704 EXPERIMENT STATION EECORD. 



flask Is then placed over a Bunsen or ring burner (best if heated over the free 

 flauK') and brought as rapidly as possible to a boil. The boiling is continued 

 for exactly five minutes, tlie flask removed, allowed to stand for one minutr. 

 the excess of permanganate carefully destroyed by standard oxalic acid solution 

 (1 cc.=l cc. permanganate) and the permanganate again added until a trace 

 of pink api>ears and persists for one minute. From the total volume of per- 

 manganate the volume of oxalic acid usetl is deducted. 



" In order that the results obtained may always be comparable an excess of 

 at least 2 cc. must at all times remain." 



Examinations of a large number of samples of water by this method indicate 

 that oxygen consumption is of little value in judging highly colored surface 

 waters. With ground waters which ai'e colorless or nearly so there appears 

 to be a somewhat close relation 'between high oxygen consumed and high bac- 

 terial flora and vice versa. Five minutes' boiling is thought to be sufficient to 

 decompose all easily oxidizable organic matter, and this is believed to be all 

 that is necessary to determine in such analysis. 



New methods of analysis {Mem. Dir. Foincnto [Peru], 1907-S, vol. 1, pp. 



S0-S8). — Methods used in the analysis of guanos and soils are briefly described. 



Further notes on humus acids, A. J. Van Schermbeek (Join: Pralct. Chem., 



n. ser., 78 (1908), No. 11-18, pp. 285-288). — The author reiterates his criticisms 



of the Tacke-Siichting method (E. S. H., 20, p. 308). 



The isolation of dihydroxystearic acid from soils, O. Schreiner and E. C. 

 JSIHOREY {Jour. Amer. Chem. Soc., 30 {1908), JSo. 10, pp. 1599-1607, pi. i).— The 

 methods employed in isolating this body are described and tests of its toxicity 

 in experiments with wheat seedlings are reported. It was found that the 

 toxicity of the substance was "as great in a concentration of 100 parts per 

 million as in a concentration of 200 parts per million, which is approximately 

 a saturated solution, and the toxic effect is marked even when the concentration 

 is as low as 20 parts per million." 



Organic chemistry for advanced students, J. B. Cohen {^ew York and Lon- 

 don, 1907, pp. VIII+632). — Chemical theories and other related topics are dis- 

 cussed in this volume. Special interest for students of nutrition attaches to 

 the chapters on carbohydrates, fermentation and enzym action, the purin group, 

 and the proteids, which summarize the more important work which has been 

 done and the theories at present held. 



Physiological chemistry, W. D. Halliburton {Ann. Rpts. Prog. Chem. [Lon 

 don], 4 (1907), pp. 226-260). — ^A critical summary and review of investigations 

 reported on the chemistry of proteids and other questions of physiological 

 chemistry. 



Hydrolysis of vicilin from the pea, T. B. Osborne and F. W. Heyl {Jour. 

 Biol. Chem., 5 {1908), Xo. 2-3, pp. 187-195).— The results of hydrolysis of 

 vicilin are very similar to those obtained with legumin, the most marked dift'er- 

 ence being that vicilin yielded no glycocoll. Less alanin and arginin and more 

 glutaminic acid were also found than in legumin. " It is probable that vicilin 

 is a distinct protein or mixture of proteins and not an altered product of 

 legumin, for the seeds of the vetch which contain legumin yield no vicilin." 



Hydrolysis of legumelin from the pea, T. B. Osborne and F. W. Heyl {Jour. 

 Biol. Chem., 5 {1908), Ao. 2-3, pp. 197-205).— The products obtained by the 

 hydrolysis of legumelin from the pea {Pisum sativum) were studied in com- 

 parison with other pea proteids and leucosin of wheat. 



" The results of this hydrolysis show legumelin to be distinctly different in 

 constitution from the other proteins with which it is associated in the pea. 

 The properties and ultimate composition of legumelin closely resemble those of 

 leucosin from the wheat embryo, and this resemblance extends not only to the 



