4i6 THE BEGINNINGS OF LIFE. 



explain the results of many experiments, in a manner 

 different from that which has been generally accepted. 



Those experiments which I have already detailed 

 tend to show, in opposition to the widely-accepted 

 views of Gay-Lussac, that the presence of free oxygen 

 is not necessary even for the initiation of certain 

 processes of fermentation or putrefaction, since such 

 processes may occur m vacua. Dr. Child, however, 

 had previously shown that fermentation might take 

 place in a closed flask containing nothing but freshly- 

 prepared nitrogen gas in contact with the fermentable 

 fluid (see p. 347). 



My experiments have been conducted, to a certain 

 extent, in accordance with a method which is in daily 

 use for the preservation of meats and various kinds of 

 provisions. Curiously enough, Gay-Lussac, Gerhardt, 

 and other chemists came to the conclusion that oxygen 

 was necessary for the initiation of fermentation and 

 putrefaction, because meats or vegetables can only be 

 preserved by a process somewhat similar to that which 

 I have adopted in my experiments that is, by sealing 

 them hermetically in vessels from which all air has 

 previously been expelled by heat. So prepared, the 

 most changeable meats or vegetables will often preserve 

 all their freshness for many years a fact which has 

 been attributed principally to the absence of oxygen gas. 

 Now, however, by a certain modification of the experi- 

 ment, I find that fermentation and putrefaction will 

 occur in vacua, and am consequently led to the opposite 



