342 THE BEGINNINGS OF LIFE. 



He came to the conclusion that if fluids with an ' 

 alkaline reaction were raised to the temperature of 

 boiling water, the organisms contained in them were 

 not all destroyed, because such fluids were subsequently 

 found by him to yield living things when experimented 

 with in the manner adopted by Schwann; and simi- 

 larly he believed that the organisms in these fluids 

 were destroyed when the fluids had been raised for 

 however short a time to a temperature of noC 

 (230 F), because, after such treatment no organisms 

 were to be met with in the flasks to which calcined 

 air alone had been admitted. 



The conclusions drawn by M. Pasteur from his re- 

 searches on the subject at present under discussion, may 

 be summed up thus : (i) When acid solutions of organic 

 matter are employed, no living things are to be met with 

 in repeating Schwann's experiments, because all pre- 

 existing organisms are destroyed, and living things are 

 believed to be incapable of arising de novo; but (2) when 

 neutral or slightly alkaline solutions are made use of, 

 organisms may be met with if such infusions are merely 

 raised to the temperature of 100 C, though (3) they are 

 never to be seen when similar infusions have been raised 

 to a temperature of noC. On account of these sup- 

 posed facts, and on the strength of a chain of indirect 

 evidence, M. Pasteur assumes, that whilst Bacteria are 

 destroyed in acid fluids at a temperature of iooC, their 

 hypothetical c germs ' are not destroyed in a neutral or 

 slightly alkaline fluid at ioo 3 C, though they do cease 



