TABLE _of the Combinations of Sulphuric Acid with the Salifiable Bases, in the order of affinity._
_Names of the bases._ _Resulting compounds._ _New nomenclature._ _Old nomenclature._
Barytes Sulphat of barytes Heavy spar. Vitriol of heavy earth.
Potash potash { Vitriolated tartar. Sal { de duobus. Arcanum { duplicatam.
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.
In the manufactories for making sulphuric acid in the large way, the mixture of nitre and sulphur is burnt in large close built chambers lined with lead, having a little water at the bottom for facilitating the condensation of the vapours. Afterwards, by distillation in large retorts with a gentle heat, the water passes over, slightly impregnated with acid, and the sulphuric acid remains behind in a concentrated state. It is then pellucid, without any flavour, and nearly double the weight of an equal bulk of water. This process would be greatly facilitated, and the combustion much prolonged, by introducing fresh air into the chambers, by means of several pairs of bellows directed towards the flame of the sulphur, and by allowing the nitrous gas to escape through long serpentine canals, in contact with water, to absorb any sulphuric or sulphurous acid gas it might contain.