3* PHYSIOLOGICAL CHEMISTRY. 



increase in the uric acid resulted, pointing to the presence in 

 the liver extract of some agent capable of effecting the com- 

 bination. The best results were obtained with dialuric acid 

 salts, and tartronic acid and urea. The significance of these 

 special reactions will be pointed out later, the fact of impor- 

 tance here being the behavior of the liver extract in the com- 

 bination. It has been found that liver extracts have also the 

 power of converting purine bodies into uric acid. It is likely 

 that the other organs furnish active agents capable of perform- 

 ing the same work, but probably in lower degree. 



THE BILE. 



The formation of bile is one of the important functions of 

 the liver and the amount secreted in man is several hundred 

 grams daily. Some of the uses of the bile have been referred 

 to in earlier chapters under the head of digestion phenomena. 

 Other functions will be discussed presently. 



AMOUNT AND COMPOSITION. 



The volume of the bile secreted seems to be subject to varia- 

 tions which are not well understood. Through the aid of a 

 biliary fistula it is possible to collect the total excretion in dogs 

 and other animals which are easily experimented upon and 

 determine the rate of flow and the whole amount. The vol- 

 umes reported by different observers are not in good agree- 

 ment. The amounts secreted by different animals in 24 hours 

 for each kilogram of body weight vary between 12 grams for 

 the goose and 137 grams for the rabbit. For man the 

 amounts observed have varied between about 150 and 1,000 

 grams daily. 



The flow of the bile is increased, as far as volume is con- 

 cerned at any rate, by the administration of certain remedies. 

 These are known as cholagogues and among them calomel, 

 certain resins, rhubarb and oil of turpentine are perhaps best 

 known. That the solids of the secretion are increased is a 

 disputed question. It is proper to state here that many of the 



