A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c22.s4.t1: Sample I

v1.c22.s4.t1.1

The powder was reddish brown in colour; and slightly magnetic; 0·6638 g was boiled a few hours with hydrochloric acid in a current of carbonic acid gas. On adding a drop of potassium ferricyanide solution to a drop of the iron solution, a faint blue colour was noticed. Weight of insoluble residue, which was simply siliceous matter, was equal to 0·107g; the oxide of iron was therefore equal to 0·6638g—0·107g.=0·5568g. The solution, distinctly yellow in colour, was treated with ammonia and the precipitate, ignited in the usual way, weighed 0·560 g. The sample was thus practically ferric oxide (Fe₂ O₃).