PARTS OF ROOTS AND STEMS. 
161 
ranean region. The bulbs are collected late in August, 
and after the removal of the membranous outer scales 
and the central portion, the fleshy scales are cut into 
transverse pieces and dried by solar or artificial heat. 
The article used in France is collected from bulbs 
having reddish scales and is obtained from Algeria 
and Malta. 
Description. — In irregular, curved, flat, narrow, 
somewhat translucent pieces 3 to 5 cm. long, 5 to 8 
mm. wide, 2 to 7 mm. thick, whitish, lemon-yellow or 
light brown, epidermis forming a thin layer, mesophyl 
more or less shrunken, slightly crystalline and with 
numerous circular projections of fibrovascular bundles ; 
fracture brittle when dry, tough when damp ; odor 
slight ; taste bitter and acrid. 
Constituents. — Squill contains a number of active 
principles, of which the most important are the gluco- 
side scillitoxin, which resembles digitoxin physiologi- 
cally, and scillipicrin, an amorphous, bitter principle, 
which is employed as a diuretic. It also contains 
mucilage, sugar and calcium oxalate. 
III. PARTS OF ROOTS AND STEMS. 
PITH, WOOD AND BARK. 
The active principles are not uniformly distributed 
throughout all parts of the roots and stems, but are 
usually found in greatest amount in the bark. This 
is true of herbaceous plants as well as of trees and 
shrubs, but in most of the medicinal roots and rhizomes 
it has not been found economical to separate the bark 
from the wood, which may also contain some of the 
active principle. A large number of the barks alone 
of shrubs and trees are used medicinally. By the 
term bark is usually meant all that portion of the root 
or stem which is developed outside of the cambium, 
