~ Nov. 25, 1869] 
NATURE 
105 
period, such as this from Albano. We must probably go 
many ages back from the date of the Italians of the 
Bronze Age, who dwelt in these neat huts, to the date 
of the rude Stone Age cave-men of Central France, the 
contemporaries of the reindeer and the mammoth, which 
they delineated with such remarkable artistic vigour. One 
of these people’s interesting drawings (p. 324) is given 
STONE-AGE SCULPTURES 
here, representing a snake or eel, two horses’ heads, and 
a human figure (which Lord Monboddo would probably 
have claimed as special evidence). This may possibly be 
the earliest known portrait of man. 
The advocates of the theory that savages are degenerate 
descendants of civilised men, have still full scope in point- 
ing out the ‘imperfections of their adversaries’ evidence 
and argument. But the new facts, as they 
come in month by month, tell steadily in 
one direction. ‘The more widely and 
deeply the study of ethnography and 
prehistoric archeology is carried on, the 
stronger does the evidence become that 
the condition of mankind in the remote 
antiquity of the race is not unfairly re- 
presented by modern savage tribes. 
Ha Be davORe 
Wy 
THE ORIGIN OF SPECIES CONTROVERSY. 
Habit and Intelligence, in their Connection with the 
Laws of Matter and Force. A Series of Scientific 
Essays. By Joseph John Murphy. (Macmillan and 
Co., 1869.) 
lie 
THE flood of light that has been thrown on the obscurest 
_and most recondite of the forces and forms of Nature by 
the researches of the last few years, has led many acute 
and speculative intellects to believe that the time has 
arrived when the hitherto insoluble problems of the origin 
of life and of mind may receive a possible and intelligible, 
if not a demonstrable, solution. The grand doctrine of 
the conservation of energy, the all-embracing theory of 
evolution, a more accurate conception of the relation of 
matter to force, the vast powers of spectrum analysis on 
one side, showing us as it does the minute anatomy of the 
universe, and the increased efficiency of the modern 
microscope on the other, which enables us to determine 
with confidence the structure, or absence of structure, in 
the minutest and lowest forms of life, furnish us with a 
converging battery of scientific weapons which we may 
well think no mystery of Nature can long withstand. Our 
literature accordingly teems with essays of more or less 
pretension on the development of living forms, the nature 
and origin of life, the unity of all force, physical and 
mental, and analogous subjects. 
The work of which I now propose to give some account» 
is a favourable specimen of the class of essays alluded to, 
for although it does not seem to be in any degree founded 
on original research, its author has studied with great 
care, and has, in most cases, thoroughly understood, the 
best writers on the various subjects he treats of, and has 
brought to the task a considerable amount of original 
thought and ingenious criticism. He thus effectually 
raises the character of his book above that of a mere 
compilation, which, in less able hands, it might have 
assumed. 
The introductory chapter treats of the characteristics 
of modern scientific thought, and endeavours to show, | 
“that the chief and most distinctive intellectual charac- 
teristic of this age consists in the prominence given to 
historical and genetic methods of research, which have 
made history scientific, and science historical : whence 
has arisen the conviction that we cannot really understand 
anything unless we know its origin ; and whence also we 
have learned a more appreciative style of criticism, a 
deeper distrust, dislike, and dread, of revolutionary 
methods, and a more intelligent and profound love of 
both mental and political freedom.” The first six chap- 
ters are devoted to a careful sketch of the great motive 
powers of the universe, of the laws of motion, and of the 
conservation of energy. The author here suggests the 
introduction of a useful word, radiance, to express the 
light, radiant heat, and actinism of the sun, which are 
evidently modifications of the same form of energy,—and 
amore precise definition of the words force and strength, 
the former for forces which are capable of producing 
motion, the latter for mere resistances like cohesion. 
He enumerates the primary forces of Nature as, gravity, 
capillary attraction, and chemical affinity, and notices as 
an important generalisation “that al/ primary forces are 
attractive; there is no such thing in Nature as a primary 
repulsive force” (p. 43). Now here there seem to be two 
errors. Cohesion, which is entirely unnoticed, is surely 
as much a primary force as capillary attraction, and, 
in fact, is probably the more general force, of which the 
other is only a particular case ; and elasticity is the effect 
of a primary repulsive force. In fact, at p. 26, we find 
the author arguing that a// matter ts perfectly elastic, for, 
when two balls strike together, the lost energy due to im- 
perfect elasticity of the mass is transferred to the mole- 
cules, and becomes heat. But this surely implies re- 
pulsion of the molecules ; and Mr. Bayma has shown, in 
his “Molecular Mechanics,” that repulsion is as neces- 
sary a property of matter as attraction. 
The eighth chapter discusses the phenomena of crys- 
tallisation ; and the next two, the chemistry and dynamics 
of life. The reality of a “ vital principle” is maintained 
as “the unknown and undiscoverable something which 
the properties of mere matter will not account for, and 
which constitutes the differentia of living beings.” Besides 
the ‘formation of organic compounds, we have the 
functions of organisation, instinct, feeling, and thought, 
which could not conceivably be resultants from the or- 
dinary properties of matter. At the same time it is 
admitted that conceivableness is not a test of truth, and 
that all questions concerning the origin of life are questions 
of fact, and must be solved, not by reasoning, but by ob- 
servation and experiment; but it is maintained that the 
