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Alkalies and Neutral Salts.

part n r,

mixture in small quantities at a time into a red hot crucible.The deflagration being finished, let the salt cool, and preserveit in a well stopped glass vessel."

In this process the sulphur is oxidized, and converted partlvinto sulphuric acid, and partly into sulphurous acid, by unitingwith the oxygen afforded by the decomposition of the nitricaoid of the nitrate, which is effected by the degree of heatemployed. During the deflagration, however, a part of theacid is volatilized in the form of nitrous oxide, and conse-quently the oxygen evolved is not sufficient to acidify all thesulphur, and the unaltered portion remains united with a por-tion of potash. The sulphuric and sulphurous acids combinewith the remainder of the potash; and hence the product is amingled mass, consisting of sulphate or supersulphate of pot-ash ; sulphate of potash; and sulphuret of potash.

Qualities. — This salt has a sensibly acid taste, and reddensinfusion of litmus. It is almost wholly dissolved in eight partsof water at 60°; and by exposure to the air it is altogetherconverted into sulphate of potash. In general I have foundthat it emits no sulphureous odour on the addition of sulphu-ric acid, and is not precipitated by acids; but in other speci -mens prepared with equal care sulphur was thrown down bythe muriatic acid.

Medical properties and uses. — The same as those of sulphate-of potash; and consequently it is scarcely ever used.

AQUA ALCALINA OXYMURIATICA. Dub. Oay-muriatic alkaline Water.

" Take of muriate of soda dried, tiw pounds •, manganesein powder, a pound ,• water, sulphuric acid, each too pounds,Mix together the muriate of soda and manganese, put theninto a matrass, and add the water; then, by means of a pro-per apparatus, add gradually, and at intervals, the sulphuricacid ; and transmit the disengaged gas through a solution con-sisting of four ounces of {sub) carbonate of kali, and twenty-nine ounces by measure of water. Towards the end of dieoperation apply a moderate heat to the matrass. The spe-cific gravity of this solution is to that of distilled water as1087 to 1000."

For this process Woulfe's apparatus is necessary; two-thirdsof the alkaline solution being put into the second bottle, andthe remainder into the third. The sulphuric acid in the ma-trass unites with the soda of the muriate, and disengages themuriatic acid; which receiving oxygen from the black oxideof manganese is converted into oxymuriatic acid, and passesover in the gaseous form into the alkaline solution, where itunites with the potash of the subcarbooate, and sets free the

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