BOTANIC MATERIA MEDICA, 307 
emetic. The preparations of opium are more 
numerous than any other drug in the list of 
Materia Medica. It is given in form of tTiNnc- 
TURE, COMP. TINCTURE, WINE, EXTRACT, POWDER, 
and PLASTER; also aS a DEODORIZED TINCTURE. 
The dose varies, and much depends upon the 
quantity of opium in the preparation, The 
dose of the tincture is from ro to 25 drops; of 
the paregoric, 1 or z fluid drachms (4 to 8 
grams); of the powder and extract, 1 or 2 
grains. Opium is an ingredient in the Dovers 
powder, the aromatic chalk powder and comp. 
kino powders. For further account see Dis- 
pensatory, 17th Edition. 
Pistacia Lentiscus, Mastiche or Lentisk 
Tree.—Natural order Terebinthacee Anacar- 
diacez, native of the Grecian Archipelago, and 
cultivated in the Island of Scio. This tree or 
shrub tarely attains a greater height than 12 
feet, adorned with pinnatifid leaves, the leaflets 
of which are small, oval and lanceolate in shape, 
and arranged in from 8 to 10 pairs; the flowers 
are without petals, dicecious in character, and 
in axillary racemes. The male flowers are in 
compound catkins, each supported by a bract 
having 5 stamens which are nearly sessile; 
ovary, one-celled; fruit, small, round and drupe- 
like, of a brown-red color and containing a sol- 
itary seed. The Mastich is obtained from the 
Pistacia Lenticus tree, by making vertical in- 
cisions into the bark of the male tree, and the 
juice allowed to concrete. Mastic or Mastich, 
as it occurs in commerce, is in globular or in 
elongated tears about the size of a pea, having 
a pale-yellow color and is semi-transparent, 
