234 Scientific .Labors and Character of 



The controversy was conducted with such consummate skill, that 

 each I'ejoinder seemed conclusive in favor of the writer ; and die 

 reader could hardly help saying as the country justice did, to each of 

 the advocates in succession, " You've got your case." For example, 

 when Davy brings forward the fact, that charcoal ignited to white- 

 ness and presented to chlorine under the most favorable circumstan- 

 ces, abstracts no oxygen from it, we feel compelled to believe, that 

 it has none. Nor does it satisfy us to say, as his antagonist did, that 

 this fact makes equally against his own hypothesis ; since, if chlorine 

 be a supporter of combustion analogous to oxygen, as Davy supposed, 

 it ought to enter into combination with the carbon under these circum- 

 stances.* Murray here forgot, that it is not necessary for bodies to 

 agree in all respects in order to be arranged in the same class ; — that 

 if they did thus agree, they would not be analogous in their charac- 

 ters but identical. Gold undoubtedly belongs to the same class of 

 bodies with lead ; but in their affinities for oxygen, these two bodies 

 differ widely. Ammonia belongs to the same class of bodies with 

 potash ; but in their composition, they differ as much as possible. 

 But though we do not attach any weight to this reply urged by Dr. 

 Murray, and repeated by his son,f yet when he urges the argument 

 that the chlorine does not give up its oxygen to the carbon, because 

 the muriatic acid which would be left, cannot exist without water, we 

 are confounded, if not convinced ; for, to say that muriatic acid can 

 exist without water, was assuming one of the principal points at issue. 



On the other hand, when Murray converts carbonic oxide into 

 carbonic acid by mixing it with chlorine, J we feel it impossible any 

 longer to resist the evidence that chlorine contains oxygen ; but in the 

 reply of his antagonist, we are shewn that this change might take 

 place in consequence, not of the transfer of oxygen from the chlorine 

 to the carbonic oxide, but by the abstraction of carbon from the lat- 

 ter, forming with chlorine and hydrogen (for the presence of this ele- 



" This method of evading the conclusion of Davy in favor of his hypothesis, derived 

 from the want of action of v.'hite hot charcoal upon chlorine, has been often repeated, 

 and by cheinists of eminence ; but the objeclion appears to us to be unfair, because 

 a strong attraction for ignited carbon is a known property of oxygen; and if a body 

 when exposed to the action of charcoal white hot, does not exhibit this property, the 

 fact furnishes a strong presumption, that the liody contains no oxygen ; but this 

 fact does not prove that the I'ocly in question is not a supporter of combustion. It 

 may still be enlitled to that character on account of its burning sulphur, phosphorus, 

 and the metals, while its want of affinity for charcoal macks a specific difference be- 

 tween it and oxygen. 



t In the recent ediiion of Murray':- E]tment-<. + Mich. Journal, vol. 28. 



