CHEMISTRY. 717 



of the microscopical analysis of foods and condiments. Special attention is given 

 to determining the purity of such materials and the detection and identification of 

 the principal impurities and adulterants. Chapters are devoted to the analysis of 

 flours and other milling products of cereals and leguminous seeds, and starches and 

 sago, vegetables, fruits, tea, coffee, cocoa and similar products and spices. A chapter 

 is also devoted to directions for recognizing with the microscope the more common 

 adulterants of powdered spices. 



Practical guide to the analysis of ■water, W. Ohlmuller (Guide pratique pour 

 Vanahjse de 1'eait. Paris: Librairie Voly technique Baudry et Cie, 1898, pp. 289, pi. 1, 

 figs. 77). — Translated by L. Gautier from the second German edition of Die Unter- 

 8uchung des Wassers. 



Determination of organic substances in -water, A. Pagnoul (Ann. Sci. Agron., 

 1898, II, Xo. 1, pp. 9-7, 96). — Water containing, as a rule, 20 mg. of organic matter 

 in various forni3»was tested with permanganate of potash immediately after prep- 

 aration, and after standing 40 days in an open flask exposed to sunligbt and in a 

 closed flask in darkness. The results were very discordant and indicate that there 

 is no reliable factor for calculating organic matter from oxygen absorbed. 



On the facilities for standardizing chemical apparatus afforded by foreign 

 governments and our own, L. A. Fischer (Jour. Amer. Chem. Soc., 20 (1898), Xo. 

 IS, pp. 912-927, pis. 2). — In addition to describing these facilities and discussing the 

 standardizing of chemical apparatus, the author describes a device used by the 

 Office of Standard Weights and Measures for making flasks, and recommends the 

 adoption of the following units of measurement: 



"(1) The liter, as defiued by the International Committee of Weights and Meas- 

 ures, viz, the volume of the mass of a kilogram of pure water at the temperature 

 of maximum density, and under a pressure of 760 mm. of mercury. 



"(2) Density, defined as the ratio of the mass of a substance to that of an equal 

 volume of pure water at its maximum density (4 C C). 



"(3) The centigrade degree of the hydrogen thermometer of the International 

 Bureau of Weights and Measures. 



"I also recommend that some convenient temperature be adopted, at which all 

 volumetric apparatus shall contain their stated capacities." 



Extraction apparatus for laboratories, B. Donner (Chem. Ztg., 22 (189S), No. 

 94, p. 996, figs. 2). — A convenient arrangement by which any number of extraction 

 liquids may be used in succession on a given substance, without transferring it from 

 one containing vessel to another. With one adjustment of the parts the apparatus 

 acts as an ordinary continuous extraction apparatus. By substituting for the dis- 

 tillation flask with the extraction liquid another containing water and making a 

 slight readjustment of the condenser, we have a steam drier so arranged that the 

 liquid left in the substance is vaporized and is thenrecondensed and collected. — J. t. 



ANDERSON. 



A new electric agitator, E. Van Melckebeke (Bui. Assoc. Beige Chim., 12 (1898), 

 Xo. 9, pp. 331-334, fig. 1). — The stirring rods are attached to a metal rod carried by 

 an armature oscillating between 2 electro-magnets, so arranged that the stirring 

 rods may be given either a backward and forward or a rotary motion. 



An improved apparatus for the estimation of carbonic acid in minerals, etc., 

 A. Marshall (Jour. Soc. Chim. Ind., 17 (1898), Xo. 12,p-p. 1106,1107, fig. i).— A method 

 depending upon the measurement of the volume of gas evolved is described. 



A new crucible — the tube crucible, E. Murmann (Monatsh. Chem., 19 (1898), p. 

 403, fig. 1; abs. in Jour. Soc. Chem. Ind., 17 (1898), Xo. 12, p. 1181).— The crucible has 

 a perforated bottom, ending in a straight or bent tube. 



Collen's device for recovering the ammonium sulphate from coke ovens 

 (L'Engrais, 13 (1898), Xo. 44, p. 1046). 



