THERMAL DEATH-POINT OF LIVING MATTER. 697 



flasks and their contents have been thorcxighlj raised to the tempera- 

 ture of boiling water for ten minutes or more. These experiments we 

 may mentally label as series A. Other experiments, which we may 

 similarly label series B, had also shown that a brief exposure in the 

 moist state to a temperature considerably below the boiling-point of 

 water, is destructive to all kinds of living matter submitted to its 

 influence. The experiments of series A, therefore, taken in con- 

 junction with those of series B, must (if the latter results are as 

 reliable as the former) be held to prove that living matter can origi- 

 nate independently, or de novo^ through the mere productive proper- 

 ties of certain infusions or solutions. 



If the facts are true, is it possible to stave ofl" the conclusion ? 

 While the candid reader is asking himself this question, I may 

 further point out to him that, as the previously discredited results 

 belonging to series A are no longer denied, doubt is now only possible 

 upon a subject hitherto supposed to be settled — namely, as to whether 

 living matter is really killed by exposure in the moist state to a 

 temperature of 212°Fahr. Obviously, at such a juncture, it rested 

 more especially with the panspermatists, who chose still to be oppo- 

 nents of " spontaneous generation," to show that this belief concerning 

 the destructive efiicacy of boiling water, upon the truth of which they 

 had previously relied, was erroneous — seeing that the advocates of 

 spontaneous generation had demonstrated the truth of their position 

 with reference to experiments A. Should the panspermatists fail to 

 produce this evidence as to the untruthfulness of their old view, they 

 must not expect to hear that they have the best of the argument ; 

 and still less will they be able to hold their ground if, while abstain- 

 ing themselves from all experiments belonging to series B, their 

 scientific opponents do make careful investigations in this direction, 

 and arrive at the conclusion that not only was the old opinion right 

 as to the destructive action of boiling water, but that living matter 

 unaccustomed to the influence of heat is killed by a brief exposure 

 even to the much lower temperature of 140°Fahr. 



This is the present aspect of the problem, and those most interested 

 in it may remember that knowledge would not advance in the rapid 

 way which it does, were it not for the fact that the difiiculties of one 

 generation of men often disappear before the clearer, because more 

 unprejudiced, vision of the next. Growing gradually more familiarized 

 with the facts, those who come after us will be more and more influ- 

 enced by them, and at the same time less warped by theoretical con- 

 siderations already out of harmony with our present state of knowl- 

 edge. We are now in a stage of transition. We are gradually learn- 

 ing to accept the doctrines of Evolution, as applicable to different de- 

 partments of knowledge, though, as is so frequently the case when new 

 doctrines are being adopted, this transition is being effected by many 

 in a partial manner — they, unconsciously perhaps, endeavor to make 



