ASCLEPIAS n.
A genus of plants including the milkweed, swallowwort, and some other species having medicinal properties. Asclepias butterfly (Zoöl.), a large, handsome, red and black butterfly (Danais Archippus), found in both hemispheres. It feeds on plants of the genus Asclepias.
BACK a.
-- Back filling (Arch.), the mass of materials used in filling up the space between two walls, or between the inner and outer faces of a wall, or upon the haunches of an arch or vault. -- Back pressure. (Steam Engine) See under Pressure. -- Back rest, a guide attached to the slide rest of a lathe, and placed in con…