Previous to its introduction as a technical term, the word _tique_, _ticq_, _tic_, was in current use in France, and applied in the first place to animals. In 1655 Jean Jourdin described the _tique_ of horses. In eighteenth-century literature tic appears in the sense of a "recurring, distasteful act"--as expressed by the _Encyclopædia_--especially in individuals revealing certain eccentricities of mind or character. This old-time opinion is worth remembering, particularly in view of latter-day theories. Once adopted by the eighteenth-century physicians, the application of the word was extended in various directions. André (1756) was the first to mention _tic douloureux_ of the face, an affection excluded to-day by common consent from the category of true tics. Simple, painless convulsive tic, spreading from face to arms, and to the body as a whole, was differentiated by Pujol in 1785-7. During the earlier half of the nineteenth century no solid progress was achieved by the work of Graves, François (of Louvain), Romberg, Niemeyer, Valleix, or Axenfeld. It is to the clinical genius of Trousseau that we owe the rediscovery of tic, the careful observation of its objective manifestations, and the recognition of accompanying mental peculiarities. In spite of the fact that he considered it a sort of incomplete chorea, and classed it[2] nosologically with saltatory and rotatory choreas and with occupation neuroses, Trousseau's original account remains a model of clinical accuracy: Non-dolorous tic consists of abrupt momentary muscular contractions more or less limited as a general rule, involving preferably the face, but affecting also neck, trunk, and limbs. Their exhibition is a matter of everyday experience. In one case it may be a blinking of the eyelids, a spasmodic twitch of cheek, nose, or lip; in another, it is a toss of the head, a sudden, transient, yet ever-recurring contortion of the neck; in a third, it is a shrug of the shoulder, a convulsive movement of diaphragm or abdominal muscles,--in fine, the term embodies an infinite variety of bizarre actions that defy analysis. These tics are not infrequently associated with a highly characteristic cry or ejaculation--a sort of laryngeal or diaphragmatic chorea--which may of itself constitute the condition; or there may be a more elaborate symptom in the form of a curious impulse to repeat the same word or the same exclamation. Sometimes the patient is driven to utter aloud what he would fain conceal. The advantage of this description is its applicability to every type of tic, trifling or serious, local or general, from the simplest ocular tic to the disease of Gilles de la Tourette. Polymorphism is one of the tic's distinguishing features.