CHAPTER IX. 



THE EXPERIMENTAL PROOF. UNTENABILITY OF 

 PASTEUR'S CONCLUSIONS. 



Different results obtainable by Schwann's method of experimentation. 

 M. Pasteur's conclusions. Presence of air in flasks not essential. 

 Evolution in vacua previously thought impossible. New method 

 of experimentation. Results with acid infusions. Abundance of 

 living organisms. Experiments with acid saline solutions. These 

 not often yielding Bacteria, but rather Torula or Fungi. 



M. Pasteur does not adequately consider the nature of the fluid employed. 

 Thinks too exclusively about the germ -killing powers of acid or 

 alkaline fluids. Pays no attention to opposing views. Negative re- 

 sults equally capable of explanation on either hypothesis. Importance 

 of positive results. M. Pasteur not entitled to his conclusion about 

 germs in alkaline solutions. His indirect evidence negatived by 

 direct evidence. Other explanations more probable. Difference in 

 degree of fermentability between acid and neutral states of same 

 solution. Experiments in illustration. Differences seen with 

 solutions fully exposed to air and germs. Similar in kind to those 

 quoted by M. Pasteur. Fluids most favourable for growth also 

 most favourable for evolution. Fertility of any given solution 

 often in the inverse ratio to its acidity. Effect of acidity intensified 

 by high temperatures. Improbability of M. Pasteur's explanations 

 in face of these results. 



THE experiments most frequently cited as adverse to 

 the possibility of the de novo origination of living 

 things, have been stated to be those of Schwann, or re- 

 petitions of them by other experimenters. And yet, as 



