2485. Arnold's Writing Fluid

2485.     Arnold's Writing Fluid. Arnold's writing fluid is a mixture of sulphate of indigo and ordinary ink. It flows freely from the pen and at last becomes very black. On account of the large quantity of acid it contains, it is very destructive to steel pens, and for this evil we know of no cure.

2486. Blue Fluid for Making Blue-Black Writing Ink

2486.    Blue Fluid for Making Blue-Black Writing Ink. Prussian blue in fine powder, 1 ounce placed in a common phial, and concentrated hydrochloric acid, 2 ounces, poured over it. Effervescence ensues, and the mixture soon assumes the consistence of a thin paste. After 24 hours it may bo diluted with 8 or 9 ounces of water, and preserved in a glass bottle. The intensity of this color may be lessened by water. It forms an excellent blue writing fluid.

2487. Fine "Writing Fluid

2487. Fine "Writing Fluid. Dissolve ceruleo-sulphate of potassa or ammonia (soluble indigo) in hot water, and when cold decant the clear. It is an intense blue, and dries nearly black; is perfectly incorrosive, and very permanent and easy flowing. It may be thickened with gum water, or diluted with pure rain water, as required.

2488. Readers Patent Blue "Writing Fluid"

2488.    Readers Patent Blue "Writing Fluid". Prepare a solution of iodide of iron, from iodine, iron, and water; add to the solution half as much iodine as first used. Pour this solution into a semi-saturated solution of ferroprussiate of potash, containing nearly as much of the salt as the whole weight of iodine. Collect the precipitate, wash it, and finally dissolve it in water, to form the blue ink. The solution from which the precipitate is separated, evaporated to dryness, and the residue fused, re-dissolved, and crystallized, yields pure iodide of potassa.

2489. Indelible Writing Fluid

2489.     Indelible Writing Fluid. To good gall ink, add a strong solution of fine soluble Prussian blue in distilled water. This addition makes the ink which was previously proof against alkalies, equally proof against acids, and forms a writing fluid which cannot be erased from paper by any common method of fraudulent obliteration without the destruction of the paper. This ink writes greenish blue, but afterwards turns intensely black.

2490. Precautions in Making Writing Fluids

2490. Precautions in Making Writing Fluids. All the preceding receipts for writing fluids, under proper management, produce excellent products. Care must be taken in all cases that the ingredients be pure, and unless this precaution is attended to, success is doubtful. Either of the preceding blue fluids may be used as indelible ink to mark linen, and will be found very permanent, provided the part be first moistened with alum water and dried.

2491. Gold Ink

2491.     Gold Ink. Gold ink is prepared in the following way: Genuine gold leaf is rubbed with honey on a plate of agate or ground glass by means of a flat pestle, until the whole presents a uniform mass, in which no distinct particles of gold can be recognized. (See No. 2517 (To Pulverize Gold and Silver Leaf).) This mass is carefully removed into a vessel with water, which will dissolve the honey, and leave the gold in an extremely disintegrated state behind. The water has, according to the size of the vessel, to be removed twice or three times, when all the saccharine matter will have been washed away. The remaining gold is then mixed with a sufficient quantity of a solution of gum-arabic, shaken well, and is ready for use. (See No. 2518 (Liquid Gold, for Vellum, etc.).) The writing is to be rubbed, after drying, with a flat piece of ivory, when it will present the lustre of pure gold.