass is used as cement; in a liquid state it is employed for painting all sorts of articles which are to be rendered waterproof and durable. Cardboard covers, which are coated with it two or three times, become as hard as wood. The Chinese paint their houses with “shio liao” and glaze their barrels with it, in which they transport oil and other greasy substances.

«LUTES.»

Lutes always consist of a menstruum and dissolved or suspended solids, and they must not be attacked by the gases and liquids coming in contact with them. In some cases the constituents of the lute react to form a more strongly adhering mass.

The conditions of application are, in brief:

(_a_) Heating the composition to make it plastic until firmly fixed in place.

(_b_) Heating the surfaces.

(_c_) Applying the lute with water or a volatile solvent, which is allowed to volatilize.

(_d_) Moistening the surfaces with water, oil, etc. (the menstruum of the lute itself).

(_e_) Applying the lute in workable condition and the setting taking place by chemical reactions.

(_f_) Setting by hydration.

(_g_) Setting by oxidation.

These principles will be found to cover nearly all cases.

Joints should not be ill-fitting, depending upon the lute to do what the pipes or other parts of the apparatus should do. In most cases one part of the fitting should overlap the other, so as to make a small amount of the lute effective and to keep the parts of the apparatus rigid, as a luted joint is not supposed to be a particularly strong one, but rather one quickly applied, effective while in place and easily removed.

Very moderate amounts of the lute should be used, as large amounts are likely to develop cracks, be rubbed off, etc.

A classification may be given as follows:

(1) Plaster of Paris.

(2) Hydraulic cement.

(3) Clay.

(4) Lime.

(5) Asphalt and pitch.

(6) Rosin.

(7) Rubber.

(8) Linseed oil.

(9) Casein and albumen.

(10) Silicates of soda and oxychloride cements.

(11) Flour and starch.

(12) Miscellaneous, including core compounds.

I. Plaster of Paris is, of course, often used alone as a paste; which quickly {33} solidifies, for gas and wood distillation retorts, etc., and similar places where quickness of setting is requisite. It is more often, however, used with some fibrous material to give it greater strength. Asbestos is the most commonly used material of these, as it will stand a high temperature. When that is not so important, straw, plush trimmings, hair, etc., are used as binders, while broken stone, glass, and various mineral substances are used as fillers, but they do not add anything to the strength. These lutes seem to be particularly suitable for oil vapors and hydrocarbon gases.

Formulas:

(1) Plaster and water. (2) Plaster (wet) and asbestos. (3) Plaster (wet) and straw. (4) Plaster (wet) and plush trimmings. (5) Plaster (wet) and hair. (6) Plaster (wet) and broken stone, etc.

II. Hydraulic Cement.—Cement is used either alone or with sand, asbestos, etc. These lutes are suitable for nitric acid. When used with substances such as rosin or sulphur, cement is probably employed because it is in such a fine state of division and used as a filler and not because of any powers of setting by hydration.

Formulas:

(1) Cement—neat. (2) Cement and asbestos. (3) Cement and sand.

III. Clay.—This most frequently enters into the composition of lutes as a filler, but even then the very finely divided condition of certain grades renders it valuable, as it gives body to a liquid, such as linseed oil, which, unless stiffened, would be pervious to a gas, the clay in all cases being neutral. Thus, for luting pipes carrying chlorine, a stiff paste of clay and molasses has been suggested by Theo. Köller in _Die Surrogate_, but it soon gives way.

Formulas:

(1) Clay and linseed oil. (2) Same, using fire clay. (3) Clay and molasses.

(1) Is suitable for steam, etc.; (2) for chlorine, and (3) for oil vapors.

IV. Lime is used in the old lute known as putty, which consists of caustic lime and linseed oil. Frequently the lime is replaced by chalk and china clay, but the lime should be, in part at least, caustic, so as to form a certain amount of lime soap. Lime is also used in silicate and casein compositions, which are very strong and useful, but will be described elsewhere.

Formulas:

(1) Lime and boiled oil to stiff mass. (2) Clay, etc., boiled oil to stiff mass.

V. Asphalt and Pitch.—These substances are used in lutes somewhat interchangeably. As a rule, pitch makes the stronger lutes. Tar is sometimes used, but, because of the light oils and, frequently, water contained, it is not so good as either of the others.

Asphalt dissolved in benzol is very useful for uniting glass for photographic, microscopical, and other uses. Also for coating wood, concrete, etc., where the melted asphalt would be too thick to cover well. Benzol is the cheapest solvent that is satisfactory for this purpose, as the only one that is cheaper would be a petroleum naphtha, which does not dissolve all the constituents of the asphalt. For waterproofing wood, brick, concrete, etc., melted asphalt alone is much used, but when a little paraffine is added, it improves its waterproofing qualities, and in particular cases boiled oil is also added to advantage.

Formulas:

1. Refined lake asphalt.

2. Asphalt 4 parts
Paraffine 1 part

3. Asphalt 10 parts
Paraffine 2 parts
Boiled oil 1 part

Any of these may be thinned with hot benzol or toluol. Toluol is less volatile than benzol and about as cheap, if not cheaper, the straw-colored grades being about 24 cents per gallon.

Examples of so-called “stone cement” are:

4. Pitch 8 parts
Rosin 6 parts
Wax 1 part
Plaster 1/4 to 1/2 part

5. Pitch 8 parts
Rosin 7 parts
Sulphur 2 parts
Stone powder 1 part

These compositions are used to unite slate slabs and stoneware for domestic, engineering, and chemical purposes. Various rosin and pitch mixtures are used for these purposes, and the proportions of these two ingredients are determined by the consistency desired. Sulphur and stone powder are added to prevent the formation of cracks, sulphur acting chemically and stone powder mechanically. {34} Where the lute would come in contact with acid or vapors of the same, limestone should not be the powder used, otherwise it is about the best. Wax is a useful ingredient to keep the composition from getting brittle with age.

A class of lutes under this general grouping that are much used are so-called “marine glues” (q. v.). They must be tough and elastic. When used for calking on a vessel they must expand and contract with the temperature and not crack or come loose.

Formulas:

6. Pitch 3 parts
Shellac 2 parts
Pure crude rubber 1 part

7. Pitch 1 part
Shellac 1 part
Rubber substitute 1 part

These are used by melting over a burner.

VI. Rosin, Shellac, and Wax.—A strong cement, used as a stone cement, is:

1. Rosin 8 parts
Wax 1 part
Turpentine 1 part

It has little or no body, and is used in thin layers.

For nitric and hydrochloric acid vapors:

2. Rosin 1 part
Sulphur 1 part
Fire clay 2 parts

Sulphur gives great hardness and permanency to rosin lutes, but this composition is somewhat brittle.

Good waterproof lutes of this class are:

3. Rosin 1 part
Wax 1 part
Powdered stone 2 parts

4. Shellac 5 parts
Wax 1 part
Turpentine 1 part
Chalk, etc. 8 to 10 parts

For a soft air-tight paste for ground-glass surfaces:

5. Wax 1 part
Vaseline 1 part

6. A strong cement, without body, for metals (other than copper or alloys of same), porcelain, and glass is made by letting 1 part of finely powdered shellac stand with 10 parts of ammonia water until solution is effected.

VII. Rubber.—Because of its toughness, elasticity, and resistance to alterative influences, rubber is a very useful constituent in lutes, but its price makes its use very limited.

Leather Cement.

1. Asphalt 1 part
Rosin 1 part
Gutta percha 4 parts
Carbon disulphide 20 parts

To stand acid vapors:

2. Rubber 1 part
Linseed oil 3 parts
Fire clay 3 parts

3. Plain Rubber Cement.—Cut the crude rubber in small pieces and then add the solvent. Carbon disulphide is the best, benzol good and much cheaper, but gasoline is probably most extensively used because of its cheapness.

4. To make corks and wood impervious to steam and water, soak them in a rubber solution as above; if it is desired to protect them from oil vapors, use glue composition. (See Section IX.)

VIII. Linseed Oil.—This is one of the most generally useful substances we have for luting purposes, if absorbed by a porous substance that is inert.

Formulas: 1. China clay of general utility for aqueous vapors.

Linseed oil of general utility for aqueous vapors.

2. Lime forming the well-known putty.

Linseed oil forming the well-known putty.

3. Red or white lead and linseed oil.

These mixtures become very strong when set and are best diluted with powdered glass, clay, or graphite. There are almost an endless number of lutes using metallic oxides and linseed oil. A very good one, not getting as hard as those containing lead, is:

4. Oxide of iron and linseed oil.

IX. Casein, Albumen, and Glue.—These, if properly made, become very tough and tenacious; they stand moderate heat and oil vapors, but not acid vapors.

1. Finely powdered casein 12 parts
Slaked lime (fresh) 50 parts
Fine sand 50 parts
Water to thick mush.

A very strong cement which stands moderate heat is the following:

2. Casein in very fine powder 1 part
Rubbed up with silicate of soda 3 parts

A strong lute for general purposes, {35} which must be used promptly when made:

3. White of egg made into a paste with slaked lime.

A composition for soaking corks, wood, packing, etc., to render them impervious to oil vapors, is:

Gelatine or good glue 2 parts Glycerine 1/2 to 1 part Water 6 parts Oil of wintergreen, etc., to keep from spoiling.

X. Silicate of Oxychloride Cements.—For oil vapors, standing the highest heat:

1. A stiff paste of silicate of soda and asbestos.

Gaskets for superheated steam, retorts, furnaces, etc.:

2. Silicate of soda and powdered glass; dry the mixture and heat.

Not so strong, however, as the following:

3. Silicate of soda 50 parts
Asbestos 15 parts
Slaked lime 10 parts

Metal Cement:

4. Silicate of soda 1 part
Oxides of metal, such
as zinc oxide; litharge,
iron oxide,
singly or mixed 1 part

Very hard and extra strong compositions:

5. Zinc oxide 2 parts
Zinc chloride 1 part
Water to make a paste.

6. Magnesium oxide 2 parts
Magnesium chloride 1 part
Water to make a paste.

XI. Flour and Starch Compositions.—

1. The well-known flaxseed poultice sets very tough, but does not stand water or condensed steam.

2. Flour and molasses, made by making a stiff composition of the two. This is an excellent lute to have at hand at all times for emergency use, etc.

3. Stiff paste of flour and strong zinc-chloride solution forms a more impervious lute, and is more permanent as a cement. This is good for most purposes, at ordinary temperature, where it would not be in contact with nitric-acid vapors or condensing steam.

4. A mixture of dextrine and fine sand makes a good composition, mainly used as core compound.

XII. Miscellaneous.—

1. Litharge.
Glycerine.

Mixed to form a stiff paste, sets and becomes very hard and strong, and is very useful for inserting glass tubes, etc., in iron or brass.

For a high heat:

2. Alumina 1 part
Sand 4 parts
Slaked lime 1 part
Borax 1/2 part
Water sufficient.

A class of mixtures that can be classified only according to their intended use are core compounds.

I.—Dextrine, about 1 part
Sand, about 10 parts
With enough water to form a paste.

II.—Powdered anthracite coal, with molasses to form a stiff paste.

III.—Rosin, partly saponified by soda lye 1 part
Flour 2 parts
Sand (with sufficient water) 4 parts

(These proportions are approximate and the amount of sand can be increased for some purposes.)

IV.—Glue, powdered 1 part
Flour 4 parts
Sand (with sufficient water) 6 parts

For some purposes the following mixture is used. It does not seem to be a gasket or a core compound:

V.—Oats (or wheat) ground 25 parts
Glue, powdered 6 parts
Sal ammoniac 1 part

_Paper read by Samuel S. Sadtler before the Franklin Institute._

«PASTES:»

«Dextrine Pastes.»—

I.—Borax, powdered 60 parts
Dextrine, light yellow 480 parts
Glucose 50 parts
Water 420 parts

By the aid of heat, dissolve the borax in the water and add the dextrine and glucose. Continue the heat, but do not let the mixture boil, and stir constantly until a homogeneous solution is obtained, from time to time renewing the water lost by evaporation with hot water. Finally, bring up to full weight (1,000 parts) by the addition of hot water, then strain through flannel. Prepared in this manner the paste remains bright and clear for a long time. It has extraordinary adhesive properties and dries very rapidly. If care is not taken to keep the cooking temperature below the boiling point of water, the paste is apt to become brown and to be very brittle on drying. {36}

II.—Dissolve in hot water a sufficient quantity of dextrine to bring it to the consistency of honey. This forms a strong adhesive paste that will keep a long time unchanged, if the water is not allowed to evaporate. Sheets of paper may be prepared for extempore labels by coating one side with the paste and allowing it to dry; by slightly wetting the gummed side, the label will adhere to glass. This paste is very useful in the office or laboratory.

III.—Pour over 1,000 parts of dextrine 450 parts of soft water and stir the mixture for 10 minutes. After the dextrine has absorbed the water, put the mixture over the fire, or, preferably, on a water bath, and heat, with lively stirring for 5 minutes, or until it forms a light milk-like liquid, on the surface of which little bubbles begin to form and the liquid is apparently beginning to boil. Do not allow it to come to a boil. Remove from the fire and set in a bucket of cold water to cool off. When cold add to every 1,000 parts of the solution 51 parts glycerine and as much salicylic acid as will stand on the tip of a knife blade. If the solution is too thick, thin it with water that has been boiled and cooled off again. Do not add any more glycerine or the solution will never set.

IV.—Soften 175 parts of thick dextrine with cold water and 250 parts of boiling water added. Boil for 5 minutes and then add 30 parts of dilute acetic acid, 30 parts glycerine, and a drop or two of clove oil.

V.—Powder coarsely 400 parts dextrine and dissolve in 600 parts of water. Add 20 parts glycerine and 10 parts glucose and heat to 90° C. (195° F.).

VI.—Stir 400 parts of dextrine with water and thin the mass with 200 parts more water, 20 parts glucose, and 10 parts aluminum sulphate. Heat the whole to 90° C. (195° F.) in the water bath until the whole mass becomes clear and liquid.

VII.—Warm 2 parts of dextrine, 5 parts of water, 1 part of acetic acid, 1 part of alcohol together, with occasional stirring until a complete solution is attained.

VIII.—Dissolve by the aid of heat 100 parts of builders’ glue in 200 parts of water add 2 parts of bleached shellac dissolved previously in 50 parts of alcohol. Dissolve by the aid of heat 50 parts of dextrine in 50 parts of water, and mix the two solutions by stirring the second slowly into the first. Strain the mixture through a cloth into a shallow dish and let it harden. When needed cut off a piece of sufficient size and warm until it becomes liquid and if necessary or advisable thin with water.

IX.—Stir up 10 parts of dextrine with sufficient water to make a thick broth. Then, over a light fire, heat and add 25 parts of sodium water glass.

X.—Dissolve 5 parts of dextrine in water and add 1 part of alum.

«Fastening Cork to Metal.»—In fastening cork to iron and brass, even when these are lacquered, a good sealing wax containing shellac will be found to serve the purpose nicely. Wax prepared with rosin is not suitable. The cork surface is painted with the melted sealing wax. The surface of the metal is heated with a spirit flame entirely free from soot, until the sealing wax melts when pressed upon the metallic surface. The wax is held in the flame until it burns, and it is then applied to the hot surface of the metal. The cork surface painted with sealing wax is now held in the flame, and as soon as the wax begins to melt the cork is pressed firmly on the metallic surface bearing the wax.

«To Paste Celluloid on Wood, Tin, or Leather.»—To attach celluloid to wood, tin, or leather, a mixture of 1 part of shellac, 1 part of spirit of camphor, 3 to 4 parts of alcohol and spirit of camphor (90°) is well adapted, in which 1 part of camphor is dissolved without heating in 7 parts of spirit of wine of 0.832 specific gravity, adding 2 parts of water.

«To Paste Paper Signs on Metal or Cloth.»—A piece of gutta percha of the same size as the label is laid under the latter and the whole is heated. If the heating cannot be accomplished by means of a spirit lamp the label should be ironed down under a protective cloth or paper in the same manner as woolen goods are pressed. This method is also very useful for attaching paper labels to minerals.

«Paste for Fastening Leather, Oilcloth, or Similar Stuff to Table or Desk Tops, etc.»—Use the same paste for leather as for oilcloth or other goods, but moisten the leather before applying the paste. Prepare the paste as follows: Mix 2 1/4 pounds of good wheat flour with 2 tablespoonfuls of pulverized gum arabic or powdered rosin and 2 tablespoonfuls of pulverized alum in a clean dish with water enough to make a uniformly thick batter; set it over a slow fire and stir continuously until the paste is uniform and free from lumps. When the mass has become so stout that the wooden spoon or stick will stand in it {37} upright, it is taken from the fire and placed in another dish and covered so that no skin will form on top. When cold, the table or desk top, etc., is covered with a thin coat of the paste, the cloth, etc., carefully laid on and smoothed from the center toward the edges with a rolling pin. The trimming of edges is accomplished when the paste has dried. To smooth out the leather after pasting, a woolen cloth is of the best service.

«To Paste Paper on Smooth Iron.»—Over a water bath dissolve 200 parts, by weight, of gelatine in 150 parts, by weight, of water; while stirring add 50 parts, by weight, of acetic acid, 50 parts alcohol, and 50 parts, by weight, of pulverized alum. The spot upon which it is desired to attach the paper must first be rubbed with a bit of fine emery paper.

«Paste for Affixing Cloth to Metal.»—

Starch 20 parts Sugar 10 parts Zinc chloride 1 part Water 100 parts

Mix the ingredients and stir until a perfectly smooth liquid results entirely free from lumps, then warm gradually until the liquid thickens.

«To Fix Paper upon Polished Metal.»—Dissolve 400 parts, by weight, of dextrine in 600 parts, by weight, of water; add to this 10 parts, by weight, of glucose, and heat almost to boiling.

«Albumen Paste.»—Fresh egg albumen is recommended as a paste for affixing labels on bottles. It is said that labels put on with this substance, and well dried at the time, will not loosen even when bottles are put into water and left there for some time. Albumen, dry, is almost proof against mold or ferments. As to cost, it is but little if any higher than gum arabic, the white of one egg being sufficient to attach at least 100 medium-sized labels.

«Paste for Parchment Paper.»—The best agent is made by dissolving casein in a saturated aqueous solution of borax.

«Medical Paste.»—As an adhesive agent for medicinal purposes Professor Reihl, of Leipsic, recommends the viscous substance contained in the white mistletoe. It is largely present in the berries and the bark of the plant; it is called viscin, and can be produced at one-tenth the price of caoutchouc. Solutions in benzine may be used like those of caoutchouc without causing any irritation if applied mixed with medicinal remedies to the skin.

«Paste That Will Not Mold.»—Mix good white flour with cold water into a thick paste. Be sure to stir out all the lumps; then add boiling water, stirring all the time until thoroughly cooked. To 6 quarts of this add 1/2 pound light brown sugar and 1/4 ounce corrosive sublimate, dissolved in a little hot water. When the paste is cool add 1 drachm oil of lavender. This paste will keep for a long time.

«Pasting Wood and Cardboard on Metal.»—In a little water dissolve 50 parts of lead acetate and 5 parts of alum. In another receptacle dissolve 75 parts of gum arabic in 2,000 parts of water. Into this gum-arabic solution pour 500 parts of flour, stirring constantly, and heat gradually to the boiling point. Mingle the solution first prepared with the second solution. It should be kept in mind that, owing to the lead acetate, this preparation is poisonous.

«Agar Agar Paste.»—The agar agar is broken up small, wetted with water, and exposed in an earthenware vessel to the action of ozone pumped under pressure into the vessel from the ozonizing apparatus. About an hour of this bleaches the agar agar and makes it freely soluble in boiling water, when solutions far more concentrated than has hitherto been possible can be prepared. On cooling, the solutions assume a milky appearance, but form no lumps and are readily reliquefied by heating. If the solution is completely evaporated, as of course happens when the adhesive is allowed to dry after use, it leaves a firmly holding mass which is insoluble in cold water. Among the uses to which the preparation can be applied are the dressing of textile fabrics and paper sizing, and the production of photographic papers, as well as the ordinary uses of an adhesive.

«Strongly Adhesive Paste.»—Four parts glue are soaked a few hours in 15 parts cold water, and moderately heated till the solution becomes perfectly clear, when 65 parts boiling water are added, while stirring. In another vessel 30 parts boiled starch are previously stirred together with 20 parts cold water, so that a thin, milky liquid without lumps results. The boiling glue solution is poured into this while stirring constantly, and the whole is kept boiling another 10 minutes.

«Paste for Tissue Paper.»—

(_a_) Pulverized gum arabic 2 ounces
White sugar 4 drachms
Boiling water 3 fluidounces {38}
(_b_) Common laundry starch 1 1/2 ounces
Cold water 3 fluidounces

Make into a batter and pour into

Boiling water 32 fluidounces

Mix (_a_) with (_b_), and keep in a wide-mouthed bottle.

«Waterproof and Acidproof Pastes.»—

I.—Chromic acid 2 1/2 parts
Stronger ammonia 15 parts
Sulphuric acid 1/2 part
Cuprammonium solution 30 parts
Fine white paper 4 parts
II.—Isinglass, a sufficient quantity
Acetic acid 1 part
Water 7 parts

Dissolve sufficient isinglass in the mixture of acetic acid and water to make a thin mucilage.

One of the solutions is applied to the surface of one sheet of paper and the other to the other sheet, and they are then pressed together.

III.—A fair knotting varnish free from surplus oil is by far the best adhesive for fixing labels, especially on metal surfaces. It dries instantly, insuring a speedy job and immediate packing, if needful, without fear of derangement. It has great tenacity, and is not only absolutely damp-proof itself, but is actually repellent of moisture, to which all water pastes are subject. It costs more, but the additional expense is often infinitesimal compared with the pleasure of a satisfactory result.

«Balkan Paste.»—

Pale glue 4 ounces White loaf sugar 2 ounces Powdered starch 1 ounce White dextrine 1/4 pound Pure glycerine 3 ounces Carbolic acid 1/4 ounce Boiling water 32 ounces

Cut up the glue and steep it in 1/2 pint boiling water; when softened melt in a saucepan; add sugar, starch, and dextrine, and lastly the glycerine, in which carbolic acid has been mixed; add remainder of water, and boil until it thickens. Pour into jars or bottles.

«Permanent Paste.»—

I.—Wheat flour 1 pound
Water, cold 1 quart
Nitric acid 4 fluidrachms
Boric acid 40 grains
Oil of cloves 20 minims

Mix the flour, boric acid, and water, then strain the mixture; add the nitric acid, apply heat with constant stirring until the mixture thickens; when nearly cold add the oil of cloves. This paste will have a pleasant smell, will not attract flies, and can be thinned by the addition of cold water as needed.

II.—Dissolve 4 ounces alum in 4 quarts hot water. When cool add as much flour as will make it of the usual consistency; then stir into it 1/2 ounce powdered rosin; next add a little water in which a dozen cloves have been steeped; then boil it until thick as mush, stirring from the bottom all the time. Thin with warm water for use.

«Preservatives for Paste.»—Various antiseptics are employed for the preservation of flour paste, mucilage, etc. Boric and salicylic acids, oil of cloves, oil of sassafras, and solution of formaldehyde are among those which have given best service. A durable starch paste is produced by adding some borax to the water used in making it. A paste from 10 parts (weight) starch to 100 parts (weight) water with 1 per cent borax added will keep many weeks, while without this addition it will sour after six days. In the case of a gluing material prepared from starch paste and joiners’ glue, borax has also demonstrated its preserving qualities. The solution is made by mixing 10 parts (weight) starch into a paste with water and adding 10 parts (weight) glue soaked in water to the hot solution; the addition of 1/10 part (weight) of borax to the solution will cause it to keep for weeks. It is equal to the best glue, but should be warmed and stirred before use.

«Board-Sizing.»—A cheap sizing for rough, weather-beaten boards may be made by dissolving shellac in sal soda and adding some heavy-bodied pigment. This size will stick to grease spots. Linseed oil may be added if desired. Limewater and linseed oil make a good heavy sizing, but hard to spread. They are usually used half and half, though these proportions may be varied somewhat.

«Rice Paste.»—Mix the rice flour with cold water, and boil it over a gentle fire until it thickens. This paste is quite white and becomes transparent on drying. It is very adherent and of great use for many purposes.

«Casein Paste.»—A solution of tannin, prepared from a bark or from commercial tannin, is precipitated with limewater, the lime being added until the solution just turns red litmus paper blue. The supernatant liquid is then decanted, {39} and the precipitate is dried without artificial heat. The resulting calcium tannate is then mixed, according to the purpose for which the adhesive is intended, with from 1 to 10 times its weight of dry casein by grinding in a mill. The adhesive compound is soluble in water, petroleum, oils, and carbon bisulphide. It is very strong, and is applied in the form of a paste with water.

«PASTES FOR PAPERHANGERS.»

I.—Use a cheap grade of rye or wheat flour, mix thoroughly with cold water to about the consistency of dough, or a little thinner, being careful to remove all lumps; stir in a tablespoonful of powdered alum to a quart of flour, then pour in boiling water, stirring rapidly until the flour is thoroughly cooked. Let this cool before using, and thin with cold water.

II.—Venetian Paste.—

(_a_) 4 ounces white or fish glue 8 fluidounces cold water (_b_) 2 fluidounces Venice turpentine (_c_) 1 pound rye flour 16 fluidounces (1 pint) cold water (_d_) 64 fluidounces (1/2 gallon) boiling water

Soak the 4 ounces of glue in the cold water for 4 hours; dissolve on a water bath (glue pot), and while hot stir in the Venice turpentine. Make up (_c_) into a batter free from lumps and pour into (_d_). 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.

III.—Strong Adhesive Paste.—

(_a_) 4 pounds rye flour 1/2 gallon cold water (_b_) 1 1/2 gallons boiling water (_c_) 2 ounces pulverized rosin

Make (_a_) into a batter free from lumps; then pour into (_b_). Boil if necessary, and while hot stir in the pulverized rosin a little at a time. This paste is exceedingly strong, and will stick heavy wall paper or thin leather. If the paste be too thick, thin with a little hot water; never thin paste with cold water.

IV.—Flour Paste.—

(_a_) 2 pounds wheat flour 32 fluidounces (1 quart) cold water (_b_) 1 ounce alum 4 fluidounces hot water (_c_) 96 fluidounces (1/2 gallon) boiling water

Work the wheat flour into a batter free from lumps with the cold water. Dissolve the alum as designated in (_b_). Now stir in (_a_) and (_c_) and, if necessary, continue boiling until the paste thickens into a semitransparent mucilage, after which stir in solution (_b_). The above makes a very fine paste for wall paper.

V.—Elastic or Pliable Paste.—

(_a_) 4 ounces common starch
2 ounces white dextrine
10 fluidounces cold water

(_b_) 1 ounce borax
3 fluidounces glycerine
64 fluidounces (1/2 gallon) boiling water

Beat to a batter the ingredients of (_a_). Dissolve the borax in the boiling water; then add the glycerine, after which pour (_a_) into solution (_b_). Stir until it becomes translucent. This paste will not crack, and, being very pliable, is used for paper, cloth, leather, and other material where flexibility is required.

VI.—A paste with which wall paper can be attached to wood or masonry, adhering to it firmly in spite of dampness, is prepared, as usual, of rye flour, to which, however, are added, after the boiling, 8 1/3 parts, by weight, of good linseed-oil varnish and 8 1/3 parts, by weight, of turpentine to every 500 parts, by weight.

VII.—Paste for Wall Paper.—Soak 18 pounds of bolus (bole) in water, after it has been beaten into small fragments, and pour off the supernatant water. Boil 10 ounces of glue into glue water, mix it well with the softened bolus and 2 pounds plaster of Paris and strain through a sieve by means of a brush. Thin the mass with water to the consistency of a thin paste. The paste is now ready for use. It is not only much cheaper than other varieties, but has the advantage over them of adhering better to whitewashed walls, and especially such as have been repeatedly coated over the old coatings which were not thoroughly removed. For hanging fine wall paper this paste is less commendable, as it forms a white color, with which the paper might easily become soiled if great care is not exercised in applying it. If the fine wall paper is mounted on ground paper, however, it can be recommended for pasting the ground paper on the wall.

«LABEL PASTES:»

«Pastes to Affix Labels to Tin.»—Labels separate from tin because the paste becomes too dry. Some moisture is presumably always present; but more is required to cause continued adhesion in the case of tin than where the container is of {40} glass. Paste may be kept moist by the addition of calcium chloride, which is strongly hygroscopic, or of glycerine.

The following formulas for pastes of the type indicated were proposed by Leo Eliel:

I.—Tragacanth 1 ounce
Acacia 4 ounces
Thymol 14 grains
Glycerine 4 ounces
Water, sufficient to make 2 pints

Dissolve the gums in 1 pint of water, strain, and add the glycerine, in which the thymol is suspended; shake well and add sufficient water to make 2 pints. This separates on standing, but a single shake mixes it sufficiently for use.

II.—Rye flour 8 ounces
Powdered acacia 1 ounce
Glycerine 2 ounces
Oil of cloves 40 drops

Rub the rye flour and acacia to a smooth paste with 8 ounces of cold water; strain through cheese cloth, and pour into 1 pint of boiling water, and continue the heat until as thick as desired. When nearly cold add the glycerine and oil of cloves.

III.—Rye flour 5 parts
Venice turpentine 1 part
Liquid glue, a sufficient quantity

Rub up the flour with the turpentine and then add sufficient freshly prepared glue (glue or gelatine dissolved in water) to make a stiff paste. This paste dries slowly.

IV.—Dextrine 2 parts
Acetic acid 1 part
Water 5 parts
Alcohol, 95 per cent. 1 part

Dissolve the dextrine and acetic acid in water by heating together in the water bath, and to the solution add the alcohol.

V.—Dextrine 3 pounds
Borax 2 ounces
Glucose 5 drachms
Water 3 pints 2 ounces

Dissolve the borax in the water by warming, then add the dextrine and glucose, and continue to heat gently until dissolved.

Another variety is made by dissolving a cheap Ghatti gum in limewater, but it keeps badly.

VI.—Add tartaric acid to thick flour paste. The paste is to be boiled until quite thick, and the acid, previously dissolved in a little water, is added, the proportion being about 2 ounces to the pint of paste.

VII.—Gum arabic, 50 parts; glycerine, 10 parts; water, 30 parts; liq. Stibii chlorat., 2 parts.

VIII.—Boil rye flour and strong glue water into a mass to which are added, for 1,000 parts, good linseed-oil varnish 30 parts and oil of turpentine 30 parts. This mixture furnishes a gluing agent which, it is claimed, even renders the labels proof against being loosened by moisture.

IX.—Pour 140 parts of distilled cold water over 100 parts of gum arabic in a wide-necked bottle and dissolve by frequent shaking. To the solution, which is ready after standing for about 3 days, add 10 parts of glycerine; later, 20 parts of diluted acetic acid, and finally 6 parts of aluminum sulphate, then straining it through a fine-hair sieve.

X.—Good glue is said to be obtained by dissolving 1 part of powdered sugar in 4 parts of soda water glass.

XI.—A glue for bottle labels is prepared by dissolving borax in water; soak glue in this solution and dissolve the glue by boiling. Carefully drop as much acetic acid into the solution as will allow it to remain thin on cooling. Labels affixed with this agent adhere firmly and do not become moldy in damp cellars.

XII.—Dissolve some isinglass in acetic acid and brush the labels over with it. There will be no cause to complain of their coming off, nor of striking through the paper. Take a wide-mouthed bottle, fill about two-thirds with commercial acetic acid, and put in as much isinglass as the liquid will hold, and set aside in a warm place until completely dissolved. When cold it should form a jelly. To use it place the bottle in hot water. The cork should be well-fitting and smeared with vaseline or melted paraffine.

«How to Paste Labels on Tin.»—Brush over the entire back of the label with a flour paste, fold the label loosely by sticking both ends together without creasing the center, and throw to one side until this process has been gone through with the whole lot. Then unfold each label and place it on the can in the regular manner. The paste ought not to be thicker than maple syrup. When of this consistency it soaks through the label and makes it pliable and in a condition to be easily rubbed into position. If the paste is too thick it dries quickly, and does not soak through the label sufficiently. After the labels have been placed upon the cans the latter must be {41} kept apart until dry. In putting the paste upon the labels in the first place, follow the method of placing the dry labels over one another, back sides up, with the edge of each just protruding over the edge of the one beneath it, so that the fingers may easily grasp the label after the pasting has been done.

«Druggists’ Label Paste.»—This paste, when carefully made, is an admirable one for label use, and a very little will go a long way:

Wheat flour 4 ounces Nitric acid 1 drachm Boric acid 10 grains Oil of cloves 5 drops Carbolic acid 1/2 drachm

Stir flour and water together, mixing thoroughly, and add the other ingredients. After the stuff is well mixed, heat it, watching very carefully and removing the instant it stiffens.

«To Attach Glass Labels to Bottles.»—Melt together 1 part of rosin and 2 parts of yellow wax, and use while warm.

«Photographic Mountants (see also Photography).»—Owing to the nature of the different papers used for printing photographs, it is a matter of extreme importance to use a mountant that shall not set up decomposition in the coating of the print. For example, a mountant that exhibits acidity or alkalinity is injurious with most varieties of paper; and in photography the following formulas for pastes, mucilages, etc., have therefore been selected with regard to their absolute immunity from setting up decomposition in the print or changing its tone in any way. One of the usual mountants is rice starch or else rice water. The latter is boiled to a thick jelly, strained, and the strained mass used as an agglutinant for attaching photographic prints to the mounts. There is nothing of an injurious nature whatever in this mountant, neither is there in a mucilage made with gum dragon.

This gum (also called gum tragacanth) is usually in the form of curls (i.e., leaf gum), which take a long time to properly dissolve in water—several weeks, in fact—but during the past few years there has been put on the market a powdered gum dragon which does not occupy so many days in dissolving. To make a mucilage from gum dragon a very large volume of water is required. For example, 1 ounce of the gum, either leaf or powder, will swell up and convert 1 gallon of water into a thickish mucilage in the course of 2 or 3 weeks. Only cold water must be used, and before using the mucilage, all whitish lumps (which are particles of undissolved gum) should be picked out or else the mucilage strained. The time of solution can be considerably shortened (to a few hours) by acidifying the water in which the gum is placed with a little sulphuric or oxalic acid; but as the resultant mucilage would contain traces of their presence, such acids are not permissible when the gum-dragon mucilage is to be used for mounting photographs.

Glycerine and gum arabic make a very good adhesive of a fluid nature suited to mounting photographs; and although glycerine is hygroscopic by itself, such tendency to absorb moisture is checked by the reverse nature of the gum arabic; consequently an ideal fluid mucilage is produced. The proportions of the several ingredients are these:

Gum arabic, genuine (gum acacia, not Bassora gum) 4 ounces Boiling water 12 ounces Glycerine, pure 1 ounce

First dissolve the gum in the water, and then stir in the glycerine, and allow all _débris_ from the gum to deposit before using. The following adhesive compound is also one that is free from chemical reactions, and is suited for photographic purposes:

Water 2 pints Gum dragon, powdered 1 ounce Gum arabic, genuine 4 ounces Glycerine 4 ounces

Mix the gum arabic with half the water, and in the remainder of the water dissolve the gum dragon. When both solids are dissolved, mix them together, and then stir in the glycerine.

The following paste will be found a useful mountant:

Gum arabic, genuine 1 ounce Rice starch 1 ounce White sugar 4 ounces Water, q. s.

Dissolve the gum in just sufficient water to completely dissolve it, then add the sugar, and when that has completely dissolved stir in the starch paste, and then boil the mixture until the starch is properly cooked.

A very strong, stiff paste for fastening cardboard mounts to frames, wood, and other materials is prepared by making a bowl of starch paste in the usual way, and then adding 1 ounce of Venice turpentine per pound of paste, and {42} boiling and stirring the mixture until the thick turpentine has become well incorporated. Venice turpentine stirred into flour paste and boiled will also be found a very adhesive cement for fastening cardboard, strawboard, leatherette, and skiver leather to wood or metal; but owing to the resinous nature of the Venice turpentine, such pastes are not suitable for mounting photographic prints. The following half-dozen compounds are suitable mountants to use with silver prints:

Alcohol, absolute 10 ounces Gelatine, good 1 ounce Glycerine 1/2 to 1 ounce

Soak the gelatine in water for an hour or two until it is completely softened; take the gelatine out of the water, and allow it to drain, and put it into a bottle and pour alcohol over it; add the glycerine (if the gelatine is soft, use only 1/2 ounce; if the gelatine is hard, use 1 ounce of the glycerine), then melt the gelatine by standing the bottle in a vessel of hot water, and shake up very well. For use, remelt by heat. The alcohol prevents the prints from stretching or cockling, as they are apt to, under the influence of the gelatine.

In the following compound, however, only sufficient alcohol is used to serve as an antiseptic, and prevent the agglutinant from decomposing: Dissolve 4 ounces of photographic gelatine in 16 ounces of water (first soaking the gelatine therein for an hour or two until it is completely softened), then remove the gelatine from the water, allow it to drain, and put it into the bottle, and pour the alcohol over it, and put in the glycerine (if the gelatine is soft, use only 1/2 ounce; if the gelatine is hard, use 1 ounce of the glycerine), then melt the gelatine by standing the bottle in a vessel of hot water, and shake up well and mix thoroughly. For use, remelt by heat. The alcohol prevents the print from stretching or cockling up under the influence of the gelatine.

The following paste agglutinant is one that is very permanent and useful for all purposes required in a photographic studio: Take 5 pints of water, 10 ounces of arrowroot, 1 ounce of gelatine, and a 1/2 pint (10 fluidounces) of alcohol, and proceed to combine them as follows: Make arrowroot into a thick cream with a little of the water, and in the remainder of the water soak the gelatine for a few hours, after which melt the gelatine in the water by heating it, add the arrowroot paste, and bring the mixture to the boil and allow to boil for 4 or 5 minutes, then allow to cool, and mix in the alcohol, adding a few drops of oil of cloves.

Perhaps one of the most useful compounds for photographic purposes is that prepared as follows: Soak 4 ounces of hard gelatine in 15 ounces of water for a few hours, then melt the gelatine by heating it in a glue pot until the solution is quite clear and free from lumps, stir in 65 fluidounces of cold water so that it is free from lumps, and pour in the boiling-hot solution of gelatine and continue stirring, and if the starch is not completely cooked, boil up the mixture for a few minutes until it “blows,” being careful to keep it well stirred so as not to burn; when cold add a few drops of carbolic acid or some essential oil as an antiseptic to prevent the compound from decomposing or becoming sour.

A useful photographic mucilage, which is very liquid, is obtained by mixing equal bulks of gum-arabic and gum-dragon mucilages of the same consistence. The mixture of these mucilages will be considerably thinner than either of them when alone.

As an agglutinant for general use in the studio, the following is recommended: Dissolve 2 ounces of gum arabic in 5 ounces of water, and for every 250 parts of the mucilage add 20 parts of a solution of sulphate of aluminum, prepared by dissolving 1 part of the sulphate in 20 parts of water (common alum should not be used, only the pure aluminum sulphate, because common alum is a mixture of sulphates, and usually contaminated with iron salts). The addition of the sulphate solution to the gum mucilage renders the latter less hygroscopic, and practically waterproof, besides being very adhesive to any materials, particularly those exhibiting a smooth surface.

«MUCILAGES:»

«For Affixing Labels to Glass and Other Objects.»—I.—The mucilage is made by simply pouring over the gum enough water to a little more than cover it, and then, as the gum swells, adding more water from time to time in small portions, until the mucilage is brought to such consistency that it may be easily spread with the brush. The mucilage keeps fairly well without the addition of any antiseptic.

II.—Tragacanth 1 ounce
Acacia 4 ounces
Thymol 14 grains
Glycerine 4 ounces
Water, sufficient to make 2 pints

{43}

Dissolve the gums in 1 pint of water, strain and add the glycerine, in which the thymol is suspended; shake well and add sufficient water to make 2 pints. This separates on standing, but a single shake mixes it sufficiently for use.

III.—Rye flour 8 ounces
Powdered acacia 1 ounce
Glycerine 2 ounces
Oil of cloves 40 drops
Water, a sufficient quantity.

Rub the rye flour and the acacia to a smooth paste with 8 ounces of cold water; strain through cheese cloth, and pour into 1 pint of boiling water and continue the heat until as thick as desired. When nearly cold add the glycerine and oil of cloves.

IV.—One part, by weight, of tragacanth, when mixed with 95-per-cent alcohol to form 4 fluidounces, forms a liquid in which a portion of the tragacanth is dissolved and the remainder suspended; this remains permanently fluid, never deteriorates, and can be used in place of the present mucilage; 4 to 8 minims to each ounce of mixture is sufficient to suspend any of the insoluble substances usually given in mixtures.

V.—To 250 parts of gum-arabic mucilage add 20 parts of water and 2 parts of sulphate of alumina and heat until dissolved.

VI.—Dissolve 1/2 pound gum tragacanth, powdered, 1/4 pound gum arabic, powdered, cold water to the desired consistency, and add 40 drops carbolic acid.

«Mucilage of Acacia.»—Put the gum, which should be of the best kind, in a flask the size of which should be large enough to contain the mucilage with about one-fifth of its space to spare (i. e., the product should fill it about four-fifths full). Now tare, and wash the gum with distilled water, letting the latter drain away as much as possible before proceeding further. Add the requisite quantity of distilled water slowly, which, however, should first have added to it about 10 per cent of limewater. Now cork the flask, and lay it, without shaking, horizontally in a cool place and let it remain quietly for about 3 hours, then give it a half turn to the right without disturbing its horizontal position. Repeat this operation three or four times during the day, and keep it up until the gum is completely dissolved (which will not be until the fourth day probably), then strain through a thin cloth previously wet with distilled water, avoiding, in so doing, the formation of foam or bubbles. This precaution should also be observed in decantation of the percolate into smaller bottles provided with paraffine corks. The small amount of limewater, as will be understood, is added to the solvent water in order to prevent the action of free acid.

«Commercial Mucilage.»—Dissolve 1/2 pound white glue in equal parts water and strong vinegar, and add 1/4 as much alcohol and 1/2 ounce alum dissolved in a little water. To proceed, first get good glue and soak in cold water until it swells and softens. Use pale vinegar. Pour off the cold water, then melt the glue to a thick paste in hot water, and add the vinegar hot. When a little cool add the alcohol and alum water.

«To Render Gum Arabic More Adhesive.»—I.—Add crystallized aluminum sulphate in the proportion of 2 dissolved in 20 parts of water to 250 parts of concentrated gum solution (75 parts of gum in 175 parts of water).

II.—Add to 250 parts of concentrated gum solution (2 parts of gum in 5 parts of water) 2 parts of crystallized aluminum sulphate dissolved in 20 parts of water. This mixture glues even unsized paper, pasteboard on pasteboard, wood on wood, glass, porcelain, and other substances on which labels frequently do not adhere well.

«Envelope Gum.»—The gum used by the United States Government on postage stamps is probably one of the best that could be used not only for envelopes but for labels as well. It will stick to almost any surface. Its composition is said to be the following:

Gum arabic 1 part Starch 1 part Sugar 4 parts Water, sufficient to give the desired consistency.

The gum arabic is first dissolved in some water, the sugar added, then the starch, after which the mixture is boiled for a few minutes in order to dissolve the starch, after which it is thinned down to the desired consistency.

Cheaper envelope gums can be made by substituting dextrine for the gum arabic, glucose for the sugar, and adding boric acid to preserve and help stiffen it.