1913] Alfred P. Lothrop 291 



Chemistry of the University of Pittsburgh.) Boas and P have 

 shown that various cholesterol esters diffuse from ether Solution 

 through rubber into ether; cholesterol-stearate, for example, with a 

 molecular weight of 652.51, diffuses very readily. Recently I found 

 that the acid form of iodo-eosin diffuses very quickly under similar 

 conditions. This substance, with a molecular weight of 836, has 

 the composition indicated by the appended structural formula : 



co<^ • >c< >0 



53. The absence of certain enzymes from the human 

 chorion. Jacob Rosenbloom. (Laboratory of Biological Chem- 

 istry of the University of Pittsburgh.) Published in füll in this 

 issue of the Biochemical Bulletin, page 236. See also abstract 



55- 



IL ABSTRACTS OF PAPERS FROM THE COLUMBIA BIOCHEMICAL 

 DEPARTMENT AND AFFILIATED LABORATORIES 



54. The preparation of histon from flounder sperm. Walter 

 H. Eddy. Testes, obtained from cold storage flounders and pre- 

 served in alcohol, were ground and extracted with 0.8 per cent. 

 hydrochloric acid Solution. The histon was obtained from the acid 

 extract after the manner of Kossei and Kutscher, and purified by 

 washing with water, re-dissolving in 0.8 per cent. hydrochloric acid 

 Solution and reprecipitating with ammonia, several times. Like 

 ammonia-precipitated thymus histon, this histon was insoluble in 

 water and the hydrochloric acid Solution, after dialysis to neutrality, 

 gave all the characteristic histon tests. The "ammonia precipi- 

 tate," washed with water, alcohol and ether, and dried to constant 

 weight at 105° C, contained 18.08 per cent. of nitrogen (one 

 determination only, because of lack of pure material). Like that 

 of thymus histon, the hydrochloric acid extraCt of the histon from 

 flounder testes yielded, when saturated with sodium chlorid, a pre- 

 cipitate which was soluble in water. Such a Solution gave the char- 

 acteristic ammonia and alkaloidal tests, but was not precipitated 



* Rosenbloom : Biochemical Bulletin, 1912, ii, p. 67 ; Boas and Rosen- 

 bloom : Proc. Soc. Exp. Biol. and Med., 1911, viii, p. 132. 



