CHEMICAL PROCESSES IN THE INTESTINE. 489 



The bile has, as shown by MOORE and ROCKWOOD l and then especially 

 by PFLUGER, the property to a high degree of dissolving fatty acids, 

 especially oleic acid, which itself is a solvent for other fatty acids, and 

 hence, as will be seen later, it is of great importance in the absorption 

 of fat. It is also of great importance that the bile, as previously stated, 

 not only activates the steapsinogen, but that, as first shown by NENCKI 

 and RACHFORD, 2 it accelerates the fat-splitting action of the steapsin. 

 According to v. FURTH and SCHUTZ 3 the bile-salts are the active con- 

 stituents of the bile in this cleavage, and the fatty acids set free can com- 

 bine with the alkalies of the intestinal and pancreatic juices and the bile, 

 producing soaps which are of great importance in the emulsification of 

 the fats. 



If to a soda solution of about 1-3 p. m. pure, perfectly neutral 

 olive-oil is added in not too large a quantity, a transient emulsion is 

 obtained after vigorous shaking. If, on the contrary, one adds to the 

 same quantity of soda solution an equal amount of commercial olive- 

 oil (which always contains free fatty acids), the vessel need only be 

 turned over for the two liquids to mix, and immediately there appears 

 a very finely divided and permanent emulsion, making the liquid appear 

 like milk. The free fatty acids of the commercial oil, which is always 

 somewhat rancid, combine with the alkali to form soaps which act to 

 emulsify the fats (BRUCKE, GAD, LOEWENTHAL 4 ) . This emulsifying 

 action of the fatty acids split off by the pancreatic juice is undoubtedly 

 assisted by the habitual occurrence of free fatty acids in the food, as well 

 as by the splitting off of fatty acids from the neutral fats in the stomach 

 (see page 452). 



Bile completely prevents peptic zymolysis in artificial digestion, 

 because it retards the swelling up of the proteins. The passage of bile 

 into the stomach during digestion, on the contrary, seems, according 

 to several investigators, especially ODDI and DASTRE, S to have no dis- 

 turbing action on gastric digestion. According to BOLDIREFF, G after con- 

 tinuous starvation, on feeding fat and food rich in fat, as well as after 



11; Weiske, Zeitschr. f. Biologic, 22, 373; Tappeiner, ibid., 20 and 24; Mallevre, 

 Pfliiger's Arch., 49; Omeliansky, Arch. d. scienc. biol. de St. Pe"tersbourg, 7; E. Miiller, 

 Pfliiger's Arch., 83; Lohrisch, Zeitschr. f. physiol. Chem., 47 (literature); and 1. c., 

 footnote 4, p. 488. 



1 Proceedings of Roy. Soc., 60, and Journ. of Physiol., 21. In regard to Pfliiger's 

 work see Absorption. 



2 Nencki, Arch. f. exp. Path. u. Pharm., 20; Rachford, Journal of Physiol., 12. 



3 Centralbl. f . Physiol., 20. 



4 Briicke, Wien. Sitzungsber., 61, Abt. 2; Gad, Arch. f. (Anat. u.) Physiol., 1878; 

 Loewenthal, ibid., 1897. 



5 Oddi, in Centralbl. f. Physiol., 1, 312; Dastre, Arch, de Physiol. (5), 2, 316. 

 8 Centralbl. f. Physiol., 18, 457, and Pfliiger's Arch., 121. 



