LOCALIZATION OF URIC ACID DEPOSITIONS 183 



Probably special importance for the interpretation of the 

 general problem may be attributed to a discovery made in 

 Hofmeister's laboratory 27 that when thin sections of car- 

 tilage are left for some hours in a solution of sodium urate 

 they will take up uric acid. The degree of concentration of 

 the urate solution is diminished ; and at the same time when 

 the sections of cartilage are directly inspected they fre- 

 quently show white foci and diffuse opacities of uric acid 

 deposits. The great affinity of normal cartilage for uric 

 acid is manifested by the fact that when large amounts are 

 introduced into the peritoneal cavity in rabbits, the acid 

 may often be detected by the murexide reaction in the car- 

 tilages although not apparent in other tissues. The ac- 

 cumulation of uric acid in cartilage in states of increase of 

 uric acid in the blood may be explained in the same way. 

 The well-known theory of Ebstein that the dissolved uric 

 acid infiltrating the tissues acts primarily to produce an 

 inflammation and that an antecedent necrosis precedes the 

 deposition of the uric acid is no longer to be accepted in the 

 light of the above outlined discovery. That an excess of 

 purins in the body fluids may produce inflammatory changes 

 is not to be denied ; confirmation may be seen in a number of 

 observations, as that of Levinthal, 28 who, in a personal ex- 

 periment, injected half a gram of xanthin (dissolved in 

 piper azin) into his cubital vein, and a few days later, after 

 a moderate strain upon the limbs from dancing, he was sud- 

 denly seized with a fairly acute painful attack in one of his 

 knees, attended with some swelling and local heat. Deposi- 

 tions may form in the tissues, however, as shown by nu- 

 merous observations upon gradually developing tophi ex- 

 hibiting no inflammatory reactions, entirely independently 

 of any antecedent necrosis. 



27 M. Almagia (Instit. of Physiol. Chem., Strassburg), Hofmeister's Beitr., 

 7, 466, 1906. 



28 W. Levinthal (F. v. Muller's Clinic, Berlin), Zeitschr. f. physiol. Chem* 

 77, 273, 1912. 



