of the surface it covers. The heat given out melts the
subjacent tallow, and expands whatever it warms. The light, falling on
various substances, calls forth from them reactions by which it is
modified; and so divers colours are produced. Similarly even with these
secondary actions, which may be traced out into ever-multiplying
ramifications, until they become too minute to be appreciated. And thus
it is with all changes whatever. No case can be named in which an active
force does not evolve forces of several kinds, and each of these, other
groups of forces. Universally the effect is more complex than the cause.

Doubtless the reader already foresees the course of our argument. This
multiplication of results, which is displayed in every event of to-day,
has been going on from the beginning; and is true of the grandest
phenomena of the universe as of the most insignificant. From the law
that every active force produces more than one change, it is an
inevitable corollary that through all time there has been an
ever-growing complication of things. Starting with the ultimate fact
that every cause produces more than one effect, we may readily see that
throughout creation there must have gone on, and must still go on, a
never-ceasing transformation of the homogeneous into the heterogeneous.
But let us trace out this truth in detail.

Without committing ourselves to it as more than a speculation, though a
highly probable one, let us again commence with the evolution of the
solar system out of a nebulous medium.[3] From the mutual attraction of
the atoms of a diffused mass whose form is unsymmetrical, there results
not only condensation but rotation: gravitation simultaneously generates
both the centripetal and the centrifugal forces. While the condensation
and the rate of rotation are progressively increasing, the approach of
the atoms necessarily generates a progressively increasing temperature.
As this temperature rises, light begins to be evolved; and ultimately
there results a revolving sphere of fluid matter radiating intense heat
and light--a sun.

There are good reasons for believing that, in consequence of the high
tangential velocity, and consequent centrifugal force, acquired by the
outer parts of the condensing nebulous mass, there must be a periodical
detachment of rotating rings; and that, from the breaking up of these
nebulous rings, there must arise masses which in the course of their
condensation repeat the a