The Lunacy Acts of England and of Scotland are in urgent need of amendment. The parent Act for Scotland dates back to 1857, since when great changes affecting its serviceableness have taken place in the social life of the country as well as in the scientific world. It, however, definitely recognizes the paramount position of the medical profession in the treatment of mental diseases, for under its provisions no layman or magistrate is called upon to interview the patient before he is placed in a mental hospital, and no layman or visiting committee is held to be responsible for his removal when recovered. Medical men discharge these and all similar duties, and to this feature must be ascribed the success of the Scottish system. It has gained the confidence of the people' and in place of misgivings and suspicion, there is pride in our mental hospitals and in their management. No case of improper detention has ever been recorded in the law courts. The Act of 1857 has served its day and generation well, and its principles of medical responsibility and of reliance on the honour of the Medical profession are established in Scotland.

The part played by sepsis in producing nervous and mental disorders of all degrees of severity and the degree to which these can be prevented, checked, or controlled by antisepsis are singularly opportune subjects for discussion on an occasion marking the centenary of the birth of Lister. We are not only commemorating past achievement, but inaugurating a new campaign against sepsis in one of the greatest domains of medical diseases—that which bears the ill-omened title of insanity.

This subject should not be discussed, least of all in Scotland, without a tribute being paid to the work of Dr. Lewis Bruce, of Murthly, whose book, Studies in Clinical Psychiatry, published twenty-one years ago, is devoted to a consideration of the toxæmic causation of mental disorder.

Happily it is not expected that in opening a discussion the speaker should make a systematic survey of the subject under review. He may assume that those who may take part are already familiar with the main facts and features of the subject, and it is his business to make appropriate and, if possible, provoking remarks, thus focusing attention on some of the problems suggested by his own experience.

Epidemic encephalitis resembles many of the common infectious diseases in being caused by a virus which no one has seen, or has been able to grow in an artificial medium. Whether it has been possible even to transmit the disease to animals is still a matter of dispute, although the most recent work tends to confirm rather than to discredit the assertions of those who claim to have done so. This work is of the greatest interest, and it is of special importance in that it clarifies some of the difficult clinical problems which the disease presents. In particular, it seems to shed light on the question why the more acute forms of the disease are less often followed by progressive sequelæ than those in which it begins more insidiously.

Clinical and pathological experience has shown that encephalitis lethargica, like neuro-syphilis and disseminated sclerosis, is essen tially a chronic disease. For whether it declares itself acutely or insidiously, and however complete the recovery from the initial phase may appear to be, in a large proportion of cases the infection, which has evidently lain dormant for weeks, months or years, again becomes active and gives rise to the grave disabilities with which we are familiar. The distressing result is that we never know when the patient is cured. At present we are at a prognostic impasse.

My view of the nature of this disease coincides with that of Dr. Mackenzie; The disease encephalitis lethargica may be defined as an infection the toxic products of which have an affinity for the grey matter of the central nervous system, and so give rise to any of the syndromes of disease of that tissue or to any combination of such syndromes, and which runs a fickle course that may end in recovery, death, or the production of characteristic sequeæ.

Following on the momentous discovery of the causative organism of syphilis by Schaudinn and Hoffmann, some eight years later Noguchi, working under the great difficulties of his own method, demonstrated the presence of spirochætes in the brain of a general paralytic.