*94 
Analyses of Books, [May, 
and difficult of all questions. The author belongs to a class of 
thinkers, unhappily, far from common ; men who do not profess 
to be wise beyond what is demonstrated, and who will frankly 
confess ignorance rather than indulge in vague assumptions. He 
opens his ledture with a provisional definition of life. “ Life is 
the capability of undergoing that series of adtions by which an 
individual is not only maintained but determinately changed or 
developed by the attraction and disposal of particles drawn in from 
without and the extrusion of others.” Whether any definition of 
such a primary fact as life will ever be fully satisfadtory, we can 
scarcely venture to say ; but Dr. Cleland’s attempt is perhaps 
open to fewer objections than any which has been put before the 
world, especially if construed, as it may, to include reproduction. 
Whilst speaking of albumenoid matter, without which no vital 
function is ever performed, the author makes some exceedingly 
happy remarks on the question of spontaneous generation, or as 
it is now more learnedly termed, “ abiogenesis.” “ It is worth 
while to pause for a moment to note that whilet, here are enor- 
mous numbers of organic substances filling up the gradations of 
complexity between protoplasm and the simpler compounds of 
the organic world, not one of them occurs native save as a pro- 
duct of pre-existent protoplasm.” This is an important and 
undeniable truth : between the produces of the mineral kingdom 
-—save where these have been derived from the decomposition of 
matters once living — we find no transition steps leading to, or 
even pointing in the direction of, the albumenoids. It may not 
be irrelevant to point out that the organic syntheses, of which 
modern chemistry is so proud, start not from bona fide dead 
matter but from the remains of what was once living. Dr. Cle- 
land proceeds :• — “ Hence it follows that the numerous believers 
at the present day in the antiquated notion of the evolution of 
life from dead matter are placed in this dilemma — either they 
must admit that protoplasm, in the first instance, had its origin 
in other than the ordinary operations of inorganic nature, by a 
sudden spring from inorganic compounds totally at variance 
with the whole notion of an evolution, or they must be content 
to imagine an immense series of operations in days gone by 
altogether different from anything that takes place now, whereby 
simpler organic substances were formed first and protoplasm was 
formed out of them.” An eminent man of science, whilst fully 
admitting the failure of all attempts made at obtaining life with- 
out antecedent life, still thinks that if it were given us to look 
back to the earlier ages of the world, we should see what now 
appears impossible actually coming to pass. We wonder which 
horn of the dilemma he would have elected ? 
Of the two great vital fundlions — nutrition and irritability— 
our author gives his attention to the latter. He fully accepts the 
“ conclusion that with every mental acftion, whether intellectual, 
emotional, or volitional, a corresponding amount of oxidation 
