548 N. C. Nag — Notes on New SalU of Cobalt and Nickel. [No. 4 r 



The fused alkali, which to begin with was white, turned faintly yellow 

 and became distinctly crystalline as absorption went on. After the ab- 

 sorption had been completed, in a solution of the substance formed, silver 

 nitrate gave the characteristic precipitate of silver nitrite. A quantita- 

 tive determination of the silver salt gave 70'4 instead 701 per cent, of 

 silver, showing that it was silver nitrite. 



Experiments have already been made with the hydrates of sodium, 

 potassium, barium and calcium and with soda lime, and apparently the 

 same action occurs in each. It is interesting to observe that anhydrous 

 sodium carbonate when heated just to low redness in a current of 

 nitric oxide also gives a small quantity of sodium nitrite. We reserve 

 the full details of the experiments for a future communication. 



Notes from the Chemical Laboratory of the Presidency College, Calcutta. 

 Notes on New Salts of Cobalt and Nickel. — By Nagendra Chandra 

 Nag, M.A. Communicated by Alex. Pedl.br, F.R.S. 



[Received 22nd September, 1896 ; Read 4th Nov., 1896.] 



While examining some samples of bromine, last March, some 

 bromine, mixed with solution of potassium bicarbonate, was added to 

 cobalt chloride solution, with the expectation that it would give a 

 precipitate with the cobalt, but contrary to experience a green solution 

 was formed of a colour just like that of nickel salts. A green cobalt 

 salt solution was naturally very striking, and an attempt was made to 

 isolate this compound. 



While the experiments were proceeding, a paper was read before 

 the Chemical Society in London, on April 23rd, 1896, by Pi. G. Durraut, 

 who had noticed the same formation of a soluble green cobalt salt. 

 The abstract of this paper is published at page 96 of the Proceedings, of 

 the Chemical Society for 1896, but though several numbers of the Journal 

 have since appeared,, no full description of these experiments has been 

 published. In the abstract the green substance is conjectured to be a 

 cobaltate or cobaltic acid HgCoO^, and the probable reaction from 

 hydrogen peroxide, which was the process used, is given as : — 

 CoC0 a + 2 H a O 3 =H 2 Co0 4 +C0 2 + H 8 0. 



In the absence therefore of any fuller published information, and 

 as the compound obtained here was produced by a slightly different 

 process to that used by Mr. Durrant, a few particulars of the work 

 done are placed before the Society. 



To get the product free from potassium chloride, it is best to take 



