462 Messrs. Ellis and Gardner. Origin and [Nov. 8, 



cholesterol is re-absorbed, possibly in the form of esters, along with the bile 

 salts and is carried in the blood stream to the various centres and tissues for 

 re-incorporation into the constitution of new cells. 



It seemed to us that valuable data for the elucidation of the cholesterol 

 problem might be obtained by a careful study of the cholesterol and 

 cholesterol-ester content of the various organs and tissues of the body, in 

 the case of rabbits fed on diets containing varying amounts of cholesterol, 

 and also of rabbits kept in a state of inanition. In this paper we give an 

 account of our experiments on the cholesterol content of the livers of such 

 rabbits. 



Method of Estimating the Cholesterol. 

 The animals after antesthetisation were bled as completely as possible. 

 The livers were then taken out and weighed. The material was then finely 

 ground with sand and plaster of Paris. The ground mass was then allowed 

 to set, after which it was finely powdered and extracted in Soxhlet's 

 apparatus with ether for from two to three weeks. The ethereal extracts 

 were made up to a known volume with ether and carefully divided into two 

 equal parts. One part was evaporated to dryness, dissolved in alcohol, and 

 the free cholesterol directly estimated. The other half of the ethereal solution 

 was saponified with sodium ethylate. After separating the soaps, the total 

 cholesterol in the ethereal solution was estimated. The ester cholesterol 

 was determined by difference. The cholesterol was estimated by the digitonin 

 method of Windaus,* using the modified procedure fully described in 

 Part VII of this series of papers.f 



Cholesterol Content of the Livers of Rabbits fed on Green Food only. 



For this purpose a diet of cabbage leaf and cabbage stalk was selected, as 

 these substances appear to form an efficient diet. Further, cabbage is rich 

 in vegetable sterols which are largely passed unchanged in the faeces. This 

 formed a convenient means of obtaining these sterols, which were required 

 for another purpose, from the plant in quantity. 



Experiment I. — A strong healthy rabbit (A) was fed on cabbage leaf from 

 December 28, 1910, to February 1, 1911. It took 1*5 lbs. of leaf per day. 

 Twice during the experiment the cabbage leaf was mixed with some 

 extracted bran to prevent the feces getting too moist, as they were required 

 for another purpose. The rabbit maintained a practically constant weight 



* Windaus, " Tiber die Entziftung der Saponin durch Cholesterin," ' Ber. d. Deutseh. 

 Chem. Ges.,' 1909, vol. 42, pt. 1, p. 238, and 'Zeit. fur physiol. Chem.,' 1910, vol. 65, 

 p. 110. 



t 1 Eoy. Soc. Proe.,' 1910, B, vol. 82, pp. 559—568. 



