solved. Compound the intensely darkred fluid with 14 pounds of gum-Arabic and 8 ounces of white sugar, and sufficient wheat flour to give it the proper consistency.

Painting with Sympathetic Colors differs from other painting only as regards the colors used, which are simply metallic solutions possessing the property to appear only when the picture is subjected to a moderate heat, and disappearing again on cooling.

Yellow. Dissolve brown cupric oxide in hydrochloric acid, assisting the action of the acid with heat. The solution is olive-green, and by evaporation furnishes grass-green crystals. Dissolve 1 part of these crystals in 8 of water, and add a little gum.

Green. Pulverize 1 part of cobalt, place the powder in a matrass and add 4 parts of aqua regia. Digest the mixture at a moderate heat; then add part of common salt and dilute with 16 parts of water. Filter the fluid, and when it is to be used mix it with a little gum.

Blue. Pulverize 1 part of cobalt, and heat in a matrass with 2 of nitric acid. When the cobalt is dissolved pour the solution into a vessel and gradually add solution of potash until precipitation ceases. Let the mixture stand quietly for some time, then pour off the clear fluid and wash the residue entirely free from acid with water. Let the precipitate drain off, and then dis solve it at a moderate heat in acetic acid, adding the latter in small portions until a saturated fluid is obtained. This solution, mixed with a little gum, is used as a blue color.

It is best to choose for this kind of painting a winter landscape, executed in water colors. Buildings, if such are represented in the landscape, are colored with ordinary water colors with the exception of the roofs, which are painted with a sympathetic color mixed from purple-red, yellow, and some blue. Ali the rest of the scenery is painted with sympathetic colors. The sky is colored blue; mountains, meadows, leaves, etc., with the desired tints of green, etc. To liven up the picture a few flowers may be painted in the foreground. The painting as mentioned must be executed in a warm room. On carrying the colored picture into a cold room the metallic colors disappear gradually; the sky loses its summer Painter's Cream. Painters, who have blue, the cold wintery sky again_tak-long intervals between their periods of ing its place, the mountains, meadows, labor, are accustomed to cover the parts trees, etc., seem to be covered with they have painted with a preparation snow, and so on. On exposing the which preserves the freshness of the picture again to a moderate heat the colors, and which they can remove on scene is changed in a moment to a resuming work. This preparation is beautiful summer landscape. as follows: Clear nut oil 1 gill, pulverPreparation of the Colors used. ized mastic in tears ounce, and pulverPurple Red. Dissolve 1 part of co-ized acetate of lead 4 ounce. Dissolve baltic oxide in 3 of nitric acid. It is best, in order to promote the reaction of the acid, to do this in a matrass exposed to heat. When the solution is complete, add basic carbonate of potassium as long as a dirty-gray precipitate is formed, and cease immediately on the precipitate assuming a purple-red color. Then dilute the solution with 6 parts of water, filter it, and add some gum.

Rose Red. Dissolve 1 part of cobaltic oxide in 3 of nitric acid, and when the solution is complete evaporate to dryness to expel the acid; then add 1 part of nitrate of potassium and dilute the whole with 8 parts of water. The resulting rose-red color is filtered and mixed with some gum.

the mastic in oil over a gentle fire, and pour the mixture into a marble mortar over the pulverized acetate of lead; stir it with a wooden pestle, and add water in small quantities until the compound assumes the appearance and consistency of cream, and refuses to admit more water.

PAPER AND PAPER MATERIALS, MAN-
UFACTURE, STAINING, ETC. GLASS,
SAND, AND EMERY PAPER.

Preparation of the different kinds of Straw used in the Manufacture of Paper. The straw must be cleansed from all weeds; it is then cut up in

pieces from to inch long, and freed from the hard parts, especially the knots. It is then softened by boiling in water and converted by a machine into halfstuff, which is boiled in lye prepared from potash and lime, and then worked into pulp and finished paper.

The most tender straw used in the manufacture of paper is that of oats, next that of barley, wheat, and finally rye. Maize straw is prepared from the leaves and is even more tender than oats straw. The time for boiling depends on the hardness of the material, as also the strength of the lye, and the preliminary labor which may have been bestowed on the material.

Corn Leaves and Stalks are placed in lye containing, for 100 pounds of material, 40 pounds of lime and 1 pound of potash; the straw remains in the lye for 3 hours.

Oats Straw. For 100 pounds of straw a lye is required containing 50 pounds of lime and 2 pounds of potash. Time: 3 hours.

Barley Straw is first boiled for 3 hours in water and then brought into a lye containing, for every 100 pounds of straw, 50 pounds of lime and 2 pounds of potash. It is then brought into a second lye consisting of 30 to 40 pounds of lime and 1 pound of potash. Time in each lye 3 hours.

Wheat Straw is first boiled for 3 hours in water and then placed consecutively in 3 lyes, remaining in each for 3 hours. The first lye consists of 50 pounds of lime and 2 pounds of potash, and the last two of 30 pounds of lime and 1 pound of potash.

Rye Straw, being very hard, must first be boiled in water for 3 hours, and then successively for the same time in four different lyes of the same strength as those for wheat straw.

increased by abating, after the operation is finished, the pressure in the boiler while the lye is drawn off. The material is then worked into half-stuff or converted into a fibre which can be spun.

Transformation of Woolly Fibre. By submitting substances containing wool to a current of steam of 300° F. with a pressure of 5 atmospheres the woolly fibre is so changed that it melts, and in this state collects in the lower part of the boiler, while cotton, linen, and all other vegetable fibres remain unaltered. The latter are now suitable for the manufacture of paper, while the soluble matter, called "ozotine" by the inventor of the process, furnishes a very valuable substance rich in oxygen, which will without doubt be useful for many technical purposes.

Paper for Documents, Checks, etc. To make an alteration in the writing or printing by the use of acid, chloride of lime, or alkali easily perceptible the following ingredients are added to the pulp: 0.75 per cent. of iodide of potas sium, 1 per cent. of starch, 2 per cent. of sulphate or carbonate of manganese, and 2 per cent. of sulphate or carbonate of lead. The compound can be applied to the finished paper with a brush.

Improved Cigarette Paper. Tobacco leaves are ground to an impalpable powder which is sifted in a box upon a moistened sheet of cigarette paper. The sheet thus prepared is covered with another sheet, and brought under a press. Other sheets treated in the same manner are placed upon these and the whole finally subjected to strong pressure, whereby the tobacco-powder is intimately united with the moist paper. After remaining in the press for 12 to 24 hours the paper is removed and is ready for use. By a suitable mixture Process of Gaining Fibrous Sub- the color, flavor, and smell of the stance from different Plants. The various kinds of tobacco can be successplants are cleaned and cut in small fully imitated. Paper thus prepared pieces and impregnated with caustic burns uniformly, never on one side soda-lye of 1° Beaumé, then subjected only, and does not char. to hydrostatic pressure. The lye dissolves the silica, coloring matter, pectine, etc., contained in the raw material, and, in consequence of the pressure, penetrates energetically into the pores of the fibres, swelling and bursting the latter. The effect is still further

Safety Paper. To prevent erasures and alterations it has for some time been customary in France to color paper pulp with green ultramarine, and to execute the writing with diluted hydrochloric acid or solution of alum, producing white characters upon the

green ground. Some English bankers | by means of polished heated cylinders. use paper colored with litmus, upon When properly manufactured, parchwhich are printed ornamental lines ment paper has the same color and with oxalic acid. These lines of course translucency as animal parchment. As are red, but as soon as an attempt is compared with ordinary parchment made to remove the ink with acid the this paper possesses the advantage that entire ground becomes red. If it is it is very little liable to be attacked by sought to revivify the blue by means of insects. And again, the characters inalkalies, the ornamental lines also as- scribed on it cannot be effaced without sume a blue color. difficulty, and when effaced cannot be replaced by others, a perfect guarantee against all kinds of falsification. By reason of its firmness and durability it is well suited for plans and drawings, especially such as are much exposed to moisture. Further it can be used for covering books; or books, maps, etc., for use in schools, could be printed on it and would be very durable. place of animal membrane it is well suited for covering jars of fruit, extracts, etc., as also for connecting the parts of distilling and other apparatus. It furnishes an excellent substitute for animal bladder for the casings of sausages. In surgery it is employed instead of linen, oiled cloth, and gutta percha, for dressing wounds.

Cork Paper, patented in America by H. Felt & Co., is prepared by coating one side of a thick, soft, and flexible paper with a preparation of 20 parts of glue, 1 of gelatine, and 3 of molasses, and covering it with fine particles of cork lightly rolled on. The material is used for packing glass, bottles, etc. Wrapping Paper for Silver Ware. The appearance of silver ware is frequently injured by being exposed to air containing sulphuretted hydrogen or sulphurous and other acids. The small quantity of sulphuretted hydrogen contained in illuminating gas and which in burning yields sulphurous acid is frequently sufficient to spoil the appearance of all the articles in a store. To prevent this a prepared paper is reoommended. Prepare a solution of 6 parts of caustic soda in water of 20° Beaumé, then add 4 of zinc oxide and let the mixture boil for 2 hours, if possible under a pressure of 5 atmospheres. Dilute the solution, when clear, to 10° Beaumé, and it is ready for impregnating the paper.

In

Water-proof Paper transparent and impervious to grease is obtained by soaking good paper in an aqueous solution of shellac and borax. It resembles parchment paper in some respects. If the aqueous solution be colored with aniline colors very handsome paper, of use for artificial flowers, is prepared.

Peterson's Water-proof Paper. Dissolve 3 ounces of tallow soap in water, add sufficient solution of alum that the soap is entirely decomposed, and mix this fluid with a gallon of paper-pulp. The paper is in all other respects prepared in the ordinary manner, and need not to be sized. It is especially suitable for cartridge-shells.

Preparation of Parchment Paper. Dilute strong sulphuric acid with its volume of water, and allow it to cool to about 65° F. Then immerse unsized paper in the cold acid for 10 to 50 seconds according to its thickness. When the acid has acted a sufficient length of time, the paper is first well washed in cold running water, then Carbolic Acid Paper is prepared with dipped in dilute ammonia, again 3 ounces of carbolic acid to the square washed in water, and finally dried. foot. It is used for disinfecting purWhen it is left to itself to dry it be- poses, and also for packing fresh meat. comes shrivelled and has a bad appear- The process of preparing it is as folance. To guard against this the fol-lows: Melt at a moderate heat 5 parts lowing process is adopted: An endless strip of paper is passed by machinery first through a vat of the acid and then through water, ammonia, and water again; next a cloth-covered roller deprives it of a portion of the water, and finally it is pressed and smoothed out

of stearine, 6 of paraffine, and 2 of carbolic acid. Apply the melted mixture to the paper with a brush.

A still more effective paper, and which can be used for a great many purposes, is obtained by the use of a smaller quantity of nitric acid in place of carbolic

acid, the rest of the process being the

same.

Two New Varieties of Preserving Paper have been recently brought into the market. The one is obtained by immersing soft paper in a bath of salicylic acid, and then drying in the air. The bath is prepared by diluting a strong solution of the acid in alcohol with a large volume of water. This paper may then be used for wrapping up apples, etc.

The other paper used as protection against moths and mildew is best prepared from strong manilla paper by immersing it in the following bath: Seventy parts of tar oil, 5 of crude carbolic acid containing about phenole, 20 of coal-tar at a temperature of 160° F., and 5 of refined petroleum. The paper is then squeezed out, and dried by passing it over hot rollers.

consists of 20 parts of printing ink, 50 of wax, 40 of tallow, 35 of rosin, 210 of oil of turpentine, and 30 of Berlin blue.

Writing, Copying, and Drawing Paper which can be washed. The paper is made transparent by immersion in benzine and then, before the benzine volatilizes, plunged into a solution of siccative prepared in the following manner: One pound each of lead shavings and oxide of zinc are boiled for 8 hours, together with 8 ounces of hardened Venetian turpentine in 21 gallons of purified linseed-oil varnish, and then allowed to stand for a few days to cool and settle. The clear layer is then poured off and to this are added 5 pounds of white West Indian copal and 8 to 10 ounces of sandarac dissolved in spirit of wine or ether. This paper can be written or drawn upon with pen and ink or water colors; or, by using good copying ink, good copies can be taken from it without a press.

Plastic Pasteboard for Surgical Bandages is prepared by softening the raw pasteboard by beating, or, if very stiff, Tracing Paper. By the following lixiviating with alkalies, then drying very simple process ordinary drawing thoroughly, and saturating with a solu- paper can be rendered transparent, for tion of shellac, rosin, and turpen- the purpose of making tracings, and its tine, or pine rosin, elemi, etc., and, if transparency removed so as to restore necessary, coating with gutta-percha or its former appearance when the drawvarnish. ing is completed. Dissolve any quanPreparation of Tracing Paper, Trac-tity of castor oil in one, two, or three voling Linen, and Transparent Packing Paper. The paper is first treated with boiled linseed oil, and the excess of oily particles removed with benzine. The paper is then washed in a chlorine bath. When dry it is again washed with oxygenated water.

Linen is first provided with a coating of starch and then with an application of linseed oil and benzine. It is finished by being smoothed between polished rollers.

Photo-lithographic Transfer Paper, and Transfer-color belonging to it. Paper is treated with a solution of 100 parts of gelatine and 1 of chrome-alum in 2400 of water, and, after drying, with white of egg. It is sensitized in a bath consisting of 1 part of chrome-alum, 14 of water, and 4 of alcohol. The addition of the latter prevents the solution of the white of egg. On the places not exposed to the light the white of egg becomes detached, together with the color with which the exposed paper has been coated. The transfer color

umes of absolute alcohol, according to the thickness of the paper, and apply it by means of a sponge. The alcohol evaporates in a few minutes, and the tracing paper is dry and ready for immediate use. The drawing or tracing can be made either with lead-pencil or India ink, and the oil removed from the paper by immersing it in absolute alcohol, thus restoring its original opacity. The alcohol employed in removing the oil is, of course, preserved for diluting the oil used in preparing the next sheet.

Transfer Paper. Mix lard to a paste with lampblack, rub this upon the paper, remove the excess with a rag, and dry the paper. A copy of the writing can be transferred on a clean sheet of paper by placing it underneath the prepared paper and writing upon the latter with a lead-pencil or sharp point.

Tar Paper. Boil 100 pounds of tar for 3 hours, then dissolve in it a quantity of a glue prepared from rosin and