Before attempting a classification, it is desirable to define what we exactly mean by insanity. It is not an easy matter. Who is to say where the dividing line is to be drawn between the sane and the insane? The one state passes insensibly into the other, and a division, which may be valid in certain circumstances, may not be so in others.

One of the most striking developments of recent years, a development which may be seen in most countries of the civilised world, is that of the recognition of the necessity for preventive measures against disease. This necessity is not only felt in medical and scientific circles, but is, in many instances, quite as keenly appreciated by members of the general public. Few people are now indifferent to an outbreak of a serious infectious disease even in a distant land; and, in case of an outbreak in our own land, we no longer patiently watch it run its course far and wide without making strenuous efforts to check it, but by investigation we try to ascertain its cause, and by segregation and fumigation we keep it somewhat under control. The report of the spread of the “plague” in Eastern Asia at once led to an inquiry as to our preparedness to prevent its being introduced into this country, and to combat it if it gained an entrance. We have now an army of inspectors whose duty it is to watch our food-stuffs, and the way they are handled, to investigate the conditions under which our working classes are asked to labour, to inquire into the surroundings in which the people live, and to prevent pollution of the air and water. We have a service in many parts of the country to instruct mothers how to feed and attend to their children, and the children, when they go to school, are examined to discover whether they are suffering from any disability which would hinder their making use of their opportunities, or which, if not corrected, would tend to become aggravated.

It is now generally granted that a post-graduate training for medical men desirous of taking up lunacy as a speciality is essential in order that the study of the causation of insanity may progress along scientific lines, and accurate co-ordinated observations result therefrom, but it is equally necessary that the conditions and circumstances of these men on taking up work in asylums should conduce to the best interests of the speciality in question and tend to bring out the best qualities of the medical personnel. A moment's consideration proves that such conditions are conspicuous by their absence.

The study of eugenics is attracting an increasing amount of attention and interest from scientific men, legislators, and society in general.

The prevention of the propagation of degenerates, more especially of the insane, is a matter of almost daily discussion among those interested in insanity, and it is also discussed and as a rule advocated in medical journals, asylum medical superintendents' reports, and even in the daily press.

The investigations recorded in the following paper were undertaken to determine the reason for the discrepancy in the results when applying the Wassermann reaction to the cerebro-spinal fluid and blood-serum of general paralytics. The experiments have yielded results significant in other directions which are of some interest.