“ There are two kinds of spasm: tonic and clonic. Tonic spasm is a prolonged involuntary rigidity of a muscle or a group of muscles. Such spasm occurs at the beginning of an epileptic attack, during hysteria major, tetanus, angina pectoris, and meningitis. It also occurs in the muscles of the calves of the legs in swimmers, attended with pain, when it is called cramp (q.v.) . Clonic spasm is an involuntary contracting and relaxing of groups of muscles, causing twitching, jerking, and rolling movements and contortions. It is the common convulsion, or fit. ”