1908.] Destiny of Cliolesterol in the Animal Organism. 



121 



blood, we must again emphasise the fact that the weight of crude unsaponifi- 

 able matter obtained from them gives little or no idea of their cliolesterol 

 content. In our experience, the ether extract of animal tissues always 

 contains relatively large quantities of low melting oily or resinous bodies, 

 which may prove to be of very considerable importance in biochemistry, but 

 they are non-crystalline and cannot be considered as cholesterol. Further- 

 more, their amount is very variable, so that even for purposes of comparison 

 the weights of crude unsaponifiable matter are useless. Our own procedure 

 was as follows : The blood, if dried in the ordinary way, becomes a very 

 hard horny mass which even if powdered is difficult to extract. We there- 

 fore mixed the blood after whipping to prevent coagulation with sand and 

 plaster of Paris in sufficient quantity to form a friable mass. This was 

 ground up and extracted for 14 to 30 days, the heating being stopped 

 during the night so that the ether might thoroughly soak into the material. 

 The extract was saponified in the manner we have previously described, and 

 the non-saponifiable residue converted directly to benzoate in pyridine 

 solution, the cholesterol being thus weighed in the form of cholesterol 

 benzoate. 



Experiment IX. — Eabbit A. A rabbit, weighing 2 - 8 kilogrammes, was fed 

 for 21 days with 70 to 80 grammes of extracted bran per day, and then 

 killed 24 hours after the last supply of food had been placed in the cage. 

 A post-mortem examination showed that the stomach still contained some 

 food. The animal during this period lost 0'3 kilogramme in weight. The 

 weight of blood obtained was 73 grammes, from which - 14 gramme of 

 unsaponifiable matter in the form of a stiff oil was obtained. The quantity 

 of cholesterol contained in this was so small that it was not found possible 

 to isolate any in a pure state. 



Experiment X. — Eabbit B. This rabbit, weighing 2 - 2 kilogrammes, was 

 fed for three clays on extracted bran, then during 10 days on 540 grammes 

 of extracted bran, mixed with 2\ grammes of cholesterol, care being taken 

 that the whole of the cholesterol was eaten. The weight of the animal 

 remained unaltered during this period, and it was killed 24 hours after the 

 last meal had been placed in the cage. The blood obtained weighed 

 71 grammes and yielded 0-29 gramme of crude unsaponifiable matter, from 

 which - 0375 gramme of pure cholesterol benzoate was obtained. The 

 specimen, which was actually weighed without further crystallisation, melted 

 at 142° to 143° to a turbid liquid which became clear at 170°, and on 

 cooling showed the characteristic play of colours. This quantity corresponds 

 to a yield of - 0295 gramme of cholesterol or - 0415 per cent. 



Experiment XL — Eabbit C. In order to compare the cholesterol content 



