BOTANIC MATERIA MEDICA. 295 
nation with the colocynth to form the pills of 
colocynth comp.; and hyoscyami to form the 
pills of colocynth et hyoscyami. The word Aloe 
is thought to be of Hindoo origin, and supposed 
to be derived from the word e/wa. It has been 
used as a medicine from the earliest history of 
man. 
Ammoniacum, Ammoniac, Gummi Resina 
Ammoniac, Ammoniac gum resin. The juice 
concreted of the Dorema Ammoniacum—Nat- 
ural order Umbellifere. The plant from which 
we obtain the gum is perennial and rises toa 
height of 7 to 9 feet, adorned with large petio- 
late and bipinnate leaves 2 feet long, the lower 
leaflets of which are distinct, but the upper one 
confluent and deeply pinnatifid. The leaflets 
are leathery, veined beneath and entire. Flow- 
ers white and sessile, petals ovate in their out- 
lines, disk fleshy, cup-shaped with yellow sta- 
mens and pistils. This plant is a native of the 
sterile regions of Persia; it is also found in 
Africa, at least one of the species, for the Mo- 
rocco gum is still an article of commerce be- 
tween Egypt and Arabia. Ammoniac exudes 
spontaneously from the stem of the plant, and 
occurs in irregular tiers somewhat flattened, 
which are either distinct in form or in one ag- 
glutinated mass, having a yellowish or pale 
brown color externally; when fractured it pre- 
sents a waxy and cream-like appearance. The 
heat of the hand will cause it to soften, and in- 
crease the peculiar and balsamic odor. The 
taste is bitter, acrid and unpleasant; it forms 
with water a milk-like emulsion, partially solu- 
ble in alcohol and ether, but does not strike a 
