It has been ascertained that bladder is impervious to alcohol, although pervious to water; so that if a portion of alcohol be confined in a bladder, the water will be evaporated in the course of a few days, whilst the alcohol remains, but in a highly concentrated state. The following information on the subject is extracted from Ferrusac's Bulletin, Mai, 1828, and, we doubt not, may be turned to practical advantage. M. Soemmering, in a memoir to the Academy of Sciences at Munich, states that alcohol in a vessel covered with a bladder, the latter not being in contact with the fluid, loses, when exposed to a dry atmosphere, much of its water, and becomes stronger; but if the vessel thus dosed be exposed to a damp air, the alcohol attracts humidity and becomes weaker. In a second memoir the author states more particularly the effect of bringing alcohol into more immediate contact with the membrane. If a bladder be filled with 16 oz. of alcohol at 75°, and be well closed and suspended over a sand bath, or placed near a warm stove, so as to remain at the distance of more than an inch from the hot surface, it becomes in a few days reduced to a fourth of its volume, and is nearly or quite anhydrous. M. Soemmering prepares for this purpose calves' or beeves' bladders, by steeping them first in water, washing, inflating, and cleansing them from grease and other extraneous matters, tying the ureters carefully, and then returning them to the water to clear off more fully the interior mucosity. After having inflated and dried the bladders, M. Soemmering covers them with a solution of icthyocolla, one coating internally and two externally. The bladders thus become firmer, and the concentration succeeds better. It is better not to fill the bladder entirely, but to leave a small space empty. The bladder is not moist to the touch, and gives out no odour of alcohol. If the latter be below 16° Baume, the bladder then softens a little, and appears moist to the touch. Bladders prepared as above may be employed more than a hundred times, although they at length acquire a yellowish brown colour, and become a little wrinkled and leathery. The swimming bladder of the salmon is not fit for these experiments. Alcohol of 72° was put into one of them, and after an exposure of thirty-two hours, it had lost more than one-third of its volume, and was weakened 12°: the alcoholic vapour was perceived by the smell.

Of two bladders of equal size, into one was put 8 oz. of water, and into the other 8 oz. of alcohol. They were placed side by side exposed to a slight heat. In tour days the water had entirely disappeared, whilst the alcohol had scarcely lost an ounce of its weight. Mineral waters, and the water of wells, evaporate and deposit on the interior of bladders the saline particles which they contain.

the heat be conveniently managed, absolute alcohol may be obtained in from six to twelve hours. Solar heat is even sufficient to procure anhydrous alcohol. Wine placed in prepared bladders contracts no bad odour; it assumes a deeper colour, acquires more aroma and a milder taste, and becomes generally stronger Spirits of turpentine of 75° contained in a glass vessel closed with a bladder, lost nothing in four years. Concentrated vinegar lost the half of its volume in four months; the other half acquired more consistency, and had no longer an acid taste. The water of orange flowers was about one-third evaporated in a few months, appeared to have a stronger odour, and, consequently, had lost nothing of its volatile principle. These experiments of M. Soemmering clearly establishing the fact that bladder is impervious to alcohol, we have no doubt that on account of the little heat necessary to effect this rectification, it may be one of great economy, if an apparatus can be devised for conducting the process extensively and with little labour.

For this purpose we would suggest that, instead of the ordinary animal bladder, the oesophagus of oxen should be employed, as exposing a larger surface to the air, and as more convenient for fixing into a suitable framing, which might be placed in a heated apartment, or, in warm climates, to the heat of the sun. Such an arrangement u shewn in the following diagram, a a are the oesophagus bladders, distended between a framing b b and c c, which is exhibited as broken away towards the middle, to show that it may be made of any convenient length or width. The bars d d connect the upper and lower pieces, and carry the pivots or axles which turn in the cross beams or supports e e, shewn in section. The upper side of the frame b b represents a square or round tube, in which are made circular apertures for the reception of the upper ends of the bladders a a, kept open and distended by wooden rings, and properly secured by cement. The lower ends of the bladders pass through similar apertures in the bottom rail, where they are cemented and kept closed up and secured from injury by a board screwed over them into the rail c c.

We will now suppose that fifty (or any other number) of such bladders are fixed to a frame, and charged with diluted spirit, by means of a hose and nozzle connected to the cock f; that done, the cock f is to be closed. In the same manner let all the other frames in the apartment or manufactory be charged, of which there may be any number. In 100 frames 2000 or 3000 gallons might be suspended. The whole should then be submitted to a moderate heat, as of the sun, or a stove, etc. When it is found that the spirit has parted with its aqueous fluid in any of the frames, they are to be turned half way round on their pivots, by which the upper side bb becomes the under, and the cock being opened, the concentrated spirit may be discharged by means of a hose into suitable recipients. Instead of a movable or swinging frame, a fixed one might be used, by forming the bottom rail (into which the lower ends of the bladders are inserted) of a tube similar to the upper one, and fitting it with a discharge cock.