Soda soda Glauber's salt. Lime lime Selenite, gypsum, calcareous vitriol. Magnesia magnesia Epsom salt, sedlitz salt, magnesian vitriol. Ammoniac ammoniac Glauber's secret sal ammoniac. Argill argill Alum. Oxyd of zinc zinc {White vitriol, goslar { vitriol, white coperas, { vitriol of zinc. iron iron {Green coperas, green { vitriol, martial vitriol, { vitriol of iron. manganese manganese Vitriol of manganese. cobalt cobalt Vitriol of cobalt. nickel nickel Vitriol of nickel. lead lead Vitriol of lead. tin tin Vitriol of tin. copper copper {Blue coperas, blue vitriol, { Roman vitriol, { vitriol of copper. bismuth bismuth Vitriol of bismuth. antimony antimony Vitriol of antimony. arsenic arsenic Vitriol of arsenic. mercury mercury Vitriol of mercury. silver silver Vitriol of silver. gold gold Vitriol of gold. platina platina Vitriol of platina. SECT. XIV.--_Observations upon Sulphuric Acid and its Combinations._ For a long time this acid was procured by distillation from sulphat of iron, in which sulphuric acid and oxyd of iron are combined, according to the process described by Basil Valentine in the fifteenth century; but, in modern times, it is procured more oeconomically by the combustion of sulphur in proper vessels. Both to facilitate the combustion, and to assist the oxygenation of the sulphur, a little powdered saltpetre, nitrat of potash, is mixed with it; the nitre is decomposed, and gives out its oxygen to the sulphur, which contributes to its conversion into acid. Notwithstanding this addition, the sulphur will only continue to burn in close vessels for a limited time; the combination ceases, because the oxygen is exhausted, and the air of the vessels reduced almost to pure azotic gas, and because the acid itself remains long in the state of vapour, and hinders the progress of combustion.