158 J. M. HAMILL. 



III. THE RELATIONSHIP BETWEEN THE CHYLE-FAT AND 

 THE FAT OF THE FOOD. 



The question as to whether the fat in the chyle varies in nature 

 according to the kind of fat taken in the food has been exhaustively 

 investigated for the higher fats by Munk and Rosens tein (28) and 

 others. With regard, however, to the fats of the glycerides of the 

 lower fatty acids such as butyric acid we know nothing with certainty. 



Analyses of human fat show amounts of the lower fatty acids small 

 out of all proportion to the quantities taken in with the food. Thus 

 Lebedeff (18) found that human fat contained only '02 to '2 / of volatile 

 fatty acids and Jaeckle (16) from an analysis of several samples of fat 

 obtained a Reichert-Meissl number varying from '2 to '3. What then 

 is the fate of these lower fats present in considerable quantities in such 

 foods as butter and milk and yet almost absent from the fat of the body ? 

 In order, if possible, to obtain an answer to these questions the patient 

 was fed on a diet rich in butter, the chyle was then collected and 

 examined for the presence of lower fatty acids which occur in such 

 large quantities in butter. 



The patient was given as much butter as he could eat at breakfast 

 and again at dinner ; in all, more than eight ounces were taken during 

 the day. Before breakfast as much chyle as possible was allowed to 

 drain away and after this the chyle was drawn off at intervals of two 

 hours throughout the day till 10 p.m. The fat was then extracted in the 

 way already mentioned from the whole of the chyle thus collected and, 

 in the investigation to be described immediately, is called " chyle butter- 

 fat." A sample of the butter which had been administered to the 

 patient was then purified by washing it with water when melted, 

 dissolving it in ether, drying the ether solution with calcium chloride 

 and then evaporating off the ether; the fatty residue, called below 

 " pure butter-fat," was now comparable with the residue from the 

 ether extract of the chyle obtained after feeding with butter. 



The iodine value of these two fats was then determined and 

 compared with the value obtained for ordinary chyle-fat obtained from 

 the chyle collected some days previous to the experiment when the 

 patient was on normal diet. The determinations were made by Wij's 

 modification of the original Hubl method. As Lewkowitsch (19) has 

 shown this method gives extremely accurate results and is much easier 

 to use than the older process. The results obtained for the three fats 

 were as follows : 



