[151]

 

CASTING

 

The composition of the mold is of the most varied, but the materials most generally used are plaster of Paris and brick dust, in the proportion of 2 parts of the first to 1 of the second, stirred in water, with the addition of a little sal ammoniac. The best quality of plaster for this purpose is the so-called alabaster, and the brick dust should be as finely powdered as possible. The addition of clay, dried and very finely powdered, is recommended. With very delicate objects the proportion of plaster may be slightly increased. The dry material should be thoroughly mixed before the addition of water.

 

As the geometrically exact contour of the coin or medal is often the cause of breaking of the edges, the operator sometimes uses wax to make the edges appear half round and it also allows the casting to be more easily removed from the second half of the mold. Each half of the mold should be about the thickness of the finger. The keys, so called, of every plaster casting must not be forgotten. In the first casting some little half-spherical cavities should be scooped out, which will appear in the second halfround knobs, and which, by engaging with the depressions, will ensure exactness in the finished mold.

 

After the plaster has set, cut a canal for the flow of the molten casting material, then dry the mold thoroughly in an oven strongly heated. The halves are now ready to be bound together with a light wire. When bound heat the mold gradually and slowly and let the mouth of the canal remain underneath while the heating is in progress, in order to prevent the possible entry of dirt or foreign matter. The heating should be continued as long as there is a suspicion of remaining moisture. When finally assured of this fact, take out the mold, open it, and blow it out, to make sure of absolute cleanness. Close and bind again and place on a hearth of fine, hot sand. The mold should still be glowing when the casting is made. The ladle should contain plenty of metal, so as to hold the heat while the casting is being made. The presence of a little zinc in the metal ensures a sharp casting. Finally, to ensure success, it is always better to provide two molds in case of accident. Even the most practiced metal molders take this precaution, especially when casting delicate objects.

 

How to Make Castings of Insects. The object a dead beetle, for example

is first arranged in a natural position, and the feet are connected with an oval rim of wax.      It is then fixed in the center of a paper or wooden box by means of pieces of fine wire, so that it is perfectly

free, and thicker wires are run from the sides of the box to the object, which subsequently serve to form air channels in the mold by their removal. A wooden stick, tapering toward the bottom, is placed upon the back of the insect to produce a runner for casting. The box is then filled up with a paste with 3 parts of plaster of Paris and 1 of brick dust, made up with a solution of alum and sal ammoniac. It is also well first to brush the object with this paste to prevent the formation of air bubbles. After the mold thus formed has set, the object is removed from the interior by first reducing it to ashes. It is, therefore, allowed to dry, very slowly at first, by leaving in the shade at a normal temperature (as in India this is much higher than in our zone, it will be necessary to place the mold in a moderately warm place), and afterwards heating gradually to a red heat. This ncinerates the object, and melts the waxen base upon which it is placed. The latter escapes, and is burned as it does so, and the object, reduced to fine ashes, is removed through the wire holes as suggested above. The casting is then made in the ordinary manner.

 

Casting of Soft Metal Castings.

 

I.    It is often difficult to form flat back or half castings out of the softer metals so that they will run full, owing mostly to the thin edges and frail connections. Instead of using solid metal backs for the molds it is better to use cardboard, or heavy, smooth paper, fastened to a wooden board fitted to the back of the other half of the mold. By this means very thin castings may be produced that would be more difficult with a solid metal back.

 

II.   To obtain a full casting in brass molds for soft metal two important points should be observed. One is to have the deep recesses vented so the air will escape, and the other is to have the mold properly blued. The bluing is best done by dipping the mold in sulphuric acid, then placing it on a gas stove until the mold is a dark color. Unless this bluing is done it will be impossible to obtain a sharp casting.

 

Drosses. All the softer grades of metal throw off considerable dross, which is usually skimmed off; especially with tin and its composition. Should much of this gather on the top of the molten

 

---

[152]

 

CASTING

 

metal, the drosses should all be saved, and melted down when there is enough for a kettle full. Dross may be remelted five or six times before all the good metal is out.

 

Fuel. Where a good soft coal can be had at a low price, as in the middle West, this is perhaps the cheapest and easiest fuel to use; and, besides, it has some advantages over gas, which is so much used in the East. A soft-coal fire can be regulated to keep the metal at an even temperature, and it is especially handy to keep the metal in a molten state during the noon hour. This refers particularly to the gas furnaces that are operated from the power plant in the shop; when this power shuts down during the noon hour the metal becomes chilled, and much time is lost by the remelting after one o'clock, or at the beginning in the morning.

 

Molds.

 

I.    Brass molds for the casting of soft metal ornaments out of britannia, pewter, spelter, etc., should be made out of brass that contains enough zinc to produce a light-colored brass. While this hard brass is more difficult for the mold maker to cut, the superiority over the dark red copper-colored brass is that it will stand more heat and rougher usage and thereby offset the extra labor of cutting the hard brass. The mold should be heavy enough to retain sufficient heat while the worker is removing a finished casting from the mold so that the next pouring will come full. If the mold is too light it cools more quickly, and consequently the castings are chilled and will not run full. Where the molds are heavy enough they will admit the use of a swab and water after each pouring. This chills the casting so that it can be removed easily with the plyers.

 

II.   Molds for the use of soft metal castings may be made out of soft metal. This is done with articles that are not numerous, or not often used; and may be looked upon as temporary. The molds are made in part the same as when of brass, and out of tin that contains as much hardening as possible. The hardening consists of antimony and copper.

This metal mold must be painted over several times with Spanish red, which tends to prevent the metal from melting. The metal must not be used too hot, otherwise it will melt the mold. By a little careful manipulation many pieces can be cast with these molds.

 

III.  New iron or brass molds must be blued before they can be used for casting purposes. This is done by placing the mold face downward on a charcoal fire, or by swabbing with sulphuric acid, then placing over a gas name or charcoal fire until the mold is perfectly oxidized.

 

IV.   A good substantial mold for small castings of soft metal is made of brass. The expense of making the cast mold is considerable, however, and, on that account, some manufacturers are making their molds by electro-deposition. This produces a much cheaper mold, which can be made very quickly. The electro-deposited mold, however, is very frail in comparison with a brass casting, and consequently must be handled very carefully to keep its shape. The electro-deposited ones are made out of copper, and the backs filled in with a softer metal. The handles are secured with screws.

 

Plaster Molds. Castings of any metal can be done in a plaster mold, provided the mold has dried, at a moderate heat, for several days. Smoke the mold well with a brand of rosin to insure a full cast. Where there are only one or two ornaments or figures to cast, it may be done in a mold made out of dental plaster. After the mold is made and set enough so that it can be taken apart, it should be placed in a warm place and left to dry for a day or two. When ready to use the inside should be well smoked over a gaslight; the mold should be well warmed and the metal must not be too hot. Very good castings may be obtained this way; the only objection being the length of time needed for a thorough drying of the mold.

 

Temperature of Metal. Metals for casting purposes should not be overheated. If any of the softer metals show blue colors after cooling it is an indication that the metal is too hot. The metal should be heated enough so that it can be poured, and the finished casting have a bright, clean appearance. The mold may be very warm, then the metal need not be so hot for bright, clean castings. Some of the metals will not stand reheating too often, as this will cause them to run sluggish. Britannia metal should not be skimmed or stirred too much, otherwise there will be too much loss in the dross.

 

CASTING IN WAX:

See Modeling.

 

CASTINGS, TO SOFTEN IRON:

See Iron.

 

---

[153]

 

CASTOR OIL

 

CASTOR OIL:

 

Purifying Rancid Castor Oil. To clean rancid castor oil mix 100 parts of the oil at 95º F. with a mixture of 1 part of alcohol (96 per cent) and 1 part of sulphuric acid. Allow to settle for 24 hours and then carefully decant from the precipitate. Now wash with warm water, boiling for 1/2 hour; allow to settle for 24 hours in well closed vessels, after which time the purified oil may be taken off.

 

How to Pour Out Castor Oil. Any one who has tried to pour castor oil from a square, 5-gallon can, when it is full, knows how difficult it is to avoid a mess. This, however, may be avoided by having a hole punched in the cap which screws onto the can, and a tube, 2 inches long and 3/4 of an inch in diameter, soldered on. With a wire nail a hole is punched in the top of the can between the screw cap and the edge of the can. This will admit air while pouring. Resting the can on a table, with the screw-cap tube to the rear, the can is carefully tilted forward with one hand and the shop bottle held in the other. In this way the bottle may be filled without spilling any of the oil and that, too, without a funnel. It is preferable to rest the can on a table when pouring from a 1- or 2-gallon square varnish can, when filling shop bottles. With the opening to the rear, the can is likewise tilted forward slowly so as to allow the surface of the liquid to become "at rest." Even mobile liquids, such as spirits of turpentine, may be poured into shop bottles without a funnel. Of course, the main thing is that the can be lowered slowly, otherwise the first portion may spurt out over the bottle. With 5-gallon round cans it is possible to fill shop bottles in the same manner by resting the can on a box or counter. When a funnel is used for non-greasy liquids, the funnel may be slightly raised with the thumb and little finger from the neck of the bottle, while holding the bottle by the neck between the middle and ring fingers, to allow egress of air.

 

Tasteless Castor Oil.

 

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 140º F. Keep at this heat from 15 to 20 minutes, then let cool down, slowly, to 90º, 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. olivae (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 dis-

 

---

[154]

 

CASTOR OIL - CATATYPY

 

guise 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 atisfactory 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.

 

CAT DISEASES AND THEIR REMEDIES:

See Insecticides and Veterinary Formulas.

 

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 in-

 

---

[155]

 

CATATYPY - CELLULOID

 

visible 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 con- tact 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.

 

CATERPILLAR DESTROYERS:

See Insecticides.

 

CATGUT:

 

Preparation of Catgut Sutures. The catgut is stretched tightly over a glass plate tanned in 5 per cent watery extract of quebracho, washed or 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 nfected

wounds it was absorbed after 32 days.

 

CATSUP (ADULTERATED):

See Foods.

 

CATTLE DIPS AND APPLICATIONS:

See Disinfectants and Insecticides.

 

CEILING CLEANERS:

See Cleaning Preparations and Methods, and also Household Formulas.

 

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.

 

CELLS, SOLUTIONS AND FILLERS FOR BATTERY:

See Battery Solutions and Fillers.

 

CELLARS, WATERPROOF:

See Household Formulas.

 

CELLOIDIN PAPER:

See Paper.

 

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 methyloxynaphthyl, and the ketone of dioxynaphthyl, 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]

 

CELLULOID

 

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 107º 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 Franyaise 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 nitrocellulose 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, haying more firmness than those of celluloid. And the new material

 

---

[157]

 

CELLULOID

 

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 140º 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 77º 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 temper-

 

---

[158]

 

CELLULOID

 

ature of 284 to 302º 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 nitroellulose, 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 104º to 122º 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 122º to 140º 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 produc-

 

---

[159]

 

CELLULOID

 

tion 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 nitrocellulose 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. (50º 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]

 

CELLULOID

 

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 120º C. (248º 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]

 

CEMENTS

 

It is often desirable to soften celluloid so that it will not break when hammered. Dipping it in water warmed to 40º C. (104º 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 press work; 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 verdiris.

 

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.

 

CELLULOID CEMENTS AND GLUES:

See Adhesives.

 

CELLULOID LACQUER:

See Lacquer.

 

CELLULOID PUTTY:

See Cements.

 

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

 

---

[162]

 

CEMENTS

 

 

pounds ground litharge; 4 pounds whiting, and pound of hemp, cut up fine. Mix together thoroughly with linseed oil to about the consistency of putty.

 

Gutter Cement. Stir sand and fine lime into boiled paint skins while hot and thick. Use hot.

 

Cement for Pipe Joints. A good cement for making tight joints in pumps, pipes, etc., is made of a mixture of 15 parts of slaked lime, 30 parts of graphite, and 40 parts of barium sulphate. The ingredients are powdered, well mixed together, and stirred up with 15 parts of boiled oil. A stiffer preparation can be made by increasing the proportions of graphite and barium sulphate to 30 and 40 parts respectively, and omitting the lime. Another cement for the same purpose consists of 15 parts of chalk and 50 of graphite, ground, washed, mixed, and reground to fine powder. To this mixture is added 20 parts of ground litharge, and the whole mixed to a stiff paste with about 15 parts of boiled oil.

This last preparation possesses the advantage of remaining plastic for a long time when stored in a cool place. Finally, a good and simple mixture for tightening screw connections is made from powdered shellac dissolved in 10 per cent ammonia. The mucinous mass is painted over the screw threads, after the latter have been thoroughly cleaned, and the fitting is screwed home. The ammonia soon volatilizes, leaving behind a mass which hardens quickly, makes a tight joint, and is impervious to hot and cold water.

 

Protection for Cement Work. A coating of soluble glass will impart to cement surfaces exposed to ammonia not only a protective covering, but also increased solidness.

 

Cemented surfaces can be protected from the action of the weather by repeated coats of a green vitriol solution consisting of 1 part of green vitriol and 3 parts of water. Two coatings of 5 per cent soap water are said to render the cement waterproof; after drying and rubbing with a cloth or brush, this coating will become glossy like oil paint. This application is especially recommended for sick rooms, since the walls can be readily cleaned by washing with soapy water. The coating is rendered more and more waterproof thereby. The green vitriol solution is likewise commendable for application on old and new plastering, since it produces thereon waterproof coatings. From old plastering the loose particles have first to be removed by washing.

 

Puncture Cement. A patented preparation for automatically repairing punctures in bicycle tires consists of glycerine holding gelatinous silica or aluminum hydrate in suspension. Three volumes of glycerine are mixed with 1 volume of liquid water glass, and an acid is stirred in. The resulting jelly is diluted with 3 additional volumes of glycerine, and from 4 to 6 ounces of this fluid are placed in each tire. In case of puncture, the internal pressure of the air forces the fluid into the hole, which it closes.

 

To Fix Iron in Stone. Of the quickly hardening cements, lead and sulphur, the latter is popularly employed. It can be rendered still more suitable for purposes of pouring by the admixture of Portland cement, which is stirred into the molten sulphur in the ratio of 1 to 3 parts by weight. The strength of the latter is increased by this addition, since the formation of so coarse a crystalline structure as that of solidifying pure sulphur is disturbed by the powder added.

 

White Portland Cement. Mix together feldspar, 40-100 parts, by weight; kaolin, 100 parts; limestone, 700 parts; magnesite, 20-40 parts; and sodium chloride, 2.5-5 parts, all as pure as possible, and heat to 1430º to 1500º C. (2606º to 2732º F.), until the whole has become sintered together, and forms a nice, white cement-like mass.

 

Cement for Closing Cracks in Stoves. Make a putty of reduced iron (iron by hydrogen) and a solution of sodium or potassium silicate, and force it into the crack. If the crack be a very narrow one, make the iron and silicate into paste instead of putty. This material grows firmer and harder the longer the mended article is used.

 

Cement for Waterpipe.

 

I.    Mix together 11 parts, by weight, Portland cement; 4 parts, by weight, lead white; 1 part, by weight, litharge; and make to a paste with boiled oil in which 3 per cent of its weight of colophony has been dissolved.

 

II.   Mix 1 part, by weight, torn-up wadding; 1 part, by weight, of quicklime, and 3 parts, by weight, of boiled oil. This cement must be used as soon as made.

 

Cement for Pallet Stones. Place small pieces of shellac around the stone when in position and subject it to heat. Often the lac spreads unevenly or swells up; and this, in addition to being unsightly, is apt to displace the stone. This can be avoided as follows: The pallets are

 

---

[163]

 

CEMENTS

 

held in long sliding tongs. Take a piece of shellac, heat it and roll it into a cylinder between the fingers; again heat the extremity and draw it out into a fine thread. This thread will break off, leaving a point at the end of the lac. Now heat the tongs at a little distance from the pallets, testing the degree of heat by touching the tongs with the shellac. When it melts easily, lightly touch the two sides of the notch with it; a very thin layer can thus be spread over them, and the pallet stone can then be placed in position and held until cold enough.

The tongs will not lose the heat suddenly, so that the stone can easily be raised or lowered as required. The projecting particles of cement can be removed by a brass wire filed to an angle and forming a scraper. To cement a ruby pin, or the like, one may also use shellac dissolved in spirit, applied in the consistency of syrup, and liquefied again by means of a hot pincette, by seizing the stone with it.

 

DENTAL CEMENTS:

 

Fairthorne's Cement. Powdered glass, 5 parts; powdered borax, 4 parts; silicic acid, 8 parts; zinc oxide, 200 parts. Powder very finely and mix; then tint with a small quantity of golden ocher or manganese. The compound, mixed before use with concentrated syrupy zinc-chloride solution, soon becomes as hard as marble and constitutes a very durable tooth cement.

 

Huebner's Cement. Zinc oxide, 500.0 parts; powdered manganese, 1.5 parts; yellow ocher, powdered, 1.5-4.0 parts; powdered borax, 10.0 parts; powdered glass, 100.0 parts.

 

As a binding liquid it is well to use acid-free zinc chloride, which can be prepared by dissolving pure zinc, free from iron, in concentrated, pure, hydrochloric acid, in such a manner that zinc is always in excess. When no more hydrogen is evolved the zinc in excess is still left in the solution for some time. The latter is filtered and boiled down to the consistency of syrup.

 

Commercial zinc oxide cannot be employed without previous treatment, because it is too loose; the denser it is the better is it adapted for dental cements, and the harder the latter willº Bé. For this reason it is well, in order to obtain a dense product, to stir the commercial pure zinc oxide into a stiff paste with water to which 2 per cent of nitric acid has been added; the paste is dried and heated for some time at white heat in a Hessian crucible.

 

After cooling, the zinc oxide, thus obtained, is very finely powdered and kept in hermetically sealed vessels, so that it cannot absorb carbonic acid. The dental cement prepared with such zinc oxide turns very hard and solidifies with the concentrated zinc-chloride solution in a few minutes.

 

Phosphate Cement. Concentrate pure phosphoric acid till semi-solid, and mix aluminum phosphate with it by heating. For use, mix with zinc oxide to the consistency of putty. The cement is said to set in 2 minutes.

 

Zinc Amalgam, or Dentists' Zinc. This consists of pure zinc filings combined with twice their weight of mercury, a gentle heat being employed to render the union more complete. It is best applied as soon as made. Its color is gray, and it is said to be effective and durable.

 

Sorel's Cement. Mix zinc oxide with half its bulk of fine sand, add a solution of zinc chloride of 1.260 specific gravity, and rub the whole thoroughly together in a mortar. The mixture must be applied at once, as it hardens very quickly.

 

Metallic Cement. Pure tin, with a small proportion of cadmium and sufficient mercury, forms the most lasting and, for all practical purposes, the least objectionable amalgam. Melt 2 parts of tin with 1 of cadmium, run it into ingots, and reduce it to filings. Form those into a fluid amalgam with mercury, and squeeze out the excess of the latter through leather. Work up the solid residue in the hand, and press it into the tooth. Or melt some beeswax in a pipkin, throw in 5 parts of cadmium, and when melted add 7 or 8 parts of tin in small pieces. Pour the melted metals into an iron or wooden box, and shake them until cold, so as to obtain the alloy in a powder. This is mixed with 2 to 3 times its weight of mercury in the palm of the hand, and used as above described.

 

CEMENT COLORS:

See Stone.

 

CEMENT, MORDANT FOR:

See Mordants.

 

CEMENT, PAINTS FOR:

See Paint.

 

CEMENT, PROTECTION OF, AGAINST ACID:

See Acid-Proofing.

 

---

[164]

 

CERAMICS

 

CHAIN OF FIRE:

See Pyrotechnics.

 

CHAINS (WATCH), TO CLEAN:

See Cleaning Preparations and Methods.

 

CHALK FOR TAILORS.

 

Knead together ordinary pipe clay, moistened with ultramarine blue for blue, finely ground ocher for yellow, etc., until they are uniformly mixed, roll out into thin sheets, cut and press into wooden or metallic molds, well oiled to prevent sticking, and allow to dry slowly at ordinary temperature or at a very gentle heat.

 

CHAPPED HANDS:

See Cosmetics.

 

CHARTA SINAPIS:

See Mustard Paper.

 

CHARTREUSE:

See Wines and Liquors.

 

Ceramics

 

GROUND CERAMICS LAYING OIL FOR:

See Oil.

 

Notes for Potters, Glass-, and Brick-makers. It is of the highest importance,in selecting oxides, minerals, etc., for manufacturing different articles, for potters' use, to secure pure goods, especially in the purchase of the following: Lead, manganese, oxide of zinc, borax, whiting, oxide of iron, and oxide of cobalt. The different ingredients comp rising any given color or glaze should be thoroughly mixed before being calcined, otherwise the mass will be of a streaky or variegated kind. Calcination requires care, especially in the manufacture of enamel colors. Over-firing, particularly of colors or enamels composed in part of lead, borax, antimony, or litharge, causes a dullness of shade, or film, that reduces their value for decorative purposes, where clearness and brilliancy are of the first importance.

 

To arrest the unsightly defect of "crazing," the following have been the most successful methods employed, in the order given:

 

I.    Flux made of 10 parts tincal; 4 parts oxide of zinc; 1 part soda.

 

II.   A calcination of 5 parts oxide of zinc; 1 part pearl ash.

 

III.  Addition of raw oxide of zinc, 6 pounds to each hundredweight of

glaze.

 

To glazed brick and tile makers, whose chief difficulty appears to be the production of a slip to suit the contraction of their clay, and adhere strongly to either a clay or a burnt brick or tile, the following method may be recommended:

 

Mix together:

 

Ball clay                           10 parts

Cornwall stone                      10 parts

China clay                          7 parts

Flint                               6 1/2 parts

 

To be mixed and lawned one week before use.

 

To Cut Pottery. Pottery or any soft or even hard stone substance can be cut without chipping by a disk of soft iron, the edge of which has been charged with emery, diamond, or other grinding powder, that can be obtained at any tool agency. The cutting has to be done with a liberal supply of water fed continually to the revolving disk and the substance to be cut.

 

BRICK AND TILEMAKERS' GLAZED BRICKS:

 

White. When the brick or tile leaves the press, with a very soft brush cover the part to be glazed with No. 1 Slip; afterwards dip the face in the same mixture.

 

No. I Slip.

 

Same clay as brick                  9 parts

Flint                               1 part

Ball clay                           5 parts

China                               4 parts

 

Allow the brick to remain slowly drying for 8 to 10 hours, then when moist dip in the white body.

 

White Body.

 

China clay                          24 parts

Ball clay                           8 parts

Feldspar                            8 parts

Flint                               4 parts

 

The brick should now be dried slowly but thoroughly, and when perfectly dry dip the face in clean cold water, and immediately afterwards in glaze.

 

Hard Glaze.

 

Feldspar                            18 parts

Cornwall stone                      3 1/2 parts

Whiting                             1 1/2 parts

Oxide of zinc                       1 l/2 parts

Plaster of Paris                    3/4 part

 

---

[165]

 

CERAMICS

 

 

Soft Glaze.

 

White lead                          13 parts

Feldspar                            20 parts

Oxide of zinc                       3 parts

Plaster of Paris                    1 part

Flint glass                         13 parts

Cornwall stone                      3 1/2 parts

Paris white                         1 1/4 parts

 

Where clay is used that will stand a very high fire, the white lead and glass may be left out. A wire brush should now be used to remove all superfluous glaze, etc., from the sides and ends of the brick, which is then ready for the kiln. In placing, set the bricks face to face, about an inch space being left between the two glazed faces. All the mixtures, after being mixed with water to the consistency of cream, must be passed 2 or 3 times through a very fine lawn. The kiln must not be opened till perfectly cold.

 

Process for Colored Glazes. Use color, 1 part, to white body, 7 parts. Use color, 1 part, to glaze, 9 parts.

 

Preparation of Colors. The specified ingredients should all be obtained finely ground, and after being mixed in the proportions given should, in a saggar or some clay vessel, be fired in the brick kiln and afterwards ground for use. In firing the ingredients the highest heat attainable is necessary.

 

Turquoise.

 

Oxide of zinc                       8 parts

Oxide of cobalt                     1 1/4 parts

 

Grass Green.

 

Oxide of chrome                     6 parts

Flint                               1 part

Oxide of copper                     1/2 part

 

Royal Blue.

 

Pure alumina                        20 parts

Oxide of zinc                       8 parts

Oxide of cobalt                     4 parts

 

Mazarine Blue.

 

Oxide of cobalt                     10 parts

Paris white                         9 parts

Sulphate barytes                    1 part

 

Red Brown.

 

Oxide of zinc                       40 parts

Crocus of martis                    6 parts

Oxide of chrome                     6 parts

Red lead                            5 parts

Boracic acid                        5 parts

Red oxide of iron                   1 part

 

Orange.

 

Pure alumina                        5 parts

Oxide of zinc                       2 parts

Bichromate of potash                1 part

Iron scale                          1/2 part

 

Claret Brown.

 

Bichromate of potash                2 parts  

Flint                               2 parts

Oxide of zinc                       1 part

Iron scale                          1 part

 

Blue Green.

 

Oxide of chrome                     6 parts

Flint                               2 parts

Oxide of cobalt                     3/4 part

 

Sky Blue.

 

Flint                               9 parts

Oxide of zinc                       13 1/2 parts

Cobalt                              2 parts

Phosphate soda                      1 part

 

Chrome Green.

 

Oxide of chrome                     3 parts

Oxide of copper                     1 part

Carbonate of cobalt                 1 part

Oxide of cobalt                     2 parts

 

Olive.

 

Oxide of chrome                     3 parts

Oxide of zinc                       2 parts

Flint                               5 parts

Oxide of cobalt                     1 part

 

Blood Red.

 

Oxide of zinc                       30 parts

Crocus martis                       7 parts

Oxide of chrome                     7 parts

Litharge                            5 parts

Borax                               5 parts

Red oxide of iron                   2 parts

 

Black.

 

Chromate of iron                    24 parts

Oxide of nickel                     2 parts

Oxide of tin                        2 parts

Oxide of cobalt                     5 parts

 

Imperial Blue.

 

Oxide of cobalt                     10 parts

Black color                         1 1/2 parts

Paris white                         7 1/2 parts

Flint                               2 1/2 parts

Carbonate of soda                   1 part

 

Mahogany.

 

Chromate of iron                    30 parts

Oxide of manganese                  20 parts

Oxide of zinc                       12 parts

Oxide of tin                        4 parts

Crocus martis                       2 parts

 

Gordon Green.

 

Oxide of chrome                     12 parts

Paris white                         8 parts

Bichromate of potash                4 1/2 parts

Oxide of cobalt                     3/4 parts

 

Violet.

 

Oxide of cobalt                     2 1/2 parts

Oxide of manganese                  4 parts

Oxide of zinc,                      8 parts

Cornwall stone                      8 parts

 

---

[166]

 

CERAMICS

 

Lavender.

 

Calcined oxide of zinc              5 parts

Carbonate of cobalt                 3/4 part

Oxide of nickel                     1/4 part

Paris white                         1 part

 

Brown.

 

Manganese                           4 parts

Oxide of chrome                     2 parts

Oxide of zinc                       4 parts

Sulphate barytes                    2 parts

 

Dove.

 

Oxide of nickel                     7 parts

Oxide of cobalt                     2 parts

Oxide of chrome                     1 part

Oxide of flint                      18 parts

Paris white                         3 parts

 

Yellow Green.

 

Flint                               6 parts

Paris white                         4 parts

Bichromate of potash                4 1/2 parts

Red lead                            2 parts

Fluorspar                           2 parts

Plaster of Paris                    l 1/2 parts

Oxide of copper                     1/2 part

 

BODIES REQUIRING NO STAIN:

 

Ivory.

 

Cane marl                           16 parts

Ball clay                           12 parts

Feldspar                            8 parts

China clay                          6 parts

Flint                               4 parts

 

Cream.

 

Ball clay                           22 parts

China clay                          5 1/2 parts

Flint                               5 parts

Feldspar                            3 1/2 parts

Cane marl                           12 parts

 

Black.

 

Ball clay                           120 parts

Ground ocher                        120 parts

Ground manganese                    35 parts

 

Buff.

 

Ball clay                           12 parts

China clay                          10 parts

Feldspar                            8 parts

Bull fire clay                      16 parts

Yellow ocher                        3 parts

     

Drab.

 

Cane marl                           30 parts

Ball clay                           10 parts

Stone                               7 parts

Feldspar                            4 parts

 

Brown.

 

Red marl                            50 parts

China clay                          7 parts

Ground manganese                    6 parts

Feldspar                            3 parts

 

In making mazarine blue glazed bricks use the white body and stain the glaze only.

 

Mazarine blue                       1 part

Glaze                               7 parts

 

For royal blue use 1 part stain to 6 parts white body, and glaze unstained.

 

Blood-Red Stain. Numerous brick manufacturers possess beds of clay from which good and sound bricks or tiles can be made, the only drawback being that the clay does not burn a good color. In many cases this arises from the fact that the clay contains more or less sulphur or other impurity, which spoils the external appearance of the finished article. The following stain will convert clay of any color into a rich, deep red, mixed in proportions of stain, 1 part, to clay, 60 parts.

 

Stain.

 

Crocus martis                       20 parts

Yellow ocher                        4 parts

Sulphate of iron                    10 parts

Red oxide of iron                   2 parts

 

A still cheaper method is to put a slip or external coating upon the goods. The slip being quite opaque, effectively hides the natural color of the brick or tile upon which it may be used. The process is to mix:

 

Blood-red stain                     1 part

Good red clay                       6 parts

 

Add water until the mixture becomes about the consistency of cream, then with a sponge force the liquid two or three times through a very fine brass wire lawn, No. 80, and dip the goods in the liquid as soon as they are pressed or molded.

 

Blue Paviors. Blue paving bricks may be produced with almost any kind of clay that will stand a fair amount of heat, by adopting the same methods as in the former case of blood-red bricks, that is, the clay may be stained throughout, or an outside coating may be applied.

 

Stain for Blue Paviors.

 

Ground ironstone                    20 parts

Chromate of iron                    5 parts

Manganese                           6 parts

Oxide of nickel                     1 part

 

Use 1 part clay and 1 part stain for coating, and 50 or 60 parts clay and 1 part stain for staining through. Fire blue paviors very hard.

 

Buff Terra-Cotta Slip.

 

Buff fire clay                      16 parts

China clay                          6 parts

 

---

[167]

 

CERAMICS

 

Yellow ocher                        3 parts

Ball clay                           10 parts

Flint                               4 parts

 

Add water to the materials after mixing well, pass through the fine lawn, and dip the goods when soft in the liquid.

 

Transparent Glaze.

 

Ground flint glass                  4 parts

Ground white lead                   4 parts

Ground oxide of zinc                1/4 part

 

This glaze is suitable for bricks or tiles made of very good red clay, the natural color of the clay showing through the glaze. The goods must first be fired sufficiently hard to make them durable, afterwards glazed, and fired again. The glaze being comparatively soft will fuse at about half the heat required for the first burning. The glaze may be stained, if desired, with any of the colors given in glazed-brick recipes, in the following proportions: Stain, 1 part; glaze, 1 part.

 

SPECIAL RECIPES FOR POTTERY AND BRICK AND TILE WORKS:

 

Verifiable Bodies. The following mixtures will flux only at a very high heat. They require no glaze when a proper heat is attained, and they are admirably adapted for stoneware glazes.

 

I.   

Cornwall stone                      20 parts

Feldspar                            12 parts

China clay                          3 parts

Whiting                             2 parts

Plaster of Paris                    1 parts

 

II.  

Feldspar                            30 parts

Flint                               9 parts

Stone                               8 parts

China clay                          3 parts

 

III. 

Feldspar                            20 parts

Stone                               5 parts

Oxide of zinc                       3 parts

Whiting                             2 parts

Plaster of Paris                    1 part

Soda crystals, dissolved            1 part

 

Special Glazes for Bricks or Pottery at One Burning. To run these glazes intense heat is required.

 

I.   

Cornwall stone                      40 parts

Flint                               7 parts

Paris white                         4 parts

Ball clay                           15 parts

Oxide of zinc                       6 parts

White lead                          15 parts

 

II.  

Feldspar                            20 parts

Cornwall stone                      5 parts

Oxide of zinc                       3 parts

Flint                               3 parts

Lynn sand                           1 1/2 parts

Sulphate barites                    1 1/2 parts

 

III. 

Feldspar                            25 parts

Cornwall stone                      6 parts

Oxide of zinc                       2 parts

China clay                          2 parts

 

IV.  

Cornwall stone                      118 parts

Feldspar                            40 parts

Paris white                         28 parts

Flint                               4 parts

 

V.   

Feldspar                            16 parts

China clay                          4 parts

Stone                               4 parts

Oxide of zinc                       2 parts

Plaster of Paris                    1 part

 

VI.  

Feldspar                            10 parts

Stone                               5 parts

Flint                               2 parts

Plaster                             1/2 part

 

The following glaze is excellent for bricks in the biscuit and pottery, which require an easy firing:

 

White.

 

White lead                          20 parts

Stone                               9 parts

Flint                               9 parts

Borax                               4 parts

Oxide of zinc                       2 parts

Feldspar                            3 parts

 

These materials should be procured finely ground, and after being thoroughly mixed should be placed in a fire-clay crucible, and be fired for 5 or 6 hours, sharply, or until the material runs down into a liquid, then with a pair of iron tongs draw the crucible from the kiln and pour the liquid into a bucket of cold water, grind the flux to an extremely fine powder, and spread a coating upon the plate to be enameled, previously brushing a little gum thereon. The plate must then be fired until a sufficient heat is attained to run or fuse the powder.

 

POTTERY BODIES AND GLAZES:

 

Ordinary.

 

I.   

China clay                          2 1/2 parts

Stone                               1 1/2 parts

Bone                                3 parts

 

II.  

China clay                          5 parts

Stone                               2 1/2 parts

Bone                                7 parts

Barytes                             3 parts

 

III. 

Chain clay                          5 parts

Stone                               3 parts

Flint                               1/4 part

Barytes                             8 parts

 

Superior.

 

I.   

China clay                          35 parts

Cornwall stone                      23 parts

Bone                                40 parts

Flint                               2 parts

 

---

[168]

 

CERAMICS

 

II.  

China clay                          35 parts

Cornwall stone                      8 parts

Bone                                50 parts

Flint                               3 parts

Blue clay                           4 parts

 

III. 

China clay                          8 parts

Cornwall stone                      40 parts

Bone                                29 parts

Flint                               5 parts

Blue clay                           18 parts

 

IV.  

China clay                          32 parts

Cornwall stone                      23 parts

Bone                                34 parts

Flint                               6 parts

Blue clay                           5 parts

 

V.   

China clay                          7 parts

Stone                               40 parts

Bone                                28 parts

Flint                               5 parts

Blue clay                           20 parts

 

Finest China Bodies.

 

I.   

China clay                          20 parts

Bone                                60 parts

Feldspar                            20 parts

 

II.  

China clay                          30 parts

Bone                                40 parts

Feldspar                            30 parts

 

III. 

China clay                          25 parts

Stone                               10 parts

Bone                                45 parts

Feldspar                            20 parts

 

IV.  

China clay                          30 parts

Stone                               15 parts

Bone                                35 parts

Feldspar                            20 parts

 

Earthenware Bodies.

 

I.   

Ball clay                           13 parts

China clay                          9 1/2 parts

Flint                               5 1/2 parts

Cornwall stone                      4 parts

 

II.  

Ball clay                           12 1/2 parts

China clay                          8 parts

Flint                               5 1/2 parts

Cornwall stone                      2 1/2 parts

One pint of cobalt stain to 1 ton of glaze.

 

III. 

Ball clay                           13 1/4 parts

China clay                          11 parts

Flint                               4 parts

Cornwall stone                      5 parts

Feldspar                            4 parts

Stain as required.

 

IV.  

Ball clay                           18 1/2 parts

China clay                          13 1/2 parts

Flint                               8 1/2 parts

Stone                               4 parts

Blue stain, 2 pints to ton.

 

V.   

Ball clay                           15 parts

China clay                          12 parts

Flint                               6 parts

Stone                               4 parts

Feldspar                            4 parts

Blue stain, 2 pints to ton.

 

VI.   (Parian).

Stone                               11 parts

Feldspar                            10 parts

China clay                          8 parts

 

COLORED BODIES:

 

Ivory Body.

 

Ball clay                           22 parts

China                               5 1/2 parts

Flint                               5 parts

Stone                               3 1/2 parts

 

Dark Drab Body.

 

Cane marl                           30 parts

Ball clay                           10 parts

Cornwall stone                      7 parts

Feldspar                            4 parts

 

Black Body.

 

Ball clay                           120 parts

Ocher                               120 parts

Manganese                           35 parts

Cobalt carbonate                    2 parts

 

Grind the three last mentioned ingredients first.

 

Caledonia Body.

 

Yellow clay                         32 parts

China clay                          10 parts

Flint                               4 parts

 

Brown Body.

 

Red clay                            50 parts

Common clay                         7 1/2 parts

Manganese                           1 part

Flint                               1 part

 

Jasper Body.

 

Cawk clay                           10 parts

Blue clay                           10 parts

Bone                                5 parts

Flint                               2 parts

Cobalt                              1 part

 

Stone Body.

 

Stone                               48 parts

Blue clay                           25 parts

China clay                          24 parts

Cobalt                              10 parts

 

Egyptian Black.

 

Blue clay                           235 parts

Calcined ocher                      225 parts

Manganese                           45 parts

China clay                          15 parts

 

Ironstone Body.

 

Stone                               200 parts

Cornwall clay                       150 parts

 

---

[169]

 

CERAMICS

 

Blue clay                           200 parts

Flint                               100 parts

Calx                                1 part

 

Cream Body.

 

Blue clay                           1 1/2 parts

Black clay                          1 part

Cornish clay                        1 part

Common ball clay                    1/4 part

Buff color                          1/4 part

 

Light Drab.

 

Cane marl                           30 parts

Ball clay                           24 parts

Feldspar                            7 parts

 

Sage Body.

 

Cane marl                           15 parts

Ball clay                           15 parts

China clay                          5 parts

 

Stained with turquoise stain.

 

COLORED GLAZES FOR POTTERY

 

Blue.

 

White glaze                         100 parts

Oxide of cobalt                     3 parts

Red lead                            10 parts

Flowing blue                        3 parts

Enamel blue                         3 parts

 

Grind.

 

Pink.

 

White glaze                         100 parts

Red lead                            8 parts

Marone pink U.G.                    8 parts

Enamel red                          3 parts

 

Grind.

 

Buff.

 

White glaze                         100 parts

Red lead                            10 parts

Buff color                          8 parts

 

Grind.

 

Ivory.

 

White glaze                         100 parts

Red lead                            8 parts

Enamel amber                        8 parts

Yellow underglaze                   2 parts

 

Grind.

 

Turquoise.

 

White glaze                         100 parts

Red lead                            10 parts

Carbonate of soda                   5 parts

Enamel blue                         4 parts

Malachite, 110                      4 parts

 

Grind.

 

Yellow.

 

I.   

White glaze                         100 parts

Red lead                            10 parts

Oxide of uranium                    8 parts

 

Grind.

 

II.  

Dried flint                         5 parts

Cornwall stone                      15 parts

Litharge                            50 parts

Yellow underglaze                   4 parts

 

Grind.

 

Green.

 

I.   

Oxide of copper                     8 parts

Flint of glass                      3 parts

Flint                               1 part

Red lead                            6 parts

 

Grind, then take:

 

Of above                            1 part

White glaze                         6 parts

 

Or stronger as required.

 

II.  

Red lead                            60 parts

Stone                               24 parts

Flint                               12 parts

Flint glass                         12 parts

China clay                          3 parts

Calcined oxide of copper            14 parts

Oxide of cobalt                     1/4 parts

 

Grind only.

 

Green Glaze, Best.

 

III. 

Stone                               80 parts

Flint                               8 parts

Soda crystals                       4 parts

Borax                               3 parts

Niter                               2 parts

Whiting                             2 parts

Oxide of cobalt                     1/4 part

 

Glost fire, then take:

 

Above frit                          60 parts

Red lead                            57 parts

Calcined oxide of copper            5 1/4 parts

 

Black.

 

Red lead                            24 parts

Raddle                              4 parts

Manganese                           4 parts

Flint                               2 parts

Oxide of cobalt                     2 parts

Carbonate of cobalt                 2 parts

 

Glost fire.

 

WHITE GLAZES:

 

China. Frit:

 

I.   

Stone                               6 parts

Niter                               2 parts

Borax                               12 parts

Flint                               4 parts

Pearl ash                           2 parts

 

To mill:

 

Frit                                24 parts

Stone                               15 1/2 parts

Flint                               6 1/2 parts

White lead                          31 parts

 

---

[170]

 

CERAMICS

 

II.   Frit:

 

Stone                               24 parts

Borax                               53 parts

Lynn sand                           40 parts

Feldspar                            32 parts

Paris white                         16 parts

 

To mill:

 

Frit                                90 parts

Stone                               30 parts

White lead                          90 parts

Flint                               4 parts

Glass                               2 parts

 

III.  Frit:

 

Stone                               50 parts

Borax                               40 parts

Flint                               30 parts

Flint glass                         30 parts

Pearl barytes                       10 parts

 

To mill:

 

Frit                                160 parts

Red lead                            30 parts

Enamel blue                         1/2 part

Flint glass                         2 parts

 

IV.   Frit:

 

Borax                               100 parts

China clay                          55 parts

Whiting                             60 parts

Feldspar                            75 parts

 

To mill:

 

Frit                                200 parts

China clay                          16 parts

White clay                          3 1/2 parts

Stone                               3 parts

Flint                               2 parts

 

V.    Frit:

 

Stone                               40 parts

Flint                               25 parts

Niter                               10 parts

Borax                               20 parts

White lead                          10 parts

Flint glass                         40 parts

 

To mill:

 

Frit                                145 parts

Stone                               56 parts

Borax                               16 parts

Flint                               15 parts

Red lead                            60 parts

Flint glass                         8 parts

 

Earthenware. Frit:

 

I.   

Flint                               108 parts

China clay                          45 parts

Paris white                         60 parts

Borax                               80 parts

Soda crystals                       30 parts

 

To mill:

 

Frit                                270 parts

Flint                               20 parts

Paris white                         15 parts

Stone                               80 parts

White lead                          65 parts

 

II.   Frit:

Flint                               62 parts

China clay                          30 parts

Paris white                         38 parts

Boracic acid                        48 parts

Soda crystals                       26 parts

 

To mill:

 

Frit                                230 parts

Stone                               160 parts

Flint                               60 parts

Lead                                120 parts

 

III.  Frit:

Stone                               56 parts

Paris white                         55 parts

Flint                               60 parts

China clay                          20 parts

Borax                               120 parts

Soda crystals                       15 parts

 

To mill:

 

Frit                                212 parts

Stone                               130 parts

Flint                               50 parts

Lead                                110 parts

Stain as required.

 

IV.   Frit:

Stone                               100 parts

Flint                               44 parts

Paris white                         46 parts

Borax                               70 parts

Niter                               10 parts

 

To mill:

 

Frit                                200 parts

Stone                               60 parts

Lead                                80 parts

 

Pearl White Glaze. Frit:

 

Flint                               50 parts

Stone                               100 parts

Paris white                         20 parts

Borax                               60 parts

Soda crystals                       20 parts

 

To mill:

 

Frit                                178 pounds

Lead                                55 pounds

Stain                               3 ounces

 

Opaque Glaze. Frit:

 

Borax                               74 parts

Stone                               94 parts

Flint                               30 parts

China clay                          22 parts

Pearl ash                           5 1/2 parts

 

To mill:

 

Frit                                175 parts

Lead                                46 parts

 

---

[171]

 

CERAMICS

 

Flint                               10 parts

Oxide of tin                        12 parts

Flint glass                         12 parts

 

Glaze for Granite. Frit:

 

I.   

Stone                               100 parts

Flint                               80 parts

China clay                          30 parts

Paris white                         30 parts

Feldspar                            40 parts

Soda crystals                       40 parts

Borax                               80 parts

 

To mill:

 

Frit                                360 parts

Flint                               50 parts

Stone                               50 parts

Lead                                80 parts  

 

II.   Frit:

Borax                               100 parts

Stone                               50 parts

Flint                               40 parts

Paris white                         40 parts

China clay                          20 parts

 

To mill:

 

Frit                                210 parts

Stone                               104 parts

Flint                               64 parts

Lead                                95 parts

 

Raw Glazes. White:

 

I.   

White lead                          160 parts

Borax                               32 parts

Stone                               48 parts

Flint                               52 parts

 

Stain with blue and grind.

 

II.  

White lead                          80 parts

Litharge                            60 parts

Boracic acid                        40 parts

Stone                               45 parts

Flint                               50 parts

 

Treat as foregoing.

 

III. 

White lead                          100 parts

Borax                               4 parts

Flint                               11 parts

Cornwall stone                      50 parts

 

IV.  

Red lead                            80 parts

Litharge                            60 parts

Tincal                              40 parts

Stone                               40 parts

Flint                               52 parts

 

ROCKINGHAM GLAZES.

 

I.   

Litharge                            50 parts

Stone                               7 parts

Red marl                            3 parts

Oxide of manganese                  5 parts

Red oxide of iron                   1 part

 

II.  

White lead                          30 parts

Stone                               3 parts

Flint                               9 parts

Red marl                            3 parts

Manganese                           5 parts

 

III. 

Red lead                            20 parts

Stone                               3 parts

Flint                               2 parts

China clay                          2 parts

Manganese                           3 parts

Red oxide of iron                   1 part

 

Stoneware Bodies.

 

Ball clay                           14 parts

China clay                          10 parts

Stone                               8 parts

 

Ball clay                           8 parts

China clay                          5 parts

Flint                               3 parts

Stone                               4 parts

 

Ball clay                           14 parts

China clay                          11 parts

Flint                               4 parts

Stone                               5 parts

Feldspar                            4 parts

 

Cane marl                           16 parts

China clay                          10 parts

Stone                               9 parts

Flint                               5 parts

 

Glazes. Hard glaze:

 

Stone                               10 parts

Flint                               5 parts

Whiting                             1 1/2 parts

Red lead                            10 parts

 

Hard glaze:

 

Feldspar                            25 parts

Flint                               5 parts

Red lead                            15 parts

Plaster                             1 part

 

Softer:

 

White lead                          13 parts

Flint glass                         10 parts

Feldspar                            18 parts

Stone                               3 parts

Whiting                             1 1/2 parts

 

Best:

 

Feldspar                            20 parts

Flint glass                         14 parts

White lead                          14 parts

Stone                               3 parts

Oxide of zinc                       3 parts

Whiting                             1 1/2 parts

Plaster                             1 part

 

Rockingham Bodies.

 

Ball clay                           20 parts

China clay                          13 parts

Flint                               7 parts

Stone                               1 part

Cane marl                           22 parts

China clay                          15 parts

Flint                               8 parts

Feldspar                            1 part

 

---

[172]

 

CERAMICS

 

Glazes.

 

I.   

Red lead                            60 parts

Stone                               8 parts

Red clay                            3 parts

Best manganese                      5 parts

 

II.  

White lead                          60 parts

Feldspar                            6 parts

Flint                               16 parts

Red clay                            6 parts

Manganese                           12 parts

 

III. 

Red lead                            100 parts

Stone                               15 parts

Flint                               10 parts

China clay                          10 parts

Manganese                           40 parts

Crocus martis                       2 parts

 

IV.  

Litharge                            100 parts

Feldspar                            14 parts

China clay                          20 parts

Manganese                           40 parts

Oxide of iron                       2 parts

 

Jet. Procure some first-class red marl, add water, and, by passing through a fine lawn, make it into a slip, and dip the ware therein.

 

When fired use the following:

 

Glaze.

 

Stone                               60 parts

Flint                               30 parts

Paris white                         7 1/2 parts

Red lead                            140 parts

 

One part mazarine-blue stain to 10 parts glaze.

 

Mazarine Blue Stain.

 

Oxide of cobalt                     10 parts

Paris white                         9 parts

Sulphate barytes                    1 part

 

Calcine.

 

Another Process Body.

 

Ball clay                           16 parts

China clay                          12 parts

Flint clay                          9 parts

Stone clay                          6 parts

Black stain                         7 parts

 

Glaze.

 

Litharge                            70 parts

Paris white                         3 parts

Flint                               12 parts

Stone                               30 parts

Black stain                         20 parts

 

Black Stain.

 

Chromate of iron                    12 parts

Oxide of nickel                     2 parts

Oxide of tin                        2 parts

Carbonate of cobalt                 5 parts

Oxide of manganese                  2 parts

 

Calcine and grind.

 

Blue Stains.

 

I.   

Oxide of cobalt                     2 1/2 parts

Oxide of zinc                       7 1/2 parts

Stone                               7 1/2 parts

 

Fire this very hard.

 

II.  

Zinc                                6 pounds

Flint                               4 pounds

China clay                          4 pounds

Oxide of cobalt                     5 ounces

 

Hard fire.

 

III. 

Whiting                             3 3/4 parts

Flint                               3 3/4 parts

Oxide of cobalt                     2 1/2 parts

 

Glost fire.

 

Turquoise Stain.

 

Prepared cobalt                     1 1/2 parts

Oxide of zinc                       6 parts

China clay                          6 parts

Carbonate of soda                   1 part

 

Hard fire.

 

MATERIALS:

 

Tin Ash.

 

Old lead                            4 parts

Grain tin                           2 parts

     

Melt in an iron ladle, and pour out in water, then spread on a dish, and calcine in glost oven with plenty of air.

 

Oxide of Tin.

 

Granulated tin                      5 pounds

Niter                               1/2 pound

 

Put on saucers and fire in glost oven.

 

Oxide of Chrome is made by mixing powdered bichromate of potash with

sulphur as follows:

 

Potash                        6 parts

Flowers of sulphur            1 part

 

Put in saggar, inside kiln, so that fumes are carried away, and place 4 or 5 pieces of red-hot iron on the top so as to ignite it. Leave about 12 hours, then pound very fine, and put in saggar again. Calcine in hard place of biscuit oven. Wash this until the water is quite clear, and dry for use.

 

Production of Luster Colors on Porcelain and Glazed Pottery. The luster colors are readily decomposed by acids and atmospheric influences, because they do not contain, in consequence of the low baking temperature, enough silicic acid to form resistive compounds.

In order to attain this, G. Alefeld has patented a process according to which such compounds are added to the luster preparations as leave behind after the burning an acid which transforms the luster preparation into more resisting

 

---

[173]

 

CERAMICS

 

compounds. In this connection the admixture of such bodies has been found advantageous, as they form phosphides with the metallic oxides of the lusters after the burning. These phosphides are especially fitted for the production of saturated resisting compounds, not only on account of their insolubility in water, but also on account of their colorings. Similarly titanic, molybdic, tungstic, and vanadic compounds may be produced. The metallic phosphates produced by the burning give a luster coating which, as regards gloss, is not inferior to the nonsaturated metallic oxides, while it materially excels them in power of resistance. Since the lusters to be applied are used dissolved in essential oils, it is necessary to make the admixture of phosphoric substance also in a form soluble in essential oils. For the production of this admixture the respective chlorides, preeminently phosphoric chloride, are suitable. They are mixed with oil of lavender in the ratio of 1 to 5, and the resulting reaction product is added to the commercial metallic oxide luster, singly or in conjunction with precious metal preparations (glossy gold, silver, platinum, etc.) in the approximate proportion of 5 to 1. Then proceed as usual. Instead of the chlorides, nitrates and acetates, as. well as any readily destructible organic compounds, may also be employed, which are entered into fusing rosin or rosinous liquids.

 

Metallic Luster on Pottery. According to a process patented in Germany, a mixture is prepared from various natural or artificial varieties of ocher, to which 25-50 per cent of finely powdered more or less metalliferous or sulphurous coal is added. The mass treated in this manner is brought together in saggars with finely divided organic substances, such as sawdust, shavings, wood-wool, cut straw, etc., and subjected to feeble red heat. After the heating the material is taken put. The glazings now exhibit that thin but stable metallic color which is governed by the substances used. Besides coal, salts and oxides of silver, cobalt, cadmium, chrome iron, nickel, manganese, copper, or zinc may be employed. The color-giving layer is removed by washing or brushing, while the desired color is burned in and remains. In this manner handsome shades can be produced.

 

Metallic Glazes on Enamels. The formulas used by the Arabs and their

Italian successors are partly disclosed in manuscripts in the British and South Kensington Museums; two are given below:

 

 

These were ground with vinegar and applied with the brush to the already baked enamel. A great variety of iridescent and metallic tones can be obtained by one or the other, or a mixture of the following formulas:

 

 

 

Silver chloride and yellow ocher may be respectively substituted for silver carbonate and red ocher. The ingredients, ground with a little gum tragacanth and water, are applied with a brush to enamels melting about 1814º F., and are furnaced at 1202º F. in a reducing atmosphere. After cooling the ferruginous deposit is rubbed off, and the colors thus brought out.

 

Sulphur, free or combined, is not necessary, cinnabar has no action, ocher may be dispensed with, and any organic gummy matter may be used instead of vinegar, and broom is not needed in the furnace. The intensity and tone of the iridescence depend on the duration of the reduction, and the nature of the enamel. Enamels containing a coloring base copper, iron, antimony, nickel especially in presence of tin, give the best results. 

 

To Toughen China. To toughen china or glass place the new article in cold water, bring to boil gradually, boil for 4 hours, and leave standing in the water till cool. Glass or china toughened in this way will never crack with hot water.

 

How to Tell Pottery and Porcelain. The following simple test will serve: Hold the piece up to the light, and if it can be seen through that is, if it is translucent it is porcelain. Pottery is opaque, and not so hard and white as porcelain. The main differences in the manufacture of stoneware, earthenware, and porcelain are due to the ingredients used, to the way they are mixed, and to the degree of heat to which they are sub-

 

---

[174]

 

CHEESE

 

jected in firing. Most of the old English wares found in this country are pottery or semichina, although the term china is commonly applied to them all.

 

Cheese

 

Manufacture. The process of cheese making is one which is eminently interesting and scientific, and which, in every gradation, depends on principles which chemistry has developed and illustrated. When a vegetable or mineral acid is added to milk, and heat applied, a coagulum is formed, which, when separated from the liquid portion, constitutes cheese. Neutral salts, earthy and metallic salts, sugar, and gum arabic, as well as some other substances, also produce the same effect; but that which answers the purpose best, and which is almost exclusively used by dairy farmers, is rennet, or the mucous membrane of the last stomach of the calf. Alkalies dissolve this curd at a boiling heat, and acids again precipitate it. The solubility of casein in milk is occasioned by the presence of the phosphates and other salts of the alkalies. In fresh milk these substances may be readily detected by the property it possesses of restoring the color of reddened litmus paper. The addition of an acid neutralizes the alkali, and so precipitates the curd in an insoluble state. The philosophy of cheese making is thus

expounded by Liebig:

 

"The acid indispensable to the coagulation of milk is not added to the milk in the preparation of cheese, but it is formed in the milk at the expense of the milk-sugar present. A small quantity of water is left in contact with a small quantity of a calf's stomach for a few hours, or for a night; the water absorbs so minute a portion of the mucous membrane as to be scarcely ponderable; this is mixed with milk; its state of transformation is communicated (and this is a most important circumstance) not to the cheese, but to the milk-sugar, the elements of which transpose themselves into lactic acid, which neutralizes the alkalies, and thus causes the separation of the cheese. By means of litmus paper the process may be followed and observed through all its stages; the alkaline reaction of the milk ceases as soon as the coagulation begins. If the cheese is not immediately separated from the whey, the formation of lactic acid continues, the fluid turns acid, and. the cheese itself passes into a state of decomposition.

 

"When cheese-curd is kept in a cool place a series of transformation takes place, in consequence of which it assumes entirely new properties; it gradually becomes semi-transparent, and more or less soft, throughout the whole mass; it exhibits a feebly acid reaction, and develops the characteristic caseous odor. Fresh cheese is very sparingly soluble in water, but after having been left to itself for two or three years it becomes (especially if all the fat be previously removed) almost completely soluble in cold water, forming with it a solution which, like milk, is coagulated by the addition of the acetic or any mineral acid. The cheese, which whilst fresh is insoluble, returns during the maturation, or ripening, as it is called, to a state similar to that in which it originally existed in the milk. In those English, Dutch, and Swiss cheeses which are nearly inodorous, and in the superior kinds of French cheese, the casein of the milk is present in its unaltered state.

 

"The odor and flavor of the cheese is due to the decomposition of the butter; the non-volatile acids, the margaric and oleic acids, and the volatile butyric acid, capric and caproic acids are liberated in consequence of the decomposition of glycerine. Butyric acid imparts to cheese its characteristic caseous odor, and the differences in its pungency or aromatic flavor depend upon the proportion of free butyric, capric, and caproic acids present. In the cheese of certain dairies and districts, valerianic acid has been detected along with the other acids

just referred to. Messrs Jljenjo and Laskowski found this acid in the cheese of Limbourg, and M. Bolard in that of Roquefort.

 

"The transition of the insoluble into soluble casein depends upon the decomposition of the phosphate of lime by the margaric acid of the butter; margarate of lime is formed, whilst the phosphoric acid combines with the casein, forming a compound soluble in water.

 

"The bad smell of inferior kinds of cheese, especially those called meager or poor cheeses, is caused by certain fetid products containing sulphur, and which are formed by the decomposition or putrefaction of the casein. The alteration which the butter undergoes (that is, in becoming rancid), or which occurs in the milk-sugar still present, being transmitted to the casein, changes both the composition of the latter substance and its nutritive qualities.

 

"The principal conditions for the preparation of the superior kinds of cheese.

 

---

[175]

 

CHEESE

 

(other obvious circumstances being of course duly regarded) are a careful removal of the whey, which holds the milk-sugar in solution, and a low temperature during the maturation or ripening of the cheese."

 

Cheese differs vastly in quality and flavor according to the method employed in its manufacture and the richness of the milk of which it is made. Much depends upon the quantity of cream it contains, and, consequently, when a superior quality of cheese is desired cream is frequently added to the curd. This plan is adopted in the manufacture of Stilton cheese and others of a like description. The addition of a pound or two of butter to the curd for a middling size cheese also vastly improves the quality of the product. To insure the richness of the milk, not only should the cows be properly fed, but certain breeds chosen. Those of Alderney, Cheddar, Cheshire, etc., have been widely preferred.

 

The materials employed in making cheese are milk and rennet. Rennet is used either fresh or salted and dried; generally in the latter state. The milk may be of any kind, according to the quality of the cheese required. Cows' milk is that generally employed, but occasionally ewes' milk is used; and sometimes, though more rarely, that from goats.

 

In preparing his cheese the dairy farmer puts the greater portion of the milk into a large tub, to which he adds the remainder, sufficiently heated to raise the temperature to that of new milk. The whole is then whisked together, the rennet or rennet liquor added, and the tub covered over. It is now allowed to stand until completely “turned," when the curd is gently struck down several times with the skimming dish, after which it is allowed to subside. The vat, covered with cheese cloth, is next placed on a "horse" or "ladder" over the tub, and filled with curd by means of the skimmer, care being taken to allow as little as possible of the oily particles or butter to run back with the whey. The curd is pressed down with the hands, and more added as it sinks. This process is repeated until the curd rises to about two inches above the edge. The newly formed cheese, thus partially separated from the whey, is now placed in a clean tub, and a proper quantity of salt, as well as of annotta, added when that coloring is used, after which a board is placed over and under it, and pressure applied for about 2 or 3 hours. The cheese is next turned out and surrounded by a fresh cheese cloth, and then again submitted to pressure in the cheese press for 8 or 10 hours, after which it is commonly removed from the press, salted all over, and again pressed for 15 to 20 hours. The quality of the cheese especially depends on this part of the process, as if any of the whey is left in the cheese it rapidly becomes bad-flavored. Before placing it in the press the last time the common practice is to pare the edges smooth and sightly. It now only remains to wash the outside of the cheese in warm whey or water, to wipe it dry, and to color it with annotta or reddle, as is usually done.

 

The storing of the newly made cheese is the next point that engages the attention of the maker and wholesale dealer. The same principles which influence the maturation or ripening of fermented liquors also operate here. A cool cellar, neither damp nor dry, and which is uninfluenced by change of weather or season, is commonly regarded as the best for the purpose. If possible, the temperature should on no account be permitted to exceed 50º or 52º F. at any portion of the year. An average of about 45º F. is preferable when it can be procured. A place exposed to sudden changes of temperature is as unfit for storing cheese as it is for storing beer. "The quality of Roquefort cheese, which is prepared from sheep's milk, and is very excellent, depends exclusively upon the places where the cheeses are kept after pressing and during maturation.

These are cellars, communicating with mountain grottoes and caverns which are kept constantly cool, at about 41º to 42º F., by currents of air from clefts in the mountains. The value of these cellars as storehouses varies with their property of maintaining an equable and low temperature."

 

It will thus be seen that very slight differences in the materials, in the preparation, or in storing of the cheese, materially influence the quality and flavor of this article. The richness of the milk; the addition to or subtraction of cream from the milk; the separation of the curd from the whey with or without compression; the salting of the curd; the collection of the curd, either whole or broken, before pressing; the addition of coloring matter, as annotta or saffron, or of flavoring; the place and method of storing; and the length of time allowed for maturation, all tend to alter the taste and odor of the cheese in some or other particular, and that in a way readily percep-