I.— Pure castor oil  1 pint
Cologne spirit  3 fluidounces
Oil of wintergreen 40 minims
Oil of sassafras 20 minims
Oil of anise 15 minims
Saccharine  5 grains
Hot water, a sufficient quantity.

Place the castor oil in a gallon bottle. Add a pint of hot water and shake vigorously for about 15 minutes. Then pour the mixture into a vessel with a stopcock at its base, and allow the mixture to stand for 12 hours. Draw off the oil, excepting the last portion, which must be rejected. Dissolve the essential oils and saccharine in the cologne spirit and add to the washed castor oil.

II.—First prepare an aromatic solution of saccharine as follows:

Refined saccharine  25 parts
Vanillin   5 parts
Absolute alcohol 950 parts
Oil of cinnamon  20 parts

Dissolve the saccharine and vanillin in the alcohol, then add the cinnamon oil, agitate well and filter. Of this liquid add 20 parts to 980 parts of castor oil and mix by agitation. Castor oil, like cod-liver oil, may be rendered nearly tasteless, it is claimed, by treating it as follows: Into a matrass of suitable size put 50 parts of freshly roasted coffee, ground as fine as possible, and 25 parts of purified and freshly prepared bone or ivory black. Pour over the mass 1,000 parts of the oil to be deodorized and rendered tasteless, and mix. Cork the container tightly, put on a water bath, and raise the temperature to about 140° F. Keep at this heat from 15 to 20 minutes, then let cool down, slowly, to 90°, at which temperature let stand for 3 hours. Finally filter, and put up in small, well-stoppered bottles.

III.— Vanillin  3 grains
Garantose  4 grains
Ol. menth. pip.  8 minims
Alcoholis  3 drachms
Ol. ricinus 12 ounces
Ol. olivæ (imported), quantity sufficient  1 pint

M. ft. sol.

Mix vanillin, garantose, ol. menth. pip. with alcohol and add castor oil and olive oil.

Dose: One drachm to 2 fluidounces.

IV.—The following keeps well:

Castor oil  24 parts
Glycerine  24 parts
Tincture of orange peel   8 parts
Tincture of senega   2 parts
Cinnamon water enough to make 100 parts

Mix and make an emulsion. Dose is 1 ta­ble­spoon­ful.

V.—One part of common cooking molasses to 2 of castor oil is the best {154} disguise for the taste of the oil that can be used.

VI.— Castor oil 1 1/2 ounces
Powdered acacia 2 drachms
Sugar 2 drachms
Peppermint water 4 ounces

Triturate the sugar and acacia, adding the oil gradually; when these have been thoroughly incorporated add the peppermint water in small portions, triturating the mixture until an emulsion is formed.

VII.—This formula for an emulsion is said to yield a fairly satisfactory product:

Castor oil 500 c.c.
Mucilage of acacia 125 c.c.
Spirit of gaultheria  10 grams
Sugar   1 gram
Sodium bicarbonate   1 gram
VIII.— Castor oil  1 ounce
Compound tincture of cardamom  4 drachms
Oil of wintergreen  3 drops
Powdered acacia  3 drachms
Sugar  2 drachms
Cinnamon water enough to make  4 ounces.
IX.— Castor oil 12 ounces
Vanillin  3 grains
Saccharine  4 grains
Oil of peppermint  8 minims
Alcohol  3 drachms
Olive oil enough to make  1 pint.

In any case, use only a fresh oil.

How To Take Castor Oil.

—The disgust for castor oil is due to the odor, not to the taste. If the patient grips the nostrils firmly before pouring out the dose, drinks the oil complacently, and then thoroughly cleanses the mouth, lips, larynx, etc., with water, removing the last vestige of the oil before removing the fingers, he will not get the least taste from the oil, which is bland and tasteless. It all depends upon preventing any oil from entering the nose during the time while there is any oil present.

Castor-oil Chocolate Lozenges.—

Cacao, free from oil 250 parts
Castor oil 250 parts
Sugar, pulverized 500 parts
Vanillin sugar   5 parts

Mix the chocolate and oil and heat in the water, both under constant stirring. Have the sugar well dried and add, stirring constantly, to the molten mass. Continue the heat for 30 minutes, then pour out and divide into lozenges in the usual way.

CATATYPY.

It is a well-known fact that the reactions of the compounds of silver, platinum, and chromium in photographic processes are generally voluntary ones and that the light really acts only as an accelerator, that is to say the chemical properties of the preparations also change in the dark, though a longer time is required. When these preparations are exposed to the light under a negative, the modification of their chemical properties is accelerated in such a way that, through the gradations of the tone-values in the negative, the positive print is formed. Now it has been found that we also have such accelerators in material substances that can be used in the light, the process being termed catalysis. It is remarkable that these substances, called catalyzers, apparently do not take part in the process, but bring about merely by their presence, decomposition or combination of other bodies during or upon contact. Hence, catalysis may be defined, in short, as the act of changing or accelerating the speed of a chemical reaction by means of agents which appear to remain stable.

Professor Ostwald and Dr. O. Gros, of the Leipsic University, have given the name of “catatypy” to the new copying process. The use of light is entirely done away with, except that for the sake of convenience the manipulations are executed in the light. All that is necessary is to bring paper and negative into contact, no matter whether in the light or in the dark. Hence the negative (if necessary a positive may also be employed) need not even be transparent, for the ascending and descending action of the tone values in the positive picture is produced only by the quantity in the varying density of the silver powder contained in the negative. Hence no photographic (light) picture, but a catatypic picture (produced by contact) is created, but the final result is the same.

Catatypy is carried out as follows: Pour dioxide of hydrogen over the negative, which can be done without any damage to the latter, and lay a piece of paper on (sized or unsized, rough or smooth, according to the effect desired); by a contact lasting a few seconds the paper receives the picture, dioxide of hydrogen being destroyed. From a single application several prints can be made. The acquired picture—still {155} invisible—may now in the further course of the process, have a reducing or oxydizing action. As picture-producing bodies, the large group of iron salts are above all eminently adapted, but other substances, such as chromium, manganese, etc., as well as pigments with glue solutions may also be employed. The development takes place as follows: When the paper which has been in contact with the negative is drawn through a solution of ferrous oxide, the protoxide is transformed into oxide by the peroxide, hence a yellow positive picture, consisting of iron oxide, results, which can be readily changed into other compounds, so that the most varying tones of color can be obtained. With the use of pigments, in conjunction with a glue solution, the action is as follows: In the places where the picture is, the layer with the pigments becomes insoluble and all other dye stuffs can be washed off with water.

The chemical inks and reductions, as well as color pigments, of which the pictures consist, have been carefully tested and are composed of such as are known to possess unlimited durability.

After a short contact, simply immerse the picture in the respective solution, wash out, and a permanent picture is obtained.

CATGUT:

Preparation Of Catgut Sutures.

—The catgut is stretched tightly over a glass plate tanned in 5 per cent watery extract of quebracho, washed for a short time in water, subjected to the action of a 4 per cent formalin solution for 24 to 48 hours, washed in running water for 24 hours, boiled in water for 10 to 15 minutes, and stored in a mixture of absolute alcohol with 5 per cent glycerine and 4 per cent carbolic acid. In experiments on dogs, this suture material in aseptic wounds remained intact for 65 days, and was absorbed after 83 days. In infected wounds it was absorbed after 32 days.

CELERY COMPOUND.

Celery (seed ground)  25 parts
Coca leaves (ground)  25 parts
Black haw (ground)  25 parts
Hyoscyamus leaves (ground)  12 1/2 parts
Podophyllum (powdered)  10 parts
Orange peel (ground)   6 parts
Sugar (granulated) 100 parts
Alcohol 150 parts
Water, q. s. ad. 400 parts

Mix the alcohol with 150 parts of water and macerate drugs for 24 hours; pack in percolator and pour on menstruum till 340 parts is obtained; dissolve sugar in it and strain.

CELLULOID

New Celluloid.

—M. Ortmann has ascertained that turpentine produced by the Pinus larix, generally denominated Venice turpentine, in combination with acetone (dimethyl ketone), yields the best results; but other turpentines, such as the American from the Pinus australis, the Canada turpentine from the Pinus balsamea, the French turpentine from the Pinus maritima, and ketones, such as the ketone of methyl-ethyl, the ketone of dinaphthyl, the ketone of methyl-oxynaphthyl, and the ketone of dioxy-naphthyl, may be employed.

To put this process in practice, 1,000 parts of pyroxyline is prepared in the usual manner, and mixed with 65 parts of turpentine, or 250 parts of ketone and 250 parts of ether; 500 parts or 750 parts of methyl alcohol is added, and a colorant, such as desired. Instead of turpentine, rosins derived from it may be employed. If the employment of camphor is desired to a certain extent, it may be added to the mixture. The whole is shaken and left at rest for about 12 hours. It is then passed between hot rollers, and finally pressed, cut, and dried, like ordinary celluloid. {156}

The product thus obtained is without odor, when camphor is not employed; and in appearance and properties it cannot be distinguished from ordinary celluloid, while the expense of production is considerably reduced.

Formol Albumen For Preparation Of Celluloid.

—Formol has the property of forming combinations with most albuminoid substances. These are not identical with reference to plasticity, and the use which may be derived from them for the manufacture of plastic substances. This difference explains why albumen should not be confounded with gelatin or casein. With this in view, the Société Anonyme l’Oyonnaxienne has originated the following processes:

I.—The albumen may be that of the egg or that of the blood, which are readily found in trade. The formolizing may be effected in the moist state or in the dry state. The dry or moist albumen is brought into contact with the solution of commercial formol diluted to 5 or 10 per cent for an hour. Care must be taken to pulverize the albumen, if it is dry. The formol penetrates rapidly into the albuminoid matter, and is filtered or decanted and washed with water until all the formol in excess has completely disappeared; this it is easy to ascertain by means of aniline water, which produces a turbid white as long as a trace of formic aldehyde remains.

The formol albumen is afterwards dried at low temperature by submitting it to the action of a current of dry air at a temperature not exceeding 107° F. Thus obtained, the product appears as a transparent corneous substance. On pulverizing, it becomes opaque and loses its transparency. It is completely insoluble in water, but swells in this liquid.

II.—The formol albumen is reduced to a perfectly homogeneous powder, and mixed intimately with the plastic matter before rolling. This cannot be considered an adequate means for effecting the mixture. It is necessary to introduce the formol albumen, in the course of the moistening, either by making an emulsion with camphor alcohol, or by mixing it thoroughly with nitro-cellulose, or by making simultaneously a thorough mixture of the three substances. When the mixture is accomplished, the paste is rolled according to the usual operation. The quantity of formol albumen to add is variable, being diminished according to the quantity of camphor.

Instead of adding the desiccated formol albumen, it may previously be swollen in water in order to render it more malleable.

Instead of simple water, alkalinized or acidified water may be taken for this purpose, or even alcoholized water. The albumen, then, should be pressed between paper or cloth, in order to remove the excess of moisture.

Plastic Substances Of Nitro-cellulose Base.

—To manufacture plastic substances the Compagnie Française du Celluloid commences by submitting casein to a special operation. It is soaked with a solution of acetate of urea in alcohol; for 100 parts of casein 5 parts of acetate of urea and 50 parts of alcohol are employed. The mass swells, and in 48 hours the casein is thoroughly penetrated. It is then ready to be incorporated with the camphored nitro-cellulose. The nitro-cellulose, having received the addition of camphor, is soaked in the alcohol, and the mass is well mixed. The casein prepared as described is introduced into the mass. The whole is mixed and left at rest for 2 days.

The plastic pulp thus obtained is rolled, cut, and dried like ordinary cellulose, and by the same processes and apparatus. The pulp may also be converted into tubes and other forms, like ordinary celluloid.

It is advisable to subject the improved plastic pulp to a treatment with formaldehyde for the purpose of rendering insoluble the casein incorporated in the celluloid. The plastic product of nitro-cellulose base, thus obtained, presents in employment the same general properties as ordinary celluloid. It may be applied to the various manufacturing processes in use for the preparation of articles of all kinds, and its cost price diminishes more or less according to the proportion of casein associated with the ordinary celluloid. In this plastic product various colorants may be incorporated, and the appearance of shell, pearl, wood, marble, or ivory may also be imparted.

Improved Celluloid.

—This product is obtained by mingling with celluloid, under suitable conditions, gelatin or strong glue of gelatin base. It is clear that the replacement of part of the celluloid by the gelatin, of which the cost is much less, lowers materially the cost of the final product. The result is obtained without detriment to the qualities of the objects. These are said to be of superior properties, having more firmness than those of celluloid. And the new material {157} is worked more readily than the celluloid employed alone.

The new product may be prepared in open air or in a closed vessel under pressure. When operated in the air, the gelatin is first immersed cold (in any form, and in a state more or less pure) in alcohol marking about 140° F., with the addition of a certain quantity (for example, 5 to 10 per cent) of crystallizable acetic acid. In a few hours the material has swollen considerably, and it is then introduced in alcohol of about 90 per cent, and at the same time the celluloid pulp (camphor and gun cotton), taking care to add a little acetone. The proportion of celluloid in the mixture may be 50 to 75 per cent of the weight of the gelatin, more or less, according to the result desired. After heating the mixture slightly, it is worked, cold, by the rollers ordinarily employed for celluloid and other similar pastes, or by any other suitable methods.

The preparation in a closed vessel does not differ from that which has been described, except for the introduction of the mixture of gelatin, celluloid, alcohol, and acetone, at the moment when the heating is to be accomplished in an autoclave heated with steam, capable of supporting a pressure of 2 to 5 pounds, and furnished with a mechanical agitator. This method of proceeding abridges the operation considerably; the paste comes from the autoclave well mingled, and is then submitted to the action of rollers. There is but little work in distilling the alcohol and acetic acid in the autoclave. These may be recovered, and on account of their evaporation the mass presents the desired consistency when it reaches the rollers. Whichever of the two methods of preparation may be employed, the substance may be rolled as in the ordinary process, if a boiler with agitator is made use of; the mass may be produced in any form.

Preparation Of Uninflammable Celluloid.

—The operation of this process by Woodward is the following: In a receiver of glass or porcelain, liquefied fish glue and gum arabic are introduced and allowed to swell for 24 hours in a very dry position, allowing the air to circulate freely. The receiver is not covered. Afterwards it is heated on a water bath, and the contents stirred (for example, by means of a porcelain spatula) until the gum is completely liquefied. The heating of the mass should not exceed 77° F. Then the gelatin is added in such a way that there are no solid pieces. The receiver is removed from the water bath and colza oil added, while agitating anew. When the mixture is complete it is left to repose for 24 hours.

Before cooling, the mixture is passed through a sieve in order to retain the pieces which may not have been dissolved. After swelling, and the dissolution and purification by means of the sieve, it is allowed to rest still in the same position, with access of air. The films formed while cooling may be removed. The treatment of celluloid necessitates employing a solution completely colorless and clear. The celluloid to be treated while it is still in the pasty state should be in a receiver of glass, porcelain, or similar material.

The mass containing the fish glue is poured in, drop by drop, while stirring carefully, taking care to pour it in the middle of the celluloid and to increase the surface of contact.

When the mixture is complete, the celluloid is ready to be employed and does not produce flame when exposed.

The solution of fish glue may be prepared by allowing 200 parts of it to swell for 48 hours in 1,000 parts of cold distilled water. It is then passed through the sieve, and the pieces which may remain are broken up, in order to mingle them thoroughly with the water. Ten parts of kitchen salt are then added, and the whole mass passed through the sieve.

This product may be utilized for the preparation of photographic films or for those used for cinematographs, or for replacing hard caoutchouc for the insulation of electric conductors, and for the preparation of plastic objects.

Substitute For Camphor In The Preparation Of Celluloid And Applicable To Other Purposes.

—In this process commercial oil of turpentine, after being rectified by distillation over caustic soda, is subjected to the action of gaseous chlorhydric acid, in order to produce the solid monochlorhydrate of turpentine. After having, by means of the press, extracted the liquid monochlorhydrate, and after several washings with cold water, the solid matter is desiccated and introduced into an autoclave apparatus capable of resisting a pressure of 6 atmospheres. Fifty per cent of caustic soda, calculated on the weight of the monochlorhydrate, and mingled with an equal quantity of alcohol, is added in the form of a thick solution. The apparatus is closed and heated for several hours at the {158} temperature of 284° to 302° F. The material is washed several times for freeing it from the mingled sodium chloride and sodium hydrate, and the camphor resulting from this operation is treated in the following manner:

In an autoclave constructed for the purpose, camphene and water strongly mixed with sulphuric acid are introduced and heated so as to attain 9 pounds of pressure. Then an electric current is applied, capable of producing the decomposition of water. The mass is constantly stirred, either mechanically or more simply by allowing a little of the steam to escape by a tap. In an hour, at least, the material is drawn from the apparatus, washed and dried, sublimed according to need, and is then suitable for replacing camphor in its industrial employments, for the camphene is converted entirely or in greater part into camphor, either right-hand camphor, or a product optically inactive, according to the origin of the oil of turpentine made use of.

In the electrolytic oxidation of the camphene, instead of using acidulated water, whatever is capable of furnishing, under the influence of the electric current, the oxygen necessary for the reaction, such as oxygenized water, barium bioxide, and the permanganates, may be employed.

Plastic And Elastic Composition.

—Formaldehyde has the property, as known, of removing from gelatin its solubility and its fusibility, but it has also another property, prejudicial in certain applications, of rendering the composition hard and friable. In order to remedy this prejudicial action M. Deborda adds to the gelatin treated by means of formaldehyde, oil of turpentine, or a mixture of oil of turpentine and German turpentine or Venice turpentine. The addition removes from the composition its friability and hardness, imparting to it great softness and elasticity. The effect is accomplished by a slight proportion, 5 to 10 per cent.

Production Of Substances Resembling Celluloid.

—Most of the substitutes for camphor in the preparation of celluloid are attended with inconveniences limiting their employment and sometimes causing their rejection. Thus, in one case the celluloid does not allow of the preparation of transparent bodies; in another it occasions too much softness in the products manufactured; and in still another it does not allow of pressing, folding, or other operations, because the mass is too brittle; in still others combinations are produced which in time are affected unfavorably by the coloring substances employed.

Callenberg has found that the halogenous derivatives of etherized oils, principally oil of turpentine, and especially the solid chloride of turpentine, which is of a snowy and brilliant white, and of agreeable odor, are suitable for yielding, either alone or mixed with camphor or one of its substitutes, and combined by ordinary means with nitrated cellulose, or other ethers of cellulose, treated with acetic ether, a celluloidic product, which, it is said, is not inferior to ordinary celluloid and has the advantage of reduced cost.

Elastic Substitute For Celluloid.

—Acetic cellulose, like nitro-cellulose, can be converted into an elastic corneous compound. The substances particularly suitable for the operation are organic substances containing one or more hydroxy, aldehydic, amide, or ketonic groups, as well as the acid amides. Probably a bond is formed when these combinations act on the acetate of cellulose, but the bond cannot well be defined, considering the complex nature of the molecule of cellulose. According to the mode of preparation, the substances obtained form a hard mass, more or less flexible. In the soft state, copies of engraved designs can be reproduced in their finest details. When hardened, they can be cut and polished. In certain respects they resemble celluloid, without its inflammability, and they can be employed in the same manner. They can be produced by the following methods—the Lederer process:

I.—Melt together 1 part of acetate of cellulose and 1 1/2 parts of phenol at about the temperature of 104° to 122° F. When a clear solution is obtained place the mass of reaction on plates of glass or metal slightly heated and allow it to cool gradually. After a rest of several days the mass, which at the outset is similar to caoutchouc, is hard and forms flexible plates, which can be worked like celluloid.

II.—Compress an intimate mixture of equal parts of acetic cellulose and hydrate of chloride or of aniline, at a temperature of 122° to 140° F., and proceed as in the previous case.

In the same way a ketone may be employed, as acetophenone, or an acid amide, as acetamide.

III.—A transparent, celluloid-like substance which is useful for the {159} production of plates, tubes, and other articles, but especially as an underlay for sensitive films in photography, is produced by dissolving 1.8 parts, by weight, of nitro-cellulose in 16 parts of glacial acetic acid, with heating and stirring and addition of 5 parts of gelatin. After this has swelled up, add 7.5 parts, by weight, of alcohol (96 per cent), stirring constantly. The syrupy product may be pressed into molds or poured, after further dilution with the said solvents in the stated proportion, upon glass plates to form thin layers. The dried articles are well washed with water, which may contain a trace of soda lye, and dried again. Photographic foundations produced in this manner do not change, nor attack the layers sensitive to light, nor do they become electric, and in developing they remain flat.

IV.—Viscose is the name of a new product of the class of substances like celluloid, pegamoid, etc., substances having most varied and valuable applications. It is obtained directly from cellulose by mascerating this substance in a 1 per cent dilution of hydrochloric acid. The maceration is allowed to continue for several hours, and at its close the liquid is decanted and the residue is pressed off and washed thoroughly. The mass (of which we will suppose there is 100 grams) is then treated with a 20 per cent aqueous solution of sodium hydrate, which dissolves it. The solution is allowed to stand for 3 days in a tightly closed vessel; 100 grams carbon disulphide are then added, the vessel closed and allowed to stand for 12 hours longer, when it is ready for purification. Viscose thus formed is soluble in water, cold or tepid, and yields a solution of a pale brownish color, from which it is precipitated by alcohol and sodium chloride, which purifies it, but at the expense of much of its solubility. A solution of the precipitated article is colorless, or of a slightly pale yellow. Under the action of heat, long continued, viscose is decomposed, yielding cellulose, caustic soda, and carbon disulphide.

See also Casein for Celluloid Substitutes.

Celluloid Of Reduced Inflammability.

—I.—A practicable method consists in incorporating silica, which does not harm the essential properties of the celluloid. The material is divided by the usual methods, and dissolved by means of the usual solvents, to which silica has been added, either in the state of amylic, ethylic, or methylic silicate, or in the state of any ether derivative of silicic acid. The suitable proportions vary according to the degree of inflammability desired, and according to the proportion of silica in the ether derivative employed; but sufficient freedom from inflammability for practical purposes is attained by the following proportions: Fifty-five to 65 parts in volume of the solvent of the celluloid, and 35 to 45 parts of the derivative of silicic acid.

When the ether derivative is in the solid form, such, for instance, as ethyl disilicate, it is brought to the liquid state by means of any of the solvents. The union of the solvent and of the derivative is accomplished by mixing the two liquids and shaking out the air as much as possible. The incorporation of this mixture with the celluloid, previously divided or reduced to the state of chips, is effected by pouring the mixture on the chips, or inversely, shaking or stirring as free from the air as possible. The usual methods are employed for the desiccation of the mass. A good result is obtained by drying very slowly, preferably at a temperature not above 10° C. (50° F.). The resulting residue is a new product scarcely distinguished from ordinary celluloid, except that the inherent inflammability is considerably reduced. It is not important to employ any individual silicate or derivative. A mixture of the silicates or derivatives mentioned will accomplish the same results.

II.—Any ignited body is extinguished in a gaseous medium which is unsuitable for combustion; the attempt has therefore been made to find products capable of producing an uninflammable gas; and products have been selected that yield chlorine, and others producing bromine; it is also necessary that these bodies should be soluble in a solvent of celluloid; therefore, among chlorated products, ferric chloride has been taken; this is soluble in the ether-alcohol mixture.

This is the process: An ether-alcohol solution of celluloid is made; then an ether-alcohol solution of ferric perchloride. The two solutions are mingled, and a clear, syrupy liquid of yellow color, yielding no precipitate, is obtained. The liquid is poured into a cup or any suitable vessel; it is left for spontaneous evaporation, and a substance of shell-color is produced, which, after washing and drying, effects the desired result. The celluloid thus treated loses none of its properties in pliability and transparency, and is not only uninflammable, but also incombustible. {160}

Of bromated compounds, calcium bromide has been selected, which produces nearly the same result; the product obtained fuses in the flame; outside, it is extinguished, without the power of ignition.

It may be objected that ferric perchloride and calcium bromide, being soluble in water, may present to the celluloid a surface capable of being affected by moist air; but the mass of celluloid, not being liable to penetration by water, fixes the chlorinated or brominated product. Still, as the celluloid undergoes a slight decomposition, on exposure to the light, allowing small quantities of camphor to evaporate, the surface of the perchlorinated celluloid may be fixed by immersion in albuminous water, after previous treatment with a solution of oxalic acid, if a light yellow product is desired.

For preventing the calcium bromide from eventually oozing on the surface of the celluloid, by reason of its deliquescence, it may be fixed by immersing the celluloid in water acidulated with sulphuric acid. For industrial products, such as toilet articles, celluloid with ferric perchloride may be employed.

Another method of preparing an uninflammable celluloid, based on the principle above mentioned, consists in mixing bromide of camphor with cotton powder, adding castor oil to soften the product, in order that it may be less brittle. The latter product is not incombustible, but it is uninflammable, and its facility of preparation reduces at least one-half the apparatus ordinarily made use of in the manufacture of celluloid. The manufacture of this product is not at all dangerous, for the camphor bromide is strictly uninflammable, and may be melted without any danger of dissolving the gun cotton.

III.—Dissolve 25 parts of ordinary celluloidin in 250 parts of acetone and add a solution of 50 parts of magnesium chloride in 150 parts of alcohol, until a paste results, which occurs with a proportion of about 100 parts of the former solution to 20 parts of the latter solution. This paste is carefully mixed and worked through, then dried, and gives an absolutely incombustible material.

IV.—Glass-like plates which are impervious to acids, salts, and alkalies, flexible, odorless, and infrangible, and still possess a transparency similar to ordinary glass, are said to be obtained by dissolving 4 to 8 per cent of collodion wool (soluble pyroxylin) in 1 per cent of ether or alcohol and mixing the solution with 2 to 4 per cent of castor oil, or a similar non-resinifying oil, and with 4 to 6 per cent of Canada balsam. The inflammability of these plates is claimed to be much less than with others of collodion, and may be almost entirely obviated by admixture of magnesium chloride. An addition of zinc white produces the appearance of ivory.

Solvents For Celluloid.

—Celluloid dissolves in acetone, sulphuric ether, alcohol, oil of turpentine, benzine, amyl acetate, etc., alone, or in various combinations of these agents. The following are some proportions for solutions of celluloid:
I.— Celluloid  5 parts
Amyl acetate 10 parts
Acetone 16 parts
Sulphuric ether 16 parts
II.— Celluloid 10 parts
Sulphuric ether 30 parts
Acetone 30 parts
Amyl acetate 30 parts
Camphor  3 parts
III.— Celluloid  5 parts
Alcohol 50 parts
Camphor  5 parts
IV.— Celluloid  5 parts
Amyl acetate 50 parts
V.— Celluloid  5 parts
Amyl acetate 25 parts
Acetone 25 parts

Softening And Cementing Celluloid.

—If celluloid is to be warmed only sufficiently to be able to bend it, a bath in boiling water will answer. In steam at 120° C. (248° F.), however, it becomes so soft that it may be easily kneaded like dough, so that one may even imbed in it metal, wood, or any similar material. If it be intended to soften it to solubility, the celluloid must then be scraped fine and macerated in 90 per cent alcohol, whereupon it takes on the character of cement and may be used to join broken pieces of celluloid together. Solutions of celluloid may be prepared: 1. With 5 parts, by weight, of celluloid in 16 parts, by weight, each of amyl acetate, acetone, and sulphuric ether. 2. With 10 parts, by weight, of celluloid in 30 parts, by weight, each of sulphuric ether, acetone, amyl acetate, and 4 parts, by weight, camphor. 3. With 5 parts, by weight, celluloid in 50 parts, by weight, alcohol and 5 parts, by weight, camphor. 4. With 5 parts, by weight, celluloid in 50 parts, by weight, amyl acetate. 5. With 5 parts, by weight, celluloid in 25 parts, by weight, amyl acetate and 25 parts, by weight, acetone. {161}

It is often desirable to soften celluloid so that it will not break when hammered. Dipping it in water warmed to 40° C. (104° F.) will suffice for this.

Mending Celluloid.

—Celluloid dishes which show cracks are easily repaired by brushing the surface repeatedly with alcohol, 3 parts, and ether, 4 parts, until the mass turns soft and can be readily squeezed together. The pressure must be maintained for about one day. By putting only 1 part of ether in 3 parts of alcohol and adding a little shellac, a cement for celluloid is obtained, which, applied warm, produces quicker results. Another very useful gluing agent for celluloid receptacles is concentrated acetic acid. The celluloid fragments dabbed with it stick together almost instantaneously.

See also Adhesives for Methods of Mending Celluloid.

Printing On Celluloid.

—Printing on celluloid may be done in the usual way. Make ready the form so as to be perfectly level on the impression—that is, uniform to impressional touch on the face. The tympan should be hard. Bring up the form squarely, allowing for about a 3- or 4-sheet cardboard to be withdrawn from the tympan when about to proceed with printing on the celluloid; this is to allow for the thickness of the sheet of celluloid. Use live but dry and well-seasoned rollers. Special inks of different colors are made for this kind of presswork; in black a good card-job quality will be found about right, if a few drops of copal varnish are mixed with the ink before beginning to print.

Colored Celluloid.—

Black: First dip into pure water, then into a solution of nitrate of silver; let dry in the light.

Yellow: First immerse in a solution of nitrate of lead, then in a concentrated solution of chromate of potash.

Brown: Dip into a solution of permanganate of potash made strongly alkaline by the addition of soda.

Blue: Dip into a solution of indigo neutralized by the addition of soda.

Red: First dip into a diluted bath of nitric acid; then into an ammoniacal solution of carmine.

Green: Dip into a solution of verdigris.

Aniline colors may also be employed but they are less permanent.

Bleaching Celluloid.

—If the celluloid has become discolored throughout, its whiteness can hardly be restored, but if merely superficially discolored, wipe with a woolen rag wet with absolute alcohol and ether mixed in equal proportions. This dissolves and removes a minute superficial layer and lays bare a new surface. To restore the polish rub briskly first with a woolen cloth and finish with silk or fine chamois. A little jeweler’s rouge or putzpomade greatly facilitates matters. Ink marks may be removed in the same manner. Printer’s ink may be removed from celluloid by rubbing first with oil of turpentine and afterwards with alcohol and ether.

Process Of Impregnating Fabrics With Celluloid.

—The fabric is first saturated with a dilute celluloid solution of the consistency of olive oil, which solution penetrates deeply into the tissue; dry quickly in a heating chamber and saturate with a more concentrated celluloid solution, about as viscous as molasses. If oil be added to the celluloid solution, the quantity should be small in the first solution, e. g., 1 to 2 per cent, in the following ones 5 to 8 per cent, while the outer layer contains very little or no oil. A fabric impregnated in this manner possesses a very flexible surface, because the outer layer may be very thin, while the interior consists of many flexible fibers surrounded by celluloid.

CEMENTS

(See also Putties.)

For Adhesive Cements intended for repairing broken articles, see Adhesives.

Putty For Celluloid.

—To fasten celluloid to wood, tin, etc., use a compound of 2 parts shellac, 3 parts spirit of camphor, and 4 parts strong alcohol.

Plumbers’ Cement.

—A plumbers’ cement consists of 1 part black rosin, melted, and 2 parts of brickdust, thoroughly powdered and dried.

Cement For Steam And Water Pipes.

—A cement for pipe joints is made as follows: Ten pounds fine yellow ocher; 4 pounds {162} ground litharge; 4 pounds whiting, and 1/2 pound of hemp, cut up fine. Mix together thoroughly with linseed oil to about the consistency of putty.