BOTANIC MATERIA MEDICA. as 
bitterness. Used in plasters and ointments as 
a stimulant and counter-irritant. 
Colophonium, Resina Colophony, Resin, and 
comonly known as Rosin.—Obtained from the 
various species of pines growing in the south- 
ern parts of the United States, which belong to 
the Conifer family. The volatile oil is dis- 
tilled from the turpentine, and the residue is 
the Rosin of commerce. Resin occurs in semi- 
transparent masses, from the size of a marble 
to that of twenty-pound lumps. When free 
from foreign matter, such as sticks, sand, and 
like debris, the color is of a handsome amber. 
This is the yellow Resin, which when melted 
and agitated with water becomes relieved of 
some of its impurities, and constitutes the Res- 
ina Alba (white rosin) of the stores. Resin is 
soluble in alcohol, ether and the fixed and vola- 
tile oils, also in the alkalies, Resin is known to 
the chemists as. the anhydride of abietic acid, 
because by agitating the powdered Resin with 
alcohol, adzetzc acid is found. Rosin is a mild 
stimulant, but is rarely given internally, and is 
an ingredient in many of the officinal plasters 
and ointments of the pharmacopceia. For ac- 
count see Dispensatory. Rosin is largely used 
in the arts. 
