played a great _rôle_, right up to the beginning of last century, especially in Germany. In France, however, about the same time a new idea was appearing, destined to sway psychiatry for a hundred years. Pinel, whose statue fittingly stands at the gateway of the Salpetrière in Paris, took away the chains from the insane and thus freed them from the symbol of the criminal. In a very real way he formulated for the world the humane and scientific conception of modern times. A little later Esquirol and Bayle discovered that certain forms of insanity ended in death, after a relatively short time, and that certain constant changes in the brain could be demonstrated _post mortem_. Esquirol had described as an entity general paralysis of the insane, or as it was popularly called "softening of the brain," a disease which is always bound up with chronic inflammatory degeneration of the cerebral matter. Thus was laid the foundation of the dogma which you will find repeated in every text-book of psychiatry, viz. "diseases of the mind are diseases of the brain." Confirmation of this conception was added about the same time by Gall's discoveries which traced partial or complete loss of the power of speech--a psychical capacity--to a lesion in the region of the left lower frontal convolution. Somewhat later this view proved to be of general applicability. Innumerable cases of extreme idiocy or other intense mental disorders were found to be caused by tumours of the brain. Towards the end of the nineteenth century Wernicke (recently deceased) localised the speech centre in the left temporal lobe. This epoch-making discovery raised hopes to the highest pitch. It was expected that at no distant day every characteristic and every psychical activity would be assigned a place in the cortical grey matter. Gradually, increased attempts were made to trace the primary mental changes in the psychoses back to certain parallel changes in the brain. Meynert, the famous Viennese psychiatrist, described a formal scheme in which the alteration in blood-supply in certain regions was to play the chief part in the origin of the psychoses. Wernicke made a similar but far more ingenious attempt at a morphological explanation of psychical disorders. The visible result of this tendency is seen in the fact that even the smallest and least renowned asylum has, to-day, its anatomical laboratory where cerebral sections are cut, stained, and microscoped. Our numerous psychiatric journals are full of morphological contributions, investigations into the structure and distribution of cells in the cortex, and other varying source of disorders in the different mental diseases.