DEFINITIONS OF LIFE. 23 



of the mystery of Life, as a Mollusca might give, can this 

 definition afford. But this is not the only objection. 

 For, first, it is not pretended that we begin with seeking 

 for an organ evidently appropriated to nutrition, and then 

 infer that the substance in which such an organ is found 

 lives. On the contrary, in a number of cases among the 

 obscurer animals and vegetables we infer the organ from 

 the pre-established fact of its life. Secondly, it identifies 

 the process itself with a certain range of its forms, those, 

 namely, by which it is manifested in animals and vege- 

 tables. For this, too, no less than the former, presupposes 

 the arbitrary division of all things into not living and 

 lifeless, on which, as I before observed, all these defi- 

 nitions are grounded. But it is sorry logic to take the 

 proof of an affirmative in one thing as the proof of the 

 negative in another. All animals that have lungs breathe, 

 but it would be a childish oversight to deduce the con- 

 verse, viz. all animals that breathe have lungs. The 

 theory in which the French chemists organized the dis- 

 coveries of Black, Cavendish, Priestly, Scheele, and other 

 English and German philosophers, is still, indeed, the 

 reigning theory, but rather, it should seem, from the 

 absence of a rival sufficiently popular to fill the throne 

 in its stead, than from the continuance of an implicit 

 belief in its own stability. We no longer at least cherish 

 that intensity of faith which, before Davy commenced his 

 brilliant career, had not only identified it with chemistry 

 itself, but had substituted its nomenclature, even in 

 common conversation, for the far more philosophic language 

 which the human race had abstracted from the laboratory 

 of Nature. I may venture to prophecy that no future 



