I propose in this address to call your attention to some phases of mental disorder which depend on toxæmic states. These are now differentiated by the alienist, and it is only in recent times that their true nature has been unfolded. They have been long recognised as clinical features of disease, and the sources of them are as varied as are the separate toxic elements which induce them. Progress in physiological chemistry and bacteriology has now furnished us with the means to explain these conditions. The origin of these toxins is at least threefold. They may be generated in the body (auto-intoxicants), or by the malign working of microbes introduced from without, or they may arise by impregnation with organic poisons, or yet again result from the habits of alcoholism, chloralism, cocainism, and morphinism. In the majority of cases of insanity I suppose it will be conceded that there is a hereditary or inborn predisposition to the disorder, an instability or a tendency to this cerebral degeneration which may remain latent until conditions arise which are potent to elicit the breakdown. In the class of mental disorders we are now to consider there may or may not be this inherited fault of brain tissue. In many instances of toxic insanity we have to deal with persons who are already predisposed to mental instability, but in other cases a previously normal brain may be so damaged by toxic influences as to manifest aberration. We have long recognised the toxic effects on the nervous system of the altered metabolism induced by renal inadequacy in Bright's disease in the varied forms of uræmia, in that strange variety of autotoxy due to inability of the hepatic and muscular tissues to hold carbohydrate in reserve, resulting in diabetic coma, and that variety which depends on acute atrophy of the liver. We can now understand how these auto-intoxications act in disturbing the harmony of intimate brain-cell metabolism. Their effects are as certain as are those of poisons directly introduced by the mouth or under the skin. The chemical functions of the brain cell are disordered in precisely the same manner. In the ordinary practice of medicine we are familiar with states of delirium and mental aberration in the course of the various fevers and in pneumonia. Recognising these as infective disorders we now know that we are dealing with the toxic effects of invading parasites, and that amongst the manifold expressions of their presence are nervous or brain symptoms. These are frequent in pneumonia, and strangely so when the pulmonary apex is involved. The reason for this is to me inscrutable, and I can only conceive that it results from some special local nervous relations which have hitherto escaped the recognition of the physiologists. With respect both to pneumonia and the various fevers, I have to add that a careful inquiry in cases where grave nervous or mental symptoms have supervened, has almost always revealed the existence of personal or family neuropathic taint. Puerperal insanity occupies precisely the same position, and inquiries in these cases show that about one half of them occur in women of neurotic or insane proclivity. Toxic influences naturally affect them more readily and with greater gravity. The insanity of lactation probably owns a different cause, and may be attributed to debility and imperfect nutrition, acting probably in many cases upon an originally unstable brain. What has been termed “post-operative insanity,” due to infective influence, together with shock or exhaustion, and occurring within a few days after operation, may be similarly classified, although Mr. T. C. Dent is of the opinion that heredity of brain weakness plays but a small part in these cases, and that some of them apparently result from the influences of the anæsthetic agents employed or from iodoform impregnation.

I need hardly apologise to you for my appearance once more before you as a reader of a paper, yet I think it well to give you my reasons for selecting this subject for to-day's discussion. For years past I have been feeling more and more strongly that travel as treatment was being carried too far, and having often in private expressed this feeling, I think it right to assert my belief here, fully recognising that I may be looking at the subject from a wrong standpoint, and being quite ready and willing to learn by the experience of others. I recognise in myself a tendency to believe in my own experience, and thus I may be warped.

It gives me great pleasure to have an opportunity of bringing to the notice of this meeting some matters connected with electrical treatment, because I believe that in the management of mental cases a very suitable field of application may possibly be found for electricity.

As the mode of dealing with those insane persons who have committed offences bringing them under the authority of the criminal law differs in some respects from the practice followed in the case of the ordinary or non-criminal insane, I thought that on the occasion of the visit of the South-Western Division of the Medico-Psychological Association to this Asylum a brief outline of the history of the arrangements for the care and supervision of the criminal insane in England might perhaps be of interest to those members who have honoured Broadmoor with a visit to-day.

In studying epilepsy we see and study symptoms only. The pathology of the disease is very obscure, and it is mainly from its clinical features that we are able to assume the presence of detrimental changes in the more highly specialised tissues of the cerebrum. These changes may be primary or developmental as in the idiopathic type; or they may be accidental, and due to toxic agencies or traumatic injury; or they may be senile, as seen in rare cases (not accidental) occurring in late adult life or old age. Whatever the origin, a condition of nervous instability is set up, which may vary in every possible degree, from simple molecular disarrangement, giving rise to perverted functional action for a brief period of time only, to more lasting effects which conduce to morbid energising of a permanent nature.

Both in physiology and pathology the study of simple, incomplete, and degenerate forms usually sheds a light, sometimes very clear, on more complex and perfect types. For example, such works as those of Spencer, Maudsley, Laycock, and Carpenter show how much the relation of mind to organisation is elucidated by careful observations of the nervous system in the lower orders of the animal kingdom, and of its condition in the abortive and morbid specimens of the human species. In pathology, more particularly, it is not usually where disease has attained full maturity or has advanced to its last stages that we may expect to find its point of origin, mode of progress, or essential nature; rather it is where pathological change is only beginning, in tissue that deviates but little from the healthy standard, or in function that is but slightly disturbed: so in the special pathology of the nervous system much may be learned regarding the more serious diseases by minutely examining and considering the features of the slighter and less striking disorders.

Though medical science has made great advances during the nineteenth century, our knowledge of the mental functions of the brain is comparatively still obscure. Even as regards the elementary principles of mental science there is still a diversity of opinion. Thus when we state the first fundamental principle, that the brain is the organ of the mind, on which we are all agreed, we in reality differ widely according to the interpretation we give to the word “mind.”

It is a recognised fact that nervous and mental disorders are more frequent after influenza than after any of the other zymotic diseases. Dr. Risien Russell has specially referred to the action of the influenza bacillus and its toxin on the nervous system. Dr. Clouston has expressed the opinion that the effects of influenza on the mental condition of Europe far exceeded in destructive powers all the continued fevers put together. An increase in the admissions of melancholic patients into several of the asylums of this country during the prevalence of influenza has been reported at Edinburgh, Hanwell, Birmingham, Nottingham, and other institutions. Dr. Macpherson and Dr. Farquharson have discussed the pathological aspects of depressed emotions, and the physical reduction caused by influenza, as favourable to the onset of melancholia.

All histologists who have worked with the silver and sublimate methods of Golgi have experienced the great inconvenience arising from the facts that the preparations are not durable, and that in mounting them a cover-glass cannot be employed in the ordinary way. Preparations by the silver method generally remain in good condition for a somewhat longer period than those by the sublimate method; Golgi has indeed stated he has some which have remained unaltered for nine years. The sublimate method is now most commonly employed in the form of the modification of Cox, in which only one fluid is required instead of two. In preparing sections of tissues that have been kept for the necessary time in this fluid, it is practically essential to blacken the originally steel-grey deposit by one or other of the several methods by which this may now be done. Such preparations, when new, are probably unsurpassed by those obtained by any other Golgi-method; but, unfortunately, when mounted in the orthodox manner without a cover-glass, and in spite of the most careful attention to various other technical details that have been recommended for the purpose of increasing their durability, they almost constantly show disintegration of the black deposit in from four to six months, and are certainly absolutely useless within a year. Ever since Golgi's methods came into use, histologists have been endeavouring to find some means of overcoming this great disadvantage of want of durability of the preparations. The only measure of success that has so far been achieved is that obtained by means of various processes of gold toning. All gold methods are, however, notoriously uncertain in their results. This, of course, simply means that in carrying them out it is necessary to fulfil certain very precise conditions, and that these conditions are as yet imperfectly understood. Certainly the gold toning processes that have been recommended for rendering Golgipreparations permanent are no exception to this rule. Our own observations and experiments have been made chiefly upon sections of tissues preserved in Cox's solution, because we are convinced that Cox's method is for various reasons the most trustworthy process of this class that has yet been devised, and therefore the one most likely to be of service in studying pathological changes. We have tried the methods of Obregia and Golgi for toning sublimate sections with gold. With that of the former we have not had any success. On the other hand, with that of the latter (as briefly described in Jack's translation of Pollack's Methods of Staining the Nervous System) we have obtained some very beautiful purple-black preparations, which have now remained unchanged under a cover-glass for considerably over a year. In the great majority of instances, however, the results have been unsatisfactory, the deposit rapidly undergoing disintegration.

The demonstration I am about to give on the “Morbid Changes in Dementia” is a preliminary report of an investigation which I have nearly completed, and which I propose to publish in detail later.