THE BEGINNINGS OF LIFE. 15 



by the heat to which they had been subjected, so. that 

 whether they underwent change or not, may have 

 depended upon the accidental presence or absence of 

 suitable unheated organic fragments in the air ad- 

 mitted to the fluid. If germs were as omnipresent as 

 they have been represented to be, such fluids ought 

 always to have undergone change. Owing to facts 

 of this nature, M. Pasteur 1 came to the conclusion 

 that c germs' are not so universally distributed as they 

 had been supposed to be by Bonnet and Spallanzani *. 

 The unprejudiced inquirer, however, will perceive that 

 M. Pasteur was entitled to come to no such conclusion 

 concerning germs which was not equally applicable to 

 minute fragments or debris of organic matter floating 

 in the air. And, similarly, the evidence which he 

 adduces with regard to the diminution in the number 

 of the fertile flasks when they were filled with some of 

 the still air of the caves of the observatory, or with the 

 air of some high mountain regions 3 , far away from the 

 haunts of men, had no bearing upon the distribution of 

 germs which was not equally applicable to that of dead 

 organic particles. Such evidence, therefore, was value- 

 less for settling between the rival doctrines of ferment- 

 ation, and could not possibly help us to decide whether 

 living or dead ferments were necessary. Dead organic 

 particles would sink in still air in the same manner as 



1 'Ann. de Chimie et de Physique,' 1862, p. 71. 

 2 Loc. cit., pp. 75 and 76. 3 Loc. cit., pp. 83 and 84. 



