506 Messrs. Ellis and Gardner. Origin mid [Aug. 14; 



A few months after the appearance of our paper, ChosaburS Kusumoto* 

 published a series of estimations of the cholesterol content of the faeces of 

 dogs fed on horseflesh, and horseflesh with the addition of measured 

 quantities of fat bacon or carbohydrates. His results showed that the 

 cholesterol content of the food was considerably greater than that of the 

 faeces. He also found that on meat diets variable quantities of coprosterol 

 were always excreted with the cholesterol, and that the proportion of 

 coprosterol increased with the fat in the food. This explains our observations 

 on brain diets, the putrefactive changes which cause the formation of 

 coprosterol being favoured by the presence of fats. The daily outputs of 

 cholesterol observed by Kusumoto are somewhat greater than in the case of 

 the dog we used, but his daily rations were much larger. He gives no data 

 to indicate the purity of the specimens of cholesterol weighed. As dogs are 

 omnivorous feeders, it seemed desirable to examine the faeces of more truly 

 carnivorous beasts, and for this purpose the cat was selected. The faeces 

 collected during each diet period were dried in the water oven, roughly 

 powdered, or, if too greasy, ground with plaster of Paris, and extracted 

 thoroughly for many days in a Soxhlet's apparatus with ether. The ethereal 

 extracts were treated in the manner fully described in our paperj on " The 

 Cholesterol Contents of Eggs and Chicks." 



Experiments in which cats were fed on meat diet : — 



I. A cat, which had previously been fed on raw brain diet, for the purpose 

 of another experiment, for 14 days, during which it went down in weight 

 from 2 - 8 to 2 - 3 kilogrammes, was fed for 14 days on a diet of lean cooked 

 horseflesh. During this period it devoured 3125 grammes of the meat, and 

 increased in weight steadily, its weights taken every third day being 2 - 3, 2 - 5, 

 2 - 5, 2"7, and 2'9 kilogrammes. The total dried faeces weighed 98 grammes, 

 and yielded after the treatment described 2"554 grammes of unsaponifiable 

 matter in the form of an oily mass. This was crystallised from alcohol 

 repeatedly, but only - 2052 gramme of pure crystalline matter was obtained. 

 This melted at 93° — 99° C. and had the characteristic crystalline form of 

 coprosterol. The mother liquors were evaporated to dryness and treated in 

 pyridine solution with excess of benzoyl chloride. On pouring into water 

 the benzoate of coprosterol was thrown out of solution, and on washing 

 with a small quantity of alcohol was sufficiently pure for weighing. The total 

 weight of coprosterol obtained was T397 grammes, which corresponds to an 



* " Tiber den Cholesterolgehalt der Hundfa'ces bei gewohnlicher Ernahrung und nach 

 Futterung von Cholesterin," ' Biochemische Zeitschrift,' vol. 14, 1908, pp. 411 and 416. 

 t 'Koy. Soc. Proc.,' B, vol. 81, 1909, p. 129. 



