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



of an animal fed on a normal diet which contained phytosterol but not 

 cholesterol, a rabbit weighing 2 - 8 kilogrammes was fed on a liberal mixed 

 diet of cabbage, oats, and bran for a month, and killed after 24 hours as in 

 previous experiments. The blood obtained weighed 75 grammes, which 

 yielded - ll7 gramme of unsaponifiable matter as a brown oil mixed with 

 crystalline material. After treating with benzoyl chloride in the usual 

 way 0'028 gramme of greasy crystals was obtained, which were obviously 

 not pure. Under the microscope these appeared as star-shaped aggregates 

 of needles mixed with indeterminate matter, but no typical crystals of 

 cholesterol benzoate were observed, and the substance could not be further 

 purified. It is obvious that there is not sufficient cholesterol in the blood 

 of a single rabbit, when fed on a non-cholesterol, or on a normal diet, for an 

 accurate quantitative estimation. "We therefore fed six rabbits, weighing 

 1"5, 1'7, 1*4, 1*9, 1*5, 1*9 kilogrammes respectively, on a liberal diet of oats, 

 bran, and greens for a week. They were then killed and the total blood 

 taken. This weighed 500 grammes. On treatment in the usual way 

 0-464 gramme of unsaponifiable matter as a brown, slightly greasy solid 

 was obtained. This was crystallised from alcohol ; the first crops, weighing 

 respectively - 091 and 0"049 gramme, consisted, as a microscopic examination 

 showed, mainly of cholesterol, plate-like crystals of which were mixed with 

 minute spherules of some other substance. These crystals were dried and 

 treated in pyridine solution with benzoyl chloride. All the mother liquors 

 remaining were evaporated to dryness and treated with pyridine and benzoyl 

 chloride. The benzoate found was recrystallised from a measured quantity 

 of absolute alcohol ; 0"1523 gramme of pure cholesterol benzoate in all was 

 thus obtained, which, without further purification, melted correctly, and gave 

 the colour play of cholesterol benzoate ; - 1199 gramme of cholesterol 

 was thus obtained from the blood of six rabbits or - 024 per cent. 



It is clear from these experiments that Pribram was correct in his 

 conclusions, and that cholesterol can be absorbed from the intestines into 

 the blood of the animal, since in the case of the rabbits which had been fed 

 on cholesterol we were easily able to prepare and weigh pure cholesterol 

 benzoate, whereas in the case of a rabbit fed on extracted diet, or on normal 

 diet, the quantity was so small that we were unable to obtain any 

 cholesterol from it in a pure state. In order to get a precise figure for the 

 cholesterol content of the blood of the rabbit under normal conditions we 

 were obliged to deal with the blood of six rabbits. 



In the case of rabbits A, B, and C we made estimations of the cholesterol 

 contained in the brain and spinal cord, and in the rest of the animal 

 respectively. We can, however, draw no conclusions from the results of the 



