Lithographic ink is composed of tallow 2 ounces; virgin wax 2 ounces; shell lac 2 ounces ; common soap 2 ounces ; lamp black i an ounce. These materials are prepared in an iron saucepan with a cover. The wax and tallow are first put in and heated till they ignite ; whilst they are burning the soap must be thrown in in small pieces one at a time, ta king care that the first is melted before a se cond is put in. When all the soap is melted, the ingredients are allowed to continue burn ing till they are reduced one-third in volume. The shell lac is now added, and as soon as it is melted the flame must be extinguished. It is often necessary in the course of the ope ration to extinguish the flame and take the saucepan from the fire, to prevent the contents from boiling over; but if after the process above described any parts are not completely Melted, they must be disoUrrl over the fire without being again ignited. The black is now to be added, having pre viously mixed it with thick varnish, made by heating linseed oil till it will ignite from the flame of a piece of lighted paper, and allow ing it to burn till reduced to one-half. When it is completely dissolved, the whole mass should be poured out on a marble slab, and a heavy weight laid upon it to render its tex ture fine.
This article was originally published with the title "Lithographic Ink"