20 PASTEUR AND AFTER PASTEUR 



cask of crystallised tartaric acid, and on the surface 

 of the crystals I could see, to my thinking, the 

 famous stuff." 



At Prague, to his amazement, he was told that 

 they knew how to produce racemic acid ; and he 

 found that they did not, and had produced none. 

 From Prague, he turned home, tired out. He had 

 assured himself that racemic acid was indeed 

 present in samples of tartaric acid from diverse 

 countries ; that it was formed in the process of 

 refining the crude tartars ; and that no chemist had 

 ever converted pure tartaric acid into pure racemic 

 acid. To this final task he set himself ; and, after 

 many vain attempts, succeeded, by keeping cincho- 

 nine tartrate for several hours at a high tempera- 

 ture. The news of this discovery was sent to 

 Paris, and to Arbois, on June 1, 1853. Thus, in 

 five years, the work was done, once and for all. 



By the design of his life, he was always being led 

 straight, by the very conditions which Heaven put 

 on him, from each discovery to the next. That is 

 what he was for. He had taken up the problems 

 of molecular disymmetry from a purely scientific 

 motive : he had chosen, for special study, tartaric 

 acid, from a purely scientific motive. He had 

 chosen as it were at random a grape-acid, an 

 article of commerce, a product of fermentation : 

 his quest of racemic acid had compelled him to see 



