White Precipitate Vitriol

To determine the nature of the base, Lavoisier added to a solution of the gypsum some concentrated fixed alkali, drop by drop. Immediately the vitriolic acid left its base to unite with the fixed alkali and form with it vitriolated tartar [potassium sulfate]. The solution became turbid and a white precipitate formed, which when washed proved to be a very pure cal-... 

Ointment for Old Sores. Red precipitate, 4 ounce sugar of lead, 4 onuco burnt alum, 1 ounce white vitriol, 4 ounco or a little less all to be very finely pulverized have mutton tallow made warm, 4 pound . sUr all in, and stir until cool. Good. 

Brandt classed mercury, antimony, bismuth, cobalt, arsenic and zinc as semi-metals, rejecting cinnabar, vitriols, etc., from this class. He considered that true metals solidify from fusion with a convex surface. The semi-metals have a metallic appearance but are brittle under the hammer. He describes metallic zinc spiauter, conterfeth) from the East Indies, Rammelsberg, and Dalecarlia and Rattwick in Sweden, as a semi-metal. Blende is an ore of zinc and white vitriol is a compound of zinc, since it can be prepared by dissolving zinc in sulphuric acid, and if the solution of white vitriol is precipitated with alkali and the precipitate (zinc carbonate) heated with copper and charcoal, brass is produced. 

He writes in symbols red precipitate of mercury heated in a retort gave much vitriolic air, no fixed air, very little sublimate (yellowish-red), and metallic mercury. Scheele mentions his memoir on arsenic, saying that he showed how this acid can be sublimed into ordinary arsenic simply by continued heat and although I clearly perceived the reason for this, even at that time, still I was unwilling to mention it there in order to avoid prolixity . He found thdt when arsenic acid is very strongly heated it melted, boiled , and white arsenic sublimed. 

A recipe for Antwerp green is given by Fishwick, who was writing in the late eighteenth/early nineteenth centuries For lib of blue vitriol dissolved in [ ] of water, add immediately 11b of purified alkali, 4oz powdered white arsenic, dissolved previously in 1 gallon of boiling water the precipitate, from the mixture of these two solutions is to be well washed, and dry d on white paper spread on flat pieces of chalk [q.v.). This appears to be for the copper arsenite compound commonly known as Scheele s green. 

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