different liquid; in each solution also it differed with every
different metal. The most chemically positive metals were usually the
most quickly corroded, and the corrosion of each metal was usually the
fastest with the most acid solutions. The rate of corrosion at any
given temperature was dependent both upon the nature of the metal and
upon that of the liquid, and was limited by the most feebly active of
the two, usually the electrolyte. The order of rate of corrosion of
metals also differed in every different liquid. The more dissimilar
the chemical characters of two liquids, the more diverse usually was
the order of rapidity of corrosion of a series of metals in them. The
order of rate of simple corrosion in any of the liquids examined
differed from that of chemico-electric and still more from that of
thermo-electric tension. Corrosion is not the cause of thermo-electric
action of metals in liquids.

Out of fifty-eight cases of rise of temperature the rate of ordinary
corrosion was increased in every instance except one, and that was
only a feeble exception--the increase of corrosion from 60° to 160° F.
with different metals was extremely variable, and was from 1.5 to 321.6
times. Whether a metal increased or decreased in thermo-electromotive
force by being heated, it increased in rapidity of corrosion. The
proportions in which the most corroded metal was also the most
thermo-electro-positive one was 65.57 per cent. in liquids at 60° F.,
and 69.12 in the same liquids at 160° F.; and the proportion in which
it was the most chemico-electro-positive at 60 F. was 84.44 per cent,
and at 160° F. 80.77 per cent. The proportion of cases therefore in
which the most chemico-electro-negative metal was the most corroded
one increased from 15.56 to 19.23 per cent, by a rise of temperature
of 100° F. Comparison of these proportions shows that corrosion
usually influenced in a greater degree chemico-electric rather than