The bark contains a large amount of tannin. For medicinal purposes it is
reduced to powder and acts as an astringent, a tonic, and a febrifuge.
In warm climates a resin is exuded from it which solidifies in the air.
It is called Lecca gum, as it was first found near Lecca. It contains
some benzoic acid among other constituents and in ancient times was
prescribed in medicine, but is not at present, and the gum is considered
valueless.