Reviews—Ridsdale’s Cosmic Evolution. 573 
IIJ.—Cosmic Evo.xurtion, BEING SPECULATIONS ON THE ORIGIN OF 
oun Environment. By H. A. Ripspaue, A.R.S.M. 12mo. pp. 
130. (London, H. K. Lewis, 1889.) 
OWADAYS we are considerably ahead of the Hebrew cosmo- 
gonist in the means for speculating on the origin of our 
environment; but still there is a large margin of the apparently 
“unknowable” left for future philosophers to minimize if they can. 
The recently established doctrine of Evolution favours speculations 
in this quarter, especially in the minds of those who have received 
their scientific training since this doctrine has become a faith. 
The Geological Evolutionist is fortunate in being confined within 
certain limits both as regards time and space. But it is far 
otherwise with the Cosmic Evolutionist, who finds his conceptions 
rendered hazy by an Eternity which had no beginning and can have 
no end, and by a Space which is equally without limits. No wonder 
that in such speculations “the imagination” at times “is forced to 
overstep the safe boundary of reason” (p. 103). This is candid on 
the part of our author, whose object evidently is to arrive at the 
truth, so far as that is attainable by the finite mind of man. 
It is not for us to review the “General Aspect” of Cosmic 
Evolution any further than by confessing our faith in the grand and 
philosophic conception of La Place as to the physical history of the 
Solar system. The author’s inference also seems a fair one, “ that 
the evolution of present matter from the fire-vapours of the Solar 
system was analogous to the evolution of the fire-vapours from the 
universal primordial vapour of all Space.” 
But we must now leave off playing at “high jinks” in the starry 
firmament, and stick, as far as we can, to our own planet. The 
evolution of the primordial forms of matter was doubtless attended 
with a gradual loss of heat (changed perhaps into planetary motion, 
since Energy cannot be lost), increase of density and diminution of 
chemical activity. If this principle is true, there will seem to be 
an almost unbroken connection between Inorganic and Organic 
Evolution. Indeed, it might almost be said that “the chemical 
evolution proceeded till it finally induced an environment wherein 
favourable forms were matured into Life.” 
What this chemical evolution is supposed to have been we are 
told in the first chapter, which may be regarded as a sermon preached 
upon the text of increase of chemical stability, or, as he puts it, the 
“survival of the most inert.” ‘This process has been going on from 
the earliest geological ages, so that “things must have been more 
lively, chemically speaking, in the Archean period than now!” 
Moreover, it is probable, he says, that the bodies we call elements 
are merely arrangements of matter to suit the present environment, 
and that under different conditions they might be broken up. 
Change, then, ceaseless change, was the order of things. But the 
rate was much more rapid in the early stages, whilst, through the 
gradual survival of the more inert forms, it became slower. It was 
when this state of physical calm was fairly matured that the forces 
