232 On the Heat necessary to kill Bacteria, Vibriones,, fyc. [Mar. 20, 



killed by the temperature of 158° F. ? It would be of no avail to suppose 

 that the absence of putrefaction in these latter cases is due to the fact 

 that a heat of 158° F., instead of killing the organisms and their germs, 

 merely annuls their powers of reproduction, because in the other series 

 of experiments (with which these have to be compared), where similar 

 fluids are exposed to ordinary or purified air, or are shut off from the 

 influence of air altogether, the most active putrefaction and multiplica- 

 tion of organisms takes place in two, three, or four days, in spite of the 

 much more potent heat of 212° F. to which any preexisting germs or 

 organisms must have been subjected. The supposition, therefore, that 

 the Bacteria, Vibriones, and their germs were not killed in our inoculation 

 experiments at the temperature of 158° F., but were merely deprived 

 of their powers of reproduction, would be no gain to those who desire 

 to stave oif the admission that Bacteria and Vibriones can be proved to 

 arise de novo in certain cases. Let us assume this (which is indisputably 

 proved by these inoculation experiments), viz. that an exposure to a 

 temperature of 158° F. (70° C.) for five minutes deprives Bacteria, 

 Vibriones, and their germs of their usual powers of growth and repro- 

 duction — 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 experi- 

 ments, 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 pre- 

 existed 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 infusions treated in one or other 

 of the various modes already proved to be either destructive or exclusive 

 of preexistiug living things are the products of a new brood of " living" 

 particles, which, in the absence of any coexisting living organisms, must 

 have taken origin in the fluid itself. For this mode of origin of living 

 units, so long spoken of and repudiated as " spontaneous generation," I 

 have proposed the new term Archebiosis. 



