When two persons meet together to discuss some enterprise or future event, or other speculative matter, without coming to an agreement, they may separate by one thinking or calling the other an optimist and the other thinking or calling his opponent a pessimist. Thereby they settle the matter temporarily, although of course they leave it undecided and agree only to differ. What they really settle is that two congenitally different temperaments necessarily view the subject from two different aspects and conclude accordingly. They do not stay to enquire which is the true view, the one being inclined by his temperament to look on the dark side of things and see the evils, hates, strifes, sufferings, failures and follies in the world, the other inclined by his temperament to look on their bright side and accordingly see the good, love, joys, and successes in it. Why, indeed, should they stop to enquire? Every mind in the world necessarily construes it in terms of itself, and therefore feels and thinks its individual world—the mind of the fool a different world from that of the sage, the mind of the sinner from that of the saint, the mind of the Andaman Islander from that of the Anglo-Saxon, the mind of the particular person from that of his neighbour. There must naturally be one common world in the necessarily common notion of a like-structured species, but there are as many particular worlds as there are persons in it.

I. In pursuance of the intention, signified in my “Notes on the Mental Deficiency Act” in the Journal for July, 1916, to consider, as practically as may be, the subject of mental defect as a factor in the production of crime, I find it desirable to make some introductory remarks concerning the recently increasing literature of what is known as “Criminology.” This term may be properly applied to investigations undertaken with a view to giving such an account of criminal conduct and criminal men as may assist in the formation of practical measures towards the prevention of the one and the appropriate treatment of the other. Most of the more modern discussions on crime and criminals have either directly or indirectly been occasioned by the efforts of persons concerned in some way with prison administration, or otherwise specially conversant with convicted criminals, who strive to discover just principles on which to base their practice. But the growing bulk of doctrine and debate on the causation of crime, the genesis and treatment of the criminal, the meaning of “responsibility,” and even the State's “right” to “punish” offenders at all, consists to a great extent of definitely formulated theories largely based on preconceived assumptions regardless of fact, and often mutually contradictory. This occasions much difficulty to those who aim at any clear understanding of the subject; and the difficulty is increased by the frequently indefinite and equivocal use of the words “crime,” “criminal,” and “punishment,” which denote the very subjects of discussion. Thus the handling of the whole matter becomes widely diffused, leaving no firm ground on which to rest any useful conclusion. Sundry kinds of topics, sociological, ethical, psychological, and biological, become involved in the dispute, and the student may even be landed and left in the midst of such perennial controversies as those about the “freedom of the will,” and the nature, and even existence, of the relation between mind and matter.

Gowers states that the morbid state causing epilepsy “consists in some trifling alteration in the chemical constitution of the grey matter of the brain on which the instability spoken of depends.”

The ordinary biological teaching is to the effect that the inheritance of the child is not affected by the education of the parent. That dictum is not based upon a direct investigation of the matter itself, nor is it based upon an investigation of anything which is related to human intelligence. The dictum is nothing but an unwarranted deduction from observations on the colours of animals, and some experiments on amputating the tails of mice.

[The following article from the pen of the eminent biologist, M. Yves Delage, was brought under the Editors' notice through the kindness of Sir Bryan Donkin. The vein of irony and caustic humour, more or less scathing, which runs through it will, no doubt, be distasteful to those who have accepted in their totality the theories of the Freudian school, but it is as well that the teaching of that school should be presented for the nonce from a different standpoint from that adopted by its whole-souled adherents. And while it may perhaps offer some rather “strong meat” for our readers' consumption, and while, in particular, the interviews so graphically described may seem too out-spoken and realistic for some ultra-sensitive British minds, it can hardly be questioned that they are, unfortunately, true to fact; and it might be a blunder on the part of psychiatrists who cannot bring themselves to admit the soundness of the principles of Freudism to content themselves with the adoption of a merely passive attitude towards them, and, ostrich-like, to shut their eyes to an aspect of a movement which is spreading with more or less rapidity in our own and other countries outside Germany, and which in the view of many sober thinkers is, in much of its theory, scientifically unsound, and at least capable of becoming demoralizing in practice; and if, through a no doubt pardonable repugnance to anything savouring of prurience or salacity, they were to allow themselves to drift into the opposite extreme of a too meticulous and hardly justifiable prudery.

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.

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 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 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.