RESEARCHES, &c.
PART I.
ARTICLE I.
GENERAL DIVISION OF LIFE.
The definition of life is to be sought for in abstract considerations; it will be found, I believe, in this general perception: life is the totality of those functions which resist death.
Such is in fact the mode of existence of living bodies, that every thing which surrounds them tends to their destruction. Inorganic bodies act upon them incessantly; they themselves exercise a continual action, the one upon the other; and would necessarily soon be destroyed, did they not possess a permanent principle of reaction. This principle is life; not understood in its nature, it can be known only by its phenomena: the most general of which is that constant alternation of action on the part of external bodies, and of reaction on the part of the living body, the proportions of which alternation vary according to age.
There is a superabundance of life in the infant, because the reaction is greater than the action. In the adult, an
