AGRICULTUKAL CHEMISTEY AGEOTECHNY, 607 



fluid by Buscli's method 19.02 per cent. The Devarda procedure was the 

 cheapest. 



Potassium: Its qualitative detection as the cobalti-nitrite, L. T. Bowses 

 {Jour. Amer. Cliem. Soc, 33 {1011), No. 10, pp. 1566-1569). — "Summarized, 

 the procedure is as follows : Place 5 cc. of the potassium solution in a tall 

 beaker of 50 cc. or 100 cc. size, set on a mirror beside it 5 cc. of pure water in 

 a similar bealier, and add to each 2.5 cc. of sodium cobalti-nitrite reagent and 

 5 cc. of 95 per cent alcohol. If upon looking down through the solutions into 

 the mirror an equally sharp image of the observer can be seen in each beaker 

 there is no potassium present ; if the test solution shows a dimmer image than 

 the blank, potassium is present amounting to 2 or more parts per million. 

 The only precautions necessary are to avoid making the test in an atmosphere 

 dense with ammoniacal fumes, to be certain of the absence of ammonium from 

 the solution, and to be certain that the solution is neutral or slightly acid with 

 acetic acid." 



Determination of magnesium as magnesium oxid, O. Kallauner (Chem. 

 Ztg., 35 {1911), No. 125, pp. 1165, 1166). — Magnesium carbonate, oxalate, nitrate, 

 and chlorid can be converted into magnesium oxid by heating. The first 3 are 

 decomposed with ease, magnesium chlorid less readily. Quantitative results 

 could not be obtained by heating magnesium chlorid alone or in the presence 

 of mercuric oxid. The decomposition can, however, be accelerated by increas- 

 ing the temperature and the time of heating, in the Berzelius method, and by 

 repeated evaporation in the presence of mercuric oxid. Only when the pro- 

 cedure is thus carried out are the results satisfactory for technical purposes. 



The assertions of Rose and Krause are substantiated by the author's work, 

 as well as the criticism of Pfeiffer's method made by Emde and Senst. 



Some new findings in the chemistry of water, C. Blacker {Chem. Ztg., 

 S5 {1911), No. 40, pp. 353, 354; 41, PP- S70-372; 43, pp. 390-392; 44, pp. 398, 

 399). — A critical study, with particular regard to the technical and analytical 

 chemistry of water. 



The phytosterol content of soy beans, H. Matthes and A. Dahle {Arch. 

 Pharm., 2J,9 {1911), No. 6, pp. 436-4 Jf J,; ahs. in Jour. f^oc. Chem. Indus., 30 

 {1911), No. 18, p. 1124). — The unsaponifiable portion of the soy-bean oil, which 

 amounts to about 0.7 per cent, can be easily separated with petroleum ether into 

 a crystalline portion (55 per cent) and a soluble liquid portion (45 per cent). 

 The crystalline portion is composed of 2 compounds, namely, (a) about 2.4 

 per cent of phytosterol (melting point 169° C), "which has 2 double linkages 

 and is strongly levorotatory ; it is identical with the stigmasterol isolated from 

 Calabar beans by Windaus and Hauth; (b) about 97 per cent of a levorotatory 

 phytosterol with 1 doaible linkage and melting at 139°. The liquid portion of 

 the unsaponifiable portion of soy-bean oil consists of unsaturated oxygenated 

 compounds, which give the phytosterol reaction. Elementary analysis gave 

 the same proportion of carbon and hydrogen as in the case of phytosterol (b). 

 Experiments made to separate the phytosterol-like constituent of the liquid 

 portion by Windaus' method with digitonin were unsuccessful." 



In regard to the relation of the hemagglutinating and precipitating 

 capacity of plant antigens, H. Raubitschek and M. Wilenko {Ztschr. Im^- 

 munitdtsf. u. Expt. Ther., I, Orig., 5 (1910), No. 4, PP- -'/-'/M^Y).— The protein 

 precipitating and hemagglutinating properties of many phytalbumins are not 

 closely related, and the reactions must, therefore, be considered to be due. to 

 2 distinctly separate substances. In this work plant antigens were also found 

 to differ in regard to this point from inorganic colloidal acids. 



The cleavage of nitrogen-containing substances by yeast, O. Schwakz 

 (Biochem. Ztschr., 33 {1911), No. 1, pp. 30, 31; ahs. in ZentU. Biochem. u. 

 38038°— No. 7—12 2 



