the Decomposition of the Earths > &c. 217 



dification of a phlogistic chemical theory might be defended 

 on the idea that the metals and inflammable solids, usually 

 called simple, were compounds of the same matter as that 

 existing in hydrogen, with peculiar unknown bases, and that 

 the oxides, alkalis, and acids were compounds of the same 

 bases with water, and that the phcenomena presented by the 

 metals of the fixed alkalis might be explained on this hypo- 

 thesis. 



The same mode of reasoning may be applied to the facts 

 of the metallization of the earths and ammonia, and perhaps 

 with rather stronger evidences in its favour, but still it will 

 be less distinct and simple, than the usually received theory 

 of oxygenation, which I have applied to them. 



The general facts of the combustion, and of the action of 

 these new combustible substances upon water, are certainly 

 most easily explained on the hypothesis of Lavoisier ; and the 

 only good arguments in favour of a common principle of in- 

 flammability, flow from some of the novel analogies in elec- 

 trochemical science. 



Assuming the existence of hydrogen in the amalgam of 

 ammonium, its presence in one metallic compound evidently 

 leads to the suspicion of its combination in others. And in 

 the electrical powers of the different species of matter, there 

 are circumstances which extend the idea to combustible sub- 

 stances in general. Oxygen is the only body which can be 

 supposed to be elementary, attracted by the positive surface 

 in the electrical circuit; and all compound bodies, the nature 

 of which is known, that are attracted by this surface, contain 

 a considerable proportion of oxygen. Hydrogen is the only 

 matter attracted by the negative surface, which can be con- 

 sidered as acting the opposite part to oxygen : May not then 

 the different inflammable bodies, supposed to be simple, con- 

 tain this as a common element ? 



Should future experiments prove the truth of this hypo- 

 thesis, still the alkalis, the earths, and the metallic oxides 

 will belong to the same class of bodies. From pkifcina 

 potassium there is a regular order of gradation as to CI 

 physical and cnemical properties, and this would prob. 

 extend to ammonium,couid it be obtained in the fixed I : 



