In previous experimental work1 a watery colloid emulsion of cholesterol was used and proved to be such a satisfactory preparation for intraperitoneal injections in rabbits and guinea-pigs, that I employed it again as most suitable for producing a direct hypercholesterolemia. The use of such emulsions eliminates some of the objectionable features attending the prevalent method of administering cholesterol by feeding. The necessity of resorting to solvents such as fats and oils involves the production of a fat infiltration which, although not considered as pathological, necessarily masks the effects of cholesterol on the tissues to some extent and complicates the conclusions.
Instead of Merck's pure cholesterol, I used a preparation obtained from gallstones by extraction with ether in the Soxhlet apparatus. For the separation of all saponifiable substances from this ether extract, a method was employed which is based largely on Kumagawa and Sutro.2 Five grams