ACETIC FEEMENTATION. 83 



these little animalcules ; they have not time to multiply 

 to a hurtful extent. Indeed, if the operation be well 

 conducted, they do not make their appearance at all. 



Nearly all Pasteur's publications have had from 

 the moment of their appearance to undergo the severest 

 criticism. Their novelty caused them to clash with 

 the prejudices and errors current in science. His re- 

 searches on fermentation provoked lively opposition. 

 Liebig did not accept without recrimination a series 

 of researches which concurred in upsetting the theory 

 he had enunciated and defended in all his works. 

 After having kept silence for ten years, he published, 

 at Munich, where he was professor, a long memoir 

 entirely directed against Pasteur's results. In 1870, 

 on the eve of the war, Pasteur, who was at that time 

 returning from a scientific journey into Austria, deter- 

 mined to pass by Munich, with the view of attempting 

 to convince his distinguished adversary. Liebig re- 

 ceived him with great courtesy, but, hardly recovered 

 from an illness, he alleged his convalescence as a 

 reason for declining all discussion. 



Then followed the Franco-German war. Hardly 

 was it terminated when Pasteur brought before the 

 Academy of Sciences at Paris a defence of what he 

 had published, as a sort of challenge to his illustrious 

 opponent. The memoir of Liebig was filled with the 

 most skilful arguments. 



