264 



Dr. Y. Harley. On the Breaking-up 



in which the results of only two experiments were used, and the 

 period of digestion was seven hours, except in one case of removal 

 of the pancreas in which it was only six hours. 



As far as the stomach is concerned, the table shows that there is a 

 slight increase in the quantity of fat acids in dogs in which the 

 pancreas has been removed, as the percentage noted was 31*29 per 

 cent, of the total fat, while in the normal dogs which were employed 

 as control, only 18'50 per cent, of the total fat was present in the 

 form of free fat acids. This would be in favour of a greater fat 

 splitting -up activity of the stomach in dogs in which the pancreas 

 had previously been removed. That a greater splitting-up action 

 was really the cause of this increase is difficult to believe. It would 

 seem much more likely that the increased percentage of fat acid in 

 the dogs without the pancreas was due to the greater retention of fat 

 in the stomach, for in all cases in which the pancreas had been 

 removed, the expulsion of fat from the stomach was very much 

 delayed. 



The percentage quantity of fat acids present as soap in both the 

 normal and the pathological dogs is practically equal, for in both 

 cases no less than 0'63 and 055 per cent, of the free fat acids were 

 present as soap in the stomach. 



The table therefore proves that both in normal dogs as well as in 

 those in which the pancreas has been removed, the stomach is capable 

 of not only splitting up neutral fat into free fat acids and glycerine, 

 but farther, that the free fat acids are capable of finding alkalis in 

 the stomach itself wherewith to form soaps. The power of the free 

 fat acids forming soap is, however, extremely limited in the stomach. 



The principal fat-splitting action really begins, not in the stomcah, 

 but after it has left the pylorus. That this should be the case in 

 normal dogs has long been held by all physiologists, and was con- 

 sidered due to the action of the pancreas, and the degree to which 

 this occurs is shown in the table, according to which in the normal 

 dog at least 72*22 per cent, of the fat present in the small intestine 

 was in the form of free fat acids, only 24*67 per cent, being present 

 as neutral fat. But also in the case where the pancreas had been 

 entirely extirpated, so that no pancreatic juice could possibly reach 

 the intestine, and the fasting had been sufficiently long to remove any 

 pancreatic ferments which might have been previously present in 

 the intestines, we still find a large increase in the quantity of the fat 

 acids present, the fat acids being no less than 61*62 per cent, of the 

 total fat. There can be no doubt, therefore, that even when no pan- 

 creatic secretion has reached the intestines, a very considerable 

 quantity of the neutral fat is split up into free fat acids in the small 

 intestine, although the quantity there formed is not so great as when 

 the pancreatic secretion has been able to add its share of work. 



