64 THE LIFE OF PASTEUR 



wants to prepare for commercial purposes some left tartaric 

 acid, and I have given him all the necessary crystallographic 

 indications. I have no doubt he will succeed." 



Leipzig, Wednesday, September 15, 1852. " My dear 

 Marie, I do not want to wait until I have the results of my 

 researches before writing to you again. And yet I have 

 nothing to tell you, for I have not left the laboratory for three 

 days, and I know nothing of Leipzig but the street which 

 goes from the Hotel de Baviere to the University. I come 

 home at dusk, dine, and go to bed. I have only received, 

 in M. Erdmann's study, the visit of Professor Hankel, pro- 

 fessor of physics of the Leipzig Universite, who has translated 

 all my treatises in a German paper edited by M. Erdmann. 

 He has also studied hemihedral crystals, and I enjoyed talking 

 with him. 1 shall also soon meet the professor of mineralogy, 

 M. Naumann. 



' To-morrow only shall I have a first result concerning 

 racemic acid. I shall stay about ten days longer in Leipzig. 

 It is more than I told you, and the reason lies in rather a happy 

 circumstance. M. Fikcntscher has kindly written to me and to 

 a firm in Leipzig, and I heard yesterday from the head of that 

 firm that, very likely, they can get me to-morrow some tartars 

 absolutely crude and of the same origin as M. Fikentscher's. 

 The same gentleman has given me some information about a 

 factory at Venice, and will give me a letter of recommendation 

 to a firm in that city, also for Trieste. In this way the journey I 

 proposed to make in that town will not simply be a pleasure 

 trip. ... I shall write to M. Biot as soon as I have important 

 results. To-day has been a good day, and in about three or 

 four more you will no doubt receive a satisfactory letter." 



Leipzig, September 18, 1852. " My dear Marie, the very 

 question which has brought me here is surrounded with very 

 great difficulties. ... I have only studied one tartar 

 thoroughly since I have been here ; it comes from Naples and 

 has been refined once. It contains racemic acid, but in such 

 infinitesimal proportions that it can only be detected by the 

 most delicate process. It is only by manufacture on a very 

 large scale that a certain quantity could be prepared. But I 

 must tell you that the first operation undergone by this tartar 

 must have deprived it almost entirely of racemic acid. For- 

 tunately M. Fikentscher is a most enlightened man, he 

 perfectly understands the importance of this acid and he is 



