Under the heading of “Injury before Mental Symptoms” it is desirable to consider first the surgical conditions of concussion, cerebral irritability and states of compression with their associated mental symptoms, for these must form a solid background for our consideration of all those cases where there is a head injury and mental disorder supervenes. It is, of course, possible to get an unrecognized fracture of the skull following a slight injury which will cause no further disturbance than, say, a headache. An example of this is supplied in a recent report, where a prospective member of Parliament sustained a fissured fracture of the skull as a result of bumping his head against the roof of a car when going over a hump-backed bridge; but nevertheless went about his business for a month afterwards, ignorant of the fact of the fracture, although experiencing a headache, which eventually sent him to a doctor who, by radiography, was able to make the diagnosis.

It is not surprising that the treatment of mental disorder should have brought in its train a clearer insight into the ordinary course of events in the human mind. In this as in every other department of medical experience the hidden processes of nature are revealed to advantage when they become manifest in some abnormal form. One has only to think of the importance of the part played by the recognition of heart-block and of muscular paralysis in elucidating the meaning of the successive phases of the cardiac cycle. In a wider field a greater claim can be made for clinical pathology in its contributions to knowledge of the structure and function of the nervous system. In the work of Hughlings Jackson (1) alone may be recognized the foundations of a new era not only of neurological medicine and surgery, but also in the more scientific spheres of anatomy and physiology. The subtle complexities that underlie the apparently even tenor of nature's average path may first come to light when disturbed by disease.

The prime importance of classification of patients in asylums with a view to securing the best results of treatment cannot be denied. By classification is meant, not a rigid division of patients strictly according to their form of mental disorder, but rather a selective grouping of patients in wards and villas, where the amount of supervision, the nature of treatment, the extent of freedom and the general environment is best calculated to promote recovery, to discourage mental excitement, and to secure contentment and the highest possible standard of conduct in each case.

Having availed myself, when recently in Paris, of the opportunity afforded of visiting the Salpêtrière, I have made a few notes of what I witnessed in the service of M. Charcot, although, from the shortness of my visit, I was not in a position to do justice to the subject which has recently attracted so much attention—the influence of metals in anæsthesia, hystero-epilepsy, &c. I can do little more than record facts, and suspend my judgment as to their nature and the explanation which further investigation will give of them.

Knowledge of amnesia is dependent upon the subject's statement. He can tell us what he will. If he has studied the subject well, he can mislead us. He may have motives for fabricating. He may benefit, he thinks, financially, socially or in other material ways, by inventing an amnesia. A history of grave injury may produce avoidance of danger or of unpleasant work. A medical history, which the patient may think unusual, may give him prestige or sympathy. Finally, he may invent an amnesia to give the doctor a good story or to “pull his leg.”

Those who have watched a larval cod about 4 mm. in length nimbly avoiding the forceps following it for capture are in a fair way to estimate the brain-functions of an adult measuring three feet. Still more is this appreciation of such functions strengthened by the behaviour of a large grey skate in its endeavour to escape over a trawl-beam more than fifty feet long which had been arrested in its rise—just above the surface of the sea—by a temporary block in the machinery. The dexterity with which it skimmed to and fro along the beam to find where it dipped sufficiently during the movements of the ship to enable it to glide over was a study, and relief was felt when at last its intelligent perseverance was rewarded. The observation of a group of salmon on a spawning-bed, and the acquired skill of young trout in passing up a model of a salmon-ladder, are corroborative of both intelligence and memory. Moreover, if those who have given a green cod of six or eight inches a particular kind of “scale-back” (a kind of worm), and noticed, firstly, how eagerly it seized it, then tested it in its pharyngeal region, and soon ejected it, never again taking that species into its mouth, would be slow to deny that fishes, and even very young fishes, have a memory. It is well known that fishes prefer certain kinds of bait to others, probably because they retain the pleasant sensations of former occasions. Thus it is that anemones are a fatal bait for cod, lob-worms and certain Nereids for plaice, the toothsome mussel for most marine fishes, and the stripe of silvery skin (like a young rockling or mackerel-midge) so eagerly sought by the mackerel. Muddy water, again, obscures the nature of bait, and misleads both observation and memory, so that a lure which would not so readily capture in clear water is now effective, because no suspicions are roused. On the other hand, the presence of phosphorescent organisms on a mackerel- or herring-net is said to prevent a successful haul.

Recidivism is the French coined term most appropriate to express the persistent, reiterated lapses of the same individual, in that small section of habituais found in every country, both among criminals engaged in serious crimes against the person and property, and among petty offenders, whose delinquencies or misdemeanours are drunkenness, public disorder, prostitution, and vagrancy. The former are aggressive, noxious, anti-social, and, to a slight extent, industrious and productive; the latter, as a rule, are passive, idle, debauched, parasitic, and unproductive. The two types are quite distinct, and there is little or no inter mingling; that is to say, the recidivist engaging in the major crimes in the criminal calendar does not forsake the ranks of that class to become a recruit in the ranks of the minor and petty offender class, and vice-versâ.