the chemical Production and Agency of Electricity. 433 
By Mr. Volta’s apparatus, the same effects are produced in 
much less time. 
Beside the similarity which has thus been traced between the 
effects of electricity excited by the common machine and those 
observed from the electric pile, I think it appears also probable, 
that they originate from the same source. 
With regard to the latter, its power is now known to depend 
on oxidation ; so also does the excitement in the former appear 
very much to depend on the same process ; for, 
Exper. 9. I have found, that by using an amalgam of silver or 
of platina, which are not liable to be oxidated, I could obtain no 
electricity. An amalgam of tin, on the contrary, affords a good 
degree of excitement. Zinc acts still better; but the best amal- 
gam is made with both tin and zinc, a mixture which is more 
easily oxidated than either metal separately. 
Exper. 10. But, as a farther trial whether oxidation assists 
in the production of electricity, I mounted a small cylinder, with 
its cushion and conductor, in a vessel so contrived that I could 
at pleasure change the contained air. 
After trying the degree of excitement in common air, I sub- 
stituted carbonic gas, and found that the excitement was im- 
mediately destroyed, but that it returned upon re-admission of 
atmospheric air. 
In conformity to this hypothesis, we find that the metal oxi- 
dated is, in each case, in a similar state of electricity; for the 
cushion of the machine, by oxidation of the amalgam adhering 
to it, becomes negative ; and, in the same manner, zinc oxidated 
by the accumulated power of an electric pile, or simply by action 
of an acid, is also negative. 
3 K 
MDCCCI. 
