The nervous system of all vertebrates is built up of long conducting, specialized cells, termed neurons. In order to function, these neurons, or nerve-cells, must be linked together in chains or arcs. Each neuron in the chain or arc is structurally separated from other neurons by a break termed a synapse. The structural elements of a neuronic arc are, therefore, as follows:

1. 1. A sensitive receiving organ—the receptor or sense-organ.

2. 2. A centrally conducting receptor bipolar neuron.

3. 3. One or more short connector or internuncial neurons.

4. 4. A peripherally conducting effector multipolar neuron.

5. 5. An effector apparatus—for example, a muscle or a gland.

The Royal Commission on Lunacy and Mental Disorder was set up in July, 1924, to inquire into a matter of urgent public importance, that is to say:

1. (1) The existing law and administrative machinery in England and Wales in connection with the certification, detention and care of persons who are, or who are alleged to be, of unsound mind.

2. (2) The extent to which provision is or should be made in England and Wales for the treatment without certification of persons suffering from mental disorder and to make recom mendations.

When the patient, F. E—, handed me the MSS. entitled “Hallucinations and Sanity,” I recalled a paper read to this Association some ten years ago by the late Dr. Hunter Steen—a paper which Sir George Savage at the time styled as “mosetncyclopædic” (vide Journ. Ment. Sci., 1917, pp. 328 and 437). In the course of a most instructive discussion following on it, some points were raised which are especially noteworthy.

The literature dealing with coliform intestinal bacteria in patients suffering from mental disorder is extremely scanty. Goodall, Journal of Mental Science, 1927, p. 368, writes: “As resgards our knowledge of the intestinal tract as a source of infection I consider that the position is still very unsatisfactory. … For a few years prior to 1914 my colleagues and I at the Cardiff Mental Hospital Laboratory had carried out much tedious work on the bacteriology of the faces in states of acute melancholia and mania.

The structures which separate the blood from the cerebro-spinal fluid are of considerable importance in the physiology and patho logy of the brain, since they form a barrier which allows only certain substances to diffuse from the blood into the cerebro-spinal fluid. It has been found that the acute phases of certain mental and nervous diseases are associated with an alteration of the permeability of the brain membranes which form this barrier. Only recently, however, has there been any quantitative investigation of the relative dis tribution of substances in the blood and cerebro-spinal fluid; by means of this quantitative ratio the degree of deviation from the normal in various conditions of disease can be readily determined.

This paper is a preliminary account of some investigations being carried out at this hospital in regard to the possible toxicity of medinal and other hypnotic drugs, and its relationship with aceto nuria and alteration of the ammonia coefficient of the urine.

I must crave your indulgence for this ambitious title to a very short communication. My aim is to stimulate a discussion and to probe the experiences of others.

Epidemic encephalitis has become an increasingly important cause of insanity among the population, and during the past few years this disease has been seen more and more among the new admissions of mental hospitals. The various forms in which this disease may manifest itself in the chronic stage are now well known, and can be intimately studied in any large institution. Up till the present, however, no account has yet been reported, so far as I am aware, of the appearance of encephalitis lethargica among patients already resident in a mental hospital.

Cardiac infarction follows disease or occlusion of the coronary arteries. In 90% of cases it is due to atheroma with final occlusion by thrombosis; embolism accounts for the remainder. The records of the last one hundred post-mortem examinations on patients over forty-five years of age at the City Mental Hospital, Leicester, indicate that marked coronary sclerosis or atheroma with more or less occlusion occurred in 23 cases—II males and 12 females. In 5 the occlusion was almost complete, with fibroid degeneration of the myocardium, whilst in 2 cases, those to be described, occlusion was complete and followed by infarction.

That physical changes can give rise to mental symptoms has long been established; it is only necessary to recall the delirium of an acute pneumonia.