£34 ON ACETIC ACI P AND ACETATES. 



matochemical trough terminated the apparatus. I begaft 

 the operation with the lowest degree of heat possible, and 

 always endeavoured to keep it at a minimum. 



Results* The results were three products* which it was necessary 



to examine. First there remained in the retort the metal- 

 lic base; and to ascertain the state in which it was left by 

 the acid, I submitted it to the dociraastic experiments suited 

 to each metal. 



Residuum of The residuum of distilled acetate of silver dissolved in 



the acetates of m tric acid with evolution of nitrous gas. A black matter 

 * remained, which did not dissolve. This, when washed and 



dried, weighed 0*05, and was charcoal. The nitric solu- 

 tion produced the same quantity of muriate of silver as 

 0\Q5 of metallic silver. 



copper, Messrs. Adet and Darracq have said, that, after the dis- 



tillation of acetate of copper, the metal is oxided, according 

 to the former with 0*08 of oxigen ; and according to the lat- 

 ter so as to be soluble in muriatic acid. Hitherto only two 

 oxides of copper have been mentioned ; one, which is brown, 

 containing 0-20 of oxigen; the other red, containing 0*17 

 of oxigen according to Proust, but from experiments on 

 the octaedral red copper ore from Cornwall I conceive it 

 should be estimated at 0*115. I dissolved in nitric acid 

 10*000 of the residuum of the distillation of acetate of 

 copper. I filtered the solution, and 0*055 remained on the 

 filter, which had all the properties of carbon. The fil- 

 tered solution I evaporated to dryness twice, adding muri- 

 atic acid each time. I then precipitated the copper by 

 purified zinc, and obtained 0*4 of metallic copper. Now 

 if the copper had not been in the metallic state in the resi- 

 duum of the distilled acetate, I should not have obtained 

 the original weight of the matter employed ; and the defi- 

 ciency would have indicated the quantity of oxigen. On 

 another 10*000 parts 1 poured muriatic acid, carefully pre- 

 venting the contact of air: and at the expiration of ten days 

 not an atom of copper was dissolved. By reduction by 

 fire, by alkalis, and other doci mastic means, 1 satisfied 

 myself, that the copper is truly [in the metallic state in 

 the '•esiduum of the distillation of acetate of copper. Mr. 

 Darracq found an insoluble residuum of 0'22 after the 



action 



