96 THE DEATH-POINT OF 
ments), viz. that an exposure to a temperature of 158° 
(70° C.) for five minutes deprives Bacteria, Vibriones, 
and their germs of their usual powers of growth and 
reproduction—that is, that it reduces them to a state 
of potential, if not necessarily to one of actual death. 
What end would be served by such a reservation ? 
The impending conclusion could not be staved off by 
means of it. The explanation of what occurs in the 
other set of experiments, where the much more potent 
heat of 212° F. is employed, still would not be possible 
without having recourse to the supposition of a de 
novo origination of living units, so long as those which 
may have preexisted in the flasks could be proved to 
have been reduced to such a state of potential death. 
It would be preposterous, and contrary to the whole 
order of Nature, to assume that the vastly increased 
destructive influence of a heat of 212° F. had restored 
vital properties which a lesser amount (158° F.) of the 
same influence had completely annulled. 
The evidence supplied by these different series of 
experiments, in whichever way it is regarded, as it 
seems to me, absolutely compels the logical reasoner 
to conclude that the swarms of living organisms 
which so often make their appearance in boiled infu- 
sions treated in one or other of the various modes 
already proved to be either destructive or exclusive 
of preexisting living things are the products of a 
