1821.] Atomic Weight of various Metals and Acids. 137 



found in it, because his salts had not been completely freed from 

 water Even the oxalate of lane which I dried at the tempera- 

 ture of 550° would have afforded traces of hydrogen, though the 

 quantity would have been much less than Berzehus found; tor 

 its constituents (in consequence of the 0-015 of water still 

 retained) would have been : 



Hydrogen 0-0016 



Carbon I' 5 . 



Oxygen 3-0133 



4-515 

 Thus it would be a compound of about 



1 atom hydrogen, 

 156 atoms carbon, 

 235 atoms oxygen. 



These numbers are too high to be admitted, and show clearly 

 the source of Berzelius's hydrogen. 



Zinc is completely precipitated from the sulphate by oxalic 

 acid. I find that the complete precipitation of this metal is not 

 prevented by previously mixing the solution of sulphate of zinc 

 with some sulphuric acid. The composition of the crystals of 

 sulphate of zinc is as follows : 



1 atom sulphuric acid = 5*00 



1 atom oxide of zinc = 5'25 



6 atoms water = °-7o 



17-00 



17 grs. of these crystals being dissolved in water, nine grains 

 of crystallized oxalic acid were thrown into the solution, and the 

 whole was well agitated for some time. A white powder imme- 

 diately appeared, which gradually fell to the bottom, leaving a 

 transparent colourless liquid swimming over it. This liquid 

 reddened vegetable blues ; but was neither precipitated by mu- 

 riate of lime, nor carbonate of ammonia. Hence it contained 

 neither oxalic acid, nor oxide of zinc. The oxalate of zinc, 

 when washed and dried in the open air, weighed, in one experi- 

 ment, 10-5 grs.; in another, 10-43 grs. This powder being 

 exposed on a sand-bath to a temperature of 550° for several 

 hours was reduced to the weight of 7-75 grs. In this state, it 

 Was a tasteless white powder, which dissolved without efferves- 

 cence in muriatic acid, and when the solution was mixed with 

 muriate of lime, a white precipitate fell, it is obvious from this, 

 that it still contained oxalic acid. As it contained the whole 

 oxide of zinc in 17 grs. of the sulphate, it must have consisted ot 



