42 PASTEUR 



this singular substance which had once been 

 obtained by accident at Thann, which had since 

 been lost sight of, and which he was now in- 

 formed was to be found at a manufactory of 

 chemical products in Saxony. 



There followed a mad chase throughout the 

 length and breadth of Germany. Louis Pas- 

 teur kept a journal of his varied adventures, 

 which he sent to his wife and which reveals his 

 passionate ardor, his immense desire to possess 

 at last this acid which had once astonished the 

 scientific world. The chase was a heroic one. 

 Pasteur went from Leipzig to Zwichau, from 

 Zwichau to Dresden, from Dresden to Freiberg, 

 from Freiberg to Vienna, from Vienna to 

 Prague, filled alternately with emotions of hope 

 and despair, according as he thought that he 

 had found racemic acid, or that the elusive sub- 

 stance still seemed to evade him. "I will pur- 

 sue it for ten years, if need be," he wrote to 

 Mme Pasteur. 



His researches, his experiments in the manu- 

 factories, his inquiries did not hinder him from 



