707, 



Increasing Quantities of Fat in Did on Metabolism in Dogs. . 257 



In Volt's analysis the contents of the loop of the small intestine 

 .contained fat, nitrogen, and salts in a proportion very much correspond- 

 ing to that found in the above dog, and he, together with others, con- 

 siders this a normal excretion from the small intestine which goes in 

 great part to form the faeces on a diet which is well absorbed.* The 

 above result obtained in the large intestine is of importance, as it 

 shows that a similar excretion occurs in the large intestine, as that 

 already known to occur in the case of the small intestine, and this 

 observation will explain in all probability the results obtained as 

 regards cholesterin when the large intestine was removed (vide 

 page 287). 



With these preliminary remarks we can now turn to consider the 

 present research, and before doing so, it is as well to describe briefly 

 the operative procedure which was carried out. 



OperoMve Procedure. 



The dog, after being put under an anaesthetic, had its large intestine 

 thoroughly washed out by means of an enema, and after abdominal 

 section the bowel was divided just above the caecum, and also as low 

 down and as near the anus as possible. The lower part of the small 

 intestine was then stitched into the rectum, care being taken to pre- 



* v. Moraczewski lias since the writing of the present article published a paper 

 on contents of occluded portions of the intestine. His experiments are limited, 

 however, to two dogs, in both of which cases after the loop had been isolated 

 the animals were allowed to live for about a year, being well fed throughout. 



In the first dog the loop consisted of part of the ilium, caecum, and the com- 

 mencement of the colon. The material collected at the end of a year from this 

 loop was coloured, and the analysis was roughly as follows : 



Fat and 

 Qt. Solids. Water. Proteid. cholesterin. Ash. 



grams. p. c. p. c. p. c. p. c. p. c. 



360 26 74 1 43 20 



In the second dog only part of the ascending colon was isolated, so that we should 

 here get the excretion from the large intestine, not contaminated by anything from 

 the small. The contents in this case were colourless. Unfortunately the absolute 

 quantity of analysis is not stated. However, he says it contained very little proteid 

 or fat, and no cholesterin or lecithin, but principally only sodium carbonate. 



From these results Moraczewski concludes that the secretion, or rather, as I 

 should prefer, the excretion, from the different parts of the intestine differs, that 

 from the small intestine containing colouring matter, fat, and cholesterin, while 

 that from the large intestine is only sodium carbonate. 



My own analysis of the contents of the large intestine, although naturally the 

 quantity of material used was not so great and the period of collection much 

 shorter, does not lead me to entirely agree with the above results. The fat was 

 distinctly less than the quantity found in the small intestine of Moraczewski, but 

 both fat and nitrogen were undoubtedly present, and the ash was extremely small 

 ('Zeit. f. Physiol. Chera.,M898, vol. 25, p. 122). 



x2 



