348 THE BEGINNINGS OF LIFE. 



recent paper by Prof. Wyman 1 , also, in giving an 

 account of experiments which were more than usually 

 productive, he says, c The amount of infusion used 

 was from one-twentieth to one-thirtieth of the whole 

 capacity of the flask-' the object of employing this 

 comparatively small quantity of fluid being, as he 

 adds, c to have the materials exposed to as large a 

 quantity of air as possible.' These facts and reasonings 

 were consistent enough with the view that putrefactive 

 and fermentative changes were incited in the organic 

 fluids under the influence of the oxygen in the air above 

 them 2 : and this has been the doctrine most in vogue 

 amongst those who have believed in the possibility of 

 the de novo origination of living things. 



It had been stated by Spallanzani that whilst organisms 

 were procurable from hermetically-sealed flasks in which 

 the air was somewhat ratified, they were not to be 

 met with when the rarefactioji was extreme, or where 

 a vacuum existed 3 . Although this was a conclusion 

 which seemed to be generally accepted 4 , still, on re- 



1 ' American Journal of Science,' vol. xxxiv., July, 1862. 



2 Thus Gerhardt says (' Chimie Organique,' 1856, t. iv.p. 537) : ' Get 

 oxygene est en effet la cause premiere de tous les phenomenes de 

 fermentation et de putrefaction.' Dr. Child's experiments, showing that 

 organisms might be found even in presence of pure nitrogen gas, were 

 made two or three years subsequently to those we are now alluding to 

 by Prof. Wyman. 



3 See ' Obs. et exp. sur les Animalcules,' p. 140. 



4 M. Pouchet, for instance, rejected as preposterous the notion that 

 organisms could be expected to occur under such conditions, in some 

 experiments made by M. Milne-Edwards (see 'Nouvelles Experiments,' 



