gems, garnet

I took 100 parts of this substance and heated them to redness with caustic potash; the mass, diluted in water, was supersaturated with muriatic acid, and the liquor evaporated to dryness; I then redissolved it in water and filtered it: there remained upon the filter silica, which, after having been dried and heated to redness, weighed 52 grains. The filtered liquor was clear; I precipitated it with carbonate of potash, and treated the precipitate with caustic potash, which dissolved a great part of it; I filtered the liquor: there remained upon the filter a brown powder, which I redissolved in muriatic acid, from which I separated the iron by ammonia; having well washed and heated it to redness, it weighed 17 grains. I added carbonate of soda to the remainder of the liquor, and carbonate of lime was precipitated, which, after having been dried, weighed 14 grains. The alkaline liquor which held the alumina in solution was supersaturated with acid, and the alumina was reprecipitated from it by carbonate of potash: having been well washed, dried, and heated to redness, it weighed 20 grains.