206 INFLUENCE OF BILE AND BILE SALTS 



carbonate. Such alkaline reaction as bile yields with red 

 litmus, lacmoid, etc., must be due to the presence of such 

 salts as Na s HPO 4 , NaH 2 PO 4 , etc. We may measure the 

 amount of alkalinity in bile, using lacmoid as an indicator, by 

 titration with a solution of decinormal hydrochloric acid. 

 Using this method, Mr. Brown found on an average that pig's 

 bile having an acidity equal to 0.50 milligram NaOH per 

 gram had an alkalinity equal to 1.05 milligram HC1 per gram. 

 Sheep's bile with an average acidity of 0.45 possessed an 

 alkalinity of 0.91. Ox bile with an average acidity of 0.43 

 showed an average alkalinity of 1.50, while rabbit's bile flow- 

 ing directly from the liver through a fistula and not coming 

 in contact with the gall bladder had an alkalinity of 2.9 

 without any measurable acidity. These statements would 

 seem to show that the alkalinity as indicated by lacmoid is 

 considerably greater than the acidity as indicated by phe- 

 nolphthaleln, but this is not always the case, for in some of 

 our experiments, to be quoted shortly, it will be observed 

 that the acidity frequently predominates. We would call 

 special attention, however, to the observation made with 

 rabbit's bile, for if it is true that the latter fluid invariably 

 has a strong alkalinity, the addition of such a bile to neutral 

 pancreatic juice would obviously accelerate proteolysis. If 

 Rachford and Southgate used by chance the bile of the rabbit 

 in their experiments, it might help explain the great accelera- 

 tion of digestion noticed by them on addition of bile to 

 "neutral fibrin." The point, however, which we wish to 

 emphasize is that the bile of most animals under ordinary 

 conditions is not a strongly alkaline fluid, that it contains no 

 such alkali as sodium carbonate, but on the other hand is 

 possessed of a weak acidity due to the presence of certain acid 

 salts, such as the phosphates of the alkalies, together with 

 possible weak organic acids or other organic compounds. 

 The fact that the acid reacting bile fails to produce any effect 

 on blue lacmoid is convincing proof that the fluid does not 

 contain free organic acids of any strength. On the other 

 hand, fresh bile does possess a certain degree of alkalinity to 



