Oxyd of zinc zinc Nitre of zinc.
iron iron Nitre of iron. Martial nitre. Nitrated iron.
manganese manganese Nitre of manganese.
cobalt cobalt Nitre of cobalt.
nickel nickel Nitre of nickel.
lead lead Saturnine nitre. Nitre of lead.
tin tin Nitre of tin.
copper copper Nitre of copper or of Venus.
bismuth bismuth Nitre of bismuth.
antimony antimony Nitre of antimony.
arsenic arsenic Arsenical nitre.
mercury mercury Mercurial nitre.
silver silver Nitre of silver or luna. Lunar caustic.
gold gold Nitre of gold.
platina platina Nitre of platina.
SECT. XIII.--_Observations upon the Nitrous and Nitric Acids, and their
Combinations._
The nitrous and nitric acids are procured from a neutral salt long known
in the arts under the name of _saltpetre_. This salt is extracted by
lixiviation from the rubbish of old buildings, from the earth of
cellars, stables, or barns, and in general of all inhabited places. In
these earths the nitric acid is usually combined with lime and magnesia,
sometimes with potash, and rarely with argill. As all these salts,
excepting the nitrat of potash, attract the moisture of the air, and
consequently would be difficultly preserved, advantage is taken, in the
manufactures of saltpetre and the royal refining house, of the greater
affinity of the nitric acid to potash than these other bases, by which
means the lime, magnesia, and argill, are precipitated, and all these
nitrats are reduced to the nitrat of potash or saltpetre[41].
The nitric acid is procured from this salt by distillation, from three
parts of pure saltpetre decomposed by one part of concentrated
sulphuric acid, in a retort with Woulfe's apparatus, (Pl. IV. fig. 1.)
having its bottles half filled with water, and all its joints carefully
luted. The nitrous acid passes over in form of red vapours surcharged
with nitrous gas, or, in other words, not saturated with oxygen. Part of
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