204 
Analyses of Books. 
[March, 
natural. The first, with which the name of Prof. Huxley is 
especially conneaed, views life as “ a mere form of energy, 
analogous in its operation and relations to heat, light, magnetism, 
or elearicity. At the same time it is regarded as “ a property 
of the protoplasm, similarly as we ascribe ordinary physical 
properties to inorganic and inert substances.” 
On the other hand, the “ vital theory," as advocated by Dr. 
Lionel Beale, regards “life as a power, force, or property ot a 
special and peculiar kind,” temporarily influencing matter and 
its ordinary forces, but entirely different from and in no way 
correlated with any other. , t „ 
Finally, the “ natural theory,” advocated by John Brown in 
i 77 o by Fletcher in 1826, and by the author in the present work, 
views life simply as “the sum of the actions of organised beings. ? 
It is a characteristic and valuable feature of Dr. Richardson s 
work that he protests against that vagueness of language, which 
is especially dangerous in biological speculation. How often is 
the distinaion between a property, a power, and an action tor- 
gotten ! The author contends that “ a property signifies only a 
susceptibility of motion ; a power, only a means by which this 
susceptibility may be called into aaion, whilst an aaion de- 
signates the phenomena resulting from the two (power and 
susceptibility) in co-operation.” Again, in his Harveian Oration 
for 1870, Sir W. Gull remarked—" The vegetable kingdom is no 
more than an expression in a higher form of the terrestrial con- 
ditions which even common experience proves to be in a general 
way necessary to vegetable life,” and, further, the organisation 
of our bodies is “the expression of the highest correlation ot 
these external conditions.” Dr. Richardson asks for the precise 
meaning of this word “ expression,” and shows that in its ma- 
thematical sense it is quite inapplicable to individual l objects. 
He then quotes Dr. Beale’s arguments in opposition to Huxley s 
theory, none of which have been controverted. The phenomena 
of assimilation, secretion, and reproduction “ differ absolutely 
from any aftions known to occur in any kind of non-living matter 
W Nor is the vitalist theory, in turn, found more satisfactory. It 
is unsusceptible of demonstration. That life is required for the 
first formation of organised tissues cannot be denied ; but it is 
the life or living aaion of the thing organising, i.e. t of the pro- 
genitor of such organism, and not of some Vital Force, Power, 
or Influence. „ , , 
We think this work may be very profitably studied as an anti- 
dote to the modern diseases of vagueness in language, and of 
rashness and dogmatism in theory. 
