1883.J Formation of Uric Acid in the Animal Economy, 65 



The normal presence of nric acid in the spleen, liver, and other 

 organs, even of animals in which the nrinary excretion is usually free 

 from this principle, is fully discussed and explained. 



An investigation into the mutually destructive influence which uric 

 and hippuric acid exert upon each other is next detailed, and it is 

 found that such action affords a clue to the solution of many of the 

 difficulties of the subject. 



The results of the whole investigation appear to show that uric acid 

 is not, as is commonly supposed, formed in the animal body during 

 the progress of the metabolism which is constantly going on in 

 different organs and tissues, then thrown into the biood and afterwards 

 filtered or strained off by the kidneys, and thus finally eliminated 

 from the body ; but that it is absolutely formed in the renal organs 

 themselves by the action of peculiar cells; that it. probably exists in 

 these cells as the urate of an organic base yielding ammonia, or as a 

 complex organic principle, readily splitting up into uric acid and 

 ammonia ; that, for the most part, it is excreted as such urate, 

 which, however, may be changed into urate of sodium, or any other 

 metallic urate, according as it subsequently meets with one or other 

 salt; that, probably, there is always a trace of uric acid absorbal into 

 the blood from the kidney-cells ; but that, under certain circumstances, 

 e.g., when its forward progress is rendered difficult by tying the 

 cloaca or the ureters of animals, or when other obstructive causes 

 such as occur in disease, are at work, the absorption into the biood 

 becomes greatly increased, and it is then converted into urate of 

 sodium, on account of its then meeting with large amounts of the 

 chloride and phosphate of that metal ; and that it is at times 

 deposited, both in man and the lower animals, in different structures, 

 such as the cartilaginous and fibrous tissues, in the form of crystal- 

 lised urate of sodium. 



The Appendix contains the details of many experiments, especially 

 in relation to the destructive influence of hippurates and benzoates 

 upon uric acid ; and of others which show the want of such power in 

 the case of glycine, glucose, glycerine, and other substances. 



vor.. xxxv. 



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