PROCEEDINGS 



OF THE 



AMERICAN ACADEMY 



OF 



ARTS AND SCIENCES. 



VOL. X. 

 PAPERS READ BEFORE THE ACADEMY. 



I. 



RESEARCHES ON THE HEXATOIVHC COMPOUNDS OF 



COBALT.* 



By Wolcott Gibbs, M.D. 



Presented, Oct. 13, 1874. 



In the joint memoir of Genth and myself on the ammonia-cobalt bases 

 it was stated that xanthocobalt is not the only product of the action of 

 nitrous acid gas upon ammoniacal solutions of cobalt. A further inves- 

 tigation of this and other related subjects was then promised. I propose 

 now to resume the study of this class of compounds from the standpoint 

 of the chemistry of the present day. The progress of science has ren- 

 dered necessary the abandonment of my former theoretical views, as 

 well as the adoption of the new notation. It has also, as I shall en- 

 deavor to show, lent a peculiar interest to the study of the ammonia- 

 metallic bases. 



In studying the action of the alkaline nitrites upon salts of cobalt, or 

 upon those of the different series of ammonia-cobalt compounds, a prin- 

 cipal difficulty arises from the varying nature and relative proportions 

 of the products obtained under various conditions of temperature, 

 concentration of solutions employed, and duration of action. I have 

 endeavored to cover the whole ground as completely as possible. 



1. Action of A?nmoma and Amvionic Nitrite upon a Solution of 

 Cobaltic Chloride and Amfnonic Nitrate. — When a warm solution of 



* Being Part II. of Researches on the Ammonia-cobalt Bases, by Wolcott 

 Gibbs and F. A. Genth. 



VOL. X. (n. 8. ii.J 1 



