URIC-ACID INFAECTS 515 



infarcts is not at all understood. Spiegelberg 1 found it possible 

 to cause them experimentally in young dogs, in which they do 

 not occur naturally, by injection of 0.25 gram of uric acid per 

 kilo. He was unable to explain why this deposition should 

 occur in young animals but not in old, for he could not find evi- 

 dence of lessened oxidative power on the part of young animals, 

 and the solvent power of infants' urine was found equal to or 

 greater than that of adults. Other authors, however, have 

 found a lower oxidative power in young animals, and, as favor- 

 ing the idea that infants have less power to oxidize uric acid 

 than adults, is the fact that allantoin has been found in their 

 urine. Possibly the uric-acid infarcts of infants are the result 

 of the great destruction of nucleoproteids that results from the 

 change of the nucleated fetal red corpuscles to the non-nucleated 

 adult form. McCrudden considers the high concentration of 

 infants' urine an important factor. Minkowski 2 observed that 

 administration of adenin to dogs led to a deposition of uric 

 acid or some similar substance in the kidneys. Schittenhelm 3 

 found the same deposits in the kidneys of rabbits fed adenin, but 

 not when they were fed guanin. According to Nicolaier, 4 the crys- 

 tals thus deposited are not uric acid or urates, but 6-amino-2-8- 

 dioxypuriu, derived from the adenin (6-amino-purin) by direct 

 but incomplete oxidation. He could not find this substance in 

 either human urine or in a uric-acid calculus. These experi- 

 mental infarctions are undoubtedly related to the human form, 

 and indicate that the latter depend upon the presence of an ex- 

 cessive amount of unoxidized uric acid in the body. 



1 Arch. exp. Path. u. Pharrn., 1898 (41), 428. 



2 Arch. exp. Path. u. Pharm., 1898 (41), 375. 



3 Ibid.. 1902 (47), 432. 



*Zeit. klin. Med., 1902 (45), 359. 



