584 SAI/TS OF COPPER. 



copper, or potash added in moderate quantity to the same salt, 

 contains, according to Kane's analysis and my own, SO 3 , 4CuO 

 and 4 HO. By a larger quantity of potash, Dr. Kane precipi- 

 tated a clear grass green subsulphate, containing SO 3 , SCuO 

 and 12 HO. The last subsulphate loses exactly half its water 

 at 300.* 



Nitrate of copper, CuO, NO 5 -|-3HO, is formed by dissolving 

 copper in nitric acid. It crystallizes from a strong solution in 

 blue prisms, which contain 3 atoms of water, or in rhomboidal 

 plates, which contain 6 atoms of water. This salt acts upon 

 granulated tin, with nearly as much energy, as hydrated nitric 

 acid. A crystallized ammoniacal nitrate of copper, is obtained 

 by conducting a stream of ammoniacal gas into a saturated 

 solution of nitrate of copper. It is anhydrous, and contains 

 NO 5 , CuO and 2NH 3 (Kane). I would prefer to represent it 

 as a nitrate of cuprammonium + 1 eq. of ammonia, that is, 

 (NH 3 , CuO) NO 5 + NH 3 . 



Subnitrale of copper, HO, NO 5 + 3CuO, is a green pow- 

 der, produced by the effect of heat upon the neutral nitrate, at 

 any temperature between 150 and 600; or by adding a quan- 

 tity of alkali to that salt, insufficient for complete precipitation. 

 When oxide of copper is drenched with the most concentrated 

 nitric acid (HO, NO 5 ), it is this subsalt, singular as it may 

 appear, which is formed, even when the acid is in great excess ; 

 the reason seems to be, that the nitrate of water, being defi- 

 cient in constitutional water, assumes 3 atoms of oxide of cop- 

 per in its place (page 296). 



Oxalate of copper and potash, is obtained by dissolving oxide 

 of copper in binoxalate of potash ; it crystallizes with both 2 

 and 4 atoms of water. 



Acetates of copper. The neutral acetate, CuO,(C 4 H 3 O 3 ) + HO J 

 is obtained by dissolving oxide of copper in acetic acid. It 

 forms fine crystals of a deep green colour, containing 1 eq. 

 of water, which lose their transparency in air, and are soluble 

 in 5 times their weight of boiling water. This salt also forms 

 blue crystals from an acid solution, under 40, which contain 

 5HO (Wohler). The green salt is found in commerce under 

 the improper name of distilled verdigris. Acetates of copper 

 and potash unite in single equivalents, and form a double salt 



* Transactions of the Royal Irish Academy, vol. 19, p. 1 ; or An. de Ch. et de Ph. 

 t. 72, p. 272. 



