er which
has steadily flowed over geological speculation within these walls, has
been of doubtful beneficence.

The sort of geological speculation to which I am now referring
(geological aetiology, in short) was created, as a science, by that
famous philosopher Immanuel Kant, when, in 1755, he wrote his "General
Natural History and Theory of the Celestial Bodies; or an Attempt to
account for the Constitution and the mechanical Origin of the Universe
upon Newtonian principles."[49]

In this very remarkable, but seemingly little-known treatise,[50] Kant
expounds a complete cosmogony, in the shape of a theory of the causes
which have led to the development of the universe from diffused atoms of
matter endowed with simple attractive and repulsive forces.

"Give me matter," says Kant, "and I will build the world;" and he
proceeds to deduce from the simple data from which he starts, a doctrine
in all essential respects similar to the well-known "Nebular Hypothesis"
of Laplace.[51] He accounts for the relation of the masses and the
densities of the planets to their distances from the sun, for the
eccentricities of their orbits, for their rotations, for their
satellites, for the general agreement in the direction of rotation among
the celestial bodies, for Saturn's ring, and for the zodiacal light. He
finds, in each system of worlds, indications that the attractive force
of the central mass will eventually destroy its organization, by
concentrating upon itself the matter of the whole system; but, as the
result of this concentration, he argues for the development of an amount
of heat which will dissipate the mass once more into a molecular chaos
such as that in which it began.

Kant pictures to himself the universe as once an infinite expansion of
formless and diffused matter. At one point of this he supposes a single
centre of attraction set up; and, by strict deductions from admitted
dynamical principles, shows how this must result in the development of a
prodigious central body, surrounded by systems of solar and planetary
worlds in all stages of development. In vivid language he depicts the
great world-maelstrom, widening the margins of its prodigious eddy in the
slow progress of millions of ages, gradually reclaiming more and more of
the molecular waste, and converting chaos into cosmos. But what is
gained at the margin is lost in the centre; the attractions of the
central systems bring their constituents together, whic