FAT ABSORPTION. 513 



MOORE and ROCKWOOD have shown the great solvent action of the 

 bile for fatty acids, and on continuing these investigations further, 

 MOORE and PARKER have found that the bile increases the solubility 

 of soaps in water and can prevent their gelatinization, a fact which is 

 of greater importance for the absorption of fats than the solubility of 

 the fatty acids in bile. The quantity of lecithin in the bile is of great 

 importance for the solubility therein of the fatty acids as well as the 

 soaps. According to the above-mentioned investigators, the absorption 

 of fat from the intestine is essentially dependent upon the solubility 

 of the soaps and free fatty acids in the bile. The neutral fats are split 

 and the free fatty acids are in part absorbed, dissolved as such by the 

 bile, and in part combined with alkalies, forming soaps. Neutral fats 

 are regenerated from the fatty acids, and the alkali set free from the 

 soaps is secreted again into the intestine and used for the re-formation 

 of soaps. 



The importance of the bile, the soaps, and the alkali carbonates has 

 been closely studied, chiefly in the very thorough investigations of 

 PFLUGER. He has quantitatively determined the solvent power of the 

 above-mentioned bodies each alone as well as different mixtures of 

 these for the various fatty acids, and has closely studied the mode of 

 action of the bile. From his investigations he has arrived at the con- 

 clusion that no unsplit fat is absorbed, that all fats, before their absorption, 

 must first be split into glycerin and fatty acids, and that the bile, on 

 account of its solvent power for soaps and fatty acids, is sufficient for 

 the absorption of large quantities of fat eaten. The object of the forma- 

 tion of an emulsion is, according to this view, that the fat in this con- 

 dition forms such a large surface for the action of the steapsin or the 

 fat-splitting agents. 



The possibility that all the fat must be first split and that no unsplit 

 fat is absorbed is, according to these researches, not to be denied. It 

 is the opinion of the author that it is still too early to give a positive 

 verdict as to how these conditions in the intestine are brought about 

 and the conclusion must be left for further investigation. 



The next question is whether all the fat or the greater part of 

 it passes into the blood through the lymphatics and the thoracic 

 duct. According to the researches of WALTHER x and -FRANK 1 on dogs, 

 it seems that only a small part of the fats, or at least of the fatty acids 

 fed, pass into tta chylous vessels; but these observations can hardly 

 be applied to tne absorption of neutral fats, or to the absorption in 

 man under normal circumstances. MUNK and RosENSTEiN, 2 in their 

 investigations on a girl with a lymph fistula, found 60 per cent of the 



1 Walther, Arch. f. (Anat. u.) Physiol., 1890; Frank, ibid., 1892. 



2 Virchow's Arch., 123. 



