INTRODUCTORY LECTURES. 
731 
“ The resisting and contracting vessels, the fluids that circu- 
late, and the force which gives motion to the whole machine — 
these are the essential, indispensable conditions of life. All at 
once the contraction ceases; the fluids cease their current; and 
the living being no longer exists. They are, nevertheless, the 
same vessels — the same fluids; the motion alone is wanting. 
All is in a state of repose ; — it is the calm of death. A little 
time after this, and many physical agents, before chained, pow- 
erless, assert their rights, and there remains nothing of the being 
that had lived and moved. 
“ What is it, then, that has taken place in these two portions 
of time, so short, at the termination of life? Sometimes nothing 
— nothing of material consequence. Life has ceased. Life is, 
then, organization in motion. This is the primitive fact ; and be- 
yond this we cannot penetrate. But to derive, as has lately been 
done, life from organization, is it not to prejudge a question that 
cannot be resolved ? We could, with more reason, perhaps, trace 
the formation of the organs under the influence of life ; for we 
have something analogous to this in the transformations of the 
seminal molecule. By what power is it enabled to represent so 
faithfully the form of the being whence it sprung? We clearly 
perceive an intimate connexion ; but it appears that, to say which 
of these phenomena gives birth to the other, is almost impossible. 
“ We have spoken of medical science as one of the most com- 
plicated and difficult subjects with which a human mind can be 
occupied in order to impress on your minds the importance of the 
veterinary art. If medical science reposes on the grand laws 
by which organized matter is governed, the veterinary art must 
rest on the same basis. 
“In the human being, diseases assume a different type ac- 
cording to the age and character and organization of the pa- 
tient. How different from each other are the diseases of the 
male, the woman, the infant, and the old man ! We may, there- 
fore, expect that they will assume a different character in the ru- 
minant and the horse, the carnivora and the feathered biped. 
“ Our principal attention has hitherto been directed to the 
horse, but the instructions of our schools are now extending to 
every animal that has been domesticated among us, and is ser- 
viceable to us. That instruction is purely our own. It is the gift, 
or the bequest, of a few individuals belonging to ourselves, and 
to whom we owe a debt of gratitude which we shall never ade- 
quately repay. The theories, and the facts with which they have 
enriched us, were their own, not borrowed from, although sup- 
ported by, the practice of human medicine. Emancipated from 
