So far as my researches extend little attention has been paid to the subject of this paper. Yet I think it would be rash to assume that what is unrecorded is necessarily rare, even in days when so much more is put into print than any of us can either read or mark, much less digest, and when the number of writers seems in danger of exceeding the number of readers. Insanity, in some degree, as a sequela of surgical operation, though certainly rare, is, I believe, less uncommon than usually supposed, and it is chiefly in the hope of eliciting additional information from others that I venture to record my own small experience. On two subjects medical science has still an infinite deal to learn: first, the influence of disease on the mind; secondly, the influence of mind on disease. In attempting to contribute a little to the first-mentioned subject, I can really deal only with a subdivision of it, viz., the effects that may be produced on the mind by surgical measures undertaken for the relief of disease.

Recent investigations into the origin of crime point as a rule to the conclusion that all forms and manifestations of delinquency may be traced back to the operation of three causes, which have been called anthropological, social, and cosmical.∗ These three causes sometimes act individually and sometimes collectively, as well as in varying proportions, according to the nature of the crime or the character of the criminal. With respect to the second cause, it is admitted by criminalists of all schools that adverse social surroundings is one of the most potent factors in the production of crime. Some writers lay down the doctrine that crime is entirely social in its origin; they adopt as their motto the celebrated maxim of Quetelet, that society prepares crime, the criminal only executes it, and maintain that an adequate amelioration of the present unequal conditions of existence would quickly bring about the extinction of the whole criminal population.†

(1) Movement in mau has long been a subject of profitable study. Visible movement in the body is produced by muscular contraction following upon stimulation of the muscles by efferent currents passing from the central nerve-system. Modern physiological experiments have demonstrated that when a special brain-area discharges nerve-currents, these are followed by certain visible movements or contraction of certain muscles corresponding. So exact are such reactions, as obtained by experiment upon the brain-areas, that movements similar to those produced by experimental excitation of a certain brain-area may be taken as evidence of action in that area, or as commencing in discharge from that area (see Reinforcement of Movements, 35; Compound Series of Movements, 34).

This subject is probably more frequently alluded to and more fully treated in foreign than in English psychological literature. It may therefore be not unprofitable to review the details of some of the more interesting cases which have from time to time occurred in this country, and to discuss briefly their mental peculiarities.

The case of the brothers John and Richard C. is of interest, inasmuch as it presents a comparatively rare picture of psychical and physical identity.

The subject of the following notes was a girl eighteen years old, who was admitted to the Royal Edinburgh Asylum on the 28th of March of last year.