Tho apparatus employed in the process of distillation is called a still, and is of alinest infinite variety. The very simplest form is shown in Fig: 174, and consists of two essential parts, the still or boiler A, which is made of tinned copper, and entere the furnace, and the cooler or worm B, a pipe of bleck-tie or tinned copper, bent into a spiral and connected with the top of the still The liquid is boiled in the still, and the vapours passing over are condensed in the pipe, which is placed in a tub or vessel containing cold water. This simple apparatus is not much employed in distilling, as it is impossible to get sufficiently pure products from it on a commercial scale. In an arrangement of tide kind, the vapours of alcohol and water are condensed together. But if, instead of filling the cooler Nirith cold water, it be kept at a temperature of SO°, the greater part of the water will be condeused ; but the alcohol, which boils at 76-, passes through the coil uncon densed. If, therefore, the water be condensed and collected separately in this manner, and the alcoholic vapours ho conducted into another cooler, kept at a temperature below 78°, the alcohol will be obtained in a much higher elate of concentration than it would be by a process of simple distillation. Supposing, again, that vapours containing but a small qnantity of alcohol are brought into contact witg an alcoholic liquid of lower temperature than the vapours themselves, and in very small quantity, the vapour of water will be partly condensed, so that the remainder will be richer in alcohol than it was previously. But the water, in condensing, converts into vapour a portion of the spirit contained in the liquid interposed, so that the oncondensed vapours passing away are still further euriehecl by this means. Here, then, are the results obtained : the alcoholic vapours are strengthened, fit stly, by the removal of a portion of the water wherewith they were mixed; and then by the admixture with them of the vaporized spirit placed in the condenser. By the employment of some such method as this, a very satisfactory yield of spirit may be obtained, both with regard to quality, as it is extremely concentrated, and to the cost of production, since the simple condensation of the water is made use of to convert the spirit into vapour without the necessity of having recourse to fuel. The construction of every variety of distilling apparatus now in use is based upon the above principles.
The first distilling apparatus for the production of strong alcohol on an industrial scale was invented by Edward Adam, in the year 1801. The arrangement is shown in Fig. 175, in which is a still A to contain the liquor. The vapours were conducted by a tube into the egg-shaped vessel B, the tube reaching nearly to the bottom ; they then passed out by another tube into a second egg C; then, in some cases, into a third, not shown in the figure, and finally into the worm D. The liquor cond,nsed in the first egg is stronger than that in the still, while that found in the second and third is stronger than either. The spirit which is condensed at the bottom of the worm is of a very high degree of strength. At the bottom of each of the eggs, there was a tube connected with the still, by which the concentrated liquors could be run back into it. In the tube, was a stop-cock by regulating which, enough liquor could be kept in the eggs to cover the lower ends of the entrance pipes, so that the alcoholic vapours were not only deprived of water by the cooling which they underwent in passing through the eggs, but were also mixed with fresh spirit obtained from the vaporization of the liquid remaining in the bottom of the eggs, in the manner already described. Adam's arrangement fulfilled, therefore, the two conditions necessary for the production of strong spirit inexpensively ; but unfortunately it had also serious defects. The
temperature of the egg could not be maintained at a constant standard, and the bubbling of the vapours through the liquor inside created too high a pressure. It was, however, a source of great profit to its inventor for a long period, although it gave rise to many imitations and improvements of greater or less merit. Among these are the stills of Solimani and Berard which more nearly resemble those of the present day. Utilizing the experience which had been gained by Adam, Solimani, and Berard, and avoiding the defects which these stills presented, Cellier-Blumenthal devised an apparatus which has become the basis of all subsequent improvements ; indeed, every successive invention has differed from this arrangement, merely in detail, the general principles being in every case the same. The chief defect in the three stills above-mentioned was that they were intermittent, while that of Cellier-Blumenthal is continuous ;.that is to say, the liquid for distillation is introduced at one end of the arrangement, and the alcoholic products are received continuously, and of a constant degree of concentration, at the other. The saving of time and fuel resulting from the use of this still is enormous. In the case of the previous stills, the fuel con sumed amounted to a weight nearly three times that of the spirit yielded by it ; whereas, the Cellier-Blumenthal apparatus reduces the amount to one-quarter of the weight of alcohol produced. Fig. 176 shows the whole arrangement, and Figs. 177 to 181 represenS different parts of it in detail. In Fig. 176, A is a boiler, placed over a brick furnace ; B is the still, placed beside it, on a slightly higher level and is heated by the furnace flue which passes underneath it. A pipe e conducts the steam from the boiler to the bottom of the still. By another pipe d, which is furnished with a stop-cock and which reaches to the bottom of the still A, the alcoholic liquors in the still may be run from it into the boiler; by opening the valve the spent liquor may be run out at a. The glass tubes I and f show the height of liquid in the two vessels. The still is surmounted by a column C, shown in section in Fig. 177. This column contains' the arrangement shown in Fig. 178, which eon-dsts of a series of spherical copper capsules, placed one above the flier, and kept apart by threo metallic rods passing through the series. These capsules are of different ; the larger ones, which are nearly the diameter of the column, are placed with the rounded skle downwards, and are pierced with small holes ; the smaller ones are turned bottom upwards. Into tho top capsule, is made to flow a stream of the liquid to ho distilled, which, running through the small holes, falls upon the smaller capsule beneath, and from this upon the one next below, and so throughout the whole of the series until it reaches the bottom and frills into the still. The vapours rise up into the column from the still and meet the stream of spirit, converting it partially into vapour and pass out at the top, considerably enriched, into the column 1), Fig. 180, which contains a system resembling in principle that of Adam ; here the vapours are still further strengthened. Fig. 179 is an interior, and Fig 180 a sectional view of this rsolumn, tho "rectifying column," as it is eallod. It contains six vessels, placed one above the other in an inverted position. These are so disposed that the vapours traverse a thin layer of liquor in each. The condensed liquid flows back into the column 0, and the uncondenscd vapours pass into the next part of the apparatus.