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Preparations and Compositions. Part III.
poration produces an intense degree of cold ; and as this isattended with a proportional diminution of bulk in the partto which it is applied, in this way it has frequently facilitatedthe reduction of strangulated hernia.
The mixture of ether with alcohol, whether prepared di-rectly by mixing them as the Edinburgh college direct, or inthe impure state in which it comes over in the first part ofthe process for distilling ether, possesses similar virtues withether, but in an inferior degree.
.ZEther nitrosus. Dub.Nitrous Ether.
Tnke of
Nitrate of kali, dried, and in coarse powder, one pound and
a half;Sulphuric acid, one pound ;Rectified spirit of wine, nineteen ounces, by measure.
Put the nitrate of kali into a tubulated retort, placed in abath of cold water, and pour upon it gradually, and in dif-ferent portions, the sulphuric acid and spirit, previouslynixed, and allowed to cool after having been mixed.Without any external heat, or only a very slight degreeof it (such as the addition of tepid water to the bath), anethereal liquor will begin to arise, without applying fire un-der it. In a short time, the heat will spontaneously in-crease in the retort, and a remarkable ebullition will takeplace, which are to be moderated, by cooling the bath withcold water. The receiver ought also to be cooled with wa-ter or snow, and furnished with a proper apparatus fortransmitting the very elastic vapour (arising from the mix-ture, with very great force, if the heat shoulu accidentallybecome too high | through a pound of rectified spirit ofwine, placed in a cooled phial.
Put the ethereal liquor, which has distilled spontaneously, in-to a phial with a ground glass-stopper, and gradually add(closing the phial after each addition) as much very drysubcarbonate of kali in powder, as shall be sufficient to sa-turate the superabundant acid, according tu the test of lit-mus. This commonly takes place on the addition of abouta drachm of the salt; and in a short time, the nitrous etherwill swim on the surface, and is to be separated by meansof a funnel.
If it be required very pure, re-distil the ether from a water-bath, at about 140°, to one-half.
Its specific gravity is 900.