2943. Aniline Black Varnish

2943. Aniline Black Varnish. An aniline black varnish, of recent Parisian production, is the following: Dissolve 63/4 drachms avoirdupois of aniline blue, 13/4 drachms of fuchsine, and 41/2 drachms of naphthaline yellow, in 1 quart alcohol. The whole is dissolved by agitation in less than 12 hours. One application renders an object ebony black; the varnish can bo filtered, and will never deposit afterwards.

2944. Transparent Varnish for Prints and Pictures

2944. Transparent Varnish for Prints and Pictures. Dilute 1/4 pound Venice turpentine with a gill, or thereabouts, of spirits of wine. If too thick, a little more of the latter; if not enough, a little more of the former; so that it is brought to the consistence of milk. Lay 1 coat of this on the right side of the print, and, when dry, it will shine like glass. If it is not satisfactory, lay on another coat.

2945. To Make the Design of a Print Appear in Gold

2945. To Make the Design of a Print Appear in Gold. After having laid on both sides of the print one coat of the varnish described in No. 2944, in order to make it transparent let it dry a little while; then, before it is quite dry, lay some gold in leaves on the wrong side of the print, pressing it gently on with a cotton pad. By these means, all parts where these leaves have been laid will appear like massive gold on the right side. When this is all thoroughly dry, lay on the right side of it one coat of the varnish described above, and it will then be as good as any crown glass. A pasteboard may be put behind the print, to support it better in its frame.

2946. Clear Gutta-Percha Solution

2946. Clear Gutta-Percha Solution. Cut gutta-percha into thin strips and put it in a glass bottle, and add as much chloroform as makes a thick paste. This paste is then placed in very hot water, and kneaded with the fingers. After considerable manipulation the gutta percha loses much of its color, and if this process is repeated, becomes very nearly colorless, having only a pale straw tint. A chloroform solution may then be made of any strength, which is useful for many purposes - when thin, as a substitute for court plaster, and when thick, as a stopping for decayed teeth.

2947. Solvents for India-Rubber and Gutta-Percha to Make Flexible Varnish

2947.      Solvents for India-Rubber and Gutta-Percha to Make Flexible Varnish. Rubber does not dissolve easily enough to give a varnish by simply placing it in a bottle with the solvent. Sulphuric ether is one of its regular solvents, but then it must be pure rectified ether, and not the mixture of ether and alcohol which is sold for ether in many drug stores. It also must be pure rubber, and not the sulphur-vulcanized article. The pure rubber must be cut into small pieces, soaked in the ether in a warm place for about 24 hours until they are swollen up, and then it must be kneaded in a mortar. In such a way rubber varnishes may be made even with common benzine. "When treated with hot benzole (from coal tar, not benzine from petroleum), it swells to 30 times its former bulk; and if then triturated with a pestle, and pressed through a sieve, it affords a homogeneous varnish, which being applied by a flat edge of metal or wood to cloth, prepares it for forming waterproof cloth. Chloroform and the bisulphuret of carbon dissolve India-rubber and gutta-percha in the cold. Turpentine disintegrates and dissolves India-rubber and gutta-percha when hot. The fixed oils also readily dissolve them with the aid of heat. "When India-rubber remains sticky after working it, it is a proof that the temperature was too high, or that too much turpentine was used in the solutions or varnishes; turpentine rubber varnish has naturally a tendency to dry sticky; benzole or the fixed oils are better. (See No. 2248 (To Dissolve India Rubber for Cement, etc.).)