214 PROCEEDINGS OF THE AMERICAN ACADEMY 



an investigation * has been conducted here upon the atomic weight of 

 oxygen, and since then many other investigators t have taken up the 

 same subject, all but one $ confirming the result of that work. In view 

 of this fact, and also in the light of the recent recalculation of Stas's 

 results, § it seems not out of place to state the value of the atomic 

 weight of copper upon the basis = 15.87, as well as according to 

 the usual standards. 



In conclusion, the writer would express his deep sense of obligation 

 to the kind friends whose interest and advice have so materially assisted 

 the progress of the investigation. 



* Cooke and Richards, these Proceedings, xxiii. 149 and 182. Result, 

 O = 15.87. 



t Lord Rayleigh, Roy. Soc. Proc, xliii. 356 (18B8) ; W. A. Noyes, Am. 

 Chem. Journal, xi. 155, xii. 441 ; E. W. Morley, results as yet unpublished. 

 Also discussions by Crafts, Compt. Rend., cvi. 1662, and many others. 



X Keiser, Am. Chem. Journal, x. 249. Result, O = 15.95. 



§ J. D. Van der Plaats, Chem. News, liv. 186. These results point to a value 

 of oxygen between 15.87 and 15.89. 



