Manufacturer and builder, 5/1880
The very general aversion of green pigments entertained by the well informed public, by reason of the suspicion that they may contain dangerous quantities of arsenic, is well founded. On this account, it may be of interest to notice that M. Casali has claimed to have produced a green coloring matter suitable for wall papers, and other similar uses, by calcining an intimate mixture of one part of bichromate of potassa and three parts of baked gypsum. A grass-green mixture is obtained, which, on boiling with water, or on mixing with dilute hydrochloric acid, leaves a fine powder of an intense green color.
This suggestion seems to us to be very useful, as many serious and even fatal accidents have been directly traced to the poisonous effects of arsenical greens on paper useful for wall coverings, bon-bon boxes, and the like. The above recipe, if it produces a product as good as is claimed, will be not only free from objection on account of its freedom from danger, but also quite cheap.
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