Definify.com

Webster 1913 Edition

(-brŏth)

Noun.

[Origin uncertain.]

The

salt of wisdom

of the alchemists, a double salt composed of the chlorides of ammonium and mercury. It was formerly used as a stimulant.

Brande & C.

alembroth ‎(uncountable)

(archaic) The "salt of wisdom" of the alchemists, a double salt composed of the chlorides of ammonium and mercury, formerly used as a stimulant.
(Can we find and add a quotation of Brande & C to this entry?)