18 EXPERIMENT STATION RECORD. 



refractive index, to detect crystals of foreign fats. The refractive 

 index and volatile fatty acids are given for a number of vegetable and 

 animal fats, and the application of tliese data in the examination of 

 mixed butters is described. 



The examination of filled cheese, A. Devarda (Ztschr. Analyt. 

 ( Item., SO (1897), iVo. 12, pp. 75 1-766, fig. 1). — To obtain large quantities 

 of cheese fat for investigation the following method is recommended: 

 From 50 to 100 gin. of finely cut cheese is placed in a flask with 50 to 

 80 cc. water, 100 to 150 cc. ether, and 2 drops of phenolphthalein solu- 

 tion. The whole is vigorously shaken and dilute caustic potash added 

 until the reaction is distinctly alkaline, when the shaking is repented. 

 After standing a short time the layer of fat solution may be drawn oft', 

 filtered, and dried at 100^ C. 



If the fat has been thus extracted, the Reichert-Meissl method is 

 believed sufficient to indicate the presence of foreign fat. 



Water is determined in the cheese by drying the. finely cut sample 24 

 to 30 hours in vacuo over sulphuric acid at room temperature, com- 

 pleting the operation by heating to constant weight at 100° C, 2 to 6 

 hours being generally sufficient. 



The cheese, after drying by the above-described method, is finely 

 ground and extracted with water-free ether. The crude fat thus 

 obtained is dried 2 hours at 100° O. — l. h. merrill. 



A new drying oven with a constant temperature, M. O. Schu yten 

 (GJw)i). Ztg., 21 (1897), No. 100, p. 1049, fig. 1).— This is on the principle 

 of the water bath with a constant level. A double-walled drying oven 

 is connected with an automatic constant-level reservoir of pure water 

 by means of a connecting tube, which is provided with two stopcocks. 

 One of these cocks is intended to establish connection between the 

 oven and reservoir, and the other to allow egress of the liquid from 

 the oven. Sodium nitrate is dissolved in the water to elevate the boil- 

 ing point, the requisite amount being determined by trial. If the tem- 

 perature of boiling is too low, more nitrate is added; if too high, some 

 of the solution is drawn off and its place supplied with fresh water 

 from the reservoir. When the desired point has been once reached and 

 connection with the fresh-water reservoir established, the temperature 

 remains constant. The temperature of boiling of the solution is con- 

 stant so long as its density is constant, and this remains so indefinitely, 

 inasmuch as the water lost by evaporation is renewed automatically 

 from the fresh- water reservoir. — j. t. Anderson. 



Second International Congress of Applied Chemistry, 1896 (Deuxiime con- 

 gres international chimie appliquie, 1S96. Paris: Association des Chimistes dc Sucrerieet 

 Distillcrie, 1897, 5 vols. ).— This contains a report of the proceedings of the congress 

 and the papers presented, edited by F. Dupont. Volume I (pp. 721, ill.) contains 

 reports of section 1 on sugar and section 2 on" alcohol and fermented products; 

 Volume II (pp. 544), of section 3 on agricultural industries, section 4 on agricultural 

 chemistry, aud section 5 on official analysis and apparatus of precision; Volume III 

 (pp. 499, ill.), of section 6 on chemical industries, section 7 on photography, and sec- 



