The use of marking-ink is for writing on textile fabrics; it must therefore be proof against the action of hot water, soap, alkalies, etc.

The chief recipes are: - (a) 20 parts potash are dissolved in boiling water, 10 parts finely-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. (6) Triturate 1.75 dr. aniline black with 240 drops strong hydrochloric acid and 42 dr. strong alcohol. The mixture is diluted with a hot solution of 2*5 dr. gum-arabic in 170 dr. water. This ink does not attack steel pens, and is destroyed neither by mineral acids nor by caustic alkalies, (c) Neutralise 75 gr. carbonate of ammonia with pure nitric acid, and triturate 45 to 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 dr. water, 8.25 dr. crystalline chloride of copper, 10.65 dr. chlorate of soda, and 5.35 dr. chloride of ammonium; dissolve 20 dr. hydrochlo-rate of aniline in 30 dr. distilled water, and add 20 dr. solution of gum-arabic (1 part gum to 2 water), and 10 dr. 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 in 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 1/4oz. 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, ana boil for a few minutes.

Add 1/2 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 East Indian tree (Semecarpus Anacardium). The "nuts " 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 1/2 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. protochlo-ride of tin in 2 oz. water. The marks immediately acquire a bright purple colour. (A) 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, (i) 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 42 parts ammonia; 20 parts gum are then macerated into 60 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, (k) Dissolve 1 dr. nitrate of silver in 3/4 oz. water; add to solution as much liquid ammonia as will redis-solve 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. (l) Write with a solution of nitrate of silver thickened with gum and tinted with green, on fabrics previously damped with solution of carbonate of soda, (m) Dissolve separately 1 oz. nitrate of silver and 1 1/2 oz. carbonate of soda; mix the solutions, and collect the precipitate on a filter; wash well; introduce the moist precipitate into a 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-arabic; make up to 6 fl. oz. with distilled water, (n) Crimson marking ink may be made by adding 6 gr. carmine to the liquor ammonias of (m); but it soon loses its crimson tint, and becomes black, (o) Dissolve 25 gr. powdered gum copal in 200 gr. lavender oil, by the aid of gentle heat; then add 2 1/2 gr. lamp-black, and 1/2 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 lampblack. (9) First dissolve together 8.5 parts chloride of copper, 10.6 parts salt, and 53 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 parts of a gum solution (made by dissolving 1 part gum in 2 parts water), and lastly, add 10 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. A steel pen may be used for writing with it. If the cloth, after being marked, is put into tepid soap-suds, the writing acquires a fine bluish tint. The ink should be perfectly limpid, so as to penetrate the fabric; and the solutions should be mixed only when they are to be used, (r) Enough finely-powdered cinnabar to form a moderately thick liquid is very intimately mixed with egg-albumen, previously diluted with an equal bulk of water, beaten to a froth, and filtered through fine linen. Marks formed on cloth with this liquid by means of a quill are fixed after they have become dry by pressing the cloth on the other side with a hot iron, (s) The following recipe produces a marking-ink that is quite indelible, and may be applied to the calico with a printing-machine: - Peat 9 parts Venice turpentine with 4 parts olein until well incorporated. Place 10 parts soft potash soap on a slab, and work in the turpentine mixture.

Now add 6 parts lampblack (previously ground and sifted), mix well, and finally add 1 part neutral extract of indigo, (t) Dissolve 80 gr. of nitrate of silver in 1 oz. of water; add to this 15 gr. of powdered gum-arabic, and 5 or 6 drops of Tarling's red ink; shake well, keep in a stoppered bottle away from the light, and write with a quill pen. After writing, expose it to light for a short time until it becomes nice and black, (u) The following is a recipe for an indelible red ink to use with stamps on linen: - Liquefy 1 pint of balsam of capivi by aid of heat, and gradually stir in 2 oz. of thoroughly dry white curd soap cut in thin shavings, and stir until properly diffused. Then introduce a sufficient quantity of vermilion, and stir occasionally until cold, (y) Albert Smith, of Essex Road, makes a marking-ink which can be used with any pen, does not require heating, and will not injure the most delicate fabric. The ink writes with a green tinge, and turns an intense black on the first washing.

Smith says that the ink cannot be removed by any known chemical means - chloride of lime, cyanide of potassium, caustic soda, and potash having no effect upon it. (to) Marking-ink for parcels: - Dissolve asphaltum, grahamite, albertite, or any minerals of this character in naphtha or oil of turpentine to a thin fluid. It dries quickly, does not spread, and the markings are nearly indestructible, (x) A bag marking-ink that will stand good, even when bags filled with chemical manures have been in rain and sunshine over 10 days: - 1 lb. of logwood chips boiled in 1 gal. of water 10 minutes; then stir in 1/8 oz. of bichromate of potash, and boil this 10 minutes longer; then add, when eold, 1/2 lb. common gum, previously dissolved, and stir well in. This will flow well from the pen, and will mark bags with either the stencil plate or block. The cost of above ink is about 6d. per. gal.