The following formula makes an indelible crimson ink:
| Silver nitrate | 50 parts |
| Sodium carbonate, crystal | 75 parts |
| Tartaric acid | 16 parts |
| Carmine | 1 part |
| Ammonia water, strongest | 288 parts |
| Sugar, white, crystallized | 36 parts |
| Gum arabic, powdered | 60 parts |
| Distilled water, quantity sufficient to make | 400 parts |
Dissolve the silver nitrate and the sodium carbonate separately, each in a portion of the distilled water, mix the solutions, collect the precipitate on a filter, wash, and put the washed precipitate, still moist, into a mortar. To this add the tartaric acid, and rub together until effervescence ceases. Now, dissolve the carmine in the ammonia water (which latter should be of specific gravity .882, or contain 34 per cent of ammonia), filter, and add the filtrate to the silver tartrate magma in the mortar. Add the sugar and gum arabic, rub up together, and add gradually, with constant agitation, sufficient distilled water to make 400 parts.
Gold Indelible Ink.
| 1.— | Chloride of gold and sodium | 1 part |
|---|---|---|
| Water | 10 parts | |
| Gum | 2 parts | |
| 2.— | Oxalic acid | 1 part |
| Water | 5 parts | |
| Gum | 2 parts |
The cloth or stuff to be written on should be moistened with liquid No. 2. Let dry, and then write upon the prepared place with liquid No. 1, using preferably a quill pen. Pass a hot iron over the mark, pressing heavily.
India, China, Or Japan Ink.
Ink by these names is based on lampblack, and prepared in various ways. Many makes flow less easily from the pen than other inks, and are less durable than ink that writes paler and afterwards turns black. The ink is usually unfitted for steel pens, but applies well with a brush.
I.—Lampblack (finest) is ground to a paste with very weak liquor of potassa, and this paste is then diffused through water slightly alkalized with potassa, after which it is collected, washed with clean water, and dried; the dry powder is next levigated to a smooth, stiff paste, with a strong filtered decoction of carrageen or Irish moss, or of quince seed, a few drops of essence of musk, and about half as much essence of ambergris being added, by way of perfume, toward the end of the process; the mass is, lastly, molded into cakes, which are ornamented with Chinese characters and devices, as soon as they are dry and hard.
II.—A weak solution of fine gelatin is boiled at a high temperature in a digester for 2 hours, and then in an open vessel for 1 hour more. The liquid is next filtered and evaporated to a proper consistency, either in a steam- or {407} salt-water bath. It is, lastly, made into a paste, as before, with lampblack which has been previously heated to dull redness in a well-closed crucible. Neither of the above gelatinizes in cold weather, like the ordinary imitations.