1908.] Destiny of Cholesterol in the Animal Organism. 113 



the experiment were carefully collected, dried in the oven at 80° to 90° and 

 weighed. The faeces were then extracted with ether in a Soxhlet's apparatus 

 for a week or ten days. The ethereal solution was saponified according to the 

 method described in our former paper* by means of sodium ethylate. The 

 precipitated soap was filtered off and washed thoroughly with ether. The 

 ethereal filtrate and washings were freed from excess of alkali and alcohol by 

 repeatedly washing with water, dried, and the ether distilled off. The dry 

 residue was weighed and then fractionally crystallised from alcohol until no 

 further crystalline matter could be obtained. The oily residues were then 

 dried, dissolved in pyridine, and treated with excess of benzoyl chloride and 

 after standing over night poured into water. The precipitated matter was 

 filtered, taken up with ether, dried, and the ether again evaporated. The 

 residue was boiled with a little alcohol and any cholesterol that had remained 

 in the oily residue was thus obtained in the form of the highly insoluble 

 benzoate. 



Experiment I. — In order to ascertain whether it was possible to extract the 

 whole of the cholesterol from faeces by the method used, 2 grammes of 

 cholesterol were ground up with moistened faeces that had already been 

 extracted, in the proportions usually found. The mixture was dried and 

 subjected to the whole process detailed above, when 2 - 098 grammes of 

 slightly brown-coloured cholesterol were obtained — a quantitative recovery. 

 As the cholesterol recovered from natural faeces is often highly coloured and 

 can only be readily purified by treatment with animal charcoal, it was also 

 desirable to ascertain what loss occurred under the conditions usually 

 followed. The two grammes of recovered cholesterol were therefore 

 dissolved in about 50 c.c. of alcohol, boiled with about half the weight of 

 animal charcoal, and filtered by means of a hot funnel. The charcoal was 

 then washed with hot alcohol. On evaporating the alcohol and crystallising 

 the cholesterol 1*8 grammes were recovered. The loss due to boiling with 

 charcoal was therefore about 10 per cent. 



Experiment II. — In order to ascertain (1) how far it was possible to 

 extract the phytosterol from bran by simply extracting with ether for 

 several days ; (2) whether any cholesterol could be detected in the faeces, 

 after phytosterol had been eliminated as far as possible from the diet ; and 

 (3) how far the quantity of the oily unsaponifiable matter was affected by 

 the use of ether extracted food ; and (4) whether an animal could be kept in 

 a healthy state on a prolonged, ether extracted diet, a rabbit weighing 

 2-4 kilogrammes was fed from December 30, 1907, to January 15, 1908, 

 inclusive on extracted bran, moistened with a little water. The faeces were 

 * ' Koy. Soc. Proe.,' B, vol. 80, p. 212. 

 VOL. LXXXI. — B. I 



