xgoS.] UPON HEALTH AND METABOLISM. 323 



other chemicals which have been used in this series of investigations 

 in that its excretion falls only partly upon the kidneys. The effect 

 produced on the urine, therefore, cannot be ascribed directly to the 

 copper salt employed, but only to such derangements of the metab- 

 olism due thereto as would incidentally affect the composition of 

 the urine. 



The effect upon the general metabolism is of a character which, 

 though not very pronounced, is indicative of a retardation of normal 

 metabolic processes. Inasmuch as a small quantity of sulphur was 

 introduced into the system through the copper salt, the quantity of 

 this sulphur must be taken into consideration in studying the effect 

 on metabolism. There is seen to be quite a uniform tendency to 

 derange the ratio of the metabolized sulphur and nitrogen. 



The apparent increase in the relative quantities of sulphur ex- 

 creted is due rather to the diminution in the nitrogen than to an 

 actual increase in the sulphur over that which would be expected 

 from the ingestion of the sulphuric acid in the copper salt. The 

 most marked change in the sulphur compounds is in the case of 

 neutral sulphur, which shows a decided and uniform increase dur- 

 ing the administration of the copper salt and in some cases for 

 several days thereafter. 



The eft'ect produced upon the metabolism of nitrogen is more 

 important. Under the administration of sulphate of copper there 

 is a marked and constant decrease in the excretion of- urea, which 

 is a matter of great significance. Such a decrease can only be 

 regarded as an indication of a retarding effect on nitrogen metab- 

 olism. At the same time the quantity of uric acid and xanthin 

 bases are increased during the administration of the copper salt and 

 the increase in xanthin is still very marked in the after-period. 

 These two important observations indicate that the nitrogen metab- 

 olism is disturbed in a way which must be considered injurious to 

 health. 



There is also a notable effect produced upon the phosphoric acid 

 metabolism. There is a marked decrease in the total metabolized 

 phosphorus, and, while the non-metabolized phosphorus is less uni- 

 formly affected, there is a decided tendency shown to decrease the 



