Prof. Field on some of the Basic Salts of Copper, 125 



pitated ; but if, in the preparation of the hypochlorite, the alkali 

 is not thoroughly saturated, a precipitate is formed which, as 

 might be expected, contains both basic salts. 



Oocychloride of Copper. — The precipitates produced either by 

 the caustic alkalies or the alkaline hypochlorites (the copper salts 

 being in excess) appear under most circumstances to be identical, 

 viz. CuCl, 3CuO, 4HO; but other oxychlorides seem to exist. 

 Gladstone observed, in his experiments upon the hydration of 

 chloride of copper, that, under certain conditions, a precipitate 

 was occasioned which on analysis vielded 2CuO, CuCl, HO. 



Basic Nitrate of Copper (4CuO, NO 5 , 3 HO) or (CuO, NO 5 , 

 3CuOHO), and, according to Graham, (3 CuO, NO 5 , HO).— 

 This compound may be obtained either by heating the ordi- 

 nary nitrate of copper, or by the partial decomposition of its 

 solution by the caustic alkalies. When the hypochlorites are 

 added to nitrate of copper, none of this salt is produced, the 

 precipitate consisting entirely of the oxychloride. 



I succeeded some years ago in obtaining delicate crystals of 

 this salt by exposing nitrate of copper to a comparatively gentle 

 heat for many weeks. The resulting mass, on being broken, 

 displayed in. the centre a mass of brilliant prisms of a bluish- 

 green colour, perfectly insoluble in water. Analysis yielded 

 66*48 per cent, oxide of copper, agreeing with the formulae of 

 Gerhardt and Gladstone. 





Calculated. 



Found 



4 CuO . 



. . 66-22 



66-48 



INO 5 . 



. . 22-51 





3HO . 



. . 11-27 





100-00 



The action of the alkalies and alkaline hypochlorites upon the 

 sulphate, nitrate, and chloride of copper appears to be as follows: — 



When potash is added to an excess of sulphate of copper, the 

 compound 



3CuO, CuO SO 3 , 4H0 is produced. 



When an alkaline hypochlorite is added, 



3 CuO, CuCl, 4 HO* is formed. 



When potash is added to chloride of copper, 



3 CuO, CuCl, 4 HO is formed. 



And the same compound is precipitated by the addition of an 

 alkaline hypochlorite. Potash added to the nitrate of copper 



* Under certain circumstances, 



3 CuO, CuCl, 6 HO. 



