Observations on

24 o

SECTION XXIV.

Attempts to procure Air from various Sub*fiances by means of Spirit of Salt.

M R. Landriani had informed me thathe had got dephlogistica'ted airfrom corrosive sublimate , as well as fromiurbith mineral. But trying this, in thebest manner I could, immediately upon thereceipt of his letter, I was not able to pro-ctire any air from it; and though I havevaried the process, I am still unable to pro-cure any. It was this failure (from whatcause I cannot tell) that prevented myproceeding to the turbith mineral at thattime, as has been mentioned before.

I first put a quantity of corrofive subli-mate into a tall glass vessel, then filling itup with quicksilver, I Inverted it in a basonof the same, and exposed the sublimate toas much heat as the glass would bear, inthe manner described in the Introduction.The glass was even melted; but when all

was