58 LOUIS PASTEUR. 



fermentation of sugar, of mannite, of gums, of lactate 

 of lime, by the butyric vibrio, so closely resembles the 

 phenomena of putrefaction, that one might call these 

 fermentations the putrefaction of sugar and of the 

 other products. 



If it has been thought right to call the fermenta- 

 tion of animal matters putrefaction, it is because at the 

 moment of the decomposition of fibrine, of albumen, 

 of blood, of gelatine, of the substance of the tendons, 

 &c., the sulphur, and even the phosphorus, which 

 enter into their composition give rise to putrid odours, 

 due to the evil-smelling gases of sulphur and phos- 

 phorus. 



The phenomena of putrefaction being then simply 

 fermentations, differing only in regard to the chemical 

 composition of the fermenting matters, Liebig natu- 

 rally included them in his general theory of the de- 

 composition of organic matters after death. At a 

 period long antecedent to Pasteur's labours it had 

 been established that there existed in putrefying 

 matters fungi or microscopic animalculae, and the idea 

 had taken shape that these creatures might have an 

 influence in the phenomena. The proofs were want- 

 ing, but the notion of a possible relation remained. 

 "We may read in his ' Lessons on Chemistry ' with 

 what disdain Liebig mentioned these hypothetical 

 opinions. 



'Those who pretend to explain the putrefaction 



