182 PATHOLOGY OF PURIN METABOLISM 



renal and cystic calculi, the "uratic diathesis/' as well as in 

 the formation of uric acid deposits in the tissues. (It may be 

 casually added that Virchow, however, long ago expressed 

 doubt of the existence of any close relation between gout and 

 the genesis of urinary concretions ; and at the present time 

 there are metabolic pathologists of wide experience, like C. v. 

 Noorden, G. Klemperer and F. Umber, who believe that we 

 are not justified in looking upon nephrolithiasis as the result 

 of uric acid accumulation in the blood or in the tissues, and 

 that it would be better to drop entirely the popular, very 

 comprehensive and very much misused term of "the uric 

 acid diathesis. ") 26 Although the importance of these com- 

 plex conditions of solubility, as they prevail among colloid 

 and crystalloid substances in the animal juices, may be ac- 

 cepted in relation to the formation of uric acid sediments and 

 concretions, there is no real reason for seeking the explana- 

 tion of gout in this sphere. We may see one sign of progress 

 in the fact that at the present we have no appreciation of a 

 sharp distinction between " loosely combined " and " fixed " 

 uric acid (Pfeiffer for one tried to bring out such a differ- 

 entiation by means of filters charged with uric acid, on which 

 gouty urines gave up a part of their uric acid). In our 

 modern conceptions of physico-chemical solution-interrela- 

 tions there is no longer room for such schematic representa- 

 tions and for different kinds of uric acid fixation. That 

 we know but incompletely the individual physico-chemical 

 factors which determine the "fixedness" of uric acid 

 combination, is quite another matter. 



Localisation of the Uric Acid Depositions. The rea- 

 son for localization of the uric acid deposits in certain 

 positions of predilection as cartilages, joint capsules, ten- 

 dons, muscles and skin is directly related with the ques- 

 tion of the complex conditions of solubility of uric acid. 



28 Literature upon Uratic Diathesis : F. Umber, Lehrbu. d. Ernahrung und 

 Stoffwechselkrankheiten, pp. 350-356, 1909; cf. on the contrary Neubauer, 

 Internat. Kongr., Wiesbaden, 1911. 



