An Easy Method of Assaying and Classing Mineral Substances. Containing Plain and Easy Instructions for Any Person to Examine the Products of His Own Land, ... To which is Added, a Series of Experiments on the Fluor Spatosus, Or Sparry Fluor. Abstracted from the Memoirs of the Royal Swedish Academy of Sciences for the Year 1771. By John Reinhold Forster, F.R.S.
