174 
IOWA ACADEMY OF SCIENCE 
SUMMARY. 
Copper amalgam cells giving an electromotive force of 0.3468 
volts at 25° can easily be duplicated to within a few one-hundred 
thousandths of a volt. The necessary materials are to be found 
in almost all laboratories. These materials are more easily puri- 
fied than those used in the preparation of either the Clark or 
the Weston cells. 
The electromotive force of these cells is independent of the 
concentration of the copper in the amalgam. 
The temperature coefficient (0.001700 volt) is slightly higher 
than that of the Clark cell which has a temperature coefficient 
of 0.00119 volt. 
These cells are recommended for use as standards for routine 
laboratory work or in laboratories where a Weston cell is not 
available. While the electromotive force is rather small, it may 
be increased to any desired value by connecting several cells 
in series. 
Physical Chemistry Laboratory, 
The State University op Iowa. 
