In nearly every case the ring of vapor was broken into
several masses, each moving at similar velocities, and
continuing to rotate at the same distance around the
sun. These masses would take a spheroid form with a
rotatory movement in the direction of the revolution,
because their inner molecules had less velocity than
the outer. Thus were formed so many planets in a
condition of vapor. But if one of them were powerful
enough to reunite successively by its attraction all the
others around its centre of gravity, the ring of vapor
would be thus transformed into a single spheroidical
mass of vapor revolving around the sun with a rotation
in the direction of its revolution. The latter case
has been that which is the most common, but nevertheless
the solar system affords us an instance of the
first case in the four small planets which move between
Jupiter and Mars; at least, if we do not suppose,
as does M. Olbers, that they originally formed
a single planet which a mighty explosion broke up
into several portions each moving at different velocities.

"According to our hypothesis, the comets are strangers
to our planetary system. In considering them,
as we have done, as minute nebulosities, wandering
from solar system to solar system, and formed by
the condensation of the nebulous matter everywhere
existent in profusion in the universe, we see that when
they come into that part of the heavens where the sun
is all-powerful, he forces them to describe orbits either
elliptical or hyperbolic, their paths being equally possible