the mathematical deductions from them. We are not yet in a
position to say positively that the atoms are composed of
electrons, but it is clear that the experts are properly modest
in claiming only that this is highly probable. The atom seems to
be a little universe in which, in combination with positive
electricity (the nature of which is still extremely obscure),
from 1700 to 300,000 electrons revolve at a speed that reaches as
high as 100,000 miles a second. Instead of being crowded
together, however, in their minute system, each of them has, in
proportion to its size, as ample a space to move in as a single
speck of dust would have in a moderate-sized room (Thomson). This
theory not only meets all the facts that have been discovered in
an industrious decade of research, not only offers a splendid
prospect of introducing unity into the eighty-one different
elements of the chemist, but it opens out a still larger prospect
of bringing a common measure into the diverse forces of the
universe.

Light is already generally recognised as a rapid series of
electro-magnetic waves or pulses in ether. Magnetism becomes
intelligible as a condition of a body in which the electrons
revolve round the atom in nearly the same plane. The difference
between positive and negative electricity is at least partly
illuminated. An atom will repel an atom when its equilibrium is
disturbed by the approach of an additional electron; the
physicist even follows the movement of the added electron, and
describes it revolving 2200 billion times a second round the
atom, to escape being absorbed in it. The difference between good
and bad conductors of electricity becomes intelligible. The atoms
of metals are so close together that the roaming electrons pass