324 THE ANALYST. APPARATUS. An ApparGtus for the Direct Determination of the Specific Gravity of Cement. Daniel D. Jackson. (Jozwn. Soc. Chem. Ind., xxiii., 593.)-By the t use of the author’s apparatus it is claimed that a determination of specific gravity accurate to 0.01 can be obtained in about ten minutes. The apparatus consists of a specially graduated burette having a bulb at the top, the bulb holding exactly 180 C.C. from 8 mark on the neck to a mark on the burette just below the bulb. The flask is of heavy glass, and has a capacity of 200 C.C. up to a mark on the neck of its hollow ground-glass stopper. To make a determina- tion 50 grammes of the dry sample are poured into the unstoppered flask, and the bulbed burette is filled with kerosene up to the mark on the neck of the bulb.About half the kerosene is then allowed to run into the flask, and then a further quantity to wash down any cement adhering to the neck of the flask, which should now be nearly full, and the contents free from air bubbles. The ground stopper is next inserted into position, when more kerosene is run into the flask from the burette until the level of the liquid reaches the mark on the neck of the flask stopper. The specific gravity may now be read off directly on the burette stem. Thus, if the kerosene has been run out exactly to the 180 C.C. mark below the bulb, the specific gravity of the sample will be 2.50, since- 200 - 180 = 20 ( = volume displaced by 50 gramrnes of sample), and ,=2.50. 50 2u The author gives tables of temperature correc- tions, and by observing the temperature of the kero- .sene before and after the determination increased accuracy may be obtained. Good samples of Portland The apparatus is made by Emil cemenb have a specific gravity of 3.05 or over. Greiner, 78, John Street, New York City. A, R. T.THE ANALYST. 325 On the Use of Bunsen Burners and Combustion Apparatus without Coal Gas. H. D. Gibbs. (Journ. Amer. Chem. SOC., xxvi., 760.)-In places where coal- gas is not obtainable, the author proposes to use the vapours of ethyl and methyl alcohol (95 per cent.) as a substitute. The alcohol is heated to boiling by means of an alcohol lamp, or other convenient source of heat, in a 4-litre boiler, from which sufficient gas is obtained to run several combustion furnaces at the same time. Under each section of the burners of the furnace an alcohol lamp is placed to avoid condensation. The pressure in the boiler does not exceed 10 millimetres. The same arrangement is used to supply gas to ordinary Bunsen burners. In this case it is well to have one burner alight in addition to those actually required, as this allows of more easy regulation of the size of the flame. A. G. L.