ON PANCREATIC PROTEOLYSIS. 217 



the result obtained when the salts are added to the pancreatic 

 extract from another species (contrast Experiments 38 and 

 39). The results collectively certainly warrant the conclu- 

 sion that the isolated bile salts taken by themselves do not 

 exert any very marked stimulation of pancreatic proteolysis. 

 They may, on the other hand, give rise to some retardation, 

 an effect which is seemingly more characteristic of the 

 salts from pig's bile than of those common to ox bile. It is 

 to be noted, however, that the salts from pig's bile were not 

 so pure chemically as the crystallized salts separated from ox 

 bile, but frequently showed an acid reaction. 



The above somewhat unsatisfactory results have served to 

 strengthen our conviction that such limited action as normal 

 bile exerts on pancreatic proteolysis is the result mainly of 

 influence on the reaction of the digestive mixture, and that 

 many agencies other than the specific bile salts are concerned. 

 No doubt, some of these are more or less antagonistic to each 

 other. Thus, pig's bile, as has been frequently stated by 

 many observers, is liable to be extremely viscid, but the vis- 

 cidity is not always conspicuous ; at times the bile is quite 

 limpid. This [viscidity is due, in great part at least, to a 

 mucin or nucleoalbumin, precipitable by alcohol, and we have 

 found that when this substance is removed from the bile there 

 is a noticeable difference in the influence of the fluid on pro- 

 teolysis. We may cite the experiments on p. 218 : 



It is noticeable from these two experiments that the re- 

 moval of the nucleoalbumin, with possibly some of the inor- 

 ganic salts from pig's bile, diminishes in a general way the 

 retarding effect of the latter on proteolysis. Somewhat 

 noticeable also is the peculiar relationship in the rise and 

 fall of proteolysis under the influence of different percent- 

 ages of the two samples. 



With ox bile an attempt was made to separate the fluid 

 into three distinct fractions, using methods which would 

 presumably cause little or no change in the nature or com- 



