THERMAL DEATH-POINT OF LIVING MATTER. 195 



teria, presenting most rapid progressive movements accompanied by 

 quick axial rotations. Many I'ornla corpuscles and other Fungus 

 " spores " also existed, as well as portions of a mycelial filament con- 

 taining equal segments of colorless protoplasm within its thin invest- 

 ing membrane. 



A drop of the fluid containing several of these active Monads was 

 placed for about five minutes on a glass slip in a warm-water oven 

 maintained at a temperature 140 Fahr. All the movements of the 

 Monads ceased from this time, and they never afterward showed any 

 signs of life. 



These experiments are two of the most remarkable selected from 

 several others in which even higher temperatures were originally had 

 recourse to in order to free the fluids and flasks generally from any 

 thing like a trace of living matter. Nothing, that has yet been alleged 

 by way of objection to the admission of "spontaneous generation" as 

 an every-day fact, at all affects such experiments as these. The 

 shortest way out of the difficulty would therefore be to doubt the 

 facts. I can assure the reader, however, that they are as true and 

 just as reliable as those other results obtained when working with 

 lower temperatures, which, though strongly disbelieved in at first, are 

 now generally recognized as trustworthy. And, although these now 

 accredited results abundantly suffice, in face of our present knowledge 

 concerning the limits of vital resistance to heat, to establish the 

 strongest probability of the occurrence of " spontaneous generation," 

 yet such experiments as those which I have now recorded even still 

 further confirm this view, since it becomes incredible that, while all 

 known forms of living matter with, which accurate experiment has 

 been made inevitably perish at or about 140 Fahr., the particular 

 examples of the same forms which appear within our sealed flasks 

 have been able to survive a much longer exposure to 2V0-275 Fahr. 

 If this were true, then indeed would the cultivation of Science be a 

 vain pursuit "uniformity," in fact, must be postulated and granted, or 

 Science with humbled and sorrowful crest must retire from the field. 



A word or two must be said in conclusion with reference to the 

 interpretation which should be attached to such experiments as those 

 just recorded. And this subject cannot be better introduced than by 

 means of the following extract from the already-quoted and valuable 

 paper by Prof. Jeffries "VVyman. He says : " There can therefore be 

 no certainty of the existence of spontaneous generation in a given 

 solution, until it can be shown that this has been freed of all living- 

 organisms which it contained at the beginning of the experiment, 

 and kept free of all such from without during the progress of it. On 

 the other hand, this kind of generation becomes probable, whenever it 

 is made certain that Infusoria are generated in solutions in which the 

 conditions just mentioned have been complied with. We say prob- 



