PROPERTIES OF NITRATES.

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nitrogen gases at high temperatures, and yield yellowish vapours,(nitrous acid) by the affusion of sulphuric acid, especially if heatbe applied.

Remark. ..It is upon the property of the detonation of nitiateswith inflammable substances that the composition of gun-powderis founded, which consists of 5 parts of nitrate of potash, 1 ofcharcoal, and 1 of sulphur.

Powder of fusion, as it is called, consists of 3 parts of nitrateof potash, one of sulphur, and one of fine dry saw-dust. If asmall quantity of this powder is put into a walnut-shell, with athin piece of copper coin rolled up, and the money then be co-vered up with the powder, it may be melted by setting fire to themixture, which will burn vividly without injuring the shell.

A mixture of one part of nitrate of potash and two of acidu-lous tartrite of potash, (or common flour) after being detonated,forms what is denominated llack flux.

IPhite flux is produced by detonating equal parts of nitrate ofpotash and acidulous tartrite of potash, or flour, in a similarmanner.

METHODS OF OBTAINING NITRATES.

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Nitrate of potash, soda, ammonia, barytes, or strontia may beprepared by neutralizing the carbonates of these alcalies with ni-tric acid, evaporating the solution and suffering it to crystallize.Nitrate of magnesia is produced in a similar manner. Nitrate ofsilver is obtained by dissolving silver in nitric acid, evaporatingthe solution until a pellicle appears, and then setting it aside tocrystallize. Nitrate of mercury, copper, nickel, lime, or cobaltmay be produced in a similar manner. Nitrate of iron is obtainedby dissolving iron in nitric acid. On evaporating the solution ared precipitate appears consisting of iron, oxidated to its maxi-

mum.