T E E ANALYST. APPARATUS. 37 On a Modified Form of the Ostwald Burette- Calibrator. Allerton s. Cushman. (Jozmt. Amel-. Chem. SOC., xxiii., 484.)-In this calibrator the pipette has a scale engraved on its stem, as shown in the figure. The pipette must have a capacity of 2 C.C. from the mark A to about the middle of the scale. The calibration is made starting with the burette filled to the zero mark, and the pipette filled to A. The first 2 C.C. of the burette are delivered into the pipette, the reading is noted, and the pipette emptied to A ; the next 2 C.C. are then introduced, and the operation is repeated gown the scale. A second series of read- ings may be taken, starting with the burette filled to the 1 C.C. mark. Using this instrument, not a single weighing is necessary if the object is only to ascertain whether the graduations of a given burette are SUE- ciently uniform or not, and if absolute corrections are required it can be standardized much more easily than the ordinary form.A. G. L.38 THE ANALYST. Non-return Valve for Water-Pumps. L. Wacker. (Chem. Zeit., 1901, xxv., 589.)-As shown by the diagram, this apparatus consists of a glass or metal ball-valve riding on a rubber seat inside a metal or glass casing. When the pump is working properly, the valve is lifted off its seat by the suction ; but should any water return, the ball falls and retains the liquid in the upper chamber, whence it eventually drops into the lower cylinder, to be withdrawn by the removal of the cork at the bottom. F. H. L. The Engler-Ragosine Vis- cosimeter.A. Ragosine. (C'hem. Zeit., 1901, xxv., 628.)-The author has modified the Engler viscosi- meter in one or two particulars, so as to render that instrument more convenient for determinations of viscosity at somewhat elevated temperatures. As shown by the illustration, the oil - container of the apparatus is provided with a tightly-fitting cover, 5 to 8 milli- metres thick, and composed of a material which conducts heat badly. At d it has a 1 millimetre opening to admit air into the cup. The central rod is drilled with a transverse hole, through which st pin e is passed to hold the rod up while oil is running out; n is a circulating coil of copper tube, and b a draw-off pipe for the water. By this arrangement the tempera- ture of the oil will not fall more than 0.1 or 0.3" C. during a determination of viscosity at 50" C. *F. H. L. Modified Gooch Crucible. W. C. Heraeus. (Zeits. f. angew. Chem., 1901, 922.)-The crucible, which was devised by Neubituer, has, instead of a perforated bottom, a piece of spongy platinum, so that no asbestos is required. Consequently, it is simple to use, and absolutely constant in weight. The precipitate is afterwards removed by treating with solvents. The modified crucible must not be used €or barium sulphate, as this cannot be dissolved out of the pores of the platinum. A. M.