Note 576 — BOOK XII. THE NATURAL HISTORY OF TREES.

See B. xxiv. c. 14. The gum resin ammoniacum is still imported into Europe from Africa and the East, in the form of drops or cakes. It is a mildly stimulating expectorant, and is said to be the produce of the Dorema ammoniacum. There are still two sorts in commerce: the first in large masses of a yellow, dirty colour, mingled with heterogeneous substances, and of a plastic consistency. This is the phyrama of Pliny, or mixed ammoniac. The other is in tears, of irregular form and a whitish colour, brittle and vitreous when broken. This is the thrauston, or “friable” ammoniac of Pliny. Jackson says, that the plant which produces it is common in Morocco, and is called feskouk, resembling a large stalk of fennel. The ammoniac of Morocco is not, however, imported into this country, being too much impregnated with sand, in consequence of not being gathered till it falls to the ground.