RICHARDS, COLLINS, AND HEIMROD. — COPPER AND SILVER. 135 



Comparison of the Silver with the Copper Voltameter. 



Temperature of Silver Voltameter = 15° to 25°. Temperature of Copper Voltameter = —2° to 0°. 



* These determinations were made in duplicate. Thus, in Experiments 2, 3, 

 and 5, four copper cells were in the current at once. The pairs agreed within 

 themselves remarkahly well, the average deviation from the mean being only 0.03 

 milligram. 



t In these experiments, the smaller copper was ^ as large as the larger one. 



t In this determination the smaller copper was £ as large as the larger one. 



