10 EXPERIMENT STATION RECORD. 



Zvnibl. Gesam. Physiol, u. Path. Staff wcchficls, n. ser., // (1909), No. 11, pp. 687, 

 6SS). — A digest of data regarding biochemical methods designed for laboratory 

 use. 



A contribution to the biological differentiation of proteids, W. Rickmann 

 (ZlHchr. Ilcisch u. MilcJilim/., 11 (1901), No. 6, pp. 191-201; abs. in Ztschr. 

 Uniersuvli. Nahr. ii. (IcnussmH., 18 {1909), No. 3, p. 220).— The author investi- 

 gated the precipitin reaction and the deviation of comi)]ement in regard to their 

 sensitiveness in differentiating human from hog proteids. lie found that the 

 presence of 0.00001 cc. of human serum completely checks the hemolysis, 

 whereas in the presence of 0.1 cc. of hog serum hemolysis continues, so that a 

 specifity of 1 to 10,000 exists. With the precipitin reaction the specifity was 

 only 1 to 100. The deviation of the complement method is recommended to be 

 run in parallel with the precipitin reaction. 



The Bang method for the determination of sugar, H. Jessen-Hansen 

 {Compt. Rend. Lab. Carlsberg, 7 {1909), No. //, pp. 218-226; abs. in Chem. Ztg., 

 33 {1909), No. 91, Rcpcrt., p. .'//,s').— This is a critical study of the Bang method 

 for determining sugar, which the author considers the best method known for 

 the purpose. Special attention is called to the method employed in mixing the 

 solutions which go to make up the principal solution in order to obtain the 

 proper concentration. The rapidity with which the white solution is added is 

 also of great moment. The rate recommended is 20 cc. in 15 seconds, and the 

 temperature for the titration 32° C. The space occupied by the solution has a 

 definite effect on the results. 



Color reactions for sugars with the indol bodies, J. Gnezda {Compt. Rend. 

 Acad. Sci. [Paris], U8 {1909), No. 8, pp. JiS5-489; abs. in Bui. Soc. Chim. 

 France, .'/. .ser., 6' {1909), No. 15, p. 8^0). — This reaction is based upon the pro- 

 duction of a blue, brown, or green precipitate by the methylindols in alkaline 

 solutions of sugars containing the group CHO upon acidification with HCl. 



The detection of saccharose and calcium sucrate, particularly in milk, S. 

 Rothenjx'ssi;r {Ztschr. Untrrsuch. Nahr. u. Gcnussmtl., 18 {1909), No. 1-2, pp. 

 135-155). — The reagent employed consists of 20 cc. of a .5 per cent alcoholic solu- 

 tion of diphenylamin, 60 cc. of acetic acid, and 120 cc. of 1 : 1 hydrochloric acid. 

 Saccharose gives a blue coloration with this reagent. Lactose does likewise, but 

 less rapidly. 



With milk it is necessary to precipitate as much as possible of the lactose and 

 other substances. This is done by adding a solution consisting of 2 parts by 

 volume of lead acetate solution (German pharmacopoeia) with 1 part by volume 

 of 10 per cent ammonium solution, to an equal volume of the milk or cream, 

 shaking well and filtering. From .3 to 4 cc. of the filtrate are then mixed with 

 double the amount of the diphenylamin reagent and placed in the boiling water 

 bath. In about 2 to 3 minutes a blue color appears if saccharose is present to 

 the extent of 0.05 per cent. 



The estimation of the ash in sugars and sirups by the determination of the 

 electrical conductivity, H. Main {Internat. Sugar Jour., 11 {1909), No. 121, pp. 

 3S.'i-339, fig. 1). — Determining the conductivity of the ash solution by Kohl- 

 rausch's apparatus, with some modifications, is a: convenient method for indus- 

 trial work. 



The direct gravimetric determination of starch according to the method 

 of Baumert and Bode, G. Baumert {Ztschr. Untersuch. Nahr. u. Genussmtl., 

 IS {1909), Nos. 1-2, pp. 161-168). — Various influencing factors have been elimi- 

 nated and hydrochloric acid is now used in this method. 



A comparative study of the titrimetric and polarimetric methods for the 

 determination of starch, Anna Giltay and J. J. Blanskma {Pharm. Weelcbl., 

 .',6 {1909), No. 21, pp. 689-110).— A critical study of these methods for the 



