548 THE POPULAR SCIENCE MONTHLY 
slowly (through chemical attraction), then more rapidly (through the 
so-called Newtonian attraction), and always in proportion as its mass 
increases, draws the surrounding parts more and more strongly to unite 
with itself.” This central body is not strictly to be called a sun at the 
outset, for it is not yet “in a flaming state”; this it only gradually 
becomes as, in the course of the subsequent processes of readjustment, 
“the lighter and more volatile portions of the primitive matter,” fail- 
ing to maintain a movement of periodic revolution, drop into the center 
of attraction. (2) The formation of a whirl of unaggregated particles 
moving round this central body in circular but separate and intersect- 
img orbits. 
When the mass of the central body has grown to such a point that the 
velocity with which it draws particles to itself from great distances is, by the 
weak degrees of repulsion with which the particles impede one another, deflected 
into lateral motions which, by virtue of centrifugal force, encompass the central 
body in an orbit—then there are produced great whirls of particles, each of 
which, by reason of the composition of the gravitational force and the force 
making for deflection sideways, describes a curved line. These orbits all inter- 
sect one another ... and are in conflict with one another. 
(3) The transformation of this disordered whirl of particles into a 
ring or disc of particles moving in free, parallel, circular orbits round 
the central body. The conflicting movements of the preceding stage 
come eventually to such an adjustment that they interfere with one 
another as little as possible. This happens in two ways: 
First, by the particles limiting each others’ movements till they all advance 
in one direction; second, by their limiting their vertical movements towards the 
center of attraction till, all moving horizontally in parallel circles round the 
sun as their center, they no longer intersect one another’s paths, and, by the 
equalization of the centrifugal and centripetal forces, they maintain themselves 
constantly in free circular orbits. In this state, when all the particles are 
moving in one direction and in parallel circles, the conflict and collision of the 
elementary bodies is annulled, and all things are then in the condition of least 
reciprocal interference. 
Further, “in acordance with the laws of centrifugal motion, all 
these revolutions must intersect the center of attraction with the plane 
of their orbits”; and for bodies moving in a common direction round a 
common axis, there is only one such plane. Therefore, the revolving 
particles gather about “that circle which passes through the rotation 
of the axis in the center of the common attraction,” and the system 
assumes (though there are as yet no planets) that discoid form char- 
acteristic of our present planetary system. (4) The gradual formation, 
within this ring, of planets, through the attractions subsisting between 
the separate particles composing it. Kant has hitherto treated attrac- 
tion chiefly as operative between the central mass and the particles ; 
between particle and particle the relation has been one of repulsion. 
But at this point, “the attraction of the elementary bodies for one 
another begins to produce its effect, and thereby gives the start to new 
