INTRODUCTORY ADDRESS. 
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cess ; and in the thirteenth century the idea prevailed that 
the vital processes might be analogous to the chemical. 
Hence arose the absurdity of the philosopher’s stone ; for 
it was considered that if metals could be transmuted by it, 
and all their impurities removed, and as the chemical ancl 
vital proceses were one and the same, then might diseases 
be cured by it. 
Others think the nerves generate it; but this too, has 
been by no means proved. Indeed, Professor Huxley has 
lately shown, in a lecture delivered by him at the Royal 
Institution, that nerve force is not electricity ; but two im- 
portant facts were cited by him to prove that the nerve force 
is a correlate of electricity, in the same sense as heat and 
magnetism are said to be correlates of that force. These 
facts were, first, the “ negative deflection ” of Du Bois 
Raymond, which demonstrates that the activity of nerve 
affects the electrical relations of its particles ; and, secondly, 
the remarkable experiments of Eckhard, which prove that 
the transmission of a constant current along a portion of a 
motor nerve so alters the molecular state of that nerve as to 
render it incapable of exciting contraction when irritated. 
These facts, he says, even without those equally important, 
though less thoroughly understood experiments of Ludwig 
and Bernard, which appear to indicate a direct relation 
between nerve force and chemical change, seem sufficient 
to prove that nerve force must henceforward take its place 
among the other physical forces. 
Again, had the expansive power of steam not been known, 
where would have been our present modes of transit, our 
machinery, and our printing press? Where our liberty and 
our commerce? I am sure I need not say any more on this 
subject, for you are all familiar with the many ways in which 
this mighty agent is employed now-a-days. It seems to 
have become almost necessary to our very existence : as a 
community it certainly is so. 
Some of you will remember that last year I directed your 
attention to Mr. Bessemer’s invention for converting cast- 
iron into wrought or malleable iron ; by which, so it was 
stated, four times the quantity of that metal could be obtained 
in one fourth of the time, as compared with the old method 
resorted to, while it required only one hundredth part of the 
labour, through the life-destroying process of puddling being 
done away with. The plan, too, was as simple as scientific, 
or it merely consisted in forcing atmospheric air through 
he melted cast-iron ; when the oxygen of the atmosphere com- 
bined with the carbon, existing in the cast iron, and generated 
