HEAT UPON LIVING MATTER. 165 
living matter not previously inured to the influence 
of heat. 
(3.) Omitting, therefore, the facts concerning the 
existence of living organisms in thermal springs as 
being altogether peculiar, and lying outside the 
boundaries of our present inquiry, all that we know 
about the unaccustomed influence of high tempera- 
tures upon living things can easily be shown to be 
even more harmonious than it may at the first 
glance appear. We have only to bear in mind two 
or three general principles in order to be able to 
harmonise the several experimental results arrived 
at with the now very generally admitted doctrine 
as to the oneness or generic resemblance existing 
between all forms of living matter. We must bear 
in mind, first of all, the consideration enforced by 
Spallanzani, that there are different grades of 
vitality, or, in other words, different kinds of living 
matter exhibiting more or less of the phenomena 
known as vital; and that of these kinds those which 
exhibit the most active, life are those which would 
be most easily killed by heat. Thus we should 
expect the latent ‘life’ of the germ, egg, or seed 
to be less easily extinguished than the more subtle 
and, at the same time, more active life of the fully 
developed tissue element or organism; and we should 
also expect that the vegetal element or organism 
