I

An excellent varnish for leather can be made from the following recipe: Heat 400 pounds of boiled oil to 212° F., and add little by little 2 pounds of bichromate of potash, keeping the same temperature. The addition of the bichromate should take about 15 minutes. Raise to 310° P., and add gradually during 1 hour at that temperature, 40 pounds Prussian blue. Heat for 3 hours more, gradually raising to 482° to 572° F., with constant stirring.

In the meantime, heat together at 392° F., for 0.5 an hour, 25 pounds linseed oil. 35 pounds copal, 75 pounds turpentine, and 7 pounds ceresine. Mix the two varnishes, and dilute, if necessary, when cold with turpentine. The varnish should require to be warmed for easy application with the brush.

II

Caoutchouc, 1 part; petroleum, 1 part; carbon bisulphide, 1 part; shellac, 4 parts; bone black, 2 parts; alcohol, 20 parts. First the caoutchouc is brought together with carbon bisulphide in a well-closed bottle and stood aside for a few days. As soon as the caoutchouc is soaked add the petroleum and the alcohol, then the finely powdered shellac, and heat to about 125° P. When the liquid appears pretty clear, which indicates the solution of all substances, the bone black is added by shaking thoroughly and the varnish is at once filled in bottles which are well closed. This pouch composition excels in drying quickly and produces upon the leather a smooth, deep black coating, which possesses a certain elasticity.