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respecting the state of the fats of food in the stomach during diges- 

 tion. For this purpose the contents of the stomach of several dogs, 

 fed with cooked meat and neutral sheep's fat, were examined at dif- 

 ferent stages of digestion ; the acids of the stomach soluble in water 

 were removed by protracted washings with distilled water, and the 

 residue being treated with alcohol and ether, yielded solutions found 

 to contain fatty acids. In some cases the contents of the stomach 

 were first treated with alcohol, and the fatty matters thus obtained 

 subsequently washed with distilled water, and finally again dissolved 

 in alcohol and ether. These analyses constantly yielded fatty acids, 

 which, when heated with fresh sheep's bile, were found to dissolve 

 and produce an emulsion. 



In order to determine whether the cooking of the meat with which 

 the dogs had been fed had transformed any of the neutral fats into 

 fatty acids, a sample of roast meat was mixed and washed with di- 

 stilled water until the washings had completely lost their acid reac- 

 tion ; the meat was then mixed with alcohol and allowed to stand for 

 more than a week. After that time the fluid was found to be per- 

 fectly neutral, showing that no fatty acids had been formed. 



From these researches it appears that the presence of bile in the 

 intestines is closely connected with the digestion of fats. 



The results of recent investigations on excretine show that this 

 substance exists on an average in the proportion of 0*460 grm. for 

 one evacuation when the excretine is impure, and of 0*184 grm. 

 when it is pure. From the careful examination of the faeces of a 

 child one year old, I have ascertained that they invariably contained 

 no excretine, but cholesterine ; the proportion of the latter, purified 

 by repeated crystallizations, being equal to 0*036 grm. in one eva- 

 cuation, which number is, however, a very low estimate. Nothing 

 in the food could account for this singular result. It is therefore 

 most probable that excretine is only present in the evacuations of 

 the full-grown or adult individual. 



I have been most ably aided in these investigations by my assist- 

 ant, Mr. Frederick Dupre, Ph.D. 



