31G STUDIES ON FERMENTATION. 



conducted with all possible exactness, I was inclined to consider 

 Pasteur's assertions as inaccurate, and to attack them, I have no 

 hesitation now in recognizing them as true, and in proclaiming 

 the service which Pasteur has rendered to science in being the 

 first to indicate the exact relation of things in the phenomenon 

 of fermentation." In his later researches, Dr. Brefeld has 

 adopted the method which we have long employed for demon- 

 strating the life and multiplication of butyric \dbrios in the 

 entire absence of air, as well as the method of conducting 

 growths in mineral media associated with the fermentable sub- 

 stance. We need not pause to consider certain other secondary 

 criticisms of Dr. Brefeld. A perusal of the present work 

 will, we trust, convince him that they are based on no surer 

 foundation than were his former criticisms. 



To bring one's self to believe in a truth that has just dawned 

 upon one is the first step towards progress ; to persuade others 

 is the second. There is a third step, less useful perhaps, but 

 highly gratifying nevertheless, which isj to convince one's 

 opponents. 



"We, therefore, have experienced great satisfaction in learning 

 that we have won over to our ideas an observer of singular 

 ability, on a subject which is of the utmost importance to the 

 physiology of cells. 



§ VI. — Reply to the Critical Observations of Liebig, 

 Published in 1870.* 



In the Memoir which we published, in 1860, on alcoholic 

 fermentation, and in several subsequent works, we were led to 

 a different conclusion on the causes of this very remarkable 

 phenomenon from that which Liebig had adopted. The opinions 

 of Mitscherlich and Berzelius had ceased to be tenable in the 

 presence of the new facts which we had brought to light. From 



* Liebig, Sur la fermentation et la source de la force mvsctdaire 

 {Annales de Chimie et de Fhysique, 4th series, t. xxiii. p. 5, 1S70.) 



