balsam, garden, common name for the species Impatiens balsamina, a member of the jewelweed family.

balsam fir, common name for the evergreen tree Abies balsamea of NE North American boreal forests. It has small needles and cones and is used for lumber. It is also called Canada balsam, as is the resin it produces, which is used as an adhesive in optical lenses and glass slides. Balsam fir is classified in the division Pinophyta, class Pinopsida, order Coniferales, family Pinaceae.

balsam, fragrant resin obtained from various trees. The true balsams are semisolid and insoluble in water, but they are soluble in alcohol and partly so in hydrocarbons. They contain benzoic or cinnamic acid; these include Peru balsam and tolu balsam (both obtained from varieties of the South American tree Myroxylon balsamum of the pulse family), benzoin, and storax. Other resins called balsams include Mecca balsam (balm of Gilead), Canada balsam, and copaiba. Balsams are often used in medical preparations and perfumes.

Canada balsam, yellow, oily, resinous exudation obtained from the balsam fir. It is an oleoresin (see resin) with a pleasant odor but a biting taste. It is a turpentine rather than a true balsam. On standing, the essential oil in Canada balsam evaporates, leaving behind the resin as a hard, transparent varnish. Canada balsam is valued as an optical mounting cement, e.g., for lenses and microscope slides, since it yields, when dissolved in an equal volume of xylene, a noncrystallizing cement with a refractive index nearly equal to that of ordinary glass. It is used also in paints and polishes.

Aromatic resinous substance that flows from a plant, either spontaneously or from an incision, and is used chiefly in medicinal preparations. Some of the more aromatic varieties are used in incense. Balsam of Peru, a fragrant, thick, deep brown or black fluid used in perfumes, is a true balsam, from a lofty leguminous tree, Myroxylon pereirae, native to and introduced into Sri Lanka. Balsam of Tolu (Colombia) is used in perfumes and in cough syrups and lozenges; it hardens with age. Canada balsam and Mecca balsam are not true balsams.

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