There have been several inquiries into the incidence of various “neuropathic” conditions among the relatives of the mental defective, and it has been found that mental defectives often have relatives who have suffered from such conditions as cerebral hæmorrhage, epilepsy, alcoholism, etc. Thus it has been stated that 80% of mental defectives have a “positive” family history, and it is suggested that this figure (80%) supports the theory that most mental deficiency is due to hereditary factors. Before the significance of such a figure can be discussed we must first know the corresponding figure for the normal population.

This paper is a preliminary report of some investigations we are now making into the pathology of mental deficiency, mainly from the histological point of view. We have so far examined 22 cases, comprising 7 low-grade defectives showing gross neurological lesions, chiefly of extrapyramidal character, 6 microcephalics with spastic diplegia and severe mental defect, 2 able-bodied microcephalics without gross neurological signs, 1 simple able-bodied idiot and 6 mongols. In this short paper it is impossible to give even the slightest indication of the wealth of pathological material found in such a variety of widely differing conditions. A full description of our findings, together with a more detailed discussion, must be left to further papers dealing with individual groups of cases. The purpose of making a short note at this stage is to draw attention to one particular finding which struck us by its surprising constancy, i.e., a proliferation of the fibrous glia, particularly pronounced within the cerebral and often also the cerebellar white matter. In many of the cases the cortical changes were slight compared with the intense lesions of the white matter. In none of them was demyelinization a well-marked feature, nor did its severity approach that of the glial proliferation; in many it was negligible, and there were none of the fatty breakdown products, characteristic of the demyelinizing disease of the white matter called after Schilder. The gliosis was either diffused or patchy, and was often markedly perivascular; even stripe-like scars, as described by Hallervorden (10), were to be seen, although, contrary to this author's observation, there was, as a rule, no corresponding myelin defect.

A considerable diversity of opinion exists on the definition of that part of the personality which is known as temperament, and some authorities go so far as to say that no practical advantage is to be obtained in differentiating it from character. Temperament, nevertheless, is the means in every-day use by which strangers provisionally gauge the extent of their affinity to each other.

Sporadic bacillary dysentery is an accepted concomitant of lunacy, and mental hospitals, on statistical evidence, harbour more than 99% of the disease. When an epidemic of dysentery occurs, the laboratory of the mental hospital is cluttered with fæcal specimens, but when the epidemic is resolved on a solitary “carrier” and a faulty drain the disease ceases to arouse further interest. Little effort is made to assess and control the endemic level. This the author has attempted to do, in a county mental hospital of, roughly, 1,000 beds.

The Mental Treatment Act of 1930 has brought within the purview of the mental hospital that large class of psychoneurotic and “early psychotic” patients who formerly drifted despairingly in the wilderness between orthodox medicine and the quack. The purpose of this paper is to show how an attempt is being made in this hospital to deal with this heterogeneous class of patients by means of psychotherapy, carried out by the ordinary medical staff of the hospital, without interference with their routine duties.