848 PROCEEDINGS OF THE AMERICAN ACADEMY. 



in iodine solutions, this comparison is less significant than it seems to be ; 

 but certainly it does not militate against our value for the atomic weight 

 of nickel. It is of interest to note that Clarke's mathematical method 

 of selecting from among the older values led to the number 58.687. 



Professor Winkler's sixth and last paper upon this subject appeared 

 only last summer, after the work described in this paper had been com- 

 pleted.* In it he kindly points out several possible flaws and omissions 

 in our earlier paper. This criticism will be discussed at length in the 

 next paper on cobalt. 



Cambridge, Mass., October 22, 1898. 



* Zeitschr. Anorg. Chetu., XVII. 236. 



