Intestine, &c., on General Metabolism in Dogs. 85 



cent, of water was eliminated with 12 grams of fat, on increasing the 

 fat to 62 grams only 67 '87 per cent, of water is eliminated. 



In the dog in which the large intestine was entirely removed, dog 4 

 with 9'7l grams of fat, the faeces contained 76*59, but on increasing 

 the fat to 2 9 '71 grams the percentage of water increased to 79 grams 

 instead of falling as in normal dogs. 



The effect of removal of the large intestine on the breaking up of 

 fat in the alimentary canal was next investigated (Table XX). 



In the above table the quantities of neutral fat, free fat acids, fat 

 acids as soaps and cholesterin are given, and their percentage composi- 

 tion taking the total ether extract as 100. It is seen in all the dogs 

 that the quantity of free fat acids is very much greater than that of 

 the neutral fat j the quantity of fat acids as soaps and neutral fat 

 correspond very much in percentage composition. 



As far as the total quantity is concerned, that varies with the diet, 

 but on the whole is comparable, so that one can conclude that the 

 removal of the large intestine has no action in stopping either the 

 breaking up of fat or the formation of soaps in the alimentary canal. 



When we turn to the cholesterin, however, we find that there is a 

 difference. The normal dog 1 excreted 0'154 gram and 2 only 

 0*061 gram of cholesterin. After partial removal of the large intestine 

 the quantity of cholesterin corresponded very much with the normal 

 dog 1, being 0'145 gram, while in the case of both dogs, when the 

 large intestine was entirely removed, the quantity of cholesterin was 

 very much less (in dog 4 only 0'025 gram, and in dog 5 0'069 gram) ; 

 so that one may consider that the removal of the large intestine causes 

 a decrease in the quantity of cholesterin, and this is probably ex- 

 plained by the loss of so much secreting surface in the intestine as 

 would occur when the large intestine is removed. 



The colouring matter in the faeces was also investigated in the 

 normal dogs, and found in all cases to contain no bile pigment but 

 marked quantities of urobilin, while in the case of the dogs in which 

 the large intestine had been removed this was not always the case. 



As far as the contents of the intestine or its walls are concerned the 

 animals were killed with chloroform, and the presence of urobilin 

 looked for throughout the intestine. In the normal dogs in the great 

 majority of cases no trace of urobilin could be detected above the ileo- 

 caecal valve. The contents of the small intestine only gave the bile 

 reaction. 



In dog 5 the small intestine having been joined 6 cm. from the anus, 

 a slight urobilin reaction was obtained as high as 35 cm. from the anus, 

 the bile reaction as far as 78 cm. In this case evidently urobilin for- 

 mation was taking place in the small intestine comparatively speaking 

 high up. 



In dog 4 only 4 cm. of rectum was left, and only in this part was 



