by the contact of the two metals of a pair, but that it was
kept up by the mutual action of the metals on each other. He
accordingly made no attempt to discover whether any changes
took place in his circuit while the current was being
generated. The chemical action on his metals and the
dissociation in his electrolyte seem to have entirely escaped
his attention. At least, he did not attach enough importance to
them to mention them anywhere in his description of his
apparatus.

In the meantime a chemical explanation of the phenomena
observed by Galvani had been proposed in 1792 by Fabroni, a
physicist of Florence. After discussing the Sulzer phenomenon
already mentioned in this paper, Fabroni argues that the
peculiar taste caused by bringing the two metals into contact
while on the tongue is due to a chemical, rather than to an
electrical, action. He then discusses the different chemical
behavior of metals when taken singly and when placed in contact
with other metals. He says:[2]

[2] The following quotations from Fabroni have been translated
by the present writer from the German of Ostwald's
"Elektrochemie," pp. 103, ff.



I have already frequently observed that fluid mercury retains
its beautiful metallic luster for a long time when by itself;
but as soon as it is amalgamated with any other metal it
becomes rapidly dim or oxidized, and in consequence of its