On thallium

Abstract

After discussing the occurrence and distribution of the new meta in different parts of the globe, the author proceeds to describe the method adopted by him for extracting it from its ore. Thalli-ferous pyrites is distilled at a bright red heat, in quantities of about 1 cwt. at a time, in cast-iron retorts. The resulting sulphur, varying from 13 to 17 per cent, of the pyrites taken, is then dissolved in aqueous caustic soda, which leaves the sulphide of thallium as an insoluble black precipitate; this is filtered off, dissolved in acids, and the thallium precipitated in the form of iodide. This is then converted into sulphate, and the metal reduced from the solution by electrolysis. It is obtained in the coherent form by fusion under cyanide of potassium.