With commendable good-humour, keenness, and sincerity, O. has of his own accord plunged into the minutiæ of his malady, and exhibited a rare appreciation and precision in the scrutiny of his symptoms. The mere enumeration of them stamps the record as one of outstanding clinical importance, but it is the study of their pathogeny that is so fascinating. For a moment the doubt crossed our mind that O.'s explanations might be merely a reflex of information culled from scientific journals or of conversations with medical friends, but this is not so. He has been prevented by his profession both from cultivating a taste for and from devoting any leisure to psychological and physiological questions, while he evinces an actual antipathy to medical literature, fearful as he is of contracting disease. The point we are desirous of emphasising, therefore, is simply this: that the results of O.'s voluntary and unprejudiced self-examination are in perfect harmony with the declarations of our older patients and with the statements of the majority of those that have made a special study of the tics. For these reasons we have taken O. as the prototype of the _tiqueur_. CHAPTER II HISTORICAL We have just become acquainted with an individual who may, we believe, be considered the type of a species, and have described all his tics. What is a tic, then? Its etymology has not much information to furnish. The probability is that the word was originally onomatopœic, and conveyed the idea of repetition, as in tick-tack. _Zucken_, _ziehen_, _zugen_, _tucken_, _ticken_, _tick_, in the dialects of German, _tug_, _tick_, in English, _ticchio_ in Italian, _tico_ in Spanish, are all derivatives of the same root. It matters little, in fact, since the term is in general use and acceptable for its shortness and convenience. In popular language every one knows what is meant by a tic: it is a meaningless movement of face or limbs, "an habitual and unpleasant gesture," as the Encyclopædias used to say. But the definition lacks precision. A glance at the history of the word will reveal through what vicissitudes it has passed. We need but remind the reader of its exhaustive treatment in the Dictionaries, and refer him for an elaborate bibliography to a recent work by R. Cruchet,[1] to which we shall have occasion to return. There is no justification for regarding the risus _sardonicus_ of the ancients as a tic. All that we can say is that the phrase apparently stood for a complex of facial "nervous movements," whether accompanied by pains and paralyses or not. Nor can the _rictus caninus_ or the _tortura oris_ have been other than spasms or oontractures of the face.