252 THE ANALYST. APPARATUS, ETC. Receiver for Fractional Distillation under Reduced Pressure. H. Vigreux. (BUZZ. SOC. Chinz., 1908 [4], 3, 479-481.)-The receiver for fractional distillation under \! maintains a, constant vacuum reduced pressure (see figure) is combined in one piece with the condenser, which consists of a, vertical cylinder cooled internally by a stream of water, which enters and leaves the apparatus at the places in- dicated by the arrows. The tap A connects the re- ceiver bulb with the condensing portion of the apparatus, the tap B serves to discharge the dig- tillate, and the tap C admits air for the same purpose. The tap D leads to the vacuum pump, the apparatus being arranged to work either with one pump attached to F-in which case E and G are joined together by a piece of rubber tubing-or with two pumps attached to F and G. In working with one pump, when it is desired to withdraw a fraction the taps A and D are closed, the vacuum is still main- tained in the distillation flask by way of the tube c0nnecting.G and E, and the second fraction collects in the condensing cylinder.The first fraction is withdrawn by opening 13 and C, and the second fraction may then be let down into the bulb. By attaching a flask to the tube at B, three fractions limy be collected without breaking the vacuum in the bulb. When comparatively large quantities of liquid have to be distilled without interruption, it is neces- sary to have two pumps; the pump attached to G in the distillation flask, whilst the pump attached to F serves to evacuate the bulb after the withdrawal of each fraction before connecting it with the cylinder.J. 3’. B.THE ANALYST. 253 Standard Light for Estimating Colour in Malt Extracts and Beer. J. W. Lovibond. (Jot~rn. Iizst. Brewing, 1908, 14, 2-5.)-1n using Lovibond's tintometer for estimating the colour values of worts and beers, in cases where a good north light is not obtainable, the author recommends the light of the standard candle adopted by the gas referees. The illuminating surface is a complex screen large enough to fill both apertures of the instrument with an even light. The screen is made up of one red absorbent of 0.5 unit value and two diapersers, each of 0.5 unit north light dispersive value. The intensity of the light at the recommended distance of 1 inch from the end of the optical instrument is 36 units; the dispersive side of the screen should be towards the light.Under these conditions the author found that a wide range of measurements, without exception, gave readings in accord with those of north daylight. In studying the influence of daylight at various distances from the window of a room-k, with lights of different intensities and qualities (CJ J. L. Baker and H. F. Hulton, Jozmt. Inst. Brewing, 1906, 12, 302)-the author found that, when using a screen of tissue paper fixed to the window, the results were constant at all distances up to 10 feet, with light-intensities ranging from 24 to 18 units. But when the light was obtained from the opal reflector attached to the box of the instrument, considerable divergences were observed as the instrument waa moved further back into the room, and were quite unreliable when the light-intensity fell below 14 cnits.J. F. B. Modified Spectroscopie Apparatus. Go P. Baxter. (Jounz. Amer. C h m , SOC., 1908, 30, 577-578.)-A form of container for the solution to be examined i s shown in Fig. 1. The light passes lengthwise through the tube, B, and is focussed upon the slit, S, by the solution in the part of the tube, A, which acts as a cylindrical lens. If the tube, B, is long, the length of the path of the outside and middle rays of the beam is essentially the same. so that the absorption is nearly the same in all parts of the beam. A convenient form of fulgurator is shown in Fig. 2. The two glass tubes, AA, are fused togsther in a nearly parallel position by means of a short piece of glass rod, B. One of the wires at the bottom of the tubes is bent in the form of a U, so that the end is directly below and parallel with the wire in the other tube. The end of the lower wire may be covered with a glass capillary, C, in the usual way. The tubes can be readily transferred from one solution to another, and are easily cleaned or rinsed. If a ---" I L u- figrre E g v r e 2 rod be used to join the tubes together, the tubes may be brought so near without danger of short-circuiting that the apparatus is narrow enough to be inserted in a wide test-tube. If the tubes are joined by means of a tube, there is some difficulty from this source. w. P. s.