(U(> EXPERIMKNT STATION RECORD. 



the :iniiii()iiiuiii salt (chlorid or siilpliatc) is dissolvi'd in the smallest possible quan- 

 tity of cold water. The solution is then heatiMl to l)oiling and mixed with an excess 

 of l)oilini!; 10 percent solution of sodium picrate. The liquid is allowed to cool 

 gradually, and when (luite colil is decanted, the portion adhering to the crystals l)eing 

 removed by means of lilter i)ai)er. The crystals are then dried at (50 to 70° C. and 

 weighed. Carl)onates, cyanids, and compounds of potassium, rul)idium, and caesium 

 (hut not of lithium) interfere with this reaction. 



A method for the determination of ammonia, A. ScniTTENnELM {Ztf^chr. 

 Pkysiol. Cheiii., .iO (/.W;/), j>. 7.>'; <il>.s. In ('hem. Zlg., 27 {190S), No. 81, Repert. IS, p. 

 251). — A modillcation of the Kriiger-Reichs method, adapted to clinical purposes, is 

 described. 



Estimation of nitrates in waters by the Schultze-Schloesing method, L. L. 

 DE KoNiNCK [Bul. Assoc. Belxjc Chilli., J7 [190o),pp. 117-120; ahs. in C'hem. Centhl., 

 1903, II, No. 7, pp. 461, 462; Jour. C'hem. Soc. [London], 84 {WOS), No. 493, II, p. 

 754). — In this method the gas evolved by tlie action of hydrochloric acid and ferrous 

 chlorid is collected over potassium hydroxid and the resulting nitric oxid is finally 

 measured over water. The author, however, prefers to first decompose the carljo- 

 nates. It was found that bromids do not interfere with the reaction. In estimating 

 silica in water containing nitrates the author prefers to acidify with sulphuric acid 

 instead of hydrochloric acid, especially when a platinum dish is used. 



On the determination of nitrate nitrogen in presence of organic nitrogen, 

 T. Pfeiffek {Ztschr. Analyt. Chem., 42 {1903), No. 9-10, pp. 612-617; abs. in Chem. 

 Centhl., 1903, II, No. 20, p. 1145). — Referring to a recent article by Liechti and Rit- 

 ter (E. S. R., 15, p. 121), the author reports further studies of the accuracy of 

 Schloesing's method, which bear out his conclusions drawn from previous investiga- 

 tions, that the presence of annnonium salts and organic compounds of nitrogen seri- 

 ously interfere with the accuracy of this method, causing the results to be too low. . 



The determination of nitrogen by the Kjeldahl method, R. B. Gibson {Jour. 

 Arner. Chem. Soc, 26 {1904), ^^o. 1, pp. 105-110). — Owing to the recent discussion of 

 the reliability of the Kjeldahl method for the determination of nitrogen in organic 

 compounds, the author made control determinations of nitrogen in uric acid, hippuric 

 acid, tyrosin, leucin, urethane, thiourea, i^henylmethyloxypyrimidin, aminobenzoic 

 acid, and caseinogen by the Kjeldahl-Gunning method. 



The results are believed to afford no occasion to question the usefulness or accuracy 

 of the the Kjeldahl method as applied to physiological-chemical work. It is stated 

 that "when due care is exercised to procure a proper decomposition and oxidation 

 of the substances analyzed, uniformly satisfactory determinations can readily be 

 obtained. For substances of unknown structure, however, the results furnished by 

 the Kjeldahl process should not be accepted without verification by other methods." 



The results of recent investigations in proteid chemistry, P. A. Levene 

 {Science, n. .'<er., 19 {1904), No. 472, p. 106). — A brief note on a paper presented by 

 the author at a meeting of the Society for Experimental Biology and Medicine, call- 

 ing attention to the results of some of the more recent work on the chemistry of 

 proteids, which is of especial interest as explaining biological phenomena. 



On vegetable protein, O. Nagel {Jour. Soc. Chem. Iiul, 22 {1903), No. 24, pp. 

 1337, 1338). — Notes are given on the preparation of vegetable albumin from certain 

 oil cakes, of which sesame and rape seed are preferred, and of vegetable casein from 

 soy beans. 



A new Kjeldahl apparatus, M. Vogtherr {Chem. Ztg., 27 {1903), No.. 80, pp. 

 988, 989; ahs. in Chem. Centhl., 1903, II, No. 20, p. II4I). 



Phosphomolybdic acid as a reagent for the detection of the amino group, 

 F. SEiLEit and A. Verda [Chem. Ztg., 27 {1903), No. 91, pp. 1131-1125). 



Provisional methods of the Hawaiian Sugar Chemists' Association {Hono- 

 lulu: Ildvaiian (Inzette Co., Ltd., 1903, pp. 10). — This contains the provisional methods 

 of the association for the analysis of sugar cane, bagasse, waste molasses, and press 



