DISTIL 
off the dills with fuch rapidity ; for the greater the quan¬ 
tity of fpirit diddled in tire year, the lefs will be the duty 
per gallon, fince the expence of the licence is the fame, 
whether the (till be worked off one thoufand, or one or 
two hundred thoufand times a-year. 
The principle of the improvement in the Scotch flills, 
feems to center in this one point: The greater the quan¬ 
tity of heat that can be made to pafs through the body 
of the dill in a given time, the greater will be the quan¬ 
tity of vapour, and confequently of fpirits, produced in 
that time : and certainly it is not eafy to conceive how 
this can be attained in any way fo effectually as by mak¬ 
ing the dill all bottom, as it were, and applying the heat to 
every part of that bottom. 
The objedf of the Scotch didillers being to favc time 
and excife duties, it follows obvioufly that their con- 
fumption of fuel mud be great. But for fituations where 
fuel is fcarce and expenfive, the following diddling ap¬ 
paratus has been lately recommended, which originated 
in Denmark, where it has been employed with great fuc- 
cefs. Fig. 2, in the annexed engraving, reprefents this 
apparatus. A, is a large wooden veffel, bound round 
with iron, into which the liquid to be diddled is intro¬ 
duced, and which may be of any fize at pleafure. A hole 
is made in the bottom of the veffel, which occupies about 
a fourth part of its furface. In this opening, which ferves 
as an air-hole, the furnace b is placed. This furnace may 
be made with mod advantage of drong copper, as iron 
would be foon ruded by the fnrrounding fluid, and there¬ 
fore would not lad half fo long as copper. This furnace 
is in nothing different from a common wind-furnace, only 
that the upper part of it, which in the former is open for 
the convenience of the workmen, is here flmt, and the 
aperture for introducing the fuel is lengthened : c is the 
tube dedined for introducing the fuel ; it paffes through 
the fide of the veffel, and can be flnit by the door d , in 
order to afl'ord an uniform paflage to the heat through 
the draught tubes. It is neceffary that the tube dedined 
for introducing the fuel fliould have the fame height and 
breadth as the fire-place e, and it will be better that the 
whole furnace fliould be rather fquare than round, as the 
fire by.thefe means can be better managed ; and when 
the tube is flint by the door d, no unneceffary efcape of 
beat, notwithdanding its width, is to be apprehended : f, 
is the afli-hole, which is dedined not only to receive the 
afhes that fall from the grate, but to favour theaccefs of 
the atmofpheric air neceffary for maintaining the fire. 
It is therefore requifite that the veffel fhould be placed 
on two blocks, that the air may find a paffage under the 
bottom. It is of great importance that the lower part 
of the furnace be well joined to the bottom of the veffel, 
to guard againd the fluid running out. From the upper 
part of the furnace a draught tube, g, proceeds alfo 
through the fide of the veffel. This tube, according to 
the fize of the apparatus, mud project from it from two 
to fix inches. Above this tube there is a fecond draught 
tube, h, which, by the tube i, having a right-angled knee 
at each end, communicates with the tube g, while the 
other end of it is dedined to convey off the fmoke and 
foul air. According to the fize of the veffel, this tube 
is at the didance of from fix inches to a foot above the 
tube g. If it be neceffary that the furnace fliould be 
well fadened to the bottom of the veffel, it is no lefs ne- 
ceffary that the parts where the tubes pafs through the 
tides of the veffel fhould be well joined and completely 
water-tight, in order to prevent the fluid from oozing 
through. Around the upper edge of the veffel there is 
a copper ring from three to four inches in breadth, in or¬ 
der to receive the copper fhoulder l, which, as well as 
the cover, may be luted or rendered air-tight by means 
of paper or linen rags daubed over with pade. In a com¬ 
mon dill, this part is not feparated from the body, but 
makes with it a whole : but here this advantage is ob¬ 
tained, that the veffel, by removing the fhoulder, may 
be much eafier cleaned than the common dill. 
Vol. V. No. 323. 
LATION. so? 
It will be of confiderable advantage if the upper aper¬ 
ture of the fhoulder be equal in breadth to two-thirds.of 
the breadth of the veffel ; and the circumference of the 
head, vi, mud be little inferior to that of the veffel. The 
vapours thereby efcape more eafily ; by which means the 
didillation is much promoted. The neceflity of the gut¬ 
ter which goes round the top is evident, and in mod ap- 
paratufes it is employed. It is found, however, that 
there is no abfolute need for a head upon any dill; for 
it rather tends to promote a condenfation of the vapour, 
and its falling back into the body of the dill. A flat 
cover is all that is neceffary. The vapour then, by its 
continued eladic force, finds its way into the worm, and 
is condenfed in its defcent. The fpace between the fur- 
face of the liquor and the cover fhould, however, be fuf- 
ficient to prevent the contents from boiling up into the 
worm. It is neceffary that the tube n fliould at the up¬ 
per end be as wide as pofiible. In mod didilleries it is a 
common fault that this tube is too narrow. By this fault 
the free efcape of the vapour is impeded, and the didil¬ 
lation not a little retarded ; whereas, when the tube is 
fufficiently large, half the time will be fufficient for the 
operation. 
As the condenfation of the deam, particularly in large 
didillations, is not completely effedfed by a Ample tube 
proceeding through the cooler, particularly in diddling 
on a large fcale, where the neceffary degree of heat can¬ 
not be always accurately maintained, fpiral tubes have 
hitherto been employed : which, indeed, anfwer the pur- 
pofe, but, on account of their expenfe and the difficulty 
of cleaning them, cannot always be employed with con¬ 
venience : but in this apparatus there is a contrivance by 
which a confiderable furface is prefented to the deam for 
cooling it, without being attended with the above in- 
conveniencies. This confids of a copper box, open at 
both ends, from one foot to a foot and a half in breadth, 
and from two to three inches in height, lying on its flat 
fide. It is tinned on the infide, and to both ends of it 
are applied clofe covers, from the middle of each of which 
a tube projedts ; the one, 0, in the upper cover, is dedined 
for receiving the beak of the dill. From the under one 
the condenled vapour flows into the lower veflel. The 
copper box p paffes through the oblique-lying cafk or re¬ 
frigeratory veffel q, and projedfs fome inches beyond both 
its ends, in order to receive the covers. The box may 
be cleaned without any difficulty : the expence of it will 
not be one-half that of a worm, and yet it w ill anfwer 
the purpofe of the latter completely. 
When didillation is to be performed, the veffel may be 
filled half a foot above the upper tube h, and at the fame 
time that tube may be connedfed with the tube i, by flip¬ 
ping their ends into each other. The fire made in 
the furnace will then exercife an equal adtion on all fides : 
the heat proceeds through the tube g into the upper 
draught tube k\ both tubes, as well as the furnace, are 
completely furrounded by the fluid ; and the advantage 
of this apparatus in regard to the faving of fuel may be 
readily conceived, as that in the furnace can have no ac¬ 
tion but on the fluid, and as the heat which paffes through 
the tubes is applied to the fame purpofe. If we calculate, 
on the other hand, how much fuel is neceffary before the 
thick brickwork of common dills can be fufficiently 
heated, and how much heat is lod without being able to 
exercife any adtion on the dill itfelf, the fuperior advan¬ 
tage of this apparatus will be felf-evident. If fo much 
of the diltilled liquor hat palfed over as to convince one 
that the tube h can no longer be completely furrounded 
with the liquid, but that it mud lie above it; in that 
cafe it will be neceffary, in order that the afeending va¬ 
pour may not be dilated too much by fuperfluous heat, 
to remove the connedting tube i, by which means the 
communication betw'een the upper tube and-the furnace 
is intercepted. 
One defedl, which this apparatus has in common with 
the ufual dill, is, that the grains and flinty parts bum 
10 T very 
