OF THE ROOM FOR DISTILLATION.
We have hitherto considered the liquor as containing only principles
upon which the air has no action, and from which it can only extract
some watery vapors; and, in fact, all those principles contained in the
liquor are fixed. The action of the fire may concentrate, but not
volatilize them.
The liquor is now changed by the fermentation; it contains no longer the
same principles, but has acquired those which it had not, which are
volatile, and evaporate easily. They must therefore be managed
carefully, in order not to lose the fruits of an already tedious labor.
The spirit already created in the fermented liquor, must be collected by
the distillation; but in transporting it to the still, the action of the
external air must be carefully avoided, as it would cause the
evaporation of some of the spirit. A pump to empty the hogsheads, and
covered pipes to conduct the liquor into the still, is what has been
found to answer that purpose. A good distilling apparatus is undoubtedly
the most important part of a distillery. It must unite solidity,
perfection in its joints, economy of fuel, rapidity of distillation, to
the faculty of concentrating the spirit. Such are the ends I have
proposed to myself in the following apparatus.
The usual shape of stills is defective; they are too deep, and do not
present enough of surface for their contents. They require a violent
fire to bring them to ebullition; the liquor at bottom burns before it
is warm at the top.
My still is made upon different principles, and composed of two pieces,
viz. the kettle, and its lid. The kettle, forming a long square, is like
the kettle of infusion, already described, and only differs from it in
being one foot deeper. The lid is in shape like an ancient bed tester;
that is to say, its four corners rise into a sharp angle, and come to
support a circle 16 inches diameter, bearing a vertical collar of about
two inches. This collar comes to the middle of the kettle, and is
elevated about 4 feet from the bottom. The lid is fastened to the
kettle. The collar receives a pewter cap, to which is joined a pipe of
the same metal, the diameter of which decreases progressively to a
little less than 3 inches: this pipe, the direction of which is almost
horizontal, is 5 feet long.
My still, thus constructed, is established upon a furnace like that of
the infusion room. I observe that the side walls are only raised to the
half of the height of the kettle. A vertical pipe is placed on the side
opposite to the pewter one, and serves to fill up the still: it is
almost at the height of the fastening of the lid, but a little above. On
the same side, on a level with the bottom, is a pipe of discharge,
passing across the furnace: this pipe must project enough to help to
receive or to direct the fluid residue of the distillation; its diameter
must be such as to operate a prompt discharge of the still.
OF THE URNS.
These are copper vessels, thus called from their resembling those
funeral vases of the ancients. Mine have a bottom of about 18 inches
diameter; they are two feet high, have a bulge of 6 inches near the top,
and then draw in to form an overture of about 8 inches.
On one side, towards the top, there is a copper pipe 2 inches diameter,
projecting externally 2 or 3 inches, and bent in an elbow: it enters the
internal part of the urn, and descends towards the bottom, without
touching it; there it is only a slight curve, and remains open.
The external part of that pipe is fitted to receive the pewter pipe of
the still; they are made so as to enter into one another, and must fit
exactly. The round opening at the top of the urn receives a cap with a
pewter pipe, made like that of the still. It is likewise five feet
long, and its size in proportion to the opening: this goes and joins
itself to the second urn, as the still does to the first. The pipe of
this second goes to a third, and the pipe of this last to the worm. The
three urns bear each a small pipe of discharge towards the bottom.
This apparatus must be made with the greatest care. Neither the joints,
the different pipes of communication, nor the nailings, must leave the
smallest passage to the vapors. The workman must pay the greatest
attention to his work, and the distiller must lute exactly all the parts
of the apparatus that are susceptible of it: he must be the more careful
as to luting it, as this operation is only performed once a week, when
the apparatus is cleaned. At the moment of the distillation, the master
or his foreman must carefully observe whether there is any waste of
vapors, and remedy it instantly. The still and urns ought to be well
tinned.