100 W. Gihhs and F. A. Genth 



this class of bodies. Accordingly we should prefer to write tlie 

 formiila of clilorid of Luteocobalt 



GNHr^Cos . Cl3 



employing tlie connecting circumflex, as Kolbe has suggested, 

 as a symbol of conjugation. Adopting this view, we have the 

 following conjugate radicals, which we assume as existing in the 

 ammonia-cobalt bases precisely in the same sense in which we 

 assume Coa as existing in the sesquichlorid and sesquioxyd of 

 cobalt, 



Roseocobalt, - - - - 5NH3.C02 



Purpureocohalt, - - • SNHa , Cos 



Luteocobalt, - - . - 6NH3.C02 

 Xanthocohalt, - . - KO2 . 5NII3 . C02, 



We 



factory explanation of the fact that two of the ammonia-cobalt 

 bases are triacid, forming in all cases neutral compounds with 

 three equivalents of acid, two are biacid bases, and of these 



_ J — J ^^^^ _ — ^ 



four equivalents of acid. 



.pounds 



In these cases we meet with the same difficulty which occurs 

 with the ordinary salts of sesquioxyds ; thus sesquioxyd of iron 

 may unite with one, two, or three equivalents of acid, though 



appear 



While some chem- 



ists assume that salts of sesquioxyd of iron containing one or 

 two equivalents of acid are basic, others consider the different 

 equivalents of oxygen as united in different modes, so that the 

 oxyd may be, according to circumstances, 



FeaOa 

 FeaO . O2. 



Peligot's theory of the constitution of sesquioxyd of uranium 

 is another case in point ; as this oxyd unites with but a single 

 equivalent of acid, it may be considered, as Peligot has shown, 

 as the oxyd of a radical, U2O2 .0, so that in this case also, the 

 rule that a base unites with as many equivalents of acids as the 

 base itself contains equivalents of oxygen is satisfied- 



To explain the biacid character of two of the ammonia-cobalt 



in them the existence of sec- 

 ondary radicals containing oxygen. Thus in Purpureocohalt 

 and Xanthocohalt the primary radicals are 



5NH3"^02 



NoCoXHs.Coa; 



bases, 



assume 



