It is true a hardened _tiqueur_ may be relieved of his tic, but the potentiality remains. He is still at the mercy of the impulse to tic, should it arise. Cruchet gives the history of a young man who suffered in succession from convulsive movements of negation, facial tic, blinking of the eyes, abrupt yawning, and twitches of the shoulder--all in the space of two years. Each disappeared in its turn, independently of treatment, without leaving any trace behind. In cases of this description a new tic is ever imminent. The facility with which one tic replaces another is a matter of common observation. We have often had occasion to observe relapses, or partial relapses, in which an altogether new tic suddenly makes its appearance on the top of one which has either been improving or has actually been checked. Apart, however, from obdurate forms of long standing, especially such as are accompanied by signs of grave mental defect, we maintain that the subjection of patients to appropriate treatment for an adequate period has a favourable influence on prognosis. The curability of tic was denied by Oddo, but he has recently seen fit to change his opinion, and to confine his pessimistic views to Gilles de la Tourette's disease. The prognosis of the mental state of victims to tic is outwith our province: it is a topic long since handled by psychiatrists. We may ask, however, whether any particular prognostic import is to be attached to the tics themselves. In cases of Gilles de la Tourette's disease the progressive unfolding of motor disorders suggests a corresponding evolution of psychical derangements which may end in dementia. Brissaud warns us that in cases of mental torticollis we must be on our guard against the apparition of some much more redoubtable affection than the torticollis, for that, sometimes, is an incident in the prodromal stage of general paralysis of the insane. Séglas has had a case of ærophagic tic which eventually became one of general paralysis, and a similar instance occurred in the practice of one of us. Not long ago Dufour[193] advanced the opinion that the occurrence of a motor syndrome consisting of the automatic movements of tic, in a case of delusional insanity, heightens the gravity of the prognosis as regards chronicity. It had been already remarked by Morel that such of the insane as contract tics usually degenerate into dements. Most of the contributors to the study of idiocy have noted the relation between the degree of intellectual debility and the extent of the automatic and rhythmical movements. In this connection Joffroy has made some interesting statements.