Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Home › Pigments › Purple of Cassius
Purple of Cassius
To a moderately dilute solution of sesquichloride of iron, add a solution of protochloride of tin, until the mixture becomes green, and dilute the mixture with an equal bulk of water. Next prepare a solution of terchloride of gold, as neutral as possible, in the proportion of 1 part gold in 360 parts water; then add the tin solution, with constant stirring, as long as any precipitate is produced. Wash the precipitate as quickly as possible by decantation, and dry at a gentle heat. 2723. Buisson's Preparation of Purple of Cassius. Two solutions of tin are required. The first consists of a neutral solution of 1 part tin in nitric acid. The second is made by dissolving 2 parts tin in a mixture of 1 part hydrochloric acid with 3 parts nitric ally made from Japan varnish, sugar of lead, litharge, etc., and are necessary in such paints as are preferably prepared without boiled oil.