to account for the constitution and the mechanical origin of the uni- verse upon Newtonian principles'*.
In this very remarkable, but seemingly little-known treatise †, 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 ‡. 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, which then by the heat evolved are converted once more into molecular chaos. Thus the worlds that are, lie between the ruins of the worlds that have been and the chaotic materials of the worlds that shall be ; and in spite of all waste and destruction Cosmos is extending his borders at the expense of Chaos.
Kant's further application of his views to the earth itself is to be found in his ' Treatise on Physical Geography '§ (a term under which the then unknown science of geology was included), a subject which he had studied with very great care and on which he lectured for many years. The fourth section of the first part of this Treatise is called " History of the great changes which the earth has formerly
- Grant (' History of Physical Astronomy,' p. 574) makes but the briefest
reference to Kant.
†" Allgemeine Naturgeschichte und Theorie des Himmels ; oder Versuch von der Verfassung und dem mechanischen Ursprunge des ganzen Weltgebaudes nach Newton'schen Grundsatzen abgehandelt." — Kant's ' Sammtliche Werke,' Bd. i. p. 207.
‡ Systeme du Monde, tom. ii. chap. 6.
§ Kant's ' Sammtliche Werke,' Bd. viii. p. 145.
