NOTE BY THE TRANSLATORS, 



WE have included in this translation two letters of 

 Schonbein's (of 12th February and 29th March 1847), 

 and also a paper of Schonbein's, "On various chemical 

 states of oxygen," which are not in the German edition. 

 They were discovered in January 1899 (after the latter 

 had been published), together with about 200 other 

 letters addressed to Berzelius, in the Berzelius Museum 

 at Stockholm, by Herr Lindstrom. They were placed 

 in the University Library at Bale for a time, in order 

 that we might obtain copies of them, and we wish to 

 express our thanks to the authorities of the Library 

 for their kindness in permitting us to do so. Schon- 

 bein's paper, which has never before appeared in print, 

 is of interest both generally and as throwing light on 

 the views which he expresses in his letters to Berzelius. 



F. V. D. 



1ST. V. S. 



