Note 488 — Chapter XIII · OF POISONING WITH ARSENIC.
Reading edition
It appears that arsenic does not always undergo this change. Berzelius once kept some fragments in an open phial for three years without observing any change in appearance or weight. [Annales de Chimie et de Physique, xi. 240.] Buchner once made a similar observation, and is inclined to think that oxidation does not occur, if the metal is quite pure. [Repertorium für die Pharmacie, xxi. 29.]