3. (Science: medicine) The act of tapping or striking the surface of the body in order to learn the condition of the parts beneath by the sound emitted or the sensation imparted to the fingers. Percussion is said to be immediate if the blow is directly upon the body; if some interventing substance, as a pleximeter, is, used, it is called mediate. Center of percussion. See Center. Percussion bullet, a bullet containing a substance which is exploded by percussion; an explosive bullet. Percussion cap, a small copper cap or cup, containing fulminating powder, and used with a percussion lock to explode gunpowder. Percussion fuze. See Fuze. Percussion lock, the lock of a gun that is fired by percussion upon fulminating powder. Percussion match, a match which ignites by percussion. Percussion powder, powder so composed as to ignite by slight percussion; fulminating powder. Percussion sieve, Percussion table, a machine for sorting ores by agitation in running water.
Origin: L. Percussio: cf. F. Percussion. See Percuss.