Metallic alloys, like all other combinations, have a point of saturation. It would even appear, from the experiments of Mr de la Briche, that they have two perfectly distinct degrees of saturation.

Table of the Combinations of Azote in the state of Nitrous Acid with the Salifiable Bases, arranged according to the affinities of these Bases with the Acid.

Names of the bases.Names of the neutral salts.
New nomenclature.Notes.
BarytesNitrite of barytes.{
Potashpotash.{These salts are only
Sodasoda.{known of late, and
Limelime.{have received no particular
Magnesiamagnesia.{name in the old
Ammoniacammoniac.{nomenclature.
Argillargill.{
{As metals dissolve both in nitrous and
Oxyd of zinczinc.{nitric acids, metallic salts must of
ironiron.{consequence be formed having
manganesemanganese. {different degrees of oxygenation.
cobaltcobalt.{Those wherein the metal is
nickelnickel.{least oxygenated must be
leadlead.{called Nitrites, when more so,
tintin.{Nitrats; but the limits of this
coppercopper.{distinction are difficultly
bismuthbismuth.{ascertainable. The older
antimonyantimony.{chemists were not acquainted
arsenicarsenic.{with any of these salts.
mercurymercury.{
silver{It is extremely probable that gold, silver
gold{and platina only form nitrats, and cannot subsist
platina{in the state of nitrites.

Table of the Combinations of Azote, completely saturated with Oxygen, in the state of Nitric Acid, with the Salifiable Bases, in the order of the affinity with the Acid.

Bases.Names of the resulting neutral salts.
New nomenclature.Old nomenclature.
Barytes Nitrat ofbarytesNitre, with a base of heavy earth.
Potash potashNitre, saltpetre. Nitre with base of potash.
Soda sodaQuadrangular nitre. Nitre with base of mineral alkali.
Lime limeCalcareous nitre. Nitre with calcareous base. Mother water of nitre, or saltpetre.
Magnesia magnesiaMagnesian nitre. Nitre with base of magnesia.
Ammoniac ammoniacAmmoniacal nitre.
Argill argillNitrous alum. Argillaceous nitre. Nitre with base of earth of alum.
Oxyd ofzinc zincNitre of zinc.
iron ironNitre of iron. Martial nitre. Nitrated iron.
manganese manganeseNitre of manganese.
cobalt cobaltNitre of cobalt.
nickel nickelNitre of nickel.
lead leadSaturnine nitre. Nitre of lead.
tin tinNitre of tin.
copper copperNitre of copper or of Venus.
bismuth bismuthNitre of bismuth.
antimonyantimonyNitre of antimony.
arsenic arsenicArsenical nitre.
mercury mercuryMercurial nitre.
silver silverNitre of silver or luna. Lunar caustic.
gold goldNitre of gold.
platina platinaNitre 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 the acid condenses in the recipient in form of a dark orange red liquid, while the rest combines with the water in the bottles. During the distillation, a large quantity of oxygen gas escapes, owing to the greater affinity of oxygen to caloric, in a high temperature, than to nitrous acid, though in the usual temperature of the atmosphere this affinity is reversed. It is from the disengagement of oxygen that the nitric acid of the neutral salt is in this operation converted into nitrous acid. It is brought back to the state of nitric acid by heating over a gentle fire, which drives off the superabundant nitrous gas, and leaves the nitric acid much diluted with water.