12 PROCEEDINGS OP THE AMERICAN ACADEMY 



Co, 



fNHg-Cl 

 NHg-Cl 

 NH^-NHg-Cl 



NH3-NH3-CI 



NH3-CI 



NH3-CI 



It thus forms the type of a special octamin series, the relations of 

 which to the salts which I have described are easily seen by comparing 

 the formulas which I have given. Rose has not described any other 

 salts of this series. It seems possible that my series may be derived 

 from this by acting upon the chloride with argentic nitrite : we may 

 have 



Co,(NH3)3Cls + 4AgN0,= Co,(NH3),(NO,),Cl, + 4AgCl, 



but I have as yet made no experiments in this direction. Finally 

 Kiinzel * described, many years since, a hyposulphate, to which he gave 

 the formula CoA + ^NHg-l- 2S2O5 (old style). This formula be- 

 comes, in my view, Co2(NH3)sSPi3, and the salt then belongs to the 

 octamin series ; but it is possible that its empirical constitution has not 

 yet been correctly given. 



In treating of the salts of my new series, it appeared to me more in 

 accordance with the theoretical views which I have adopted to abstain 

 from trivial names. All the members of this series may however be 

 regarded as containing the complex atom Co2(NH3)g-(N02)4, which 

 alone is constant and which from one point of view may be regarded 

 as a diatomic radical or residue, and those who justify the use of 

 trivial names by their convenience may find the name " Croceocobalt " 

 expressive and appropriate. 



5. The salts described by Fremy f under the names of chloride, 

 nitrate, and sulphate of Fuscocobalt contain also eight atoms of am- 

 monia, and may be regarded as belonging to the octamin series. These 

 salts have, according to Fremy, respectively the formulas : — 



Co2(NH3)3.0.Cl, + 30H2, 

 Co.,(NH3)3.0.(N03),+30H2, 

 Co2(NH3)3.0.(SOj2 + 40H2, 



in modern notation. They are brown resinous masses, are difficult to 

 obtain m a state of purity, and have as yet been but little studied. If 



* Journal fiir prakt. Cliemie, Ixxii. 218. 



t Ann. de Chimie et de Physique [3], tome xxxv. p. 257. 



