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“ property” of protoplasm is at present wholly unproved, and, 
upon the face of it, very unlikely. 
We may fairly assert, on the other hand, that the phenomena of 
vitality are due to the fact that living protoplasm is temporarily 
the seat of forces which do not reside in dead protoplasm; and 
the onus of proving the contrary rests clearly with those who 
assert that all protoplasm is, ex hypothesi , in a state of active 
or potential vitality. Upon quite as good grounds might it be 
said that man is composed of some forty chemical elements, 
combined with water in various proportions, and that the 
properties of the resulting compound are not only that of 
digesting, respiring, moving, &c., but also of thinking, speak -- 
ing, writing books, building ships, and the like. These, 
however, are the properties — -in a loose sense of this word — of 
the living man, in spite of the fact that the dead body cannot 
be shown to differ in chemical composition from the living 
one, until a certain period after death has elapsed. All such 
arguments ignore the effects of form and collocation as vehicles 
for transmitted forces. 
Again, assuming with modern physiologists and naturalists 
that the protoplasm of all living beings is essentially identical, 
it is clear that only such vital phenomena can be said to be 
“ properties ” of protoplasm — in any sense, or upon any theory 
— as are manifested by protoplasm in all organisms and under 
all conditions. Even then, if we were to admit the propriety 
of considering living protoplasm at all in connection with such 
an argument, we should still have to face the difficulty that 
the vital phenomena of different organisms differ, as one may 
say, immeasurably, while the protoplasm remains the same. 
This is an insuperable obstacle to our accepting the theory 
that life is a “ property ” of protoplasm ; for though a sponge 
and a man both “live,” in the strict sense of the term, 
there is fixed between the vital phenomena of the two (in- 
cluding their mental processes under this head) an absolutely 
impassable gulf. 
It should not be overlooked, however, that there is a theory 
first propounded by Dr. Fletcher,* and subsequently deve- 
loped by Dr. Drysdale,f which would escape the difficulty 
above pointed out by the assumption that protoplasm really 
has no existence except in the living body. Upon this theory, 
the living matter of the organism (protoplasm) is not only “ in 
a somewhat different chemical state from that in which it 
* Rudiments of Physiology. 1835. 
t The Protoplasm''. c Theory of Life. 1874. 
