100 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



TABLE II. 



TABLE III. 



aluminium contains traces of iron and behaves almost like iron. In 

 Table IV. I give the measurements for Zn, Cd, and Pt against mer- 

 cury, and also the measurements for Cd|Pt in several solutions. The 

 figures in this table are not very accurate, with the exception of those 

 made against mercury in a halogen solution. While the measurements 

 are very easy to make in KCl, KBr, or KI solutions, with the other 

 salts there appear such large and apparently causeless variations that 



