temperature, or about 100 times that of a bismuth and antimony couple.

Heating one of the metals, either the positive or negative, of a
voltaic couple, usually increased their electric difference, making
most metals more positive, and some more negative; while heating the
second one also usually neutralized to a large extent the effect of
heating the first one. The electrical effect of heating a voltaic
couple is nearly wholly composed of the united effects of heating each
of the two metals separately, but is not however exactly the same,
because while in the former case the metals are dissimilar, and are
heated to the same temperature, in the latter they are similar, but
heated to different temperatures. Also, when heating a voltaic pair,
the heat is applied to two metals, both of which are previously
electro-polar by contact with each other as well as by contact with
the liquid; but when heating one junction of a metal and liquid
couple, the metal has not been previously rendered electro-polar by
contact with a different one, and is therefore in a somewhat different
state. When a voltaic combination, in which the positive metal is
thermo-negative, and the negative one is thermo-positive, is heated,
the electric potential of the couple diminishes, notwithstanding that
the internal resistance is decreased.

Magnesium in particular, also zinc and cadmium, were greatly depressed
in electromotive force in electrolytes by elevation of temperature.
Reversals of position of two metals of a voltaic couple in the tension
series by rise of temperature were chiefly due to one of the two
metals increasing in electromotive force faster than the other, and in
many cases to one metal increasing and the other decreasing in
electromotive force, but only in a few cases was it a result of
simultaneous but unequal diminution of potential of the two metals.