Psychiatry in its literal sense is the medical treatment of mental disorders, which necessarily implies the scientific investigation of the nature and causes of these disorders. Psychiatry is therefore indissolubly linked with the medical and biological sciences, and participates not only in their solidarity, but also in their unrest, for every advance in these sciences intimately affects its outlook. In addition it has undergone—and is still undergoing—vicissitudes peculiar to itself which are unknown in other departments of medicine.

We are all familar with the clinical picture of a case of epidemic encephalitis of the Parkinsonian type: the fixed flexion attitude, festinating gait, mask-like face and general slowing of all voluntary movement. What is the explanatory pathology of each and all of these physical signs ?

This sequel of encephalitis lethargica has attracted much attention on account of its great frequency. It was found in 70 out of 129 cases studied by Mme. Lévy. In the earlier pathological studies of the syndrome attention was focussed chiefly on the midbrain; recent researches have proved that the changes in the nervous system are more widespread than were at first apparent.

Hitherto the treatment of post-encephalitis has been profoundly unsatisfactory, and for the most part only palliative.

There are at present in mental hospitals some 200 cases; this is only a fraction of those not certified, and consists of an asocial class impossible to deal with outside a mental hospital.

In a previous paper (Journ. Ment. Sci., April, 1928, p. 269) the writer has pointed out that a culture tube of tyrosine bouillon, if inoculated from the fæces of a healthy person, incubated for forty-eight hours and distilled, will be found to contain not more than 0.008% of phenol, or at most 0.015%. If, on the other hand, similar cultures are made from mental patients they will contain 0.02 to 0.03% of phenol in one half of the persons examined. In all these cases the phenol is formed by the action of bacteria on the tyrosine in an alkaline medium. The most important phenol-producing bacterium in the insane is B. Morgani, which can be demonstrated in 25% of acute cases, while B. phenologenes, Berthelot, is found in a smaller number. The paper referred to dealt with the toxic effects of B. Morgani and the results of vaccination with this organism. In the present paper another aspect of the matter will be considered, namely, the production of tyramine from tyrosine by intestinal bacteria, and whether poisoning by this substance may be a cause of mental disturbance.

The following is the first of a series of communications relating to urinary excretion in cases of mental disorder with special reference to acid excretion. In this paper it is proposed only to deal with the make-up of urinary acidity and the methods for the determination of the acid characters. It is well known that respiratory regulation constitutes the first line of defence against change of body reaction, and that the kidneys afford the second protection against alteration by variations in the acid-base ratio of the urine. It is also fully established that urinary acidity is dependent on the nature of diet ingested, but it is not so well recognized that the urinary reaction is also dependent on the adequacy of the respiratory compensatory mechanism, and it would appear that those interested in dietetics and chemical effects on urinary acidity have not appreciated sufficiently the significance of the physiological influences, and those concerned with the respiratory side have been apt to disregard the influence of diet. The organism promptly defends itself against alkalinity by the excretion of bicarbonate, whether the alkalinity be due to ingested alkali or excessive exhalation of acid (CO2), and this excretion of bicarbonate appears to be independent of any particular renal threshold for bicarbonate. The response of the organism to acidity, however, is a much longer process, and in this case the kidney compensation takes the form of retention of base by ammonium base production and the retention of bicarbonate by alteration of the ratio of mono- and dibasic phosphate excreted according to the equation—

In the normal subject the reaction of the urine denotes the tendency to reaction change of the blood and organism—a tendency which is adjusted by the respiratory mechanisms. To maintain a constant blood pH and CO2/NaHCO3, the kidney retains or rejects base and the lungs increase or decrease acid (C02) output, these compensatory processes being interdependent. With a definite relationship between urinary acidity, blood alkali reserve and alveolar air CO2 tension the ratios are maintained. Urinary reaction represents the acid or alkaline “pressure”on the organism. The reaction of the blood and tissues depends on the adequacy of respiratory adjustment: in fact, as Henderson says, “low pH (acidity) in a fluid buffered like blood can never be due immediately to any other cause than relatively depressed breathing.”

The preceding studies on the acid-base equilibrium in psychotics have made it evident that the failure to adjust must be attributed in the first instance to an inadequacy of the respiratory compensatory mechanism, and can be in no sense attributable to either a deficiency in the buffering power of the blood itself or to an increased organic acid production (acidosis). We have endeavoured to determine the excitability of the respiratory centre to the stimulus created by CO2. For this purpose a number of psychotic patients were tested as to the excitability of the respiratory centre to air containing 2% CO2 and the reaction compared with that obtaining in a number of normal subjects.

In the search for somatic disturbance in connection with the insane, either as a cause or as an effect of mental disorder, the acid-base balance has afforded a field of exploration from time to time. Epilepsy, in particular, has provided material for research on these lines. Bigwood (1) (1924) suggested that the epileptic seizure was preceded by an alkalosis, leading to a lowered blood-calcium content, which, in turn, induced the fit. Marrack and Thacker (2 and 3) (1926) disproved this theory, but found that a high blood-ammonia content obtained at times in epilepsy (4), but was not related to the fit. It was actually a starvation phenomenon. There has been biochemical work on other lines in epilepsy in regard to nitrogen retention (5) on the sugar content, but all with negative results.

The progress made in recent years in the study of vitamins has been phenomenal in that many disorders previously regarded as of infective origin have been shown to arise from deficiency of some particular item of the diet, which quantitatively is infinitesimal in relation to the total bulk of food taken. Although some five vitamins have been identified and their value established, as yet only one has been isolated in pure form and has acquired the distinction of a chemical formula. This vitamin—fat-soluble D—has a powerful influence in the prevention and cure of rickets; and its relation to dentition and caries of the teeth has been established by careful and prolonged experiment. So far as we know at present vitamin D can be obtained by the body from three different sources. The effects on health of sunlight and ultra-violet rays on the skin have been shown to arise from the capacity of the cells of the sebaceous glands of the skin to manufacture under these influences, from the various sterols they contain, a substance—vitamin D—which is then picked up by the blood-stream and distributed throughout the body. The second source is the fat taken in the diet, butter and cream being particularly rich in this respect. It has also been proved that food exposed to ultra-violet radiation acquires in an added degree the capacity to ward off the ill-effects of vitamin D deficiency. The third and, from the point of view of accurate laboratory control, the most important source is that in the form of ergosterol, a compound related to cholesterol, produced by extraction from yeast and other substances. Ergosterol can be obtained in more or less pure form, and after being subjected for a definite time to irradiation by ultra-violet rays becomes converted into a substance which has all the effects of vitamin D.

The aims and objects of mental deficiency institutions in England have altered fundamentally more than once since they were first started. These alterations have, in many respects, been quite as substantial as the changes in outlook of the mental hospitals.

The scope of this contribution is to give an account of the administrative and clinical methods at the Boston Psychopathic Hospital, to give a picture of the clinical material, and to discuss the advantages and disadvantages of the system.

In July, 1927, at a British Medical Association meeting, in the Obstetrics and Gynæcology Section, G. I. Strachan dealt with the mental side of the hygiene of menstruation. He made the statements that in cases where menstruation was influenced in mental disease it was usually in the direction of excess, and moreover he had found no justification for the text-book statement that insanity was usually accompanied by amenorrhœa. A study of the more important text-books of psychiatry reveals a paucity of information on the subject, and this has stimulated me to collect any facts which have bearing on this interesting problem.