Cobaltous into Cobaltic Nitrite. YL 



was that of barium rather than of cobalt, the formula, 



BaaCo' Co"'2(NO,)io.s (OH)i.., O-TSBaCNOä)^, 25-5H,0, 



can be given to their second preparation of the barium salt, and with 

 markedly closer approximation to the results of analysis than that 

 reached by their formula. Their silver salt, in which it is improb- 

 able that either cobaltous metal or nitrate was present, may have 

 its given formula rearranged so as to make it appear as a derivative 

 of the silver salt (AgN02N02)3Co"'2(OH)3, here described, thus: — 



(AgNO. N02)3Co";(OH),,(OH)Ag, H,D. 



It has not been found possible to get time and opportunity to 

 extend this research by further work upon Rosenheim and 

 Koppel' s solution and its derivative hydroxynitrites or upon 

 Lang's solution. But enough has been accomplished probably 

 to justify the expectation that all hydroxycobaltinitrites will prove 

 to be of the type of the salts met with in this investigation. 



The author is greatly indebted to Professor T. Haga for 

 valuable advice given him during the course of this work and to 

 Professor E. Divees, F. R. S., for assistance in expressing the 

 significance of the results of the experiments and in preparing the 

 text of the paper. 



College of Science, 



Imperial University, Tokyo. 



