374 ON THE CHOLESTERIN-ESTERS 



obtained; they melted after recrystallization at 43-44 C., 

 thus corresponding to cholesteryl oleate. 



Duck serum. Considerable difficulty was experienced in 

 obtaining characteristic cholesteryl oleate preparations from 

 duck serum. The products showed admixture of apparently 

 amorphous material, and melted at about 60 C. From one 

 half liter serum, however, about 0.4 gram (0.08 per cent) of 

 crystals was obtained. After recrystallization, the crystals 

 melted at 42-44 C. By extracting the serum residue with 

 alcohol-ether, one half gram of a crystalline product was 

 obtained. The preparation, when purified, melted at 76 C., 

 giving evidence of the probable presence of a considerable 

 quantity of cholesteryl palmitate (melting, when pure, at 

 77 C.). 



The blood-corpuscles. That cholesterin may occur in an 

 uncombined state in the blood-corpuscles seems probable from 

 the recent analyses of Abderhalden,* who found noticeable 

 quantities of cholesterin in them, while fatty acids were 

 absent, or present only in very small amounts. The older 

 statements of Hoppe-Seyler f lead to similar conclusions ; and 

 Wooldridge J stated that he obtained cholesterin free from 

 fats and lecithin by extracting the stroma of blood-corpuscles 

 with cold ether. In the present experiments, crystals of 

 cholesterin were repeatedly obtained from the blood-corpuscles 

 by direct extraction with ether. The corpuscles were separated 

 from defibrinated blood by centrifugalization or by subsidence, 

 and after treatment once or twice with one per cent sodium 

 chloride solution to remove any adherent serum, were rendered 

 laky and extracted. The ether extract corresponded in its 

 behavior with the description given by Wooldridge; on 

 evaporation it yielded a residue of needle-shaped crystals 

 occasionally arranged hi rosettes. After recrystallization 



* Abderhalden, Zeitschrift f . physiol. Chemie, 1897, xxiii, p. 522 ; Ibid., 1898, 

 xxv, p. 108. 



t Hoppe-Seyler and Thierfelder, Handbuch der chemischen Analyse fur 

 Aerate, p. 408. 



t Wooldridge, Archiv fur Physiologic, 1881, p. 389. 



