12 CONTENTS 



PAGE 



XVI. Schonbein to Berzelius, 30th September 1845, . 79 



XVII. Schonbein to Berzelius, 5th March 1846, . . 81 



XVIII. Schonbein to Berzelius, 20th June 1846, . . 86 



XIX. Berzelius to Schonbein, 18th November 1846, . 88 



XX. Schonbein to Berzelius, 12th February 1847, . . 91 



XXI. Berzelius to Schonbein, 12th March 1847, '. . 95 



XXII. SchSnbein to Berzelius, 29th March 1847, . . 99 



Appendix. On various chemical states of oxygen, 106 



