JOTJENAL OP THE COLLEGE OF SCIENCE, IMPERIAL UNIVERSITY, 

 TOKYO, JAPAN. 



VOL. XXVIII., ARTICLE 2, 



The Change of Cobaltous into Cobaltic Nitrite. 



By 



Tsuneo Suzuki, Fiigaicushi. 



College of Science, Iwjierial University, Tohijn. 



Very little is known of what happens to cobaltous nitrite 

 when it is produced in sokition in the absence of acids or dissolved 

 salts. In 1860 the Swedish chemist, Lang, published the fact that 

 such a solution of cobaltous nitrite left on evaporation blackish 

 brown crystals of highly basic cobaltic nitrite (K. S. Vet. Äkad. 

 Handl., 1860; Fogg. Ann., 1.863, 118, 282). According to Hampe 

 {Annalcn, 1803, 125, 343), the red saline mass, thus obtained, 

 contains cobaltous as well as cobaltic nitrite. Neither Lang nor 

 Hampp: gave quantitative results. 



In order to get Lang's crystals', precipitated calcium carbonate 

 suspended in a very little water was dissolved up by passing in 

 nitrous gases, cobalt sulphate in equivalent quantity was added, 

 and the calcium sulphate filtered off. Lang and Hampe both 

 used barium nitrite, but the difficulty of separating barium 

 sulphate, when precipitated from a cold neutral solution, made 

 the use of calcium nitrite be preferred in the present research. 

 The filtrate from the calcium sulphate was evaporated almost to 

 dryness in a vacuum desiccator at a temperature of 30"^ and the 



