38 Mr. Davy's Lecture on some 
principle. It may be considered almost as a mere arrangement 
of facts ; and with some extensions it seems capable of being 
generally applied. 
Bodies possessing opposite electrical energies with regard 
to one and the same body, we might fairly conclude would 
likewise possess them with regard to each other. This I have 
found by experiment is the case with lime and oxalic acid. 
A dry piece of lime, made from a very pure compact second- 
ary limestone, and of such a form as to present a large 
smooth surface, became positively electrical by repeated con- 
tacts with crystals of oxalic acid : and these crystals placed 
upon the top of a condensing electrometer, and repeatedly 
touched by the lime, which after each contact was freed from 
its charge, rendered the gold leaves negatively electrical. 
The tendency of the mere contacts of the acid and alkali with 
the metal would be to produce opposite effects to those exhi- 
bited, so that their mutual agency must have been very 
energetic. 
It will not certainly be a remote analogy to consider the 
other acid and alkaline substances generally, and oxygene and 
hydrogene as possessing similar electrical relations ; and in 
the decompositions and changes presented by the effects of 
electricity, the different bodies naturally possessed of chemical 
affinities appear incapable of combining, or of remaining in 
combination, when placed in a state of electricity different 
from their natural order. Thus, as we have seen, the acids 
in the positive part of the circuit, separate themselves from 
alkalies, oxygene from hydrogene, and so on ; and metals on 
the negative side, do not unite to oxygene, and acids do not 
remain in union with their oxides ; and in this way the attrac- 
