376 SALTS 



From the preceding details we see that the 

 greater number of the salts of lead are anhy- 

 drous ; and the few which contain water seldom 

 have more than 1 or 2 atoms in the integrant 

 particle of salt. The acetate of lead is the salt 

 which contains most water. The quantity 

 amounts to 3 atoms to the integrant particle of 

 acetate, while the diacetate (if we suppose it 

 sufficiently dried) contains 10 atoms. 



17. SALTS OF COPPER. 



The black oxide of copper alone seems ca- 

 pable of combining with acids and forming salts ; 

 for, except the protomuriate, we do not know 

 any salt of copper containing the suboxide for a 

 base. From the composition of the salts of cop- 

 per, there can be no reason to doubt that 5 re- 

 presents the atomic weight of black oxide of 

 copper. 



Sulphate, 1. Sulphate of copper. This well known and 

 beautiful salt has been often described. It al- 

 ways reddens vegetable blues, however carefully 

 prepared ; and by long boiling its aqueous solu- 

 tion with peroxide of copper in the requisite 

 proportion, we form an insoluble sulphate of cop- 

 per, containing twice as much oxide united to 

 the acid as in the soluble salt. It must there- 

 fore be a disulphate. Sulphate of copper is com- 

 posed of 



