BRACHYSTOCHRONE n.
A curve, in which a body, starting from a given point, and descending solely by the force of gravity, will reach another given point in a shorter time than it could by any other path. This curve of quickest descent, as it is sometimes called, is, in a vacuum, the same as the cycloid.
QUEBRACHO n.
A Chilian apocynaceous tree (Aspidosperma Quebracho); also, its bark, which is used as a febrifuge, and for dyspnoea of the lung, or bronchial diseases; -- called also white quebracho, to distinguish it from the red quebracho, a Mexican anacardiaceous tree (Loxopterygium Lorentzii) whose bark is said to have similar pr…