Fig. 97 illustrates a little earthenware distilling apparatus in use among the Japanese. It consists of 4 pieces: a boiler a, on to which fits a short cylinder with a perforated bottom 6, and over this a condenser c, with a cover d. The cover being removed, a stream of cold water can be kept running into the condenser by means of a bamboo, and the overflow carried off by the spout at its base. Round the base of the inner side of the middle cylinder runs a ledge which forms a channel opening into an exit spout. The materials for distillation are put into the boiler, and the whole is placed on the ordinary hibatchi, or domestic fire-box. The vapour passes through the perforated bottom of the cylinder, collects in drops on the dome-shaped inner surface of the condenser, runs down into the channel before described, and is collected at its exit from the spout. This little contrivance is known by the Japanese under the name of lambik or rambiki, which is doubtless some corruption, through the Dutch, of the word alembic. In the country districts peppermint is largely used as a corrective for water rendered muddy and otherwise unsuitable for drinking by rains, as well as for other domestic purposes, and this apparatus is one of the means employed for its distillation.
A very convenient and complete still is shown in Fig. 98. The body holds over 3 gal.; the condenser has 7 straight tubes surrounded with the cold water introduced by a rubber tube from a hydrant or bucket of water placed higher than the still, and carried off as it becomes warmed by another tube as indicated by the arrows. By the siphon arrangement shown in the cut, it is possible to feed the still from a reservoir whilst distillation is in progress, thus using a 3-gal. still where a much larger one would have been necessary. The still may be set into a kettle partly filled with water and thus used as a water-bath, or a shallow dish with flat rim, which accompanies the still, may be placed between the 2 brass ring bands and clamped securely.
Having for some time been in need of an apparatus for distilling a quantity of water at a time, and finding none in the market answering the purpose, A. B. Stevens, of Detroit, Mich., arranged the apparatus shown in Fig. 99 for continuous distillation, which has thus far answered all that is required of it. As soon as the water passes out of the boiler a the float b lowers, letting a fresh supply of water from the condenser c through d, thereby keeping the water in the boiler at a constant level. This avoids the necessity of adding a large quantity of cold water at once, the effect of which would be to reduce the temperature of the water below the boiling-point.
Cold water is supplied to the condenser through e, and as it becomes heated and rises to the top, it is carried off through f. The boiler and condenser are joined at g.
The apparatus is not patented, and should any pharmacist desire to make one for his own use he can do so; should he prefer one ready-made, Stevens will furnish them to order, size 10 in. diameter, all of copper, with 6 ft. of rubber tube, for 8 dollars (say 35s.).
For the purpose of distilling a series of samples at one time, Dr. B. Land-mann has devised an apparatus which appears to be very compact, and may be fastened against the wall, so as not to interfere with other available space in the laboratory. It consists (Fig. 100) of a common, tinned-iron cooler A, ill} in. long, 12 in. high, and 2 in. deep, with a series of openings a, for passing through the condensing tubes, and an inlet and outlet for water, g and h. The cooler stands upon 2 iron supports b, about 9f in. long, to the front ends of which is attached the gas-pipe f, which is provided with 6 stop-cocks and a lateral burner. The 2 iron sop-ports are firmly held in place by the 2 parallel rods e, and the iron framework d, which is 1 3/4 in. distant from the cooler, has a height of 8 in., and a width of 2j in. The receivers are placed upon a board which is laid across the supports c As it is necessary that quite a number of connecting tubes should be on hand, it is advisable to bend them all after a pattern or drawing made upon a board.
Should the corks through which the cooling tubes a pass not be sufficiently tight, it is only necessary to pour melted paraffin through the orifice g, until it has coated the bottom of the apparatus.
The distilling apparatus represented in Fig. 101 is intended primarily for the use of pharmaceutical chemists or druggists, but it possesses features which will recommend it to many who have need of a trustworthy and quick-acting still. The wide delivery tube is a useful feature, allowing as it does for the accuisolation of vapour, and permitting the introduction of the hand. The body of the still is of wrought iron or copper, with a lid fitting on ground edges, and held together by screw-clamps, as seen in the engraving. A gauge is fitted to show the quantity of liquid in the still. The condenser consists of a number of glass tubes, which, if they are 1 in. diameter and 24 in. long, expose a surface of 264 in., while that of the surrounding cylinder is only 188 1/2 in. The ends of the condenser tubes are drawn together and tapered, as shown in cut, to permit, if desired, the collection of the distillate in a narrow-mouthed bottle. The advantage gained by this apparatus, aside from teh general one of convenience, is thus seen to be in the notable increase of condensing surface it exposes, which to that extent increases the effectiveness of the device - i. e. its rapidity of action.