272 _ On definite Proportions. 
believed, that ammonia is an oxide, without admitting that 
hydrogen is the same base in a lower degree of oxidation. 
Now hydrogen, which in this view of the subject we con- 
sider as an oxidated substance, has all the properties of a 
simple one; it has the same comparative capacity for satu- 
ration with oxygen and sulphur as the metals have, and in 
all triple combinations of carbon, oxygen, and hydrogen, 
we have reason to consider the hydrogen as a simple sub- 
stance. Notwithstanding these difficulties, the whole may 
be pretty easily explained. 
In describing the combustion of copper in the vapour of 
sulphur, I have expressed an opinion, that the appearance 
of fire in combustion, and the evolution of heat in chemical 
combinations in general, must be owing to precisely the 
same internal cause as the appearance of fire and the ex- 
trication of heat between the conductors of a powerful 
electrical column. The knowledge that we already possess 
of electricity, as a chemical agent, allows us no longer to 
think of any process as chemical, without being at the same 
time electrical; and we are indebted to Davy’s important 
investigations for the discovery, that two bodies, which 
exhibit an affinity for each other, appear to possess, whenever 
they come into contact, that is, whenever they are about to 
unite, electricities of an opposite nature, and this the more 
distinctly, as their mutual affinity is greater. If we com- 
pare this with our experience relating to electrochemical 
decompositions in the column, we find the most conyin- 
cing proofs, that every phenomenon of combination or se- 
paration must be electrochemical. What electricity itself 
1s, how it is attached to different substances, and deter- 
mines their chemical properties, we are wholly ignorant; 
and we are more likely to be misled than enlightened by 
speculations on this subject, advanced by persons who 
pronounce their opinions with great confidence, yet with- 
out possessing sufficient experience to enable them to judge 
on rational grounds. 
Experience has informed us, that a variety of substances 
are collected in the electrical circuit at the same pole with 
oxygen, and other substances at the same pole with hy- 
drogen. The latter we name [positively] electrical, the 
former [negatively.] We have seen that most of the me- 
tals belong to the first of these classes, but sulphur, phos 
phorus, and some other substances, to the Jast. If now 
we apply this remark to ammonia, we find that it affords, 
by the operation of the electrical discharge, nitrogen on the 
positive and hydrogen on the negative side. Nitrogen 
therefore 
