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no difference to be discerned by any means of examination yet adopted 
between the two forms. The living matter, which, at the very earliest 
period of his development, represents man, is, as far as I know, not dis- 
tinguishable from the forms of living matter of which the simple bodies 
Dr. Wallich has so lucidly described to us are made up. And therefore 
the difference cannot be chemical. Neither can it be called physical, nor 
mechanical, nor can it be due to difference in machinery or mechanism, for 
none is to be discovered. The difference is enormous, and it is of a most 
remarkable kind, but it is not to be explained by any facts in physical science 
with which we are acquainted. All we know is, that under certain conditions 
one form of living matter grows and produces a certain kind of structure, 
and that under different conditions certain other forms of living matter grow 
and produce a structure that is totally different. The difference between the 
two is not in molecular or chemical constitution. They do not remarkably 
differ in chemical composition, and we may safely say it is impossible thus 
to explain the difference. That is the whole of the matter ; the difference in 
the results cannot be explained by physics or chemistry, and I do not think 
it ever will be so explained. The difference is one which can only be spoken 
of under another term altogether, and this is a word to which many object 
very strongly. I allude to the word “ vital.” The difference in question is a 
vital difference, dependent not on a property which belongs to matter itself 
as matter, or derived from any properties in connexion with the elements 
which enter into the composition of the living matter. Whether the genera- 
tion of living matter was spontaneous or not cannot be proved, but much 
scientific speculation is built upon the theory of spontaneous generation. 
However necessary such a theory may be to the doctrine of evolution, there 
are no scientific facts which can at all warrant the conclusion that non-living 
matter only, under any conceivable circumstances, can be converted into 
living matter, or at any previous time has, by any combination, or under any 
conditions that may have existed, given rise to the formation of anything 
which possesses, or has possessed, life. (Applause.) 
