274 COLLOIDS IN BIOLOGY AND MEDICINE 



H. SCHADE rightly sees in every section through a stone, a " valu- 

 able document written by nature on the development and course 

 of gallstone disease. " 



Gout. 



Gouty deposits, tophi, which form in the joints by preference, 

 offer a certain analogy to ossification processes. In uric acid arthri- 

 tis as well, the blood is from time to time supersaturated with a 

 difficultly soluble salt, monosodium urate, which precipitates under 

 favorable conditions. 



Gout is regarded as a disease of nuclein metabolism. We must 

 forego a discussion of this part of the question at present, and limit 

 ourselves to determining the influence exerted by the colloids of the 

 organism upon the deposition of urates, the most characteristic 

 phenomenon in the disease picture of uric acid arthritis. Two 

 papers by H. BECHHOLD and J. ZiEGLER* 3 as well as by F. GUDZENT,* 

 which appeared in 1912, have given a certain direction to these 

 views. 



Until the appearance of these papers, no stress was laid on the 

 question whether uric acid appeared as such or as urates in the organ- 

 ism. The reason for this was that all analytical investigations deter- 

 mine the uric acid, and since it was known that uric acid is much less 

 soluble in water than its alkaline salt, it was taken for granted that 

 the same condition held for the fluids of the body, especially for the 

 serum. H. BECHHOLD and J. ZIEGLER showed, however, that no 

 free uric acid but only urates, chiefly sodium urate, exist in the body, 

 and they showed, moreover, that sodium urate was much less solu- 

 ble in serum than is uric acid. The subsequent publication of 

 F. GUDZENT confirmed and explained this experimental result by the 

 electrolytic dissociation of the electrolytes in question. F. GUDZENT 

 started with the idea that albuminous substances play no part in 

 these processes, but H. BECHHOLD and J. ZIEGLER have shown that 

 this assumption is erroneous. A few figures will explain what has 

 been stated. 



1 In dissolving sodium urate in these two ways, we do not obtain the same equilibrium. Only 

 1 : 40,000 monosodium urate dissolves in serum (&), but if monosodium urate is permitted to form by 

 dissolving uric acid in serum (a), then 1 : 1925 dissolves. [This is probably due to the protective ac- 

 tion of the serum, as the result of which some of the sodium urate remains colloidally dispersed. Tr.] 



