410 EXPERIMENT STATION RECOED. 



individual specific effects in each case. The unionized molecules may also take 

 part in these reactions. The accelerations can not be explained in as simple a 

 manner except, perhaps, for the cases where increased formation of active lipase 

 (as by manganous salts) may be assumed." 



Action of enzyms on hexose phosphate, V. J. Harding (Proc. Roy. Soc. 

 [London'\, Ser. B, 85 {1912), No, B 581, pp. 418-422; aJ)S. in Jour. Chem. Soc. 

 [London], 102 {1912), No. 601, I, p. 928).— The lipase from the castor bean and 

 emulsin from almonds hydrolyze hexose phosphate slowly, and no hydrolysis 

 at all is produced by the pancreas of the bovine. Zymin in an aqueous solu- 

 tion hydrolyzes hexose sulphate slowly. An autolyzed yeast juice was found 

 strongly hydrolytic, and the enzym producing it can be precipitated from the 

 juice with alcohol and ether. 



Nephelometry in the study of proteases and nucleases, I, P. A. Kobee 

 {Jour. Biol. Chem., 13 {1913), No. 4, pp. 485-498, figs. 2). — This describes a 

 microchemical method in which the nephelometer is employed for following the 

 digestion of a soluble protein, edestin. The instrument, which is described in 

 detail, can be made from a Duboscq colorimeter. 



" The readings of the nephelometer platted against the ratios of the solu- 

 tions, for a given standard solution and a given height of standard, seem to fol- 



« s{l-x)k 

 low a uniform curve which can be expressed in the equation J/="^ ^2 — 



where y = height of * unknown ' solution, s = height of standard solution, 

 X = ratio of solutions. The studies of various precipitants for protein and 

 other organic substances in dilute solutions are in progress with the view of 

 extending the application of this method generally. The ease, the rapidity, 

 and the accuracy of the method would make it very useful, if the proper pre- 

 cipitants can be found. By proper dilution it can be used for large amounts 

 of substances, and is sensitive enough to determine 0.00002 gm. with a per-, 

 centage error of less than 2 per cent. The determination of casein in milk 

 and the estimation of minute quantities of ricin are receiving immediate atten- 

 tion." 



Nephelometry in the study of proteases, II, P. A, Kobeb {Jour. Amer. 

 Chem. Soc, 35 {1913), No. 3, pp. 290-292). — "The nephelometer can be used for 

 studying the digestion of casein when a 3 per cent solution of sulphosalicylic 

 acid is used as a precipitant. This reagent does not precipitate amino acids, 

 peptids, peptones, and urinary constituents under the conditions given for 

 nephelometry. The nephelometric constant for casein with this precipitant 

 was found to be 0.2." 



On the purification of phosphatids, H. MacLean {Bio-chem. Jour., 6 {1912), 

 No. 4, pp. 355-361). — "The alcohol-soluble phosphatid of kidney and muscle is 

 lecithin with a N : P ratio of 1:1. Though substances containing different 

 amounts of nitrogen are obtained in the different extracts, the application of 

 the method described — emulsification and precipitation with acetone — gives a 

 single product of the nature of an ordinary lecithin. No alcohol-soluble sub- 

 stance having a higher percentage of nitrogen than that of lecithin has been 

 found. 



" From an aqueous extract of the nitrogenous impurity of lecithin a sub- 

 stance of basic nature crystallizes out; after the separation of this substance 

 the mother liquor is very effective in curing polyneuritis (beri-beri). This 

 explains the anomalous results of many observers who have endeavored to 

 cure pigeons suffering from beri-beri by lecithin." 



Tannic acid fermentation, I, L. Knudson {Jour. Biol. Chem., I4 {1913), 

 No. 3, pp. 159-184, figs. 2). — ^The results show that "tannic acid is toxic to a 

 large number of fungi at relatively low concentrations. Aspergillus niger is a 



