66 Studies of Diffusion through Rubber Membranes [Sept. 



3. Ether extract of heart muscle (ox). Fat, fatty acid, lipo- 

 chrome, and cholesterol were detected in the dialysate from ether 

 extracts of the heart muscle of oxen. Lecithans did not diffuse. 



4. Ether extract of kidney and liver (dog). Fat, fatty acid, 

 lipochrome, and cholesterol appeared in the diffusates from ether 

 extracts of dog kidneys and livers. Lecithans did not dialyze. 



5. Ether extract of blood (dog). Fat, fatty acid, lipochrome, 

 and cholesterol occurred in the dialysates from ether extracts of dog 

 blood. No lecithans dialyzed. 



6. Ether extract of carrots. The coloring matter dialyzed 

 very rapidly from ether extracts of carrots. A small amount of fat 

 was also present in the dialysate. 



7. Ether extract of Xanthoma (skin). The yellow coloring 

 matter dialyzed very quickly from an ether extract of xanthomatous 

 skin, but it faded in twelve hours. 



8. Ether extract of cerumen. Cholesterol, fat, and fatty acid 

 were present in the dialysates from ether extracts of cerumen. 

 Neither the coloring matter nor the lecithans diffused. 



g. Ether extract of yeast. The dialysates from ether extracts 

 of yeast exhibited a peculiar opalescence, even at the end of six 

 weeks' dialysis. A small amount of fat dialyzed, but lecithans did 

 not diffuse. 



10. Ether Solutions of individual substances er special prod- 

 ucts. The following substances or special products, when subjected 

 to diffusion by the method described above, were found to be 

 diffusible : 



Acetic acid Ethyl butyrate Palmitic acid 



Acetone Formic acid Potassium palmitate* 



Beta-hydroxy-butyric acid GlyceroP Potassium stearate* 



Butter (fresh and rancid) Lactic acid Propionic acid 



Butyric acid Lead oleate Sodium palmitate* 



Cholesterol-acetate Mutton tallow Sodium stearate* 



' When ether-alcohol Solutions of glj'cerol are dialyzed against ether-alcohol, 

 and alcohol Solutions of glycerol are dialyzed against ether, the dialysates contain 

 glycerol. 



* Treated with water, then with alcohol to the point of precipitation, then 

 with ether until a precipitate was produced. The filtrate was dialyzed against 

 water, alcohol, and ether in identical proportions. 



