50 



DE. BASTIAN ON THE 



the "germ theory of disease," is thereby almost as powerfully in- 

 fluenced as if the former alternative had been established with 

 complete certainty. 



YI. Experiments with Superheated Fluids. 

 There can be no doubt that many organic fluids which have been 

 heated only a few degrees above the boiling-point, and which 

 are subsequently kept at a temperature of 86° P. (30° C), will 

 remain barren. 



It is well known that neutral or faintly alkaline fluids will ferment 

 after exposure to this higher temperature better than acid fluids. 

 If, as I have endeavoured to prove, the former fluids have, owing to 

 their constitution, a greater tendency to ferment than acid fluids, 

 this is only what might have been expected. It stands to reason 

 that if heat beyond a certain intensity tends to stifle the ferment- 

 able qualities of organic liquids, a lower degree of heat would ex- 

 tinguish these qualities in the less fermentable fluids than would 

 suf&ce to annul them in the more fermentable fluids. If ferment- 

 ability is a quality of organic fluids inseparable from, or solely 

 dependent upon, the presence of certain living organisms, then 

 the fact of fermentability persisting in an organic liquid after it 

 had been heated to 105° C. (221° I\), would have been a proof that 

 living organisms in some form could withstand the influence of 

 such a temperature. 



M. Pasteur found that specimens of milk and of sweetened 

 yeast-water neutralized by carbonate of lime would in fact often 

 ferment after they had been heated to 105° C, ; and he very 

 soon arrived at the conclusion that this was owing to the sur- 

 vival of Bacteria and Vibrio germs in these fluids. Finding, 

 however, that in his hands even such fluids were invariably steri- 

 lized after they had been exposed for a few minutes to a tempe- 

 rature of 110° C. (230° E.), M. Pasteur proclaimed that such a 

 degree of heat was certainly destructive of all germs in fluids 

 — even of those above mentioned which, as he thought, most 

 stubbornly resisted the destructive influence of heat. 



The experiments already recorded have shown that Pasteur's 

 explanation of the cause of the fermentation of the neutral fluids 

 after boiling and after heating them to 105° C, is without suflS- 

 cient foundation in fact — that it is, in short, directly negatived 

 by strict crucial experiments. 



I now have to bring forward additional evidence tending to 



