This makes a thick gummy varnish which is of little use except as for its waterproof qualities. Allen’s formula for a cellulose substitute might have a value if it were carried further. It is made up of 100 pounds of rosinous wood pulp treated with animal gelatin, 100 pounds asphalt, and 10 pounds asphalt oil, all heated and molded.

The Greening process, which is English, is more elaborate than Allen’s, but seems a bit laborious and costly. This process calls for the treatment of the cellulose by a mixture of sulphuric acid and nitrate of potash, and, after drying, a treatment to a bath of liquid carbonic acid. When dry again, it is mixed in a retort with refined rosin, gum benzoin, castor oil, and methylated alcohol. The distillate from this is dried by redistilling over anhydrous lime.

Another curious line of substitutes is that based upon the use of glue and glycerine. Some of these have uses, while others, that look very attractive, are of no use at all, for the simple reason that they will absorb water almost as readily as a dry sponge. The first of these is more than 30 years old and is said to be of French origin. The formula is:

Ten years later this was approached by an English formula in which in place of {620} the nutgall and acetic acid, chromic and tannic acids were substituted, and a modicum of ground cork was added as a cheapener probably. Some four years later an ingenious Prussian gave out a formula in which to the glue and glycerine and tannic acid were added Marseilles soap and linseed oil. None of the above have ever had a commercial value, the nearest approach being the glue and glycerine compound used as a cover for gas tubing.

The substitutes that have really come into use generally are made either from linseed, cottonseed, or maize oil. Scores of these have been produced and thousands of dollars have been spent by promoters and owners in trying to make these gums do just what crude rubber will. A German formula which was partially successful is

Add 20 pounds sulphur and heat to 375° F.

To prevent rubber tubes from drying up and becoming brittle, they should be coated with a 3 per cent aqueous solution of carbolic acid, which preserves them. If they have already turned stiff and brittle, they can be rendered soft and pliant again by being placed in ammonia which has been made liquid with double the amount of water.

In France rubber tubes are used as a core for casting pipes from cement and sand. In order to construct a connected pipe conduit in the ground, a groove is dug and a layer of cement mortar spread out. Upon this the rubber tube is laid, which is wrapped up in canvas and inflated. The remaining portion of the channel is then filled up with cement mortar, and as soon as it has set, the air is let out of the rubber hose and the latter is pulled out and used as before.

To cover cloth with rubber, there are chiefly employed for dissolving the rubber, naphtha, alcohol, and benzol. They are mixed with purified solid paraffine, and ground together.

Rubber boots and shoes are rendered waterproof by melting 4 parts of spermaceti and 1 part of rubber on a moderate fire, adding tallow or fat, 10 parts, and lastly 5 parts of copal varnish or amber varnish. This mixture is applied on the shoes with a brush. It should be stated that the rubber used for this purpose must be cut up very small and allowed 4 to 5 hours to dissolve.

To rid rubber articles of unpleasant odor, cover both sides with a layer of animal charcoal and heat to about 140° F.

To prevent gas from escaping through rubber hose, cover it with a mixture prepared as follows: Dissolve 5 parts of gum arabic and 3 parts of molasses in 15 parts of white wine and add, with constant stirring, 6 parts of alcohol in small quantities. Stirring is necessary to prevent the alcohol from precipitating the gum arabic.

This is applied to the edges of the joint by means of a pledget of cotton wrapped on the end of a little stick, and press the jointed parts well together.

One may repair rubber bulbs by the following method: Put some pure gum in three times its bulk of benzine, and cork tightly. Let stand several days. Get some rubber in sheet form; it will be better if it is backed with cloth. To make a patch, dampen some little distance around the hole to be mended with benzine. After a moment, scrape with a knife; repeat the process several times till the site to be patched is thoroughly clean. Cut a patch from sheet of rubber a little larger than the hole to be mended, and apply to its surface several coats of the benzine solution. Then apply a good coat of the solution to both patch and about the hole, and press the patch firmly in place. Again apply the solution to make coating over the patch, and allow to dry till it will not stick to the finger. Do not use for several days.

Cracked rubber goods may be {621} successfully mended in the following manner: Before patching, the cracked surfaces to unite well must be dried, entirely freed from all dirt and dust and greased well, otherwise the surfaces will not combine. In case of a cover, waterproof coat, or rubber boots, etc., take a moderately thick piece of india rubber, suited to size of the object, cut off the edges obliquely with a sharp knife moistened in water, coat the defective places as well as the cut pieces of rubber with oil of turpentine, lay the coated parts together and subject them for 24 hours to a moderate pressure. The mended portions will be just as waterproof as the whole one. Rubber cushions or articles containing air are repaired in a very simple manner, after being cleaned as aforesaid. Then take colophony, dissolve it in alcohol (90 per cent) so that a thick paste forms, smear up the holes, allow all to harden well, and the rubber article, pillow, ball, knee caps, etc., may be used again.

Glycerine has been also recommended, and it may be used with advantage in certain cases. The articles must first be cleaned with the brush and warm water, as above detailed. Heat them in water and rub them with a wad of cotton soaked in glycerine, drawing the wad over them, backwards and forwards. This wad should be wrapped with good stout wire, the ends of which are prolonged, to serve as a handle. Where possible the articles should be stricken with the glycerine inside and out, the article being, naturally, held out of the boiling water, sufficiently, at least, to make bare the part being rubbed at the time. Let rest for 24 hours, and repeat this process. With goods kept in stock, that show a tendency to grow brittle, this treatment should be repeated every 6 months or oftener. Never put away tubing, etc., treated in this manner until every particle of moisture has drained off or evaporated.

Another authority, Zeigler, has the following on this subject: Tubing, bands, and other articles of vulcanized caoutchouc that have become brittle and useless, may be restored to usefulness, indeed, to their pristine elasticity, by treating them as follows: First, put them in a hot aqueous solution of tannic acid and tartar emetic. Next, transfer them to a cold aqueous solution of tannic acid and calcium sulphate. Mix the two solutions and heat to about the boiling point, and transfer the articles to the hot solution. This treatment should be maintained from 1 day to 3 or 4, according to the nature and condition of the articles.

To restore rubber stoppers that have become too hard for usefulness, digest them in 5 per cent soda lye for about 10 days at 86° to 104° F., replacing the lye repeatedly. Next, wash the stoppers in water and scrape off the softened outer layer with a knife, until no more can be removed. The stoppers (which have become quite soft and elastic again) are next rinsed in warm water to remove the caustic soda. If it is desired to trim them it should be done with a knife moistened with soap spirit.

According to another method, the ground scraps are steamed with soda lye under pressure, washed twice thoroughly for the elimination of the lye, and dried in the vacuum. Subsequently mix between cold rollers with 5 to 10 per cent of benzol or mineral oil and steam for some hours under hydraulic pressure at 4 atmospheres. The product thus obtained is rolled in plates and added to the mixture. The finely ground dry waste must not be stored for a long time in large quantities, as it hardens very easily and takes fire.

Old articles of vulcanized rubber are first “devulcanized” by grinding, boiling with caustic soda, and washing thoroughly. After drying, the scraps are heated to 302° F. with linseed oil in a kettle provided with stirring mechanism which is kept in continual motion. When the rubber has dissolved, a quantity of natural or coal-tar asphalt is added, and as soon as the contents of the kettle have become well mixed, the temperature is raised so high that dense fumes begin to rise and air is forced through the mass until a cooled sample shows the desired consistence. This composition being very tough and flexible, forms an excellent covering for electric cables. It finds many other uses, the proportions of rubber, asphalt, and oil being varied in accordance with the purpose for which it is designed.

Sulphur chloride is dissolved in carbon disulphide in various proportions, according to the degree of hardness the vulcanized object is to receive; the rubber cast is plunged in the solution and left there from 60 to 70 seconds. On removing, it is placed in a box or space warmed to 80° F., and left long enough for the carbon disulphide to evaporate, or about 90 to 100 seconds. It is then washed in a weakly alkaline bath of water, and dried.

Another method (recommended by Gerard) depends upon letting the rubber lie in a solution of potassium ter or penta sulphide, of 25° Bé., heated to about 280° F. for 3 hours.

RUBBER CEMENTS: See Adhesives.

RUBBER GLOVES, SUBSTITUTE FOR: See Antiseptics.

RUBBER, ITS PROPERTIES AND USES IN WATERPROOFING: See Waterproofing.

RUBBER VARNISHES: See Varnishes.

RUBY SETTINGS: See Watchmakers’ Formulas.

RUOLTZ METAL: See Alloys.

RUM, BAY: See Bay Rum. {623}

RUST PREVENTIVES

(See also Enamels, Glazes, Paints, Varnishes, Waterproofing.)

In spite of the numerous endeavors to protect metal objects from oxidation, a thoroughly satisfactory process has not yet been found, and we still have to resort to coatings and embrocations.

By covering the metals with a pale, colorless linseed-oil varnish, a fat or spirit lacquer, an unfailing protection against oxidation is obtained. This method, though frequently employed, however, is too laborious and expensive to admit of general use, and instead we frequently see employed ordinary or specially composed greases, especially for scythes, straw-knives, and many other bright iron goods. These greases are not suited to retard oxidation, for they are without exception acid-reacting bodies, which absorb oxygen in the air and under the action of light, thus rather assisting oxidation than retarding it. A covering of wax dissolved in oil of turpentine would be more recommendable, because wax is an impervious body, and a firm and rather hard layer remains after evaporation of the oil of turpentine, which excludes the air. If the treatment with the wax salve is carefully attended to no other objection can be urged against this preserving agent than that it is likewise comparatively expensive if used in large quantities. As regards the greases, and treatment with petroleum or vaseline, the easy attrition of these substances is another drawback, which makes a lasting protection impossible.

According to Shedlok, cast-iron articles are treated with acids, then exposed to the action of steam, hot or cold water, and dried. The receptacle is exhausted of air and a solution of pitch, rosin, rubber, or caoutchouc, applied under pressure. Objects prepared in this manner are said to be impervious even to weak acids.

The inoxidizing process of Ward is founded on the simultaneous employment of silicates and heat. The cast iron or wrought iron are coated with a siliceous mass by means of a brush or by immersion. This covering dries quickly, becomes liquid when the articles are exposed to a suitable heat, and soaks into the pores of the metal, forming a dense and uniform coat of dull black color after cooling, which is not changed by long-continued influence of the atmosphere, and which neither scales nor peels from the object. By the admixture of glass coloring matters to the siliceous mass, decorated surfaces may be produced.

Another inoxidation process for cast iron is the following: The cast-iron objects, such as whole gas chandeliers, water pipes, ornaments, balcony railings, cooking vessels, etc., are laid upon an iron sliding carriage 3.5 meters long and are exposed in a flame furnace of special construction first 15 minutes to the influence of gas generators with oxidizing action, then 20 minutes to such with reducing action. After being drawn out and cooled off the inoxidized pieces take on a uniform slate-blue shade of color, but can be enameled and ornamented in any manner desired. In applying the enamel the corroding with acid is obviated, for which reason the enamel stands exceedingly well.

A bronze-colored oxide coating which withstands outward influences fairly well, is produced as follows: The brightly polished and degreased objects are exposed from 2 to 5 minutes to the vapors of a heated mixture of concentrated hydrochloric acid and nitric acid (1:1) until the bronze color becomes visible on the articles. After these have been rubbed well with vaseline, heat once more until the vaseline commences to decompose. After cooling, the object is smeared well with vaseline. If vapors of a mixture of concentrated hydrochloric acid and nitric acid are allowed to act on the iron object, light reddish-brown shades are obtained, but if acetic acid is added to the above named two acids, oxide coatings of a bronze-yellow color can be obtained by the means of the vapors. By the use of different mixtures of acids any number of different colorings can be produced.

“Emaille de fer contre-oxide” is the name of an enamel which is said to protect iron pipes cheaply. The enamel is composed as follows: One hundred and thirty parts powdered crystal glass, 20.5 parts soda, 12 parts boracic acid. These substances mixed in the most careful manner are melted together in crucibles, the mass is chilled and transformed into a fine powder by crushing and grinding. The iron pipes and other objects of iron are first cleaned in the usual manner by corroding, dried and then coated with a very dilute gum arabic solution or any other gluing agent, and the powdered mass is spread over them by means of a sieve. The objects thus powdered are put in a room which is heated to 160° C. to drive out all moisture and are heated {624} to dark redness, at which temperature the oxide coating melts.

Those processes, which produce a black protoxide layer on the iron by heating iron objects in supersaturated aqueous vapor, have not stood the test, as the layer formed will drop off or peel off after a short time, thus opening the way for rust after all.

The anti-rust composition called rubber oil is prepared as follows, according to the specification of the patent: The crude oil obtained by the dry distillation of brown oil, peat and other earthy substances is subjected to a further distillation. Thinly rolled India rubber, cut in narrow strips, is saturated with four times the bulk of the oil and left alone for a week or so. The mass thus composed is then subjected to the action of mineral sperm oil or a similar substance, until an entirely uniform clear substance has formed. This substance, which is applied on the metallic surfaces in as thin a layer as possible, forms a sort of film after slowly drying, which is perfectly proof against atmospheric influences.

The rust-preventive composition of Jones & Co., Sheffield, is a composition of wax, fat, turpentine, and small quantities of iron oxide.

According to a process patented by A. Buchner in Germany, the iron objects are first painted with a mixture of an alkaline glue solution and rosin soap. The alkaline mass enters all the pores and fissures and prevents the rust from extending under the coating. After the first coat is dry a second one is applied of the following composition: Five parts linseed oil boiled with peroxide of manganese; 2.25 parts turpentine; 0.25 parts benzol; 20 parts zinc dust, carbonate of calcium, lead oxide, or peroxide of manganese. The mixing of the liquid with the powders must be done immediately before use, as the mass solidifies after 10 hours, and is then no longer of working consistency. The second coating, which should only be thin, hardens quickly. The paint is weatherproof, does not peel off or blister, and adheres so firmly that it can only be removed with mechanical means.

A patented process to prevent rusting of wrought or cast iron consists in applying with a brush a strong solution of potassium dichromate and drying in a stove or over an open fire. Drying at ordinary temperature is not sufficient. To ascertain if the heat is strong enough the iron is moistened with a little water. So long as this takes up any color the heat must be increased. When the proper degree of heat is reached a fine deep black layer results, which is not acted upon by water, and protects the surface from the action of the atmosphere.

A permanent lustrous rust preventive is secured as follows: The well-cleaned iron parts are suspended for a few minutes in a blue vitriol solution, so that a delicate skin of copper forms on the surface; if the pieces rinsed off with water are then moved about for a few minutes in a solution of sodium hyposulphite faintly acidulated with hydrochloric acid, they assume a blue-black coating of copper sulphide, which is equally permanent in air and in water. The black surface may be immediately rinsed with water, dried with a rag or blotting paper, and polished at once. It possesses a steel-blue luster, adheres well to the iron, will stand treatment with the scratch brush, and protects against rust in a most satisfactory manner.

Mix and cover the articles with the solution. The latter will take the lacquer better if warmed slightly, but may be easily covered in the cold, if necessary.

The deposit of magnetic oxide may also be obtained by electrolysis. The iron object is placed at the anode in a bath of distilled water heated to 176° F. The cathode is a copper plate, or the vessel itself, if it is of iron or copper. By electrolysis a layer of magnetic oxide is formed. Other peroxides may be deposited in the same manner. With an alkaline solution of litharge, a very adherent, brilliant, black deposit of peroxide of lead is secured. Too energetic a current must be avoided, as it would cause a pulverulent deposit. To obtain a good coating it is necessary, after putting the objects for a moment at the positive pole, to place them at the other pole until the oxide is completely reduced, and then bring them back to their first position.

II.—Dry tallow, 25 parts; white wax, 23 parts; olive oil, 22 parts; oil of turpentine, 25 parts; mineral oil, 10 parts. Apply with a brush at the fusing temperature of the mixture.

II.—Carefully heat benzine and add half its weight of white wax, which dissolves completely in this ratio. This solution is applied to the tools by means of a brush. It is also said to protect against the action of acidiferous fumes.

III.—Take a pound of vaseline and melt with it 2 ounces of blue ointment—what druggists call one-third—and add, to give it a pleasant odor, a few drops of oil of wintergreen, cinnamon, or sassafras. When thoroughly mixed pour into a tin can—an old baking-powder can will do. Keep a rag saturated with the preventive to wipe tools that are liable to rust.

RUST SPOT REMOVER: See Cleaning Preparations and Methods.

SACCHARINE IN FOOD: See Food.

SADDLE GALLS: See Veterinary Formulas.

SADDLE SOAP: See Soap.

SALAMANDRINE DESSERT: See Pyrotechnics.

SALICYL (SWEET): See Dentifrices.

SALICYLIC ACID IN FOOD: See Foods.

SALICYLIC SOAP: See Soap.

SALTS, EFFERVESCENT

Granulated effervescent salts are produced by heating mixtures of powdered citric acid, tartaric acid, sodium bicarbonate, and sugar to a certain temperature, until they assume the consistency of a paste, which is then granulated and dried.

If effervescent caffeine citrate, anti-pyrin, lithium citrate, etc., are to be prepared, the powder need not be dried before effecting the mixture, but if sodium phosphate, sodium sulphate, or magnesium sulphate are to be granulated, the water of crystallization must first be removed by drying, otherwise a hard, insoluble and absolutely non-granulable mass will be obtained. Sodium phosphate must lose 60 per cent of its weight in drying, sodium sulphate 56 per cent, and magnesium sulphate 23 per cent.

Naturally, water and carbonic acid escape on heating, and the loss will increase with the rise of temperature. For the production of the granulation mass it must not exceed 158° F., and for drying the grains a temperature of 122° F. is sufficient.

The fineness of the mesh should vary according to the necessary admixture of sugar and the size of the grains.

If the ingredients should have a tendency to cling to the warm bottom, an effort should be made immediately upon the commencement of the reaction to cause a new portion of the surface to come in contact with the hot walls.

When the mass is of the consistency of paste it is pressed through a wire sieve, paper or a fabric being placed underneath. Afterwards dry at sufficient heat. For wholesale manufacture, surfaces of large size are employed, which are heated by steam.

In the production of substances containing alkaloids, antipyrin, etc., care must be taken that they do not become colored. It is well, therefore, not to use heat, but to allow the mixture to stand in a moist condition for 12 hours, adding the medicinal substances afterwards and kneading the whole in a clay receptacle. After another 12 hours the mass will have become sufficiently paste-like, so that it can be granulated as above.

According to another much employed method, the mass is crushed with alcohol, then rubbed through a sieve, and dried rapidly. This process is somewhat dearer, owing to the great loss of alcohol, but presents the advantage of furnishing a better product than any other recipe.

Effervescent magnesium citrate cannot be very well made; for this reason the sulphate was used in lieu of the citrate. A part of the customary admixture of sulphate is replaced by sugar and aromatized with lemon or similar substances.

An excellent granulation mass is obtained from the following mixture by addition of alcohol:

The total loss of this mass through granulation amounts to from 10 to 15 per cent.

To this mass, medicinal substances, such as antipyrin, caffeine citrate, lithium citrate, lithium salicylate, phenacetin, piperacin, ferric carbonate, and pepsin may be added, as desired. {627}

In order to produce a quinine preparation, use tincture of quinine instead of alcohol for moistening; the quinine tincture is prepared with alcohol of 96 per cent.

Basis for Effervescent Salts.—

Powder the citric acid and add the tartaric acid and sodium bicarbonate. This basis may be mixed with many of the med­i­ca­ments commonly used in the form of granular effervescent salts, in the proportion which will properly represent their doses and such substances as sodium phosphate, magnesium sulphate, citrated caffeine, potassium bromide, lithium citrate, potassium citrate, and others, will produce satisfactory products. A typical formula for effervescent sodium phosphate would be as follows:

Dry the sodium phosphate on a water bath until it ceases to lose weight; after powdering the dried salt, mix it intimately with the citric acid and tartaric acid, then thoroughly incorporate the sodium bicarbonate. The mixed powders are now ready for granulation. The change in manipulation which is suggested to replace that usually followed, requires either a gas stove or a blue-flame coal-oil stove, and one of the small tin or sheet-iron ovens which are so largely used with these stoves. The stove itself will be found in almost every drug store; the oven costs from $1 to $2.

The oven is heated to about 200° F. (the use of a thermometer is desirable at first, but one will quickly learn how to regulate the flame to produce the desired temperature), and the previously mixed powders are placed on, preferably, a glass plate, which has been heated with the oven, about ¹/₂ pound being taken at a time, dependent upon the size of the oven. The door of the oven is now closed for about one minute, and, when opened, the whole mass will be found to be uniformly moist and ready to pass through a suitable sieve, the best kind and size being a tinned iron, No. 6. This moist, granular powder may then be placed upon the top of the oven, where the heat is quite sufficient to thoroughly dry the granules, and the operator may proceed immediately with the next lot of mixed powder, easily granulating 10 or more pounds within an hour.

Sugar has often been proposed as an addition to these salts, but experience has shown that the slight improvement in taste, which is sometimes questioned, does not offset the likelihood of darkening, which is apt to occur when the salt is being heated, or the change in color after it has been made several months. It should be remembered that in making a granular effervescent salt by the method which depends upon the liberation of water of crystallization, a loss in weight, amounting to about 10 per cent, will be experienced. This is due, in part, to the loss of water which is driven off, and also to a trifling loss of carbon dioxide when the powder is moistened.

Effervescent Powders:

Magnesian Lemonade Powder.—

Rub the essence into the dry ingredients, work well together, sift, and bottle.

Magnesian Orgeat Powder.—

Thoroughly amalgamate the dry ingredients. Rub in the oil of almonds and sufficient essence of vanilla to give a slight flavor. Work all well together, sift, and bottle.

Raspberryade Powder.—

Rub the essence well into the sugar, and mix this with the soda and acid. Then work in sufficient liquid carmine to make the powder pale red, sift through a fine sieve, and pack in air-tight bottles. {628}

Ambrosia Powder.—

Amalgamate the whole of the above, and afterwards sift and bottle in the usual manner.

Noyeau Powder.—

After the dry ingredients have been mixed, and the essence rubbed into them, sift and bottle the powder.

Lemon Sherbet.—

Having thoroughly mixed the dry ingredients, add the lemon, rubbing it well in between the hands; then sift the whole thrice through a fine sieve, and cork down tight.

As oil of lemon is used in this recipe, the blending must be quite perfect, otherwise when the powder is put in water the oil of lemon will float.

Any other flavoring may be substituted for lemon, and the sherbet named accordingly.

Cream Soda Powder.—