plied to the bottom of the cone (C); the heat is diffused by means of the dispersion board (H) about 4 inches square, which is placed over the orifice, and is regulated by the "hit and miss" regulator shown at (G). A thermometer may be inserted at (M), and a rapid current is produced if the chimney, constructed as shown, is heated at the angle of the tube at (K).—Phar. Jour. Trans., March 31, 1883, 808. Constant Level Water-Bath-Simple Construction. Mr. Fr. Schimmel describes the following simple construction of a constant level water-bath which is illustrated by Fig. 17. A reservoir (A) of any desired capacity, FIG. 17. Schimmel's Constant Level Water-Bath. filled with water and securely stoppered, is placed in a situation somewhat higher than the water-bath. From near its bottom projects a glass-tube (a) of about 7 mm. bore, which is curved and is fitted into the cover of the water-bath. At a place corresponding to the line at which it is desired to maintain the level in the water-bath, a round hole (b), corresponding to the full bore, is blown into the glass tube. As soon as the liquid in the water-bath sinks below the level of the hole b, air enters the reservoir, and water runs into the bath until the hole is below the level.— New Rem., Aug. 1882, 228; from Dingler's Polyt. Jour., 244, 150. Graphite-Bath-A Substitute for the Sand-Bath.—The use of sand for heating purposes, though used from time immemorial, is not wholly rational, sand being a very bad conductor of heat. Mr. Kristalta has lately recommended the substitution of pounded fragments of graphite: they let the heat pass much better, do not oxidize, and do not soil the inclosing vessel. "L'Electricité" commends the method to electricians who have to make researches in thermo-electricity, adding that small shot of iron would serve nearly the same purpose. For more intense heats, it is known, melted lead can be used.-New Rem., Feb. 1883, 53. Improved Vacuum-Pan.-Mr. C. Wahl, of Chicago, has invented an improvement in vacuum-pans, which is intended to shorten the time during which the liquid to be concentrated remains in the pan. Its essential features are illustrated in Fig. 18. The pan is provided with the usual attachments: eye-glasses, D; a condenser, F; vacuum-gauger thermometer, etc.; but the liquid to be evaporated, instead of being filled into the pan in one bulk, passes gradually through the spiral-shaped canal or gutter, A. The space formed between this continuous channel and the bottom of the pan is used as a steam jacket, the heating capacity of which is increased by a coil of steam-pipe, B, running along on the bottom of the channel. d and represent the inlets, and e and f the outlets for the steam. The liquid to be concentrated runs in at b, and after being concentrated, issues at g, and runs into a vessel, G, located about thirty feet below the vacuum-pan. Where the localities do not admit of this latter arrangement, the concentrated liquid must be pumped out, in which case, vessels to be used alternately will be found convenient for the reception of the concentrated mass. It will be seen that the operation of this pan is continuous, and that its working can be regulated with the precision of clockwork by the admission of liquid through the faucet b. While in the old style pans large batches containing up to fifty barrels are treated at the same time, being exposed to the high tempera ture for hours and more; in Wahl's pan every drop, so to speak, is treated by itself, and leaves the pan after having attained the desired concentration, which is accomplished in a few minutes, owing to the effective. application of heat, which has to penetrate a low column of liquid of one-half to two inches height at the utmost.-New Rem., Feb. 1883, 43. Small Distilling Apparatus.-Mr. Egrot, a French manufacturer of distilling apparatus, has constructed a small stationary still on the model of the larger ones manufactured by him, which is illustrated and described in New Remedies," April, 1883, 105-106. The apparatus is particularly adapted to the strengthening of weak alcohol, and may doubtless find application in pharmaceutic laboratories in which large quantities of alcohol are recovered from fluid extracts, etc. The same manufacture, has constructed a Steam Kettle, intended, primarily, for cooking with a view to avoiding the unequal heating of the contents of the kettle, such as occurs often when an open fire is employed. Such kettles, which are illustrated and fully described on page 107 of the same journal, would be serviceable for many pharmaceutical purposes. An Apparatus for Simultaneous Distillation of a Number of Volatile Liquids, as used by the Experimental Institute for wine and fruit culture at Klosternenburg, near Vienna, is illustrated and described in "New Rem.," Aug. 1882, 231. Apparatus for Subduing the Foaming of Certain Liquids during Distil lation. Dr. J. Loewe has devised a simple contrivance, Fig. 20, by means of which the annoying foaming which takes place during the distillation of many liquids, particularly those containing recently formed alcohol, may be subdued. FIG. 19. Instead of conducting the vapor of the distillation through the ascending portion of the glass tube passing through the cork in the neck of the flask, the glass tube is made to pass into the flask in the shape shown in the cut. A small bulb being blown in the centre of the bend, the two branches of the tube are adjusted close to each other, and the ascending portion cut off a short distance below the cork. The distance from the cork to the bottom of the bulb should be such that the bulb is only a few millimetres from the bottom of the flask when the cork is tightly inserted. During the boiling of the liquid any ascending foam or bubbles break when coming in contact with the cork, and the accompanying moisture flows down along the glass tube without entering the orifice at a to an appreciable extent. The calibre of the glass tube should not be too small, to avoid tension of the vapors in the flask.-New Rem., Feb. 1883, 42, from Dingl. Pol. Journ., 245, 219. GENERAL LABORATORY OPERATIONS. Hot Water Wash-Bottle-Construction-The wash-bottle illustrated by the accompanying cut (Fig. 21) is fitted with a triply perforated Indiarubber stopper. One of the perforations contains the usual dischargetube, and another the blowing tube. The latter is somewhat enlarged at the inner end, and is provided with one of Bunsen's India-rubber valves which only opens in the direction of the interior of the flask. The third perforation carries a glass-tube with stop-cock, the lower end of the tube being obliquely cut off. While the water is being heated, the stop-cock is opened to permit the escape of steam. When the wash-bottle is to be used the stop-cock is closed. The described arrangement causes the blowing tube to remain cool, and only a short blowing is required to cause a jet of water to be delivered. To arrest this, it is only necessary to open the stopcock.-New Rem., Mar. 1883, 71, from Zeitsch. f. Anal. Chem., 1883, 60. Platinum Dishes-Repairing.-Mr. Garside, in the Chemiker Zeitung, reports his success in repairing a platinum dish as follows: A small platinum dish had in some way received an injury in the shape of a small hole near its centre. To repair it I first made a convex plaster cast of the dish, to serve as a sort of anvil. Next, I procured a piece of sheet platinum of three inches in diameter, and cleaned and polished the same thoroughly, as also the parts of the dish surrounding the opening. The dish being placed on the cast, the hole was covered by the piece, against which the flame of a stationary blow-pipe was now directed. A small scissors was used as a hammer. By softly hammering on the small piece, I succeeded after some time in combining the same completely with the body of the dish, so that it could hardly be noticed when not carefully examined. The dish could now be used again for all purposes, the mended spot holding out well. The plaster cast cracked in all directions, but retained strength enough for the purpose.-New Rem., Jan. 1883, 22. Asbestos Capsules-Preparation.-J. Bering, desiring to obtain asbestosplaster of a concave shape, so as to fit the external form of evaporating dishes or capsules, and not being able to procure such from any dealer, succeeded in preparing them from the flat asbestos plates of commerce as follows: The plate is covered in a flat-bottomed vessel with cold water, so that it is a few millimeters below the surface of the latter. After two, or at most three, minutes (a longer soaking would dissolve the binding material contained in the plates sold in trade), the plate is removed, and, after the water has drained off as much as possible, it is, while still moist, thoroughly rubbed with talc on both sides. A porcelain-capsule, corresponding in size to the asbestos-plate is then evenly pressed with the hand against the outside of the capsule, any wrinkles being smoothed down with some hard substance or with the thumb-nail. If the plate is to be made still more concave, it is afterwards pressed against the inside of the capsule, particular care being taken to press it evenly and to smoothen it near the bottom. The asbestos-capsule may now be dried by exposure to the air, or more rapidly, in an air-bath which is at first heated slowly, but afterwards as high as possible. It thereby becomes quite hard and acquires a "ringing" sound when it is struck with a hard substance. It is essential after soaking the asbestos-plate in water, to remove all airbubbles, before pressing it into the desired form. Asbestos-capsules thus prepared form an excellent substitute for the sand-bath.-New Rem., Mar. 1883, 77, from Report d. Anal. Chem., 1882, 297. FIG. 21. b Absorption Apparatus-New Construction.-When sulphuric acid is used as a drying medium for gases, it is generally used in this way, that fragments of pumice stone are saturated with the acid and packed in Utubes, through which the gas is then made to pass. Yet, the filling, cleaning, and handling of these tubes is not free from objections. Winkler has now devised a new form of apparatus (Fig. 22) which is thought to save time and to permit even a still closer contact of the gas-bubbles with the acid than was possible in the U-tubes. The new spiral absorption-apparatus is formed of a spirally twisted tube of thin glass, which is expanded to a globe below the exit at a, and which is made to stand firmly on a level surface by means of three attached glass-legs. The current of gas is conducted into the apparatus through b and c, the latter being the finely-drawn-out point of the conducting tube, fused into the opening of the spiral tube. The gas being compelled to pass through this narrow opening, is thereby divided into fine bubbles, which, resembling a continuous string of pearls, ascend along the sloping top of the spiral. The latter being filled with sulphuric acid, each bubble is thereby thoroughly с Winkler's Absorption |