Crayons, Lithograph′ic

Prep. 1. Tallow-soap, 7 parts; white wax, 6 parts; melt by a gentle heat, and add lamp-black, 1 part; keep it melted with constant stirring, for 20 or 30 minutes, then let it cool a little, and cast it into moulds. 2. White wax, 4 parts; shell-lac and hard tallow-soap, of each 2 parts; lamp-black, 1 part; as last. 3. Spermaceti, white wax, and hard tallow-soap, of each equal parts; lamp-black, q. s. to colour. Obs. Some makers melt the soap, wax, and lamp-black in an iron ladle, over a brisk fire, and allow the mixture to blaze for a few seconds before adding the shell-lac, which is no sooner thoroughly incorporated than the heat is increased until the ma again kindles, when it is at once removed from the fire and stirred until it is cool enough to be poured into the moulds. This method leads to trouble and lo , without any corresponding advantage. These crayons are used to draw designs upon lithographic stones.