THE BEGINNINGS OF LIFE. 345 



already mentioned, Schwann's results were by no means 

 universally adverse to this possibility. Sometimes 

 living organisms were met with in his flasks, when the 

 fluids employed were such as underwent the vinous 

 fermentation. Many other observers have also found 

 organisms in fluids from hermetically-sealed flasks 

 which had been strictly subjected to the conditions 

 prescribed by Schwann ; and that not unfrequently 

 when the change which the fluid had undergone was 

 of a putrefactive rather than of a fermentative cha- 

 racter. Amongst those who have obtained these posi- 

 tive results may be named Mantegazza, Pouchet, Joly, 

 Musset, Wyman, Bennett, Child, and others including 

 even Pasteur himself 1 . 



But, as soon as M. Pasteur discovered that organisms 

 were undoubtedly to be met with under these con- 

 ditions, and irrespective of the limitations established 

 by Schwann, he sought to include all such exceptional 

 cases under a new general rule. After further experi- 

 ments he came to the conclusion that living organisms 

 might be encountered in almost any suitable neutral or 

 slightly alkaline solution, which had been submitted to 

 Schwann's conditions, though, on the contrary, they were 

 not to be met with when the solutions employed had 

 an acid reaction. This rule was represented by M. 

 Pasteur to be absolute. And, although the results of 



1 As it would be impossible to give any adequate account of all these 

 valuable experiments, we must refer the reader to the works, already 

 cited, in which they are detailed. 



