In the minds of all those who have considered brain problems there is now a firm assurance, attained by the process of induction from fact, that there is nothing connected with human disease or conduct or emotion or volition with which it has not to do. We see that to make an efficiently working brain has been Nature's chief aim from the moment of conception right on though life, and that its mental action has been the highest of all its aims. There are, no doubt, questions of extreme difficulty, if we are to understand such problems as mind-cures, hypnotism, spiritualism, telepathy, autosuggestion, and mental disease and defects. We are fully aware that we must first, by careful study of brain and mind-working, attain a more accurate knowledge of the normal before we can solve the abnormal conditions.

The brain contains some three thousand million cells, each one actively producing, energising, controlling, stimulating, or co-ordinating the physical, the mechanical, the bio-chemical and the mental energies of man. Onefourth of those cells, at least, have to do with mind, the others being devoted to sensation, muscular movements, nutrition and bodily inhibitions; but all are coordinated and connected by fibres capable of co-relating the energy which each cell produces. They are arranged in separate groups or areas, each with a special function; the whole forming a vast telephone system, as it were, most complicated but orderly, with combined localisation, solidarity and general harmony of action. The cells are arranged in different levels,' each higher in function and in a position of command in regard to the level below it, thus forming a sort of hierarchy. The cells that have to do with mind are all in the highest level; and we now have ground for thinking that they lie chiefly in the 'forebrain,' which is the last to be evolved and the first to decay in old age and in mental disease. Many of those groups of cells have the function of controlling the action of others. There are 'centres of inhibition' everywhere; but the mental areas are, or should be if in health, the supreme controlling centres. In children, in poor brains, in undeveloped brains, in hysterical, unstable and insane brains, those highest centres of control are so weak that their conjoined action becomes irregular and abnormal, bodily and mental control being thus lost or impaired.

Over a large portion of the highest level of the brain the special work of each group of cells or 'area' is now known. If our speech-areas are diseased we cannot speak; if the hearing areas are destroyed we cannot hear; if the areas for the legs are hurt we cannot walk; if the purely mental areas are disordered we cannot think; if the areas of inhibition are diseased we cannot exercise mental or bodily control. Not only so, but if the cells of the eyeareas, for example,'are unduly excited, objects are thought to be seen which do not exist in reality, and hallucinations result. It takes the highest kind of brain of all to be able to reason correctly; but, if the mental areas in such a brain are disturbed in action or diseased, correct reasoning is impossible. A quart of whisky circulating in the brain of the profoundest philosopher on earth will make him a fool for the time being.

One of the most striking of the qualities of a braincell is that by which every impression made on it, either from the outside world through the senses or from the working of another part of the brain, is registered and leaves a permanent impression which can be at any time reproduced as a memory or an automatic movement. We do not know precisely in what this 'registration' consists; but a certain molecular or bio-chemical change has certainly taken place in the substance of the cell, through which it has received a new potentiality that it did not possess before. Memory has thus a physical basis. It is like a gramophone disc with a new tune traced on it, or a photographic plate before development. The disc can ever after reproduce its music, and the plate can show its pictures. The brain-cell has similarly a 'memory' impressed on it which lasts till disease or old age obliterates it. But what a content does every human brain thus carry-millions of sense-impressions and past movements, hundreds of thousands of ideas lying hid through some physico-bio-chemical process! The printing in the largest book in existence does not compare with even a poor human brain in its contents. Thousands of words, for instance, lie in every educated brain. No mere mental effort can thus impress or receive these if the brain-cells are not at the time impressionable. No mere volitional effort can reproduce them if those cells are not in activity and the brain is not in health.

When an impression is made on a brain-cell or a group of cells by an object outside the organism, say a tree, before the eye, its picture is first formed on the retina; an impression of that passes up through the optic nerve to a lower area in the brain, then up to the cortex where the processes of perception and apperception take place; and, if the faculty of attention is in exercise, a 'presentation' of the tree is made on consciousness and may associate itself with similar ideas. All this is written in the brain-cells, and during life forms a part of their constitution. When the memory of the tree comes up at any later time, a process called 'representation' takes place, during which the picture is there before consciousness, but not so vivid as the original presentation; and it is recognised to be a memory, not the thing itself. It may by some persons be visualised,' but still can be accurately distinguished by a healthy brain as not being the objective tree. In morbid conditions of the brain, as in many forms of insanity, in dreaming, in specially excitable states of the brain, in hysteria sometimes, in hypnotic conditions, in states of intense religious feeling, or when certain poisons, such as Indian hemp (hashish), are circulating in the brain, these representations are so vivid that they may be mistaken for presentations. This explains the mechanism of seeing ghosts, of visions, of supposed communications from the spiritual world and states of ecstasy. Then the brain-cells speak, or see, or hear, or taste, without objective causes. Such conditions of brain must be taken into account before we can understand mind-cures. The brain cannot do two contrary things at once. When used as a vehicle of abstract thought, it cannot send volitional stimuli for muscular exercise. If it is occupied with cheerful and optimistic feelings, it will not receive distinct impressions from a rheumatic joint or a neuralgic face. It cannot feel pleasure and pain at the same time. It is also a 'creature of habit'; what it does once it tends to do again, and much more readily. Therefore we should keep it occupied with anti-painful emotions if we are to effect mind-cures in a scientific way.

The consideration of this marvellous quality and constitution of the brain-cells enables us to put on a scientific rational basis the ideas of sub-conscious' and 'super-conscious' mind, now so much referred to, but so

little understood. Frederick Myers' 'subliminal consciousness' may thus become a possible scientific conception. A sub-consciousness or even a' latent' consciousness is really no consciousness at all, if the word is used in a proper sense. Consciousness is either present or it is not. There may be, no doubt, a vivid, or an obscure, or a partial consciousness. There may be even a false consciousness, as in dreaming or in some of the hypnotic conditions or vivid representations, but these are entirely different from a 'sub-consciousness.' What really exists is a potential consciousness.

From the point of view of modern scientific medicine we should like to use an exclusively non-metaphysical terminology, but that is not yet possible. We have not yet devised suitable terms. In science we must think of mind, not as a self-existing, self-acting entity, but as an energy which is as dependent on brain and brain-memories for its exhibition as electricity, motion, or heat are on matter. Those forces have their own laws of action, but they cannot arise or be manifested except through matter. In many respects the brain is to the mind as matter is to electricity. The theory of 'parallelism,' as to the co-relation of mind and brain-action, seems best to fit the facts, though it does not explain them. The 'sub-conscious' mind may be described as the brain-cells charged with mental impressions, but inactive.

Mental disease always implies disorder of both body and mind as a consequence of the brain being disturbed in its working. Its cure, therefore, must always take the body into account. The mental areas in the brain may, however, be diseased or disturbed without other demonstrable bodily disturbance. Electricity or heat may powerfully affect the matter through which they are generated. The heat that is produced by coal may be turned on to burn still further its source. In this sense mind may act on body and cure some of its diseases.

To understand how the brain, on receiving a mental stimulus, acts in curing bodily disease, it is necessary to look at some ordinary physiological effects which the highest level of the brain under a mental stimulus can produce on the body. A young woman hears or sees or thinks of something that rouses the emotional feeling of modesty; at once the capillary blood-vessels in her cheeks

dilate, and she blushes. A vaso-motor centre in her braincortex, connected with the emotional and sex centres, has been excited into activity, and by means of its nervous connexion with the cheek has dilated the blood-vessels there. The whole process is from beginning to end a brain process, though, since the emotions are consciously 'felt,' we no doubt require the Ego' for the full explanation of the feeling. Determination' of blood to particular parts of the body by brain-mental influences is provided for under many emotional states. Interference with the heart's action in various ways, by quickening, retardation, stoppage and irregularity due to emotional and brain causes, are well-known facts, so much so, that 'the heart' has come to be another word for the feelings. To determine blood to parts of the body or the brain affected by certain diseases is often to heal them. A modern German surgeon, Bier, has devised an artificial method of such determination of blood to assist the healing of certain surgical sores and wounds.

The effects of brain-mental stimuli on the action of the stomach, bowels, and digestion are also well known. Who has not had his appetite or digestion suddenly stopped by anxiety, or by hearing a piece of bad news? This is done through the brain-cells of the digestive centres. The bad effects of worry on the general health and nutrition of the body are known to everyone. The brain-cells then act less vigorously; the flow of blood to them through their capillaries-each cell has capillary vessels to supply it with nourishment-is lessened; the general feeling of well-being, of bien-être, is lost; the countenance becomes sallow, the blood poor, the muscles flabby; and exertion, bodily and mental, becomes painful instead of being pleasurable-all these bodily and mental effects being due to abnormal action in the mental centres of the brain.

The apparatus for the production of these and hundreds of other bodily effects, good and evil, exists in the brain. It is part of the normal bodily armamentarium. When, through this apparatus, certain diseases are cured during hypnotism or 'faith-healing,' there is no more miracle or special mystery about the process than the perpetual miracle of the daily work of the human brain, or its exact parallelism with our varied mental conditions,