Let us from this point of view contemplate the following series of
chemical elements, which is a representation of the so-called voltaic
series:

Graphite, Platinum, Gold, Silver, Copper, Iron, Tin, Lead, Zinc,
Aluminium, Magnesium, Sodium, Potassium.

Any two of these metals constitute a voltaic cell. Its electromotive
force is determined by the distance in the series between the metals
used. Just as in the case of frictional electricity, the kind of
electricity which is supplied by a certain metal depends on whether the
other metal with which it is coupled stands to the right or to the left
of it in the series.1

Let us now see what happens in a galvanic cell when the two different
metals are simultaneously exposed to the chemical action of the
connecting fluid. Each metal by itself would undergo oxidation with
greater or less intensity, and the calorific energy hidden in it would
become free in the form of heat. This process suffers a certain
alteration through the presence of the second metal, which sets up an
alchemic tension between the two. Instead of a proper segregation of
the primary polarity, heat-dust (in this case, heat-oxide), the heat
remains matter-bound and appears on the surface of the two metals in a
secondarily split form as positive and negative electricity.

The similarity between this process and the frictional generation of
electricity is evident.

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