306 Influence of Removal of Large Intestine, &c., on Dogs. 



of the nitrogen given in the diet was absorbed, the quantity diminish- 

 ing with the increased quantity of fat. 



In partial removal of the large intestine from 89 to 90 per cent, of 

 the nitrogen was absorbed, the quantity not decreasing as in the 

 normal dogs with the increase of the fat in the diet. When the entire 

 large intestine is removed only 84 per cent, of the nitrogen given in 

 the diet was absorbed. The quantity absorbed is uninfluenced by the 

 increase of fat in the diet.* 



One may therefore conclude that 10 per cent, at least of the nitro- 

 gen in the diet is absorbed by the large intestine, and in all probability 

 a very much larger quantity, as we have seen the large intestine itself 

 excretes a nitrogen-containing substance. (Tables III, V, VIII.) 



7. The effects of removal of the large intestine on the breaking up 

 of fat in the alimentary canal. 



In comparing the separate analyses of the fat contained in the faeces, 

 it is found the fat acids, neutral fat, and fat acids present as soaps 

 remain practically the same in dogs with and without the large intestine. 

 It would, however, appear that the quantity of cholesterin tends to 

 decrease in the faeces in the absence of the large intestine. 

 (Table XX.) 



8. The action of the removal of the large intestine on urobilin 

 formation. 



In normal dogs the faeces were found to contain no bile, but large 

 quantities of urobilin, while when the large intestine was removed this 

 was not always the case, as in some, especially soon after the operation, 

 large quantities of bile pigment would be recognised in the faeces with 

 little or no urobilin. 



On examining the walls of the intestine it was found that the urobilin 

 reaction in normal dogs as a rule could only be obtained beyond the 

 ileo-csecal valve. In two dogs in which the large intestine was removed 

 only a slight urobilin reaction was discovered in the ilium. 



9. The influence of fat on the total alkaline and aromatic sulphates. 

 In normal dogs increasing the quantity of fat in the. diet causes,. 



with the decrease in the quantity of nitrogen in the urine, a corre- 

 sponding diminution in the quantity of total sulphates. This steady 

 decrease in the total sulphates is not due to a diminution in the quan- 

 tity of the aromatic sulphates, but of the alkaline sulphates, since the 

 aromatic sulphates are only very slightly decreased. 



In consequence of this decrease in the alkaline sulphates the ratio of 

 A : B is decreased, so that if one only referred to the ratio one would 

 be led to believe that there was an increase in the intestinal putre- 

 faction, while in reality there is no increase but rather a decrease, as 

 indicated by the slight diminution in the quantity of aromatic sul- 

 phates. (Table XX. Dogs 1 and 2.) 



* Experiment 5 (J) is admitted for the reasons already given. 



