288 Dr. Murray on the Chemical Constitution of [Oct. 



ment, like the hydrogen of sulphuric acid, must, in the action of 

 the base, be combined with oxygen, and abstracted in the state 

 of water. The small portion of hydrogen, therefore, stated by 

 Berzelius, must be considered as derived from error of experi- 

 ment ; and its presence would be admitted more readily from 

 the idea of some portion of hydrogen being essential to the 

 constitution of the acid, as necessary to form what was regarded 

 as its compound radical. In subsequent experiments, accord- 

 ingly, Berzelius found reason to infer that the proportion was 

 smaller than he had at first assigned. The minute quantity 

 which he does suppose to exist in real oxalic acid (less than one 

 per cent.) he brings forwards as a difficulty in the atomic hypo- 

 thesis. A fraction of an atom, he remarked, cannot be supposed ; 

 and, therefore, the small quantity of hydrogen must be considered 

 as an entire atom. But from the proportions, it must be held to 

 be combined with 27 atoms of carbon, and 18 atoms of oxygen, 

 that is, with 45 other atoms — a combination certainly altogether 

 improbable ; and any arrangement that can be conceived 

 scarcely lessens the difficulty. Mr. Dalton endeavoured to 

 obviate this, by supposing that in the analysis of Berzelius the 

 hydrogen is underrated. But the reverse is the case. The 

 solution may now be easily given. In the composition which 

 properly constitutes oxalic acid, the proportion of hydrogen is 

 sufficiently large to present no difficulty. And in what was 

 considered as real oxalic acid existing in the dry oxalates, there 

 is no reason to suppose that hydrogen exists, ft is also obvious, 

 that the proportion of oxygen and carbon in a dry oxalate is that 

 constituting carbonic acid ; for although in the action of the 

 acid on the base a portion of its oxygen is abstracted with its 

 hydrogen, a corresponding portion of oxygen is added from the 

 base or metallic oxide, and a ternary compound is established. 



The proportion of hydrogen indicated in the composition of 

 oxalic acid is not conformable to either of the two proportions 

 of carbon and hydrogen, which constitute the two compounds 

 at present admitted as constituting the only definite compounds 

 of these elements, the carburetted and supercarburetted hydro- 

 gen. It is much less even than that in the latter, which 

 contains the lower proportion. Yet there is every reason to 

 conclude, from the law which has been illustrated in reviewing 

 . the composition of sulphuric acid, that it must exist in a definite 

 relation to the simple radical of the acid, that is, to the carbon, 

 conformable to the other relations which subsist between them. 

 It follows, therefore, either that there is an error of analysis, in 

 consequence of which the proportion of hydrogen is greatly 

 underrated, or that there are other definite proportions in which 

 carbon and hydrogen combine than those which are at present 

 admitted. The coincidence in the results of the analysis by 

 Gay-Lussac and by Berzelius, in a great measure precludes the 

 former supposition; and indeed an error so great would require 



