1882.] Analyses of Books . 295 
of material takes place in the brain.” This correspondence, he 
holds, is of the strictest character. But he does not agree with 
the assertion that the thought and the accompanying coincident 
cerebral change are one and the same thing. Such view he finds 
unthinkable, because “ any physical change, whatever its cha- 
racter in detail, is mere movement in space, and that is an idea 
utterly incomparable with the idea of thought.” He mentions 
another difficulty in the way of identifying thought with its phy- 
sical conditions : — “ Each thought, each memory, has a distinct- 
ness from all others, at the same time that it exists for the 
thinker alone ; while not only is physical change an objective 
antecedent of the subjective changes by which it is appreciated, 
but the particular physical change which takes place in any nerve- 
cell or living corpuscle of the brain when in action is always of 
one and the selfsame desciption, to wit, a combustion or oxida- 
tion and a corresponding eleCtric disturbance.” 
Concerning these electric changes he adds : — “ Living muscle 
and nerve separated in blocks from the body, so long as they are 
at rest, are in a state of remarkable eleCtric tension of a descrip- 
tion different from anything found in dead matter ; but as soon 
as they are irritated this tension is diminished or ceases.” This 
phenomenon is not understood, and calls for prolonged study, — 
study which, by the way, will scarcely be possible in England 
under its present hysterical regime. 
We come to another problem : it is admitted that though the 
sensation bears a proportion to the stimulus, yet “the amount of 
subsequent mental action set up by a sensation has no quantita- 
tive relation to the sensation, and consequently none to the 
amount of energy liberated by the stimulus. 
The author, accepting — as will be remembered — the mind as 
an immaterial entity, finds it insufficient to say that the mental 
and physical aCtions are simultaneous. The relation seems 
closer. “ In the case of sensation you come to a stage — a 
transition-point — at which the purely physical changes are fol- 
lowed by changes both physical and mental, whilst in the origin 
of voluntary and emotional aCtions of the body there is a point 
of converse transition at which mental plus physical change is 
followed by purely physical change.” The question naturally 
arises, How are these transitions to be harmonised with the prin- 
ciple of the conservation of energy ? Dr. Cleland asks “ if energy 
has here a wider range than the material universe ? ” Two 
answers only seem to him conceivable. Either the physical re- 
sults of the action in the nerve-cells amount to the same sum as 
they would in case of the same adtion in cells unconnected with 
the mind, or to a smaller sum. The former alternative involves 
a breach of the principle of the conservation of energy, because, 
though brought about by physical energy, it is something over 
and above the normal results. If the physical results amount to 
a less sum, the difference is transformed from physical to psy* 
