The body is a vital union and communion of an infinite multitude of differentiated cells which constitute its different tissues and organs, their several functions intimately co-ordinated to serve the functions of a bodily whole; so many diversities in unity, unity in so many diversities, which is just what all nature is, what all science, when perfect, must needs be, what every well-fashioned mental organisation ought to be.

In youth, divided into its pubescent and adolescent periods, and, in relation to our subject, taking only the forms of mental disease that may come into question or relevance, besides idiocy's minor degrees, the chief to mention are simple dementia, hallucinatory, and confusional cases; melancholic, maniacal, and “transitory” attacks; periodical and circular psychoses; katatonia, hebephrenia, the paranoias; hereditary forms marked chiefly by impulse or moral perversion; cases on “mental besetment” (obsessive) basis. Many other forms of insanity, of course, exist in youth.

In recent years very numerous observers have endeavoured to ascertain if, in cases of general paralysis, micro-organisms can be demonstrated in the cerebro-spinal fluid withdrawn by means of lumbar puncture during life. All, with one or two exceptions, have obtained negative results, both from direct examination of the centrifuge deposit and from cultures, and the very general conclusion has consequently been formed that no micro-organisms are present.

In view of the general interest at home and abroad taken in “maniacal-depressive insanity,” and because of the special attention this division of the Medico-Psychological Association gives the subject to-day, the writer ventures to submit some considerations (based on his personal experience) on the value of the term.

For the purpose of this report the definition of Maniacal-Depressive Insanity as laid down by Kraepelin has been adopted.

In examining the male cases admitted to the Richmond Asylum during the year 1907, special attention was paid to the mixed variety of maniacal-depressive insanity as described by Kraepelin. The result, I must say, was disappointing, for out of 292 admissions only one case came under this head. It is only right to state that fifty-five of these cases were drafted to the Portrane Auxiliary Asylum, where I was unable to follow their history. Of these 292 cases 42 were suffering from acute mania and 59 from acute melancholia, and neglecting the cases sent to Portrane, none of these, with the one exception, departed from the ordinary course of these diseases.

The lectures of Prof. Kraepelin, as presented to us in Dr. Johnstone's excellent translation, form a fascinating study. Yet it is probable that with respect to some of them a reader is apt to rise from their perusal with a certain amount of mental confusion. His descriptions, from a clinical standpoint, are delightful reading, and lucid in the highest degree; but when, with the help of new terms, which really only express old familiar facts up to this otherwise expressed, he casts into new groupings cases which have two or three features in common, although differing considerably in their course and in the varying phases of mental disturbance which they present, there is a difficulty in following him. And any scheme of classification founded on a more or less casual and fortuitous similarity as far as a few symptoms are concerned, while ignoring important points of difference, cannot do anything else than create confusion. No doubt Kraepelin's object, so far as we can judge of it, is to group cases of insanity in such a way as to constitute a real help to diagnosis, and, what is of more importance, to prognosis, in the multitudinous phases of mental derangement which come under our notice, and this object is, so far, a meritorious one. But is the object attained by this method? Is it attainable? The fallacy—for it is nothing else but a fallacy—of regarding any mere grouping of symptoms of insanity as a distinct disease entity is apparent throughout. Insanity is protean in its manifestations, and the symptoms in any particular case may at one point of its course resemble those of one of the so-called varieties, and at another they may correspond with those of quite a different grouping. This fact alone would seem to indicate the futility and uselessness of founding any system of classification of insanity on symptomatology. The endeavour to do so can only be regarded as an impossible feat, a feat which is nevertheless being constantly attempted with a persistent fondness which is quite pathetic by most classifiers, who seem anxious to rival the punitive labours of Sisyphus or the daughters of Danaus, with similar fruitless results.

Before submitting to you my ideas on the much-disputed question of dementia præcox, there are one or two points in the papers of Drs. Jones and Urquhart to which I should wish to draw attention. I will take them in the order in which they occur.