316 
AMMOiMACUM. 
colleges refer the production of this gum to the Heracleum Gummt- 
ferum of that learned botanist;* but as the plant which Willdenow 
describes was raised by him from a seed found in the Ammoniacum 
of the shops, there is considerable doubt if it be really the plant 
which produces the gum ammoniacum; more especially as Willde- 
now could not obtain any of the gum resin from it. Mr. Jackson, 
in his account of Morocco, gives the following account of the pro- 
duction of this gum : " Ammoniacum, called Ftshook in Arabic, is 
produced from a plant similar to the European fennel, but much 
larger. In most of the plains of the interior, and particularly about 
El-araiche, and M'Sharrah Rumellah, it grows ten feet high. The 
gum ammoniac is procured by incisions in the branches, which when 
pricked, emit a lacteous glutinous juice, which being hardened by 
the heat of the sun, falls to the ground, and mixes with the red 
earth below ; hence the reason that gum ammoniac of Barbary does 
not suit the London market. It might however, with a little trouble, 
be procured perfectly pure. It is remarkable that neither bird nor 
beast is seen where this plant growo, ihf vulture only excepted. It 
is however attacked by a beetle, which perforates the plant with its 
horn, and the juice runs out at the wound." 
The Ammoniacum usually met with in the London markets, is 
brought from the East Indies, and comes packed in chests or 
cases. 
Sensible and Chemical Properties, &c. Ammoniacum 
has a nauseous, sweetish taste, followed by a bitter one, with a smell 
somewhat like that of galbanum. It softens by heat, but is not 
fusible ; when thrown upon live coals, it burns away in a flame ; it 
is partly soluble in water, forming with it a milky liquor, and also in 
vinegar: upon standing, the resinous part precipitates> It is soluble 
* The Heracleum Gummiferum belongs to the Class Pentandria, Ordtr Dyginia, 
Jiat. Ord. UmbellaTjE. Gen. Char. Fruit elliptical, emarginate, compressed, 
•triated, margined. Coro//a inflex, emarginate. Jnvo/xcre cadacous. This plant rises 
three feet in height: the branches are opposite and divaricated ; radical leaves a span 
long, cordate, three-lobed, toothed, pubescent on the under surface, petioled ; stem 
leaves opposite, somewhat cordate, three or four inches long, toothed, and stand upon 
sheathing petioles ; the flowers are produced in large, many-rajed umbels ; the marginal 
flowers are hermaphrodite, the central hermaphrodite without the germen ; the margin 
of the calyx is obsolete ; the corolla of the marginal flowers is pentapetalons and un- 
equal ; the corolla of the central is pentapetalous and equal ; the filaments support 
roundish anthers ; the gtrmen in the marginal flower is inferior, oblong ; styles two, 
inserted into a glandular body ; the stigmas capitate. — Spc^. Plant. WjUc). i. 1431.. 
