Functional disturbances of the digestive system are common accompaniments of neurasthenia. I shall avoid all attempt to classify them, and confine myself to describing certain cases in some detail with a view to bringing out the points of practical importance in causation and therapy.

In 1895 an unostentatious book quietly appeared in Leipzig and Vienna entitled Studies of Hysteria (Studien über Hysterie), written jointly by two authors, Dr. Josef Breuer and Dr. Sigmund Freud. There was no public ready to receive the book, it attracted little attention, and had a small sale. In England and America it remained almost unknown, so that it is now a satisfaction to the present writer to recall that almost the first full exposition in English of the views set forth in this book appeared in the first volume of his own Studies in the Psychology of Sex in 1898. Yet these studies of hysteria, as an attentive reader could scarcely fail to realise, turned over a new page in medical psychology, and the new page was of fascinating interest. A case of hysteria was no longer to be regarded as, on the psychic side, almost beneath a physician's serious attention, nor was it to be settled merely by an accurate description of the physical symptoms, after the manner of Charcot's school, to which school in the first place Freud himself had belonged. It was a mystery to be patiently investigated, a mystery to which the key often lay far back and forgotten in the patient's history, and when skilfully used, with knowledge and insight, the patient's medical history acquired not only psychological significance but something of the interest of a novel. Freud himself clearly recognised this and stated, even in this first book, that it was by a representation of psychic processes, “such as we are accustomed to receive from the poet,” that he had gained his insight into the nature of hysteria.

The bacillus of influenza was discovered and accurately described by Pfeiffer in 1892. Its etiological relationship to the disease is now beyond serious dispute. It is a comparatively minute bacillus, Gram-negative, and devoid of capsule or spores. The chief seat of infection is the respiratory tract. The bacillus requires very special conditions for its artificial culture. The bacteriological text-books prescribe the use of fresh blood smears, and generally state that the organism can be grown along with other bacteria—that is to say, in symbiosis with them. In the laboratory of the Scottish Asylums it was ascertained that the bacillus of influenza has the remarkable property of being stimulated to growth by mere proximity to other bacteria, and thus the alternate drill method has come to be a routine of the laboratory whenever this bacillus has to be subcultured.

The large chapter of aphasia and allied conditions of psychomotor and psychosensory disturbances is still a chapter where there are great differences of opinion, and a great heterogeneity in nomenclature.

The marked complexity of the convolutions of the brain of man, as compared with the lower animals, has suggested to numerous writers that the higher intellectual and other mental faculties characteristic of the human subject are in more or less direct relationship to the amount of grey matter in the brain. Attempts have therefore been made to measure the amount of grey matter in the brains of persons of very different degrees of intelligence and mental development. Owing to the highly complicated nature of the convolutions of the human brain, the method of estimation by direct dissection of the grey matter from the underlying white matter has not been adopted except in the case of a very few brains, most workers having approached the subject by indirect methods. Some observers have directed their attention to the measurement of the surface area of the grey matter, others to the determination of the absolute amount of cortex. Danilewsky, as a result of observations upon the specific gravity of the brain and of the grey and white matter, has calculated that the cortex forms 30 per cent. of the total brain weight. Donaldson, on the other hand, has estimated the grey matter of the hemisphere as forming 50 per cent. of the whole.

In the beginning every creature was a patriarch: it was, philosophically, not only its individual self, but also all its potential progeny. Such a creature's whole conduct was directed towards the one goal of eternal life on earth. It so happened that in very many cases the creature's best chance of success involved association with other creatures of its kind, or even of other kinds. From this arose the complication of the acquirement of tribal instincts. Tribal instincts were acquired only for patriarchal purposes, though in very many cases they proved to be the immediate cause of the creature's death. A further complication arose when certain of the creatures acquired intellect and took to thinking. Philosophically, a living thing exists only that it may produce a generation capable of producing yet another generation. A generation is important only as the cause of its next generation. Intellect often gave the creature an immediate advantage over rivals, but it glorified the individual self at the expense of the patriarchal self. This is recognised in the third chapter of Genesis, where intellect is called the serpent, and thinking is called (in Chapter II) the tree of the knowledge of good and evil. The statement that “in the day that thou eatest thereof, thou shalt surely die” declares that the race is kept going only by those who do not understand how to limit their families.

In the preceding paper it has been shown that the general or local atrophy of the brain occurring in chronic insanity is very largely due to loss of white matter. It seemed to be of interest to determine what chemical changes accompanied this shrinkage in the size of the brain. As a preliminary to an examination of the complex substances of which brain matter is composed, it was necessary to investigate the proportion of water to solids, as the figures obtained in this way are of the highest importance in regard to the interpretation of the results obtained by chemical methods. The examination of the various portions of brain tissue for the amount of water was therefore proceeded with as a routine measure. The whole of the grey or of the white matter, as the case might be, from each of the five portions, obtained as described in the preceding paper, was spread on glass plates in as thin a layer as possible and carefully weighed. The plates were then placed in a Hearson electric drying oven, the temperature of which was maintained at about 90° C. A current of dry hot air was passed into the oven from a fan attached to a small motor. After fifteen to twenty hours' exposure the plates were removed from the oven, and the solid material which remained was carefully and completely scraped off. It was then allowed to cool to room temperature and weighed. The material was returned to the oven for some hours, again removed and allowed to cool. This procedure was continued until the material attained a constant weight at room temperature. The percentage of water in each sample was then calculated.

Crimes connected with dementia paralytica and dementia of senility are relatively common, and many text-books speak of “medico-legal periods” in describing these diseases.