16 PRHESIDENT’S ADDRESS. 
ae} 
established? Is there any valid reason to conclude that at some previous 
period of its history our earth was more favourably circumstanced for 
the production of life than it is now ??1_ I have vainly souglit for such 
reason, and if none be forthcoming the conclusion forces itself upon 
us that the evolution of non-living into living substance has happened 
more than once—and we can be by no means sure that it may not be 
happening still. 
lt is true that up to the present there is no evidence of such hap- 
pening: no process of transition has hitherto been observed. But on 
the other hand, is it not equally true that the kind of evidence which 
would be of any real value in determining this question has not hitherto 
been looked for? We may be certain that if life is being produced from 
non-living substance it will be life of a far simpler character than any 
that has yet been observed—in material which we shall be uncertain 
whether to call animate or inanimate, even if we are able to detect it 
at all, and which we may not be able to visualise physically even after 
we have become convinced of its existence.?”, But we can look with the 
mind’s eye and follow in imagination the transformation which non- 
living matter may have undergone and may still be undergoing to pro- 
duce living substance. No principle of evolution is better founded than 
that insisted upon by Sir Charles Lyell, justly termed by Huxley ‘ the 
greatest geologist of his time,’ that we must interpret the past history 
of our globe by the present; that we must seek for an explanation of 
what has happened ky the study of what is happening; that, given 
similar circumstances, what has occurred at one time will probably occur 
at another. ‘The process of evolution is universal. The inorganic 
materials of the globe are continually undergoing transition. New 
chemical combinations are constantly being formed and old ones broken 
up; new elements are making their appearance and old elements dis- 
appearing.?° Well may we ask ourselves why the production of living 
matter alone should be subject to other laws than those which have 
produced, and are producing, the various forms of non-living matter; 
why what has happened may not happen? If living matter has been 
evolved from lifeless in the past, we are justified in accepting the 
*! Chalmers Mitchell (Article ‘Life,’ Encycl. Brit., eleventh edition) writes 
as follows : ‘It has been suggested from time to time that conditions very unlike 
those now existing were necessary for the first appearance of life, and must be 
repeated if living matter is to be reconstituted artificially. No support for such 
a view can be derived from observations of the existing conditions of life.’ 
‘Spontaneous generation of life could only be perceptually demonstrated 
by filling in the long terms of a series between the complex forms of inorganic 
and the simplest forms of organic substance. Were this done, it is quite possible 
that we should be unable to say (especially considering the vagueness of our 
definitions of life) where life began or ended.’—K. Pearson, Grammar of Science, 
second edition, 1900, p. 350. 
** See on the production of elements, W. Crookes, Address to Section B, Brit. 
Assoc., 1886; T. Preston, Nature, vol. Ix., p. 180; J. J. Thomson, Phil. Mag., 
1897, p. 311; Norman Lockyer, op. cit., 1900; G. Darwin, Pres. Addr; Brit. 
Assoc. 1905. 
