200 THE FOREST LANDS OF NORTHERN RUSSIA. 
of the statements which follow, I may be allowed to intro- 
duce the following statements. According to what was 
advanced by Laplace as a hypothesis, but which has come 
to be extensively accepted as a theory, the material of 
which the earth consists was once floating in space in 
widely separated masses, amongst which was in operation 
what is known as the force of gravitation, under the influ- 
ence of which, once and again and a thousand times told, 
two or more of these separate masses, reciprocally attracted, 
would coalesce, and if they happened to approximate, each 
other in a line diverging in the slightest degree from that 
of a straight line between their centres of gravity, which 
would occur in the vast—inexpressibly vast—majority of 
cases, they would begin to rotate around each other in a 
curve which would most likely lead to their conjunction, 
when the movement would issue in a rotary motion of 
the composite mass. This composite mass would in like 
manner come under the reciprocal attraction of other 
masses, single or composite, until the whole, or the greater 
part of the whole, mass of matter within the sphere of 
attraction would be condensed into a large rotating mass ; 
from this as the floating mass became further condensed, 
portions on the outer circumference would be thrown off 
by circumfugal force, as is a stone from a sling, or drops of 
water from a mop which is made to rotate rapidly; but 
these again would be gathered into smaller rotating 
masses, which would revolve around the central mass, 
which would finally be condensed as is the sun, while 
these smaller bodies would be cendensed as are the planets, 
each rotating at the distance from the sun at which it was 
thrown off; and they, in the course of their condensation, 
would throw off lesser masses, condensing into satellites or 
moons, or into elongated masses, like the rings of Mercury, 
Again, not to do more than merely mention the pheno- 
mena of volcanos, there are in many rocks appearances 
which have led careful observers of them to conclude that 
what is solid of the earth is a mere crust around a mass 
of molten matter; and modern science tends to show that 
