142 Pleading for a Geological Idea. [March, 
divided in a manner and order described by me in “ Ge- 
danken,” 1857, p. 113, and in “Two Planets beyond 
Neptune,” 1875 .* 
The evolution of the system progressed by atomic and 
molecular union, which consisted not only in the develop- 
ment of new combinations of single and compound atoms 
and molecules, but in the combination of simple to simple 
atoms, embracing within a smaller space the same measure 
of attractive force as in the sum of spaces of greater volume 
formerly occupied by them. 
I have shown that molecules consist of rings, of strata 
round one or more centres or nuclei. I have shown that 
the evolution of masses adting on each other in vacuum 
develops similar results. 
I have shown that the sun moves, in probably 11,500 years, 
round an immaterial centre, in an orbit whose eccentricity 
and extent is determined by itself and by planetary adtion. 
This solar year has its apsidal and latitudinal seasons, be- 
cause the orbit is eccentric and the orbits of the planets are 
inclined to the equator of the sun. 
I have pointed out, in speaking of heat and light, the 
existence of an interchange of matter between heavenly 
bodies, which is besides evident by the fall of meteors. 
Catastrophes. 
I have shown the part played by the relation of solid and 
fluid masses in the eccentricity of orbits of planets and 
molecules, and the changes that must occur in solids, liquids, 
and gases in passing from state to state. I have shown that 
such changes lead to catastrophic phenomena in and between 
molecules, and in and between stellar masses. 
Every inorganic or organic individuality or species has the 
more quick course of its development crossed by sudden 
changes. Are not begetting, birth, teething, the first word 
after the habit of hearing, manhood, death, catastrophes ? 
When the attraction of a planet or a comet, added to 
that of the sun, may alter a hyperbolic or parabolic course 
into an ellipsis or a spiral leading to sun or planet, the acce- 
lerating attraction of sun and planet may cause such an 
* To be found by those who care at the British Museum. From them it 
may be learned that Dr. G. H. Darwin’s theory that our moon is the offspring 
of the earth, admired by Professor Ball, and made the start for a too hasty 
speculation by the Rev. Prof. Fisher, is not quite new. What is true and 
what is erroneous in the application of the theory by Dr. Darwin I shall not 
here discuss. 
