can be gained. The oils are first purified by filtering through cloths at from 86° to 104° F., and treating with 4 to 5 per cent. of sulphuric acid of 66° B. After allowing the tarry substances to settle at 114° F., the oil is drawn off, the acid removed with quicklime, and the oil gradually cooled off to 41° F. The paraffine crystallizes and can be obtained by pressing, after which it is further purified by pressing with amyl alcohol or benzine and filtration through animal charcoal. Purification of Oils. Linseed oil should be warmed in an iron boiler and melted lead poured into it, in a thin stream, a little at a time. It should then be left for several days in a warm place, when a deposit separates and the oil becomes quite clear. Oil thus treated possesses in a high degree the property of drying quickly, and is especially suited for the manufacture of varnishes and lacquers. Cocoanut oil should be rubbed up, thoroughly incorporated with warm water, placed in a bag and pressed through it. The fluid thus obtained is brought to the boiling point, and the separating oil clarified with sugar and alum. The oil thus obtained is odorless, white, and well adapted for use in perfumery. The purification of fatty oils may be conducted in the following manner: In a tub provided with a faucet 2 lbs. of potassium permanganate are dissolved in 64 gallons of water. Eighteen gallons of oil are added and thoroughly agitated, and then left to settle for 2 days. After this time 4 gallons of warm water are added with 11 lbs. of crude hydrochloric acid, and the whole vigorously agitated. After several days' rest the water is drawn off from the oil and the latter is washed with hot water to remove the acid. For the quicker separation of the oil from the water the whole is placed in a carboy with a perforated cork, in which two tubes are fitted. One of these is a funnel tube, reaching nearly to the bottom; the other is a bent delivery tube, reaching a little way below the cork. By pouring water through the funnel tube the oil is delivered bright and clear. It is colorless and odorless. Solidification of Liquid Hydrocarbons. The liquid hydrocarbon, such as crude petroleum, refined petroleum, etc., is mixed with some melted fat, after which the mixture is acidulated, and in the form of a spray introduced into an alkaline solution. The mass coagulates and is mechanically separated from the aqueous solution. The coagulum thus obtained is made still more resisting to the influence of heat, etc., by mixing with water-glass_solution to which has been added burnt lime, gypsum, or magnesia. To regain the hydrocarbons the melted mass is compounded with dilute sulphuric or hydrochloric acid, whereby fat and hydrocarbon are separated on the surface. By using ammonia for coagulating the hydrocarbon the dried mass after heating can be formed into candles or torches. For preparing solid fuel the coagulum is mixed with powdered coke, etc. The same method can also be used for the solidification of volatile oils, fat oils, etc. It is best not to add the acid at one time, but in several portions, and to stir thoroughly after each addition. If crude petroleum is to be solidified to be used for candles or torches, it is previously purified by treatment with oxidizing agents, such as potassium manganate and permanganate, etc. Substitute for Linseed Oil. Melt 51 parts of light Burgundy pitch and mix with 23 parts of crude cotton-seed oil and part of fat oil, both previously heated to 176° F. Then add 3 parts of petroleum heated to the same temperature and heat the mixture. When cold add a trace of a mixture of oil of valerian and essence of mirbane, and allow the mixture to clarify. By boiling the cotton-seed oil before use with 3 per cent. of gold litharge a mass is obtained which can be used as a substitute for boiled linseed oil in preparing paints, varnishes, etc. To Purify Oils. Heat the oil with 2 to 3 per cent. of sodium di-sulphide to 77° to 95° F., and stir until all the sulphurous acid has escaped. The following method is especially used for rancid and bitter peanut oil and oil of almonds: Make an emulsion of the oil with a base (good results have been obtained with potash dissolved in twenty times its weight of water), add 8 98 20 50 35 50 White Vaseline Oil. To 100 parts of yellow Russian mineral oil add with 60 constant stirring 25 parts of fuming sulphuric acid in a thin stream. Continue the stirring for 30 minutes and allow the mixture to rest 4 to 5 hours. Then draw the supernatant oil from the black tar-like sediment into another boiler, and add gradually and in small portions 30 per cent. of best well-dried decolorizing powder (residue from the manufacture of potassium ferrocyanide.) Continue the stirring with constant heating for 2 hours and then let the oil rest 4 to 6 hours. Draw the oil off and bring it into a double walled filter heated by steam and filled with decolorizing powder. Should the oil coming from the filter not be entirely white, pass it through a second filter and if necessary through a third until the desired whiteness is attained. The major portion of the oil retained by the decolorizing powder can be regained by pressing the latter in a filtering press, and by boiling the pressed powder with water acidulated with 5 per cent. of sulphuric acid nearly all the remainder of the oil is obtained. Solvent Power of Glycerine. Although not used to a great extent in the chemical industries as a solvent, glycerine is of considerable service for this purpose in pharmacy. Below is a table showing the solvent power of this substance. It is found that 100 parts (by weight) of glycerine will dissolve: Cupro-ammonium for Rendering Paper and Textile Fabrics Water-, Rot-, and Insect-proof. By a recently patented process called "Willesdenizing,' paper, canvas, cordage, etc., are rendered water-proof and rot-proof, and are protected against liability to injury from mould and the attacks of insects. These products are made on the large scale at Willesden, England, by the Patent Water-proof Paper and Canvas Co. Two classes of products are made. 1. Round or 'made up" goods, consisting of rope and cordage, Willesdenized netting, etc.; and, 2. Flat goods turned out in the roll. All of these fabrics are water-proof and free from any tendency to rot or mildew. The "Willesdenized" paper and canvas are made in endless rolls, and of any desired thickness. They are adapted for diverse uses, such as panel-work where great strength is required, as a roofing material which will be unaffected by the weather, and for building purposes generally. Any desired thickness of material is obtained in the finished product by pressing into one compact, homogeneous sheet several layers while they are still superficially gelatinized or "pectized" by the action of the cupro-ammonium solution. The paper, canvas, etc., by this process is treated with a solution of cupro-ammonium hydroxide, which is prepared by the action of strong am monia on copper turnings, in a current of air. The action of the solution on vegetable tissues (cellulose) is a solvent action. The extracts to be treated, however, are passed through the solution at such a rate as to simply gelatinize the exterior of the fibres without disintegrating them, so that on their emergence from the bath the goods possess sufficient coherence to permit them to be passed through a suitable drying apparatus. By this treatment the exterior film of "pectized" cellulose is converted into an elastic varnish in which all the copper taken up by the materials is retained in the combination (probably as a cupro-cellulose) and forms a perfect water-proof coating. Instead of cupro-ammonium the analogous zinc compound may be used, though its action is not so prompt as that of the copper compound. Good results are obtained by using a mixture of the two metallic compounds. The products here described have only lately been placed upon the market, but enough is known of them to make it safe to state that they possess most valuable qualities. (W.) Fabrication of Parchment. A solid parchment impermeable to water and adapted for the osmose of molasses, etc., is prepared as follows: Woollen or cotton tissues are freed by washing from gum, starch, and other foreign substances, and then passed between two rollers in a bath containing some paper pulp. The product is passed through a bath of concentrated sulphuric acid and then repeatedly dipped into one of aqueous ammonia until the acid is completely neutralized. It is then pressed between rollers, dried between two other rollers covered with felt, and finally calendered. Fire-proof Papers, Colors, and Printed Matter. Actually fire-proof paper, i. e., such as will bear a temperature of 1482° F., in connection with printers' ink or ink not affected by such a strong heat, has not been known up to this time. Some papers manufactured with asbestos will stand certain degrees of heat, but they are not suitable for writing or printing paper. L. Forbern, of Berlin, now prepares such papers of the desired qualities according to a method patented by him. As bestos fibres of the best quality are washed in solution of potassium permanganate and bleached with sulphuric acid. To 95 parts of fibre thus prepared are added 5 parts of ground cellulose such as is used in paper mills. The mass is then thoroughly mixed with an addition of glue water and borax and then worked into paper. The product is smooth and is made fit for writing by satinizing; it is claimed to resist a strong red heat. For the preparation of fire-proof printing and writing ink a mixture of platinum chloride and oil of lavender is used, to which, for black printing ink, lampblack and varnish are added, and for writing ink, Chinese ink, water, and gum-Arabic. For a good fire-proof printing ink 10 parts of platinum chloride and 25 parts of lavender oil are heated in a porcelain dish until the development of gas ceases, and 35 parts of lampblack and 30 parts of varnish added in small portions. On heating paper printed with this preparation the platinum is reduced and remains as a black-brown coating. For fire-proof writing ink a mixture of 5 parts of platinum chloride, 15 of lavender oil, 18 of Chinese ink, 1 of gum-Arabic, and 64 of water is used. Colored fire-proof inks are produced by an admixture of metallic underglaze colors. Gas-pipes from Paper. A strip of manilla paper equal in width to the length of the pipe to be made is passed through a vessel with melted asphalt, and then wrapped firmly and uniformly around an iron core until the required thickness is attained. The pipe is then subjected to powerful pressure, after which the outside is strewn over with sand, and the whole cooled in water. The core is then removed and the inside of the pipe coated with a waterproof composition. These pipes are claimed to be perfectly gas-tight and much cheaper than iron pipes, and very resisting to shocks and concussions. Luminous Paper. The luminous mass consists of 4 parts of potassium bichromate, 4 of gelatine, and 50 of calcium sulphide. The constituents are thoroughly dried and mixed by grinding. One part of the resulting | and 180° F. In the trough containing powder is stirred with 2 parts of boiling water to a thickly fluid paint, 1 or 2 coats of which are applied with a brush to the paper or pasteboard to be made luminous. To avoid inequality in the thickness of the layer of paint the paper is passed through a sort of calender with rolls at a proper distance to insure a uniform spreading of the luminous mass. The rolls may be heated, if desired. the mixture are three rollers driven by steam and revolving in the same direction, over the lower side of which the paper is passed. During the manipulation a thin spray of oil of turpentine is allowed to fall upon the paper, which makes it dry more quickly and gives it a beautiful lustrous appearance. The patent applies not only to paper but to all materials containing 40 or more per cent. of cotton. To make Parchment Paper Imperme able to Oil. Dip the parchment in a hot solution of gelatine to which has been added 21 to 3 per cent. of glycerine and dry. To make the same parchment water-proof soak in a solution of 1 per cent. of linseed oil and 4 per cent. of caoutchouc in carbon di-sulphide. Manufacture of Bottles, etc., from Paper. Well-sized paper made of 10 parts of rags, 40 of straw, and 50 of brown wood-pulp is generally used. The paper is impregnated or coated on both sides with a mixture of 60 parts of defibrinated blood, 35 parts of lime powder, and 5 parts of sulphate of aluminium. After drying 10 or 12 rolled leaves are coated again, placed over each other, and then brought into heated STRAW, BLEACHING AND DYEING OF. moulds. The albumen in the blood forms a combination on pressure with the lime which is perfectly proof against spirits, etc. Bottles are made in 2 pieces, which are joined afterwards with caoutchouc cement. New Method of Manufacturing Paper Pulp. Straw or wood is digested for 12 hours in dilute milk of lime; it is then saturated with sulphur dioxide under a pressure of four atmospheres, which effects a complete disintegration of the mass in 1 or 2 hours. The mass is washed with water and subjected under pressure to the action of 3 per cent. of calcium chloride and 0.5 per cent. of aluminium sulphate dissolved in a small quantity of water. After a final washing the product resembles cotton wool in appearance and can be used for the manufacture of the finest kind of paper. Paper for Covering Boilers. Impregnate the paper with a silicate and, when dry, coat with a mixture of 2 parts of magnesia, 2 of zinc white, 4 of sodium silicate, and 1 of linseed oil. When dry apply a coat of sodium silicate. Preparation of Soap Paper. The material for impregnating the paper consists of 10 parts of glycerine, 30 of alcohol, 60 of dry glycerine soap, and 50 of ordinary dry neutral soap at a temperature varying between 162° Before straw is available for the many industrial purposes for which it is used it is subjected to a bleaching process, which is generally preceded by a cleansing bath. For the purpose of dissolving the natural coloring matter the straw is steeped in hot water and then treated with alkaline lye, consisting of 50 parts of water, 8 of potash, and 12 of soda. When taken from this bath it is successively immersed in two or three of weaker lye, and finally rinsed in boiling water. The bleaching process commences in a chlorine bath and is finished in one of sulphuric acid. Good results are also obtained by treating the straw, after the cleansing process, with sulphur vapors, but in order to obtain beautiful shades of color it is advisable in this case to color the straw after the treatment with a little picric acid by immersing it in a bath consisting of 24 pounds of water and drachm of crystallized picric acid. Besides, with sulphur vapors, the straw can also be bleached in the following manner: Immerse 30 pounds of straw in warm water for a few hours, then treat it with a soda solution of 40° B. for 6 hours, and boil it for 1 hour with 1 pound of chloride of lime. Then add to the bath 1 ounce 12 drachms of hydrochloric acid diluted with 3 gallons of water and allow the straw to remain in it for hour, after which it is placed in a 1 per cent. soda bath, and finally rinsed in water. By this method the straw acquires a beautiful white color and great suppleness and elasticity. Before dyeing it is advisable to thoroughly soak the straw in order to fix the color uniformly. The most important colors are black, brown, and gray. Black for 22 Pounds of Straw. Boil the straw for 2 hours in a dye-bath of 4 pounds of logwood and 1 pound of sumach or gall nuts, and then place it in a bath of nitrate of iron (best 4° B.), rinse and dry. Black for 22 Pounds of Straw. Boil for 2 hours with logwood 4 pounds, sumachpound, and fustic or turmeric 1 pound. Then darken with green vitriol, rinse and dry. Black for 22 Pounds of Straw. Boil for 2 hours with green vitriol 4 pounds, tartar 2 pounds, and blue vitriol pound. Finish in a bath of 8 pounds of logwood, with an addition of some turmeric. Gray for 22 Pounds of Straw. Soak the straw in a solution of sodium carbonate, with an addition of some lime to remove the sulphur. Then boil for 2 hours in a dye-bath consisting of alum 4 pounds, tartaric acid 34 ounces, and, according to the desired shade, some cochineal or indigo carmine. To neutralize the cochineal add some sulphuric acid. After boiling wash the straw in slightly acidulated water. Brown for 22 Pounds of Straw. Boil for 2 hours in a dye-bath of 1 pound 10 ounces of sanders wood, 2 pounds of turmeric,pound of sumach, and 1 pound 5 ounces of logwood. Then rinse and darken according to the desired shade with 3 to 4 per cent. of green vitriol. Chestnut-brown for 22 Pounds of Straw. Catechu 1 pound 10 ounces, turmeric 2 pounds, gall nuts 6 ounces, and logwood 1 ounce. Boil for 2 hours, rinse, and finally treat with nitrate of iron of 4° B. and rinse again. Havana Brown for 22 Pounds of Straw. Soak the straw in solution of 4 to 6 pounds of alum, then dye in a bath of 13 ounces of sanders wood, 1 pound of turmeric, 3 ounces 8 drachms of sumach, and 12 ounces of logwood, and rinse. Violet for 22 Pounds of Straw. Boil for 2 hours with alum 4 pounds, tartaric acid 1 pound, and tin salt 1 pound. According to the shade desired add some extract of logwood or indigo. After dyeing, wash in water compounded with alum. Red for 22 Pounds of Straw. The mordant consists of tartar 1 pound and some tin salt. Boil for two hours. Then boil for one hour with fustic 1 pound, turmeric 7 ounces, madder 7 ounces, cudbear 1 pound, and logwood 1 pound. Then add, according to the shade desired, cudbear, archil, or madder. Green for 22 Pounds of Straw. Boil for 2 hours in a mordant of sumach 7 ounces, alum 2 pounds, and tartar 1 pound, and then add some picric acid, turmeric, and aniline green. Straw can also be dyed with aniline colors, the manipulation of which presents no difficulties. To give lustre to the articles manufactured from the dyed straw, gum or gelatine is frequently used. STRENGTH OF MATERIALS. Autographic Torsion Testing Machine, made by the Pratt & Whitney Co., Hartford, Conn. This instrument has been devised by Prof. R. H. Thurston for the special purpose of determining the torsional strength of materials of construction. It gives the investigator an autographic accord of the values of elasticity, ductility, homogeneity, and ultimate resistance of the various metals, alloys, woods, etc., used in engineering constructions, enabling him to pass a sound judgment upon the relative usefulness of such materials for the various purposes in construction for which they may be intended. The machine is constructed with special reference to convenience of operation, and provides improved methods of subjecting specimens to torsional strains, either continuously or intermittingly, through all degrees of strain to final rupture; and the autographic recording device with which the same is provided exhibits graphically throughout |