A. Hunter and W. R. Campbell 183 
If they should be confirmed, it would follow, after what has been 
said of the equa] distribution of creatinine, that the corpuscles 
contain from 5.5 to 10 times as much creatine as creatinine, 
while in the plasma it is the latter which is predominant. 
Relation between Creatine of Plasma and of Urine. 
This leads us to consider whether our results throw any light 
upon the question of the relation between the concentration of 
creatine in the plasma and its occasional appearance in the urine. 
Assuming that the permeability of the healthy kidney cells to 
creatine is constant, there would appear to be only two forms 
which this relation might assume; either creatine is promptly 
excreted upon its earliest appearance in a plasma which is nor- 
mally creatine-free, or else it passes the kidney only when its 
plasma concentration rises above a certain definite threshold.*4 
Now, if the individual data for plasma and urinary creatine are 
compared, it is impossible to detect any uniform relation between 
them. Plasma creatines of from k4 to 3.2 seem to be associated 
indifferently with the presence of creatine in the urine or its 
absence. It can perhaps be said that whenever the (uncor- 
rected) plasma creatine is lower than 1.4 the urine is creatine-free, 
and that whenever it is above 3.2 creatinuria makes its appear- 
ance; but the generalization includes in its scope such a small 
proportion of our cases that it possesses little significance. This 
apparent lack of a consistent relation is probably in part the con- 
sequence of the variable error involved in the single determination 
of plasma creatine. At any rate, when we compare averages, in 
which the error may be supposed to be more nearly constant, a 
certain regularity becomes at once apparent. 
In order to exhibit this more clearly we have in the 
33 In our preliminary communication” (p. xix), in the sentence dealing 
with the relative amounts of creatinine and creatine in the corpuscles, 
the words ‘‘first’’ and ‘‘second”’ are transposed in such a manner as to 
convey a meaning exactly the opposite of what was intended. When 
the abstract was printed this unfortunately escaped detection. 
34'The dependence of creatinuria upon a specific increase of renal per- 
meability constitutes a third possibility which cannot be entirely excluded, 
but for which there would not exist an exact analogy. 
