ON ACETIC ACID AND ACETATES. £S$ 



the copper acquired a fine metallic brilliancy throughout 

 the whole mass. A pretty bright light then seemed to flash 

 over its surface, and the metal lost its brilliancy, becoming 

 like tarnished copper. It is at this juncture, that the resi- 

 duum of the distilled acetate of copper has been considered 

 as a pyrophorus. The maximum shown by Fahrenheit's 

 mercurial thermometer during the process was 41? Q . This 

 experiment, carefully conducted in a platina crucible, in 

 order to appreciate the loss on 10*000 parts, gave 6*441 dis- 

 sipated by the fire. Some carbon remained with the metal- 

 lic copper. 



The acetate of nickel, exposed to an open fire, lets its nickel, 

 acid escape. It becomes black, and we see flashes of light 

 darting over its surface, as in the process with acetate of 

 copper. It retains a little carbon after the operation, and 

 loses tj-20'1 of 10-000. 



Ten parts of acetate of lead of the shops swelled up be- * ead » 

 fore losing their acid. A greater heat is required to decom- 

 pose this salt, than those I have mentioned; and the smell 

 is not that of acetic acid. It becomes at first black, then, 

 yellow, then red, when heated in the open air ; and its car- 

 bon burns as well as the metal. It loses 3*552. That of 

 Mr. Thenard does not swell up. In other respects it exhi- 

 bits the same appearances, but loses in the fire only 1*035. 



The acetate of zinc loses its acid, and becomes less *- inc > 

 black. It burns, and grows black. It loses 6*025; but as 

 a part is volatilized, this experiment is less to be depended 

 on than those with the other acetates. 



The red mass of acetate of iron loses commonly about ir0I »> an> * 

 4*500 : but it is difficult to obtain it in a uniform state. 



The acetate of manganese exhibits similar phenomena, manganese, 

 and loses 7*186. 



The proportions I shall now proceed to give relate only 

 to the salts that lose in the lire the quantities above- 

 mentioned. 



For the distillation of these salts, I introduced a known Distillation of 

 quantity of each into an earthen retort, or one of coated theseJCetate ** 

 glass, according to the degree of heat necessary for the 

 operation. To this I joined a tubulated matrass, and a 

 Woulf s phial containing solution of barytes; and the pneu- 



matochemical 



