3. Terchloride of gold, 11⁄2 dr.; water, 7 fl. dr.; mucilage, 2 dr.; sap green, q. s. to colour. To be written with on a ground prepared with a weak solution of protochloride of tin, and dried. Dark purple.
4. (Rev. J. B. Reade.) Nitrate of silver, 1 oz., tartaric acid (pure), 3 dr., are triturated together in a mortar in the dry state; a little water is then added, by which crystals of tartrate of silver are formed, and the nitric acid set free; the latter is then saturated with liquor of ammonia, sufficient being added to dissolve all the newly-formed tartrate of silver, avoiding unnecessary excess; lastly, a little gum and colouring matter is added.
5. (Rev. J. B. Reade.) To the last is added an ammoniacal solution of a salt of gold. Mr Reade has used for this purpose the ‘purple of Cassius,’ the hyposulphate, the ammonio-iodide, the ammonio-periodide of gold, but any other compound of gold which is soluble in ammonia will do as well. This ink is unacted on by nearly all those reagents which remove writing executed with solutions of the salts of silver alone, as cyanide of potassium, the chlorides of lime and soda, &c.
6. (Redwood.) Nitrate of silver and pure bitartrate of potassa, of each 1 oz. (or 4 parts), are rubbed together in a glass or Wedgwood-ware mortar, and after a short time liquor of ammonia, 4 oz. (16 parts, or q. s.), is added; when the solution is complete, archil, 4 dr. (or 2 parts); white sugar, 6 dr. (or 3 parts); and powdered gum, 10 dr. (or 5 parts), are dissolved in the liquor, after which sufficient water is added to make the whole measure exactly 6 fl. oz., when it is ready to be bottled for use. The last three are used in the same manner as No. 2.
7. (Dr Smellie.) From sulphate of iron, 1 dr.; vermilion, 4 dr.; boiled linseed oil, 1
oz.; triturated together until perfectly smooth. Used with type.
8. (Soubeiran.) Nitrate of copper, 3 parts; carbonate of soda, 4 parts; nitrate of silver, 8 parts; mix, and dissolve in liquor of ammonia, 100 parts. Used like No. 2.
9. (Ure.) A strong solution of chloride of platinum, with a little potassa, and sugar and gum, to thicken.
10. The fluid contained between the kernel and shell of the cashew nut. On linen and cotton it turns gradually black, and is very durable. This has been called ANACARDIUM or CASHEW-NUT INK.
11. Sulphate of manganese, 2 parts; lampblack, 1 part; sugar, 4 parts; all in fine powder, and triturated to a paste with a little water. Used with types or stencil-plates; the part, when dry, being well rinsed in water. Brown.