OXIDATION OF URIC ACID. 131 



quantity of water consumed by different animals in a 

 given time. 



When uric acid is subjected to the action of oxygen, 

 it is first resolved, as is well known, into alloxan and 

 urea. (32) A new supply of oxygen acting on the 

 alloxan causes it to resolve itself either into oxalic acid 

 and urea, into oxaluric and parabanic acids, (33) or into 

 carbonic acid and urea. 



31. In the so-called mulberry calculi we find oxa- 

 late of lime, in other calculi urate of ammonia, and 

 always in persons, in whom, from want of exercise 

 and labor, or from other causes, the supply of oxy- 

 gen has been diminished. Calculi containing uric 

 acid or oxalic acid are never found in phthisical 

 patients ; and it is a common occurrence in France, 

 among patients suffering from calculous complaints, 

 that when they go to the country, where they take 

 more exercise, the compounds of uric acid, which 

 were deposited in the bladder during their residence in 

 town, are succeeded by oxalates (mulberry calculus), 

 in consequence of the increased supply of oxygen. 

 With a still greater supply of oxygen they would have 

 yielded, in healthy subjects, only the last product of 

 the oxidation of uric acid, namely, carbonic acid and 

 urea. 



An erroneous interpretation of the undeniable fact, 

 that all substances incapable of further use in the or- 

 ganism, are separated by the kidneys and expelled from 

 the body in the urine, altered or unaltered, has led 

 practical medical men to the idea, that the food, and 



