PASTEUR, KOCH, AND OTHERS 297 



in the dedication of his book, Studies on Fermentation, 

 published in 1876: 



"To the memory of my Father, 

 Formerly a soldier under the First Empire, and Knight of the Legion of 



Honor. 

 The longer I live, the better do I understand the kindness of thy heart 



and the superiorly of thy judgment. 



The efforts which I have devoted to these studies and to those which have 



preceded them are the fruits of thy example and of thy counsel. 



Desiring to honor these precious recollections, I dedicate this book to thy 



memory." 



When Pasteur was an infant of two years his parents 

 removed to the town of Arbois, and here he spent his youth 

 and received his early education. After a period of indiffer- 

 ence to study, during which he employed his time chiefly in 

 fishing and sketching, he settled down to work, and, there- 

 after, showed boundless energy and enthusiasm. 



Pasteur, whom we are to consider as a biologist, won his 

 first scientific recognition at the age of twenty-five, in chem- 

 istry and molecular physics. He showed that crystals of 

 certain tartrates, identical in chemical composition, acted 

 differently upon polarized light transmitted through them. 

 He concluded that the differences in optical properties 

 depended upon a different arrangement of the molecules; 

 and these studies opened the fascinating field of molecular 

 physics and physical chemistry. 



Pasteur might have remained in this field of investigation, 

 but his destiny was different. As Tyndall remarked, "In 

 the investigation of microscopic organisms — the 'infinitely 

 little,' as Pasteur loved to call them — and their doings in this, 

 our world, Pasteur found his true vocation. In this broad 

 field it has been his good fortune to alight upon a crowd of 

 connected problems of the highest public and scientific 

 interest, ripe for solution, and requiring for their successful 



