fire-mist and nuclei are assumptions only, and the way by which he tries
to account for rotatory motion is clearly erroneous. The aggregation of
matter round the nuclei by gravitation would have no such tendency; no
more than a perfect balance would of itself have a tendency to move
about its fulcrum, or a falling stone to deviate from its vertical
course. Gravitation would indeed compress the particles of matter, but
its tendency and entire action is towards the nucleus; it compresses
them no more on one side of the line of their direction to the centre of
force than on any other side; and hence no _lateral_ or _rotatory
motion_ would ensue. Rotation, therefore, is yet unaccounted for; though
the author says _it is a well-known law in physics_ that when fluid
matter collects towards, or meets in a centre, it establishes a rotatory
motion; and then for illustration refers to a whirlwind or whirlpool. No
such effect would follow the conditions stated, and an entire ignorance
is betrayed of the laws of mechanical philosophy. In the whirlpool and
the whirlwind the gyration is caused by the fluid passing, not _to_ the
centre, but _through_ it and away from it; in the whirlpool downwards
through the place of exit, in the whirlwind upwards to where the vacuum
has caused the rapid aggregation.

LAPLACE was too able a mathematician to commit these elementary
blunders; he did not assume to account for rotation by inapplicable
laws, but took for granted that the sun revolved upon its axis, and
thence communicated a corresponding motion to the bodies thrown from its
surface. But our author has sought to advance beyond his teacher, and in
this way has shown his ignorance of physics by an egregious mistake. At
this point we might stop, without following the ulterior steps by which
the solar system is made to evolve out of heated vapour. Having got
rotation, though by an impossible process, the author falls into the
illustration already given of the theory of LAPLACE. The rotation of