118 Messrs. Doree and Gardner. Origin and [Dec. 18, 



In another experiment the animal ate 6758 grammes of horseflesh in 

 17 days. Making the calculation as before, we find that the dog may have 

 eaten 4 grammes of cholesterol, whereas only 1 gramme was discovered, 

 pointing again to an absorption of possibly 3 grammes. 



We did not institute any further experiments with the dog on these lines 

 on account of the numerous uncertainties involved. "We have, however, 

 lately been successful in discovering a cholesterol-free diet comparable with 

 extracted bran on which cats can be fed, and have begun an elaborate series 

 of experiments on the question which we hope to communicate in the near 

 future. Preliminary experiments on cats showed us that, as in the case of 

 dogs, the cholesterol of animal food is passed in the faeces as such, but that on 

 a brain diet these animals also convert the cholesterol into coprosterol. The 

 two following experiments may be qiioted here as bearing on this interesting- 

 point. 



Experiment VII. — A cat weighing 2 - 8 kilogrammes was fed on raw sheep's 

 brain for 14 days. The f feces were somewhat liquid, and dried at 100° to a 

 soft, sticky, glue-like mass, which was ground up with excess of sand before 

 extracting with ether. Weight of dry faeces, 245 grammes. During the period 

 of diet the animal lost - 5 kilogramme in weight, which loss, however, it 

 subsequently regained on ordinary diet ; 28 grammes of unsaponifiable matter, 

 in the form of a dark red viscid oil were obtained. By fractional crystallisation 

 from acetone between 18 and 19 grammes of brown crystalline matter were 

 separated. This consisted of coprosterol, and after further purification from 

 dilute alcohol 12 grammes of perfectly pure coprosterol were obtained. This 

 melted at 99° to 100° C, and had a specific rotatory power (in chloroform) 

 [«]»= +20°-4. 



On a diet of raw sheep's brain, therefore, the cat changes cholesterol into 

 coprosterol in the same way as we showed was the case with the dog.* If 

 we assume that sheep's brain contains 2 per cent, of cholesterol, our cat 

 should have consumed in the 14 days some 34 grammes of cholesterol, which 

 would correspond with an absorption of about 15 grammes, or 1 gramme 

 per day. Owing to the difficulty of crystallising coprosterol completely from 

 the oily matter with which it is mixed in the unsaponifiable residue, one 

 cannot claim for this estimation any high degree of certainty. It is, how- 

 ever, significant that the total weight of unsaponifiable matter obtained was 

 less than the total cholesterol that should have been consumed, and there 

 can be no doubt that the extraction of the faeces by ether was a very 

 thorough one, as it was allowed to go on for 14 days, the ether distilling over 

 during the day and being allowed to soak on the material during the night. 

 * 'Koy. Soc. Proc.,' B, vol. 80, p. 227. 



