160 A COMPENDIUM OF 
scattered, whilst the latter are in slender cat- 
kins; pistils and stamens are on separate flowers; 
stigmas usually three-lobed; the stamens num- 
ber from 3 to12; fruit an acorn, inserted within 
a capsule or indurated cup. All the species of 
oak flower in the spring and perfect their fruit 
in the autumn months. When full grown, the 
leaves are of a dull yellow-green color beneath, 
and of arich green on the upper surface; the 
edges are cut obliquely into 6 or g lobes. The 
bark, when deprived of its outer or corky layer, 
is of a pale brown color, about. 4 of an inch (6 
millimeters) thick, but of various lengths; when 
broken, the fracture is fibrous, odor slight, not 
peculiar, but possessing a very astringent, bitter 
taste; when found in the stores it is usually so 
ground or contused as to render its identity 
doubtful. White oak bark contains pectin, resin, 
and a red coloring matter, also about 8 or 10 per 
cent. of /annin. Decoctum quercus is the only 
officinal preparation recognized, and this may 
be made from any of the oak barks. 
Rhamnus Purshiana, Cascara Sagrada, of 
Chittem Bark.—Natural order Rhamnace. 
Commonly known as the American buckthorn. 
This order of the Rhamnacez is found growing 
in the Rocky Mountains and on the Pacific 
coast. It differs little in general characteristics 
from the afore-mentioned variety, but by many - 
physicians it is considered the most efficacious 
of the species, and used for the same purposes 
as the buckthorn, but up to this time little has 
been done to arrive at a correct analysis of its 
constituents, It is said to contain three resins, 
malico-tannic and oxalic acids, and a volatile otl, 
