AMMONIA-COBALT BASES. 63 



learn that a poly acid base may in like manner unite with two different acids. 

 Thus we have 



'C 8 HA„{^ - 5NH,CoA{S 3 - 5NH,Co 2 3 {^ 3 . 



The other point to which we refer, is the peculiarity in the constitution of 

 Xanthocobalt, in which one equivalent of oxygen in the secondary radical is not 

 capable of replacement by chlorine, so that we have for the chloride of this base 

 the formula 



NOToNlCCooO.CL, 

 while for the chloride of Purpureocobalt, we have 



5NlCCo 2 Cl.Cl 2 

 and not, as we might expect from the analogy of Xanthocobalt, 



5NlCCo 2 O.Cl 2 . 



The appearance of deutoxide of nitrogen as a conjunct (Paarling) is in itself 

 well worthy of attention, and Xanthocobalt forms, we believe, the only known 

 instance in which this occurs. It seems a priori probable, that iridium and 

 rhodium bases corresponding to Xanthocobalt may be prepared by passing a 

 current of NO x into ammoniacal solutions of protosalts of those metals, or into 

 solutions of Claus' bases, and we have already instituted experiments with these 

 metals, the results of which we hope hereafter to communicate. 



The theory which we have proposed for the ammonia-cobalt bases has also been 

 brought forward by Claus, and applied to his rhodium and iridium compounds. 

 Claus has extended the view in question to the ammonia compounds of metallic 

 protoxides, and we conceive with advantage, in the case of those bases which con- 

 tain more than one equivalent of ammonia, as for instance, the platinum, palla- 

 dium, and iridium bases, having the formulas 



2NH 3 .PtO 2NH 3 .PdO 2NH 3 .IrO. 



The discovery of the biacid character of Purpureocobalt and Xanthocobalt, in 

 connection with the views which we have expressed with respect to the molecular 

 structure of these bases, has led us to extend the theory of conjugation to the 

 ammonia-platinum compounds. We consider these also as conjugate bases, and 

 are of opinion that their constitution may be more simply expressed upon this 

 than upon any other view yet proposed. The ammonia-platinum bases at present 

 known are eight in number, of which two were discovered by Keiset, one by Gros, 

 two by Raewsky, and three by Gerhardt. The empirical formulas of these bases 

 are as follows : 



Reiset's first base = N 2 H 6 PtO uniacid 



" second base = NH 3 PtO " 



Gros's base = N 3 H 6 PtC10 " 



Gerhardt' s first base = NH 3 Pt0 2 " 



" second base = N 2 H 6 Pt0 2 - " 



third " = NH 3 PtC10 

 Raewsky 's first base = N 4 H 12 Pt 2 C10. 5 biacid 



" " second " = NJI 12 Pt 2 Cl 2 4 



