The most simple distilling vessel is a species of bottle or matrass, A,
Pl. III. Fig. 8. which has been bent from its original form BC to BD,
and which is then called a retort; when used, it is placed either in a
reverberatory furnace, Pl. XIII. Fig. 2. or in a sand bath under a dome
of baked earth, Pl. III. Fig. 1. To receive and condense the products,
we adapt a recipient, E, Pl. III. Fig. 9. which is luted to the retort.
Sometimes, more especially in pharmaceutical operations, the glass or
stone ware cucurbit, A, with its capital B, Pl. III. Fig. 12, or the
glass alembic and capital, Fig. 13. of one piece, is employed. This
latter is managed by means of a tubulated opening T, fitted with a
ground stopper of cristal; the capital, both of the cucurbit and
alembic, has a furrow or trench, r r, intended for conveying the
condensed liquor into the beak RS, by which it runs out. As, in almost
all distillations, expansive vapours are produced, which might burst the
vessels employed, we are under the necessity of having a small hole, T,
Fig. 9. in the balloon or recipient, through which these may find vent;
hence, in this way of distilling, all the products which are permanently
aeriform are entirely lost, and even such as difficultly lose that state
have not sufficient space to condense in the balloon: This apparatus is
not, therefore, proper for experiments of investigation, and can only be
admitted in the ordinary operations of the laboratory or in pharmacy. In
the article appropriated for compound distillation, I shall explain the
various methods which have been contrived for preserving the whole
products from bodies in this process.
As glass or earthen vessels are very brittle, and do not readily bear
sudden alterations of heat and cold, every well regulated laboratory
ought to have one or more alembics of metal for distilling water,
spiritous liquors, essential oils, &c. This apparatus consists of a
cucurbit and capital of tinned copper or brass, Pl. III. Fig. 15. and
16. which, when judged proper, may be placed in the water bath, D, Fig.
17. In distillations, especially of spiritous liquors, the capital must
be furnished with a refrigetory, SS, Fig. 16. kept continually filled
with cold water; when the water becomes heated, it is let off by the
stop-cock, R, and renewed with a fresh supply of cold water. As the
fluid distilled is converted into gas by means of caloric furnished by
the fire of the furnace, it is evident that it could not condense, and,
consequently, that no distillation, properly speaking, could take place,
unless it is made to deposit in the capital all the caloric it received
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