312 A COMPENDIUM OF 
BALSAMA ET OLEORESINA—BALSAM 
AND OLEORESINS. 
These constitute a number of natural vege- 
table products, containing resin and volatile 
oils, varying in proportion. They are usually 
semi-liquid and unctuous, and some contain 
benzoic and cinnamic acids. Medicinally, they 
are antiseptic in their nature, and for this rea- 
son are held in high esteem as curative agents. 
Many of the balsams act specifically upon the 
mucous membrane, Many of the oleoresins be- 
come hard and brittle on exposure to the air, 
due partly to loss of their volatile principle, and 
go to form ingredients with other substancesin 
making plasters, ointments, etc. 
Abies Balsamea, American Silver Fir, Bal- 
sam Fir, Canada turpentine tree.—Natural or- 
der Coniferze. Native of the northern parts of 
the United States and Canada. This tree often 
attains the height of 4o feet, and is adorned 
with solitary, small, flat leaves, entire or emar- 
ginate in their outlines. Cones (fruit) large, 
cyndrical and erect, of a purple-like color, cov- 
ered with a resinous exudation, which gives 
