256 Proceedings of Boyal Society of Edinburgh. [sess. 
as I had frequently to answer queries concerning its accuracy, I felt 
it my duty carefully to examine once more the whole question, and 
if there was any doubt about it, at once to set that doubt at rest. 
I was I confess agreeably surprised to find that Professor Salkowski 
had made a slight mistake, which when rectified places his own 
results and mine in complete accord. In order to make this point 
quite clear I will venture to reproduce Professor Salkowski’s 
results, arranging his analyses in order, beginning with the one 
having the least uric acid. 
Salkowski' s first Table (1892). 
N o. 
1 
Silver 
obtained. 
2 
Uric acid 
reckoned 
from 1. 
3 
Uric acid 
obtained. 
4 
Difference in 
mgrms. 
5 
Ratio between 
silver and uric 
acid. 
1 
•029 
•045 
•033 
-12 
4-1 : 
3 
o 
•035 
•054 
•040 
-14 
4-09 : 
3 
3 
•037 
•057 
•042 
-15 
4-2 : 
3 
4 
•045 
•070 
•056 
-14 
3-71 : 
3 
5 
•046 
•071 
•051 
-20 
4-03 : 
3 
6 
•049 
•077 
•056 
- 21 
4-02 : 
3 
7 
•050 
•078 
•067 
-11 
3-43 : 
3 
8 
•051 
•079 
•100 
+ 21 
2-24 : 
3 
9 
•054 
•084 
*070 
-14 
3-36 : 
3 
10 
•060 
•094 
•083 
-11 
3-63 : 
3 
11 
•064 
•100 
•088 
-12 
3-41 : 
3 
12 
•073 
*114 
•086 
-28 
3-96 : 
3 
I think No. 8 is evidently a spoilt analysis, for no similar result 
is ever again to he found in the tables of Salkowski, Jolin, Hermann, 
or Czapek, and the last, urine No. 12, must be considered under 
the head of “urine saturated with uric acid.” Such urines, and 
Czapek estimated some of these, stand by themselves, and probably 
require dilution before the analysis is made. Omitting these two 
cases, and arranging the results as I have done, it is evident that 
there is, in each case, an excess of the uric acid estimated from the 
silver over that actually found by Salkowski’s own process of about 
14 mgrms. This difference is as constant as one can expect, for 
Jolin and Salkowski, in performing two check analyses of the uric 
acid, in one and the same urine, by one and the same process, fail 
to get them then to coincide by 3 or 4 .mgrms. What Salkowski 
