2510. Fine Marking Ink

2510.    Fine Marking Ink. Marking linen is most conveniently effected by using a small stiff brush and a small copper plate with perforations corresponding to the letters required. This stencil plate is laid upon the linen, and the ink is rubbed into the cut-out spaces with the brush. The following ink is of service for marking linen with a stencil plate: 2 parts nitrate of silver, 4 parts dis- tilled water, 21/2 parts gum-arabic, 3 parts carbonate of soda crystals, 5 parts liquid ammonia. The best way to prepare the ink is to first dissolve the nitrate of silver in the liquid ammonia, and the gum-arabic and soda in the distilled water. The two solutions are then mixed together and slightly warmed, when the whole mixture becomes brown. A few drops of a solution of magenta makes the ink somewhat more distinct. When this method is used, the linen requires no previous preparation.

2511. Aniline Marking Ink

2511.    Aniline Marking Ink. Dissolve 81/2 grains bichloride of copper in 30 grains distilled water, then add 10 grains common salt, and 91/2 grains liquid ammonia. A solution of 30 grains hydrochlorate of aniline in 20 grains distilled water is then added to 20 grains of a solution of gum-arabic (containing 2 parts water, 1 part gum-arabic), and lastly 10 grains of glycerine. 4 parts of the aniline solution thus prepared are mixed with 1 part of the copper solution. The liquid which results has a green appearance, and may be at once employed for marking linen, since it invariably becomes black after a few days. A steel pen may be employed as well as a quill. If it is desirable not to wait so long for the appearance of the black color, a hot iron may be passed over the writing when the ink is dry, or the linen may be held over the flame of a spirit lamp, or over a hot plate, or hot water, when the black tint will readily appear. It is a good plan to put the linen, when marked, into a tepid solution of soap, which has the effect of bringing out a fine bluish tint. The ink must be so limpid that it is able to permeate the tissue of the linen, so that the marks appear on both sides. It is advisable to mix the solutions together, only when the ink has to be used. It is perfectly indelible, and so easy to write with that the finest device's may be drawn with it. This ink has the advantage of being cheaper than the ink prepared from nitrate of silver. It has also another advantage over the latter salt, viz.: that it is chemically indelible.

2512. Purple Marking Ink

2512.    Purple Marking Ink. A purple marking ink can be preparecf by mixing 1 part bichloride of platinum with 16 parts distilled water. The place where the letters have to be written must be moistened with a solution of 3 parts carbonate of soda, 3 parts gum-arabic, and 12 parts water. The spot is then dried and made smooth. After the letters have been written with the platinum ink and become dry, the linen is moistened with a solution of 1 part chloride of tin in 4 parts distilled water, when an intense and beautiful purple-red color makes its appearance.