Marking-ink.—The use of marking-ink is for writing on textile fabrics ; it must therefore be proof against the action of hot water, soap, alkalies, &c. The chief recipes are : —(a) 20 parts potash are dissolved in boiling water, 10 parts fiuely cut leather-chips, and 5 parts flowers of sulphur are added, and the whole is heated in an iron kettle until it is evaporated to dryness. Then the heat is continued until the mass becomes soft, care being taken that it does not ignite. The pot is now removed from the fire, and water is added ; the solution is strained, and preserved in bottles. This ink flows easily from the pen. (b) Triturate 1.75 grm. aniline black with 60 drops strong hydrochloric acid and 42 grm. strong alcohol. The mixture is diluted With a hot solution of 2.5 grm. gum arabic in 170 grm. water. This ink does not attack steel pens, and is destroyed neither by mineral acids nor by caustic alkalies. (c) Neutralize 75 gr. carbonate of ammonia with pure nitric acid, and triturate 45-60 gr. carmine with the solution. Mordant the fabric with a mixed solution of acetate of alumina and tin salt, and write upon it, when it is perfectly dry, with the ink. The characters will be of a Tyrian purple colour. (d) Dissolve in 60 grm. water, 8•25 grm. crystalline chloride of copper, grm. chlorate of soda, and 5.35 grm. chloride of ammonium: dissolve 20 grm. hydrochlorate of aniline in 30 grm. distilled water, and add 20 grm, solution of gum arabic (1 part gum to 2 water), and 10 grm. -glycerine ; 4 parts of the aniline liquid mixed in the cold with 1 part of the copper solution produce a greenish liquid, which may be used at once for marking linen ; but as it decomposes iu a few days, it is better to preserve the two solutions separately. The writing is at first greenish, but is blackened by exposure to steam (for example, by being held over the spout of a boiling kettle). A dry heat renders the tissue brittle. (e) First mix 1 lb. extract of logwood with 1 gal. water ; then dissolve 4 oz. sulphate of protoxide of iron in 4 oz. water ; and + oz. sulphide of potassium in 2 oz. water. Dissolve the logwood extract by boiling ; add the potassium solution to the iron solution, until the latter assumes a black colour ; then add this to the logwood solution, and boil for a few minutes. Add oz. cyanide of potassium, to fix the colour ; then gum and alcohol. (f) An excellent marking-ink is made from the resinous juice of "marking-nuts," the fruit of an E. Indian tree (Semocatpus Anacardium). The " nute " are coarsely crushed, then digested for some time in petroleum ether ; the solvent is finally allowed to evaporate spontaneously. The syrupy residue when used for marking gives a brown mark, which changes to black on applying ammonia or calcic hydrate. The marks resist chloride of lime, acids, and potassium cyanide. (g) First, moisten the place where the letters are to be written with a solution of 1 dr. carbonate of soda and 1 dr. gum arabic in 1 oz. water, and smooth the spot with a warm iron. Next, with a quill pen, write with a solution of 1 dr. bichloride platinum in 2 oz. water. Lastly, when the writing is dry, write over the letters only with a solution of 1 dr. protochloride of tin in 2 oz. water. The marks immediately acquire a bright-purple colour. (h) A quicker but more expensive method is to write with a solution of chloride of gold on the linen, previously starched and pressed ; on exposure to sunlight, the letters assume a bright rose-pink colour. (2) When a stencil-plate is used, apply with the brush a mixture of Chinese vermilion with thin copal varnish. The letters will appear red. (j) 22 parts carbonate of soda are dissolved in 25 parts distilled water ; also 17 parts nitrate of silver in 24 parte ammonia ; 20 parts gum are then macerated in GO parts water, and mixed with the soda solution ; the nitrate of silver solution is then added, together with 33 parts sulphate of copper. The ink writes a rich blue. (h) Dissolve 1 dr. nitrate of silver in oz. water ; add to solution as much liquid ammonia as will redissolve the precipitated oxide, with some sap green to colour it, and sufficient gum water to raise the volume to 1 oz. Letters written with this ink should be first fire-heated, and then exposed to the sun to blacken. The fabric requires no previous preparation. (1) Write with a solution of nitrate of silver, thickened with gum, and tinted with sap green, on fabrics previously damped with solution of carbonate of soda. (m) Dissolve separately 1 oz. nitrate of silver, and 11 oz. carbonate of soda ; mix the solutions, and collect the precipitate on a filter ; wash well ; introduce the moist precipitate into U. mortar, and add 8 scr. tartaric acid ; triturate till effervescence ceases ; add sufficient strong liquor ammonia to dissolve the tartrate of silver ; add 4 fl. dr. orchil, 4 dr. powdered white sugar, and 12 dr. powdered gum arable ; make up to 6 fl. oz. with distilled water. (n) Crimson marking-ink may be made by adding 6 gr. carmine to the liquor ammonia of (m) ; but it soon loses its crimson tint, and becomes black. (0) Dissolve N gr. powdered gum copal in 200 gr. lavender oil, by the aid of gentle heat ; then add 21 gr.
lamp-black, and gr. powdered indigo. (p) In 18 oz. water, boil 2 oz. shellac, and 1 oz. borax ; when cold, filter ; add 1 oz. gum arabic, dissolved in 2 oz. water, with the requisite quantity of indigo and lamp-black. (q) First, dissolve together parts chloride of copper, parts salt, and 5.3 parts sal ammoniac, in 60 parts distilled water ; then dissolve 20 parts hydrochloride of aniline in 30 parts water, to which has been added 20 parte of a gum solution (made by dissolving 1 part gum in 2 parts water), and lastly, add ten parts glycerine. These solutions are kept in separate bottles. For use, mix 1 part by bulk of the first solution with 4 parts by bulk of the second. Apply with a quill pen or small brush. The writing appears green at first, but blackens on exposure to a higher temperature.
Indian-ink.—The peculiar ink employed by draughtsmen is termed "Indian," because the best qualities have always come to us from India and China. In the latter country, tho manufacture of drawing-inks is a large industry, and several factories are to be found in Shanghae and other parts of the empire.
A. The Chinese mode of manufacture is as follows :—In some parts of N. China, the lamp-black, which forms the foundation of the ink, is prepared much in the same manner as in Europe (see Blacks—Lamp-black). In other districts, the following method prevails :—The furnaces are built upon the ground, with a length varying from 8 ft. to 40 ft., or even 50 ft., and with a mouth about 2 ft. in diameter. The material generally used is pine, or other resinous wood, or the resin itself, which is burned at the mouth of the furnace. Only the black deposited at the extreme end of the furnace is used for the finest ink, all the remainder being proportionately coarser. The fineness of the grain depends also upon the slowness of the combustion. The very finest black is said to be derived from pork-fat ; the next from oils and other kinds of grease. The smoothness of the ink is likewise largely dependent upon the careful sifting of the black through silken bags or sieves. The first operation in compounding the ink is to soak a quantity of the excellent glue made from buffalo-hide ; when thoroughly swollen, it is set aside, and,will keep in this state for several days. For use, the glue is melted in an iron pot, and as much lamp-black is added as will produce a soft paste. This paste is very carefully kneaded by hand. A small quantity of pea-oil is then added, and the whole is maintained at a temperature of 54°-60° (130°-140° F.), until the paste is found to be perfectly homogeneous. It is then poured out in the form of flat cakes, weighing 1-2 lb. each, and is left in that condition for many days, to " ripen." It often happens, when the weather is hot and damp, that the cakes become covered with mould ; but this does not seem to pro duce any ill effect. While one set of workmen manufacture the paste, another set fashion it into the familiar forms met with in commerce. The latter sit at a bench, with a small brazier beneath ; the workman warms a piece of the paste, kneads it vigorously in his hands, presses it into a mould, and places the latter under a long lever, on the end of which he sits, eo as to compress the ink forcibly, 4 r for some seconds ; he fills another mould in the meantime, and so the operation progresses. The moulds are made of wood, the characters to be impressed upon the cakes being engraved also on wooden dies. One of these dies is dropped into a cavity in the bottom of the mould, while another is laid on the top of the paste in the mould. Common qualities are often pressed into large moulds with several partitions, so that the cakes, when dry, can easily be broken off from each other. For wholesale manufacturing purposes, the best is simply rolled, and the sticks, perforated at one end, are strung together in bunches of doz. The drying of the cakes occupies 5-6 days, according to the temperature. Their high polish is due to brushing over with a hard brush impregnated with tree-wax (probably that secreted by Coccus Pe-la, on the branches of Fraxinus chinensis), which has the additional effect of preventing the ink soiling the hands when they are moist. The peculiar odour possessed by the finest ink is produced by mixing a small quantity of musk, or of Borneo camphor, with the paste while hot. The common qualities are unscented. The Japanese make ink in the same way, but it is inferior to the Chinese product, as, though the glue and gelatine are equally good, less care is taken in the preparation of the lamp-black. The finest ink should be slightly brown in tint ; when quite black, bluish, or grey, it is inferior. A stick of fine ink gives a clear, sharp sound, when struck ; if the tone be dull, the ink is not homogeneous. The heaviest ink is the best ; it improves in colour and brilliancy by age. The chief test of good ink is that it will produce a tint of any depth, without the slightest appearance of irregularity. Some cakes are worth 5-6s. each.