60 RESEARCHES ON THE 



lent replacement of hydrogen by ammonium and cobalt, but even that the com- 

 pound ammonium thus formed may replace cobalt in its sesqui-combinations. 

 Thus, according to Weltzien, the formula of nitrate of Luteocobalt is 



N 



H 



NH 4 

 NH 4 





Co 

 H 



- O s +3NO, 



NH 4 

 NH 4 

 Co 





N 



which is obviously reducible to the type B 2 3 +3N0 5 . 



By adopting Gerhardt's view of the constitution of the sesquioxides, Kogojski 

 reduces the formula of chloride of Luteocobalt, 6NH 3 .Co 2 Cl 3 , to the form 2NH 3 .coCl 

 in which co represents cobalt with f of its usually received equivalent. To this 

 body he gives the name Dicobaltinamin, and considers it analogous to the chlorides 

 of Diplatosamin and Palladiamin 2NH 3 .PtCl and 2NH 3 .PdCl. This view applies 

 very well to several other salts of Luteocobalt, as for example, the bromide, iodide, 

 nitrate, and chlorplatinate, the formulas of which become 



2NH 3 .coBr or N 2 H 3 co,HBr 



2NH 3 .coI or N 2 H s co,HI 



2NH 3 .coO,N0 5 or N 2 H 5 co,HO,N0 5 



2NH 3 .coCl+PtCl 2 +2HO or N 2 H 5 co,HCl+PtCl 2 +2HO. 



"We have remarked already that the compound 6NH 3 .Co 2 Cl 3 +6NH 3 .Co 2 3 ,3S0 3 , 

 which Bogojski describes, and to which he attributes the formula 



2NH 3 .coCl+2NH 3 .coO,S0 3 , or N 2 H 5 co,HCl+S0 4 H 2 ,2N 2 XI 5 co. 



has no real existence, but is merely a mixture of the chloride and sulphate which 

 are isomorphous salts. Bogoj ski's parallel between this and the sulphate of Gros's 

 base, which according to Gerhardt's view has the formula 

 N 2 H 4 pt 2 ,2HCl + N 2 H 4 pt 2 ,S0 4 H 2 



is consequently illusory. 



On the other hand, moreover, it must be remembered that Bogoj ski's view applies 

 only to the compounds of Luteocobalt, and fails entirely to reduce the formulas of 

 the other cobalt bases to more simple expressions, since it requires us, in these 

 cases, to admit fractions of equivalents. Thus the formula of the chloride of Pur- 

 pureocobalt becomes on this view 



N f H 5 coCL 



while that of its chlorplatinate must be written 



3N s H s coCl+2PtCl 2 . 



Even in the case of those compounds of Luteocobalt which contain water, Bogo- 

 jski's view ceases to give simple expressions, since in the majority of these the 

 number of equivalents of water is not divisible by three. The difficulty becomes 



