440 VICTOR C. MYERS 



erate doses of cinchophen will reduce a uric acid content of 5 or 6 mg. 

 to a mere trace in a comparatively few hours. If long continued, how- 

 ever, the drug loses this influence. This uric acid eliminating effect aj 

 pears to be quite independent of the marked analgesic effect of these drugs. 



Creatinin. Until the advent of Folin's colorimetric method for the 

 estimation of creatinin in urine in 1904, we possessed no reliable informa- 

 tion regarding this interesting nitrogenous waste product. Folin was the 

 first to show that the amount of creatinin excreted in the urine by a nor 

 naal individual on a meat free diet is quite independent of either the amount 

 of protein in the food or of the total nitrogen in the urine, the amount 

 excreted from day to day being practically constant for each individual, 

 thus pointing conclusively to its endogenous origin. In 1914 Folin (/) ap- 

 plied his colorimetric method, slightly modified, to the estimation of 

 creatinin in blood, and Folin and Denis (g) presented some quite extensive 

 data on the subject. Almost simultaneously Neubauer reported an ob- 

 servation on a case of "uremia," while Myers and Fine (g) presented sev- 

 eral analyses on two cases of nephritis showing marked retention of cre- 

 atinin. 



For perfectly normal individuals the creatinin of the blood amounts to 

 1 to 2 mg. per 100 c.c., the findings for the strictly normal being nearer 



1 than 2 mg. This statement should probably be made with some reserva- 

 tion as the method does not appear to be entirely adequate for the de- 

 termination. It is quite possible that the actual content of creatinin may 

 not be much more than 0.5 mg., the remainder being due to the inter- 

 ference of other substances in the color reaction. The figures obtainable 

 with present methods are comparable, however, and serve as a satisfactory 

 base line. The importance of this source of error would appear to de- 

 crease proportionately with a rise in the creatinin content of the blood, 

 so that the absolute accuracy of the estimation is much greater with patho- 

 logic than normal values. 



As soon as one passes to hospital patients values higher than 1 to 



2 mg. are found. Although the great majority of cases without renal 

 involvement show creatinin figures on the whole blood below 2.5 mg. per 

 100 c.c., occasionally figures as high as 3.5 mg. are encountered that are 

 not readily explained. It may be noted, however, that a slight retention 

 of creatinin (figures between 3 and 4 mg.) occurs in syphilis, certain heart 

 conditions, sometimes in fevers, and in some cases of advanced diabetes. 

 Creatinin figures above 3.5 mg. are almost invariably accompanied by an 

 appreciable urea retention and this is generally true of those above 3 mg. 

 Many of the cases below 4 mg. show improvement, but with over 4 mg. the 

 reverse is the case. It would appear from this that an appreciable re- 

 tention of creatinin, i. e., over 4 mg., does not occur until the activity of 

 the kidney is greatly impaired. That such should be the case is quite 

 natural to expect, since creatinin is normally the most readily eliminated 





