~y> HrSTORY OP COBALT AKD NICKEL. 



poaed, the rest the parts that touch the glass. The products then are 

 sublimes. muriatic acid gas mingled with oxigenized acid. The glass 



becomes tinged with blue. The muriat that is not decomposed 

 sublimes, after having melted, in flowers of a gridelin colour. 

 These flowers have acquired a kind of condensation, which 

 renders them insoluble in water for twelve hours at least : 

 but at length they afford a solution of ordinary muriat. 



Arsenit and Arseniat. 



Arsenit, how The Arsenit of cobalt is prepared by pouring a very dilute 

 prfpiut solution of cobalt into a solution of arsenit of potash. A rosy 



precipitate is formed, which retains this colour after desicca- 

 tion. 



Character of the Arsenit. 



Us characters. i . Heated in a tube closed at one end it is decomposed ; the 

 cxide of arsenic sublimes; and the glass is tinged blue. 

 2 The nitric acid dissolves it, and nitrous gas is evoled. 



3. Its solution in muriatic acid is decomposed by sulphu- 

 retted hidrogen, which precipitates orpiment. ' 



4. Caustic potash, assisted by heat, separates the blue 

 •xide. 



Arseniat. 



Arseniat. This is obtained by employing arseniat of potash, instead 



sf ar»cnit. The precipitate is rose-coloured like the arsenit.. 



Its Characters. 



ractert. *• Heated in a tube it yields no sublimate, and becomes 

 violet-coloured, without tinging the glass. 



2. Nitric acid dissolves it without giving out nitrous gas. 



3. Its muriatic solution does not become turbid by the ad- 

 dition of sulphuretted hidrogen in less than two hours after 

 they arc mixed. 



4. Caustic potash separates blue oxide and combines with 

 the acid. 



.Vat ive. The r.osy efflorescences found or minerals containing cobalt 



eon»i# 



