There are cases which seem to elude this law, and investigation has
shown that other characteristics of the rubbed bodies, such as surface
quality, can have a modifying influence. For lack of a guiding idea
they are treated in the textbooks as 'irregularities'. Observation led
by a true polarity concept shows that in these cases also the rule is
not violated. In this respect, interesting information can be gained
from the observations of J. W. Ritter (1776-1810), an ingenious
Naturphilosoph from the circle round Goethe, but to whom, also,
physical science is indebted for his discovery of the ultra-violet part
of the spectrum and of galvanic polarization. Among his writings there
is a treatise on electricity, giving many generally unknown instances
of frictional electricity which are in good accord with our picture and
well worth investigating. According to Ritter, even two crystalline
substances of different hardness, such as Calcite and quartz, become
electric when rubbed together, the softer playing the part of 'resin'
and the harder that of 'glass'.

These few facts connected with the generation of frictional electricity
are enough to allow us to form a picture of the nature of the polarity
represented by the two kinds of electricity.

We remember that in the case of the generation of heat through
friction, as a result of an encroachment upon the cohesion of the
material body involved, the relationship between levity and gravity in
it changes from 'moist' to 'dry' and that the effect of this is the
appearance of 'fire' and 'dust' as poles of a primary polarity. This
process, however, is altered when the bodies subjected to friction are
opposed to each other in the sense of a salt-sulphur polarity. The
effect then is that the liberated levity, under the influence of the
peculiar tension between the two bodies, remains bound in the realm of