Chrome Tanning.

Abstract

KNAPP, in 1858, published a paper in which he clearly described a chrome-tanning process. The liquor which he used contained a basic chloride of chromium but he stated that the leather he thus produced did not differ materially from the well-known alum-tanned leather.The first, so-called chrome leather put on the market was made according to the Heinzerling British patents of 1878. According to this process, the skins were treated in solutions containing alum, common salt, and a chromate or bichromate of the alkalies or of the alkaline earth metals, and they were afterwards subjected to the action of a benzine solution of stearhe or similar fats. No systematic attempt was made to reduce the