454

Alkalies and Neutral Salts.

PART III.

dissolved in the water, which distils over; but in both statesit is contaminated with the empyreumatic oil. The subsequentdistillations are intended to free it from this oil; which, al-though at one time it was supposed to add to the efficacyof the remedy, yet is now conceived to be useless, and adisadvantage : nevertheless, when it is completely removed bythe charcoal, this preparation does not differ from a simplesolution of the subcarbonate in water.

The volatile liquor of hartshorn found in the shops is partof the product of the distillation of bones on a great scale;and is never completely free from the empyreumatic oil,which is very perceptible in its odour and taste, and gives ita slight yellow tinge. It is often adulterated by the additionof a considerable portion of water; and this cannot be knownby its pungency, which is kept up by adding to it a smallquantity of liquor ammonia?. The fraud, however, may bedetected by mixing a small portion of the suspected liquorwith twice its bulk of alcohol; when, if no considerablequantity of salt is precipitated, it is certainlv adulterated.

LI'QUOR POTASSiE. Lond. Solution of Potash*

"Take of subcarbonate of potash, a pound; lime freshburnt, half a pound ,• boiling distilled water, a gallon. Dissolvethe subcarbonate of potash in two pints of the water. Add theremainder of the water to the lime, mix the hot liquors toge-ther, then set the mixture aside in a covered vessel, and whenit is cold, let it be strained through a cotton bag. If, on theaddition of any diluted acid, effervescence be excited, more limemust be added, and the filtration repeated. A pint of this so»-lution ought to weigh sixteen ounces."

Aqua Potass^:. Edin. Water of Potash.

" Take of lime fresh burnt, eight ounces; subcarbonate ofpotash, six ounces; boiling water, twenty-eight ounces. Let thelime be put into an iron or earthen vessel, with twenty ouncesof the water. When the ebullition ceases, immediately add thesalt, dissolved in the remaining eight ounces of the water; andhaving thoroughly mixed the whole, cover the vessel till theycool. The mixture being cooled, agitate it well, and pour itinto a glass funnel, the tube of which is obstructed with a pieceof clean linen. Cover the upper orifice of the funnel while itstube is inserted into another glass vessel, that the solution ofpotash may gradually drop through the linen into the lowervessel. When it first ceases to drop, pour a few ounces ofwater into the funnel, but cautiously, so that the fluid mayswim above the matter. The water of potash will again beginto drop. The affusion of water, however, must be repeated

« Aqua KaliPuri, P. L. 1787. Dissolution de Potasse (F.) Fiiissiges atzendes KaU(<?.) Liquore di Potassa (/.)