484 THE ANALYST. APPARATUS, ETC. Modiflcation of' Hufner's Method for the Volumetric Estimation of Nitrogen. V. v. Cordier. (Zeits. anal. Cheni., 1908, 47, 682-687.)-Nitrogen in such substances as guanidine picrate and carbonate, urea nitrate, etc., which though only sparingly soluble, are violently acted on by sodium hypobromita solution, can be volumetrically estimated in the modified Victor Meyer apparatus shown. The bulb a contains 40 to 50 C.C. of the hypobromite solution, into which the substance, contained in a small glass bulb, is allowed to drop after equilibrium of temperature has been established in the apparatus ; when the evolution of nitrogen begins to slacken, fresh hypobromite solution is introduced from the bulb b, which holds 30 to 40 c.c., without altering the volume inside the vessel.The whole apparatus may be immersed in water, if necessary. Evolution of nitrogen is com- plete in one hour. A. G. L. Primus Burner for Mine Laboratories. R. Storen. (Zeits. anal. Chem., 1908, 47, 695-696.)- For heating hot-plates and sand-baths, a Barthel Primus burner, burning benzine, is recommended, The apparatus is modified by making the burner itself of nickel instead of copper, and separating it from the benzine container by a metal tube of such length that the latter remains cold. A. G. L.THE ANALYST. 485 Compound Gas-Pipette. H. Fleissner-Przib- ram. (Chem. Zeit., 1908,32, 770.)-The compound gas- pipette shown is provided with a short through which the bulbs a and b are filled. pipette is filled, the tubef is stoppered by a short piece Steam Distillation Tube.H. Stoltzenberg. (Chem. Zeit., 1908, 32, 770.)- The tube through which steam is led into the liquid to be distilled is closed at the 3 An Improved Water-Oven. A. P. Sy. (Chem. EngiTzear, 1908, 8, 100-101.) - -This oven contains an improved device for a cone t an t -level water- supply, consist in g of an elbow-tube of sheet copper, about 13 mm. in diameter, the short arm being soldered to the oven near the base. At a height to which the oven is to be kept filled with water (about half full), a somewhat smaller side-tube is soldered on to the elbow-tube, and the whole held by a copper strap soldered to the oven and the tube a little below the side-tube of the latter. Water is supplied to the oven through a bent glass tube, one 6rtn of which hangs loosely in the elbow-tube just below the side-tube, the latter being connected to the waste-pipe.The burner, which is attached to the legs of the oven at a suitable height, and has an air-regulator, is of rectangular shape, the two long sides containing numerous small jets. A special feature of the oven is the V-shaped bottom of the inner jacket, which formation allows of the easy escape of air and steam during boiling, and thus prevents the bumping and jarring common to ovens of the ordinary type. A. R. T. Apparatus for Extracting Substances by Means of Hot Ether. W. Kulka. (Biochem. Zeitsch., 1908, 13, 134-137.)-The piece of apparatus described consists of an outer glass cylinder, like that of the ordinary Soxhlet extractor. An inner cylinder, provided with a siphon, which discharges into the extraction flask attached to the lower end of the outer cylinder, is fitted inside the latter.The substance to be extracted is placed in this inner cylinder, and the ether vapours, passing upwards in the space between the two cylinders, are condensed in a condenser situated at the486 THE ANALYST. top of the appsratus, and fall into the inner cylinder. The ether thus collected is heated by the hot vapours, and the substance is extracted oontinuously at a tern- perature approaching that of boiling ether. w. P. s. Reaction Turbine. A. Gawalowski. (Zeits. anal. Chern., 1908, 47, 697.)- - The apparatus consists of a long-stemmed glass funnel, S, terminating in two horizontal tubes, bent as shown. The stem of the funnel is surrounded by the sealed glass globe B, containing air, whilst a small glass globe, Q, containing mercury, is attached below the horizontal tubes. When placed in a liquid, the apparatus floats like a hydro- meter; if a second liquid be then poured into the funnel, it flows out by the horizontal tubes, rotating the apparatus and mixing the two liquids in doing so. A. G. L.