Dr. Bostock on Gulvanism. 141 
stances, which all coincide with the chemical hypothesis, but which 
seem to have no relation to any electrical action: 1. That the 
fluid acts only upon one of the metals : 2. That the surface of one 
of the metals is oxidated with acertain degree of rapidity: 3. That 
the oxide is removed so as to present a fresh surface to the fluid. 
If acids be employed, those are the best that dissolve the oxide; 
or if neutral salts, those which form triple compounds with the 
oxide which is produced. The chemical hypothesis affords a plau- 
sible method of accounting for the different effects of the appa- 
ratus, whether we use large or small plates: for it is not unrea- 
sonable to suppose that the electricity will become more intense 
or concentrated at every successive transmission through a new 
oxidating surface, while its absolute quantity will depend upon the 
amount of oxide that is formed. 
“* It will be perceived, that much discordance of opinion still 
exists upon the subject, and that some strong objections attach 
to every hypothesis which has yet been proposed. The most im- 
portant points to ascertain are, the difference between electri- 
city, as excited by the friction of the common machine, and that 
modification of it which is strictly called galvanism. For this pur- 
pose, the nature of electric intensity should be further investi- 
gated ; for it would appear that, if we were able to attach a more 
precise idea to this term, a considerable insight would be gained 
into the cause of this difference. Experiments somewhat similar 
to those of De Luc should be prosecuted, in which the electrical 
and chemical effects of the pile are separated from each other ; 
anda moreaccurate measure of the proper galvanic power should, 
if possible, be obtained, than any of which we are now possessed. 
The conducting power of the fluids concerned in the galvanic ap- 
paratus should be carefully examined, and-the relation of their 
chemical action to their conducting power should be ascer- 
tained.” 
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