BOTANIC MATERIA MEDICA, 381 
organs. The beaver belongs to the class Mam- 
malia, and the order Rodentia, although the 
tail differs from that of the rat family by being 
almost oval in form, and flattened horizontally, 
The castor sacs occur in pairs about 3 inches 
long and somewhat pyriform in shape, of a 
grayish-black or deep brown color, containing a 
resin-like substance of a dark brown color, with a 
peculiarly strong odor and an acrid, nauseous 
taste; fairly soluble in 95 per cent alcohol; also 
in ether. There are two kinds of castor found 
in commerce, the European and American; 
the former sacs contain about twice the amount 
of secretion, whilst the latter (the American, 
or Canadian) weigh from 1 to 4 ounces only. 
The secretion contains the following constitu- 
ents: fat, albuminotd principles, some salts, 
volatile otl, resin, carbolic acid, salicin, and cas- 
torin, The castor is adulterated occasionally 
with blood, resin, and other foreign substances; 
it is used in medicine as a stimulant, emmen- 
agogue, and antispasmodic, and given in doses 
of 5 to 30 grains; the tincture is the usual form 
of its administration. 
Cantharis, Cantharides, Spanish Flies; also 
technically called by Linnzeus, mmole, vesicato- 
rius ; by Geoffrey, cantharis vesicatoria ; and by 
Fabricius, /ytta vesicatoria (the names adopted 
by many of the Pharmacopoeias), and belong to 
the class of Insecta, and order Coleoptera.— 
There are said to be eleven or more species of 
the fly or beetle, among which are the mylabris 
cichorit, mylabris phalerata, and the cantharis 
vittata, which latter insect is a native of the 
United States, and is commonly known as the 
