600 Mr. Dow on the Plant 
quent writers, derives the name Ammoniacum from Ammon or 
Hammon, the Jupiter of the Libyans, whose temple was situated 
‘in the desert of Cyrene, near to which the plant was said to 
grow. But it appears to me that Dioscorides was altogether 
mistaken as to its native country ; and that the name Ammonia- 
cum or Armoniacum, as it is indifferently written, is really a 
corruption of Armeniacum, for it is now ascertained beyond all 
doubt that the plant is a native of Persia, and that the gum 
must have anciently been brought to Europe by way of Ar- 
menia; and we find in ancient authors the name of the apricot 
sometimes written Malum Armoniacum. 
Willdenow fancied he had obtained the plant itself; for 
having sown some seeds picked from the gum Ammoniacum, 
a species of Heracleum came up, of which he has published a 
figure and description in the ** Hortus Berolinensis," under the 
name of H. gummiferum; but as the plant possesses no smell 
analogous to Ammoniacum, and affords no gummy substance 
whatever, it is probable it was only an accidental weed, as it 
does not appear to be specifically different from Heracleum 
pyrenaicum. 
The materials from which I drew up the following descrip- 
tion were procured, by Lieut.-Colonel Wright of the Royal En- 
gineers, in the district where the gum Ammoniacum is collected, 
—namely, in the vicinity of Jezd Khast, a town of Irak El Ajam, 
the ancient Parthia, about forty-two miles south of Ispahan,— 
and presented by him along with other dried plants to the Linnean 
Society. Every part of the specimen is covered with drops of a 
gum possessing all the properties of Ammoniacum ; and this cir- 
cumstance alone, independent of any other evidence, would 
seem sufficient to remove all doubt on the subject: but besides, 
I have carefully compared the specimen with the portions of 
inflorescence and fruit, which are found abundantly intermixed 
with 
