700 URINE. 



gram per day on a mixed diet. The ratio of uric acid to urea varies con- 

 siderably with a mixed diet, but is on an average 1 : 50-1 : 70. In new- 

 born infants and in the first days of life the elimination of uric acid is 

 relatively increased, and the relation between uric acid and urea has been 

 found to be 1:6.42-17.1. 



We used to ascribe an increasing action upon the elimination of uric 

 acid to protein food, but the investigations of HIRSCHFELD, ROSEN- 

 FELD and ORGLER, SIVEN, BURIAN, and SnuR, 1 and many others have 

 positively proven that a diet rich in protein does not itself increase the 

 elimination of uric acid, but only according to the amount of nucleins 

 or purine bodies contained therein. The common assumption that the 

 elimination of uric acid is smaller with a vegetable diet than with an ani- 

 mal diet, when the quantity may be 2 grams or more per twenty-four 

 hours, is explained by this. 2 



Still a purine-free diet is not without some influence upon the elimina- 

 tion of uric acid, as the quantity of uric acid eliminated with a ' 



free diet is considerably greater than in starvation and can be increased 

 by protein feeding. The action of the food-protein is here probably an 

 indirect one, consisting in that the proteins raise the work of the digestive 

 glands and the metabolism of their cells and thereby also raise the endo- 

 genous uric acid formation (see below) somewhat. 3 Work and rest do 

 not seem to have any special influence upon the uric acid elimination, 

 although according to the confirmed statement of SIVEN and LEATHES* 

 the elimination in the night is less than in the morning hours. 



The reports in regard to the influence of other circumstances, as well 

 as of different substances, on the elimination of uric acid are diverse. 

 This is in part due to the fact that the earlier investigators used an 

 inaccurate method (HEINTZ), and also that the extent of uric-acid elimina- 

 tion is dependent in the first place upon the individuality. Thus the 

 investigators are not in accord in regard to the action of drinking- 



1 See the extensive review of the literature in Wiener, " Die Harnsaure," in Ergeb- 

 nisse der Physiologic, 1, Abt. 1, 1902. 



2 J. Ranke, Beobachtungen und Versuche iiber die Ausscheidung der Harnsaure, 

 etc. (Miinchen, 1858); Mares, Centralbl. f. d. med. Wissensch., 1888; Horbaczewski, 

 Wien. Sitzungsber., 100, Abt. 3, 1891. In regard to the action of various diets the 

 reader is referred to the above-cited authors, and especially to A. Hermann, Arch. f. 

 klin. Med., 43, and Camerer, Zeitschr. f. Biologic, 33, and Folin, Amer. Journ. of Physiol., 

 13. 



3 See Hirschstein Arch. f. exp. Path. u. Pharm., 57; Smetanka, Pfliiger's Arch., 

 138 and 149 ; Mares, ibid., 134 and 149. Contrary views, Brugsch and Schitten- 

 helm, Zeitschr. f. exp. Path. u. Therp., 4, and Siven, Pfliiger's Arch., 146. 



4 Siv6n, Skand. Arch. f. Physiol., 11; Leathes, Journ. of Physiol, 35; see also Ken- 

 naway, Journ. of Physiol., 38. 



