PASSIVE a.
strong nitric acid, chlorine, etc. It is then not easily acted upon by acids. -- Passive movement (Med.), a movement of a part, in order to exercise it, made without the assistance of the muscles which ordinarily move the part. -- Passive obedience (as used by writers on government), obedience or submission of the su…
PHOTOTAXIS; PHOTOTAXY n.
The influence of light on the movements of low organisms, as various infusorians, the zoöspores of certain algæ, etc.; also, the tendency to follow definite directions of motion or assume definite positions under such influence. If the migration is toward the source of light, it is termed positive phototaxis; if away f…
PHYSIOGRAPHY n.
reats of the earth's exterior physical features, climate, life, etc., and of the physical movements or changes on the earth's surface, as the currents of the atmosphere and ocean, the secular variations in heat, moisture, magnetism, etc.; physical geography.
PLAY n.
Motion; movement, regular or irregular; as, the play of a wheel or piston; hence, also, room for motion; free and easy action. "To give them play, front and rear." Milton. The joints are let exactly into one another, that they have no play between them. Moxon.