There is no example of two agents so closely united as Mind and Body without some mutual interference taking place, and an increased knowledge of the workings of our bodies has vastly increased the knowledge of our mental actions, and will continue to do so more and more as we continue our researches. To confine ourselves to the study of the nervous substance would be to misrepresent the union, and the knowledge of that substance, however complete, would not suffice to solve the problem.

For the past thirty years our insane population, as recorded in the annual Reports of the Commissioners in Lunacy, has steadily increased at the rate of over 1,500 a year, until in December, 1888, it had reached the alarming total of 84,340. Nor can even this large total be taken as at all fully representing the number of our insane. According to the census returns in 1871, the Commissioners' figures represented only 82·1 per cent., and in ‘81 only 86·5 per cent. of those returned as idiotic and insane; and when we remember that the census returns were made by fathers and heads of families more likely to under than overstate the numbers of afflicted in their households, we may venture to estimate that at present our insane population is fast approaching the enormous total of 100,000.

The first difficulty one meets with in deciding these points is in knowing exactly what is meant by mania. Pinel's definition of mania was insanity, marked “by a strong nervous excitement” of the mind and body, “accompanied by lesions of one or more of the functions of the understanding.” Melancholia was distinguished from it, by there being “no propensity to acts of violence,” and by the insanity being “exclusively upon one subject.”