On Oxalic ^cid. 253 



It gave me considerable uneasiness to observe, that my 

 experiments led to conclusions irreconcilcable with those of 

 chemists of such eminence and consummate skill, and it 

 was not without considerable hesitation that I ventured to 

 place any reliance upon them. I am persuaded, however, 

 that some mistaice has inadvertently insinuated itself into 

 their calculations ; since the carbonic acid alone, formed 

 during the distillation of oxalate of lime, contains consi- 

 derably more carbon than the whole quantity which they 

 assign to the oxalic acid decomposed. M. Fourcroy informs 

 us, that oxalic acid is converted into carbonic acid and wa- 

 ter, when acted upon by hot nitric acid ; and this decom- 

 position seems to have been the method employed to ascer- 

 tain the proportion of the constituents of oxalic acid j but 

 the numbers assigned by him do not correspond with this 

 statemenl. For 10 parts of hydrogen require 60 of oxygen 

 to convert them into water, and 13 of carbon require at 

 least 33 of oxygen. So that instead of 77 parts of oxygen, 

 there would have been required no less than 98 to convert 

 the hydrogen and carbon into water and carbonic acid. It 

 is true, that the surplus of oxygen may be conceived to be 

 furnished by the nitric acid ; but if this be admitted (and I 

 have no doubt from experience that the nitric acid actually 

 does communicate oxygen), it is difficult to see how the 

 constituents of oxalic acid could be determined by any such 

 decomposition, unless the quantity of oxygen furnished by 

 the nitric acid were accurately ascertained. 



[To be continued.] 



XLVII. De. 



