Destiny of Cholesterol in the Animal Organism. 489 



this method, the mixture was refluxed for 4 or 5 hours on the water-bath, 

 and then allowed to stand 24 hours. The soaps were filtered and well washed 

 with ether, or, if too large for this, extracted in the apparatus described 

 above. The ethereal solution of unsaponifiable matter was then thoroughly 

 washed free from alcohol and traces of soap, made to known volume, and an 

 aliquot portion evaporated and weighed. 



Estimation of Sterols Precipitdble In/ Digitonin. 



This estimation was carried out by the method described by Fraser and 

 Gardner (1910) on a suitable portion of the solution. 



Most of the experiments were carried out on human liver and spleen, 

 obtained from cases of healthy adults killed suddenly by accidents. In these 

 cases it was not possible to obtain the material until some 24 hours after 

 death, during which time post-mortem changes might have taken place, with 

 possible destruction of the enzymes responsible for the changes under investi- 

 gation. Control experiments were therefore made on liver and spleen obtained 

 from oxen killed at the slaughter-house by the Kosher method. The material 

 thus obtained was treated within 2 or, at most, 3 hours after death. In one 

 experiment pure cholalic acid was added to the autolysing tissue, to test the 

 statement of Abelous and Soula that the addition of a small quantity of this 

 substance would markedly increase the synthesis of cholesterol. 



Our results are given in the following Tables — (I) Liver, (II) Spleen. 



Discussion of Results. 



In all these experiments, such aliquot portions were taken for analysis as 

 would give between 018 and 025 grm. of digitonide for weighing. It was 

 not possible to use larger quantities than this owing to the scarcity of 

 digitonin, but in our experience these quantities are quite sufficient to give 

 reliable results, other things being equal. 



When we consider the large and complex series of operations necessary in 

 carrying out these experiments the errors must be considerable, however great 

 the care taken. We think that errors creep in mainly in the extraction 

 process. In the Tables we give the sterol results to the third place of 

 decimals, which would be justifiable if we were dealing with pure sterols. 

 The relatively minute errors inherent in the digitonin method itself are, of 

 course, magnified in calculating the quantities actually weighed to percentage 

 of the original material taken for autolysis and extraction. In our opinion, 

 second place may be regarded, however, as approximately correct. 



A careful consideration of the figures indicates no evidence whatever of 

 either synthesis, or destruction of cholesterol, during autolysis, and as far as 



