136 Piof. B. Moore. On the Synthesis of [.June 1-". 



It is difficult to wash the intestinal mucous membrane free from 

 attached globules of fat which lie between the villi, and hence to be 

 certain that all the fat submitted to analysis has been obtained from 

 the interior of the villi and columnar cells, and so the results 

 recorded below cannot be taken as quantitatively accurate although 

 they do undoubtedly show that a considerable amount of synthesis 

 has occurred in the villi, and that the synthesis is in progress and not 

 in that state of completion which is found in the lymph of the 

 mesenteric lacteals. 



It is hence fortunate that it was found possible to obtain lymph from 

 the small mesenteric lymph vessels in sufficient quantity to make 

 analyses of both neutral fat and free fatty acid, and so prove con- 

 clusively that the latter is practically absent by the time the lymph is 

 leaving the intestinal wall. 



It was found quite impossible to introduce a cannula into these 

 lymphatic vessels, and hence the lymph was obtained by cleansing the 

 mesenteric surface, opening the lymphatic with a fine pointed pair of 

 scissors, carefully avoiding accompanying blood vessels, and allowing 

 the lymph to escape on to the mesenteric surface. The fluid was then 

 collected in wide capillary tubes, by capillarity or suction, until a 

 sufficient amount had been obtained for the necessary analyses. 



A second method of investigating the action of the various cells 

 which the lymph, containing the fatty constituents, encounters on its 

 path of absorption, is to prepare these tissues, or extracts of them free 

 from cells, and test in vitro whether such preparations exert any 

 synthetic action. 



This method was also employed with extracts of intestinal mucous 

 membrane and lymphatic glands, and as the results differed essentially 

 from those of previous observers who had used this method, but 

 without making so complete analyses of the supposed synthesized 

 products, pancreatic extracts were also similarly tested. 



Since it was also thought that the absence of synthesis of neutral fat 

 shown by the experiments might be due to the lack of a supply of 

 energy by the cells or enzymes contained in them, an attempt was 

 made in a certain number of the experiments to supply a source of 

 energy by the addition of glucose to the soap and glycerine of the 

 other experiments. But here also the result remained negative and it 

 may be stated that throughout no appreciable synthesis of neutral fat 

 from its constituents was ever obtained. 



One positive result observed, which does possess a certain degree of 

 physiological importance, was that all three types of extract, but 

 especially that of the pancreas, possess a marked power of setting free 

 fatty acid from the soap employed. 



A protective action would be exercised in the body in this manner 

 against the appearance of the highly poisonous soaps in the circulation. 



