174 Creatinine and Creatine in Blood 
least our practice was absolutely uniform; the creatinine value 
of each color reaction was obtained by reference to the standard 
curves which we have recently deseribed.!? For the determination 
of creatinine and creatine in urine we usually employed the 
macro method, in which case the conversion of creatine was 
accomplished by the procedure of Benedict.?? Ina few instances 
we utilized the micro method of Folin.” The chief purpose of thé 
urine analysis was the detection and measurement of the creatine. 
The. creatinine results, which have yielded little of value in 
themselves, are recorded chiefly for the sake of completeness. 
The urine specimens were subjected also to a routine qualita- 
tive examination. 
Results. 
.The analytical results are shown in Table I.77 They are 
divided into the groups and subgroups already mentioned, and 
are arranged within each group so as to present an ascending 
scale of plasma creatinine. Certain other ways of arranging 
the results illustrative of special points discussed in the text 
are employed in the general averages at the end of the table. 
The corrections introduced into the table are made, as explained 
later, on the basis of conclusions reached in our critical exami- 
nation of the methods.'* The few figures given for creatine of 
the corpuscles are calculated from the whole blood and plasma 
creatine in conjunction with the relative plasma volume. | 
DISCUSSION OF RESULTS. 
It has been shown" that of the four creatinine determinations 
required in the complete analysis of blood that of the preformed 
creatinine of plasma has the best claim to accuracy. It is for 
this reason that we selected the plasma creatinine to determine 
the arrangement of our results; and for the same reason we shall 
discuss its variations before attempting to estimate the signifi- 
cance of our other data. 
18 Hunter and Campbell, J. Biol. Chem., 1916-17, xxviii, 335. 
20 Benedict, S. R., J. Biol. Chem., 1914, xviii, 191. 
1 Folin, J. Biol. Chem., 1914, xvii, 469. 
22 Many of them are taken from the thesis submitted by W. R. Camp- 
bell in partial fulfillment of the requirements for the degree of M.D., 
University of Toronto, 1917. 
