A. Hunter and W. R. Campbell es, 
Plasma Creatinine. 
In our preliminary communication” we stated that the plasma 
creatinine of normal individuals is always Jess than 1.0 mg. per 
100 cc. This opinion was based on the nine results which con- 
stitute Group II A of the larger series here presented. It is now 
apparent that these results were by no means completely repre- 
sentative. The figures of Group I show that at least for healthy 
and active males the ordinary level of the plasma creatinine is 
somewhat higher than our early estimates. Of the 30 results 
within that group no more than 8 are below 1.0mg. A majority 
(17) are included by the values 1.1 and 1.2. The lowest is 0.80, 
the highest 1.3. The average of the whole group is 1.09, or in 
round figures 1.1. These data are furnished by a number of 
separate individuals (26) sufficiently large to make them fairly 
representative of their class. 
When it was found that Group I, our second series in point 
of time, gave generally higher values than Group II A, our first, 
we were inclined for a little to question the correctness of the 
earlier analyses. We therefore, by way of control, supple- 
mented these at a considerably later date by a further series of 
eleven determinations upon strictly comparable material. The 
results, constituting Group II B, do not differ im any essential 
respect from those of Group II A. One, it is true, shows a value 
as high as any found even-in Group I; but of the remainder none 
exceeds 1.0 mg., and eight are below it. The results in the two 
subgroups therefore mutually confirm one another, and form 
together a sufficiently concordant single series. Taking them as 
such we find that the plasma creatinine of Group II ranges from 
0.707% to 1.8, or, neglecting the last as a distinctly aberrant 
value, to 1.0. The average of all is 0.89, or, if we again exclude 
23 We have in our records one case only where the plasma creatinine 
appeared to be lower even than the minimum here reported. It was 
that of a female patient without known organic disease, supposed to be 
suffering from hysteria, who might fairly enough have been included 
in Group II. Her plasma creatinine was 0.58. This value remained 
so unique that, lacking opportunity to confirm it, we have hesitated to 
place confidence in the correctness of the analysis, and have therefore 
omitted it from the table. 
