232 Notices of Books. (April, 
least alteration in themselves to make them quite like him. The 
influence fitted to produce this alteration is the presentation of 
his peculiarities before them in the example of his life or 
sufferings, in his verbal teaching or his written works. These, 
therefore, are the ‘ conditions of the environment’ which induce 
‘variation’ in a number of individuals, and convert them into 
the new species; it is not that offspring are generated in the 
parental likeness, but one species is evolved from another. 
Thus we have the wonderful fact that a new moral species can 
create the conditions which will cause others to vary into its 
likeness—the highest moral life agrees with the lowest physical 
life in possessing a protoplasmic power of multiplying itself 
indefinitely by contact. Not only has Natural Selection trans- 
ferred its action to the mind, but the environing conditions which 
occasion the mental variations before they are selected have also 
to a large extent become mental.” But this does not, as Mr. St. 
Clair remarks, explain how the variations arise which give purer 
conceptions and higher impulses to some men than to all 
the rest of mankind; neither does it explain why these danger- 
ous gifts, often bringing persecution and death to their pos- 
sessors, should have such a marvellous power of spreading, and 
prove so fascinating to many, to whom they will in all probability 
bring no better fate. He concludes that there is no other expla- 
nation but that truth and goodness have an immutable beauty 
proper to themselves, attractive to minds and consciences capable 
of perceiving the true relations of things; and that this can only 
be looked upon as due to the great Fount of all things. 
We can cordially recommend this book to all who take an 
interest in the wider bearings of the doctrine of evolution. The 
writer is thoroughly imbued with the spirit of his subject, and 
even the experienced student will find much that is suggestive in 
the way in which the facts of well-known writers are presented 
and discussed. Some of the greater philosophical difficulties 
are, it is true, avoided rather than overcome ; but we nevertheless 
feel that the book is well calculated to diminish anti-Darwinian 
prejudice, and to help forward the reconciliation of science with 
religion. 
The Conservation of Energy. Being an Elementary Treatise on 
Energy and its Laws. By Batrour Stewart, M.A., F.R.S., 
Professor of Natural Philosophy at the Owen’s College, 
Manchester. London: Henry S. King and Co. 1874. 
Crown, 8vo. 180 pp. 
Tue Doctrine of the Conservation of Energy, which was 
indicated in Mr. Justice Grove’s work on the “ Correlation of the 
Physical Forces’ some thirty years ago, has been considerably 
developed since the exact determination of the relationship which 
