Part 15 (1/2)

Barytes Nitrat of barytes Nitre, with a base of heavy earth

Potash potash Nitre, saltpetre Nitre with base of potash

Soda soda { Quadrangular nitre Nitre with base of { mineral alkali

{ Calcareous nitre Nitre with Lime lime { calcareous base Mother water { of nitre, or saltpetre

Magnesia nesia

Aillaceous nitre Nitre Argill argill { with base of earth of alum

Oxyd of zinc zinc Nitre of zinc

iron iron Nitre of iron Martial nitre Nitrated iron

anese

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 fro known in the arts under the name of _saltpetre_ This salt is extracted by lixiviation fros, froeneral of all inhabited places In these earths the nitric acid is usually conesia, soill 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 thehouse, of the greater affinity of the nitric acid to potash than these other bases, by which ill, 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 ater, and all its joints carefully luted The nitrous acid passes over in foras, or, in other words, not saturated with oxygen Part of the acid condenses in the recipient in fore red liquid, while the rest co the distillation, a large quantity of oxygen gas escapes, owing to the greater affinity of oxygen to caloric, in a high teh in the usual temperature of the ateen 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 ater

Nitric acid is procurable in avery dry clay with saltpetre This mixture is put into an earthern retort, and distilled with a strong fire The clay coreat affinity, and the nitric acid passes over, slightly ied by heating the acid gently in a retort, a sas passes over into the recipient, and very pure concentrated nitric acid remains in the retort

We have already seen that azote is the nitric radical If to 20-1/2 parts, by weight, of azote 43-1/2 parts of oxygen be added, 64 parts of nitrous gas are foren, 100 parts of nitric acid result froen between these two extreenation produce different species of nitrous acid, or, in other words, nitric acid less or as I ascertained the above proportions by h I cannot answer for their absolute accuracy, they cannot be far removed from truth Mr Cavendish, who first showed by synthetic experiives the proportions of azote a little larger than I have done; but, as it is not improbable that he produced the nitrous acid and not the nitric, that circuree the difference in the results of our experiments

As, in all experiree of accuracy is required, we must procure the nitric acid for experimental purposes, fron matter If, after distillation, any sulphuric acid is suspected in the nitric acid, it is easily separated by dropping in a little nitrat of barytes, so long as any precipitation takes place; the sulphuric acid, froreater affinity, attracts the barytes, and forms with it an insoluble neutral salt, which falls to the bottom It may be purified in the sa in a little nitrat of silver so long as any precipitation of muriat of silver is produced When these two precipitations are finished, distill off about seven-eighths of the acid by a gentle heat, and what coree of purity