7a 
to retain its full sensitiveness in presence of any amount of cobalt; and that 
it has been shown to increase the effectiveness of dimethylglyoxime about 
eight times and to be able to deteet within 24 hours less than 0.002 mg. of 
nickel in a volume of 50 ee. 
SUMMARY. 
1. A modified method of using dimethylglyoxime for detecting traces of 
nickel in cobalt salts is proposed which (1) avoids the use of large amounts 
of the reagent; (2) makes possible the detection of considerably smaller 
: quantities of nickel than has been possible heretofore. 
2. The sensitiveness of the test is shown to be unaffected by the presence 
of cobalt even in large quantities. The proposed method increases the ordin- 
ary sensitiveness of dimethylglyoxime about eight times and is capable of 
detecting about one-fifth the amount of nickel detectable by any of the pre- 
viously known methods. 
Chemical Laboratory, 
Purdue University. 
