It is remarkable, considering the advance which has been made in the study of the diseases of the mind during this century, that so little is still known concerning idiocy and idiots. With an increasing population, there is no decrease in the numbers of these helpless beings; their origin is connected with the, apparently, inevitable results of our social system; their very existence is, in most instances, a natural protest against vexatious and unreasonable interference with those great laws which govern the well-being of communities; and, both in a scientific sense as well as in a philanthropical, they have great claims for consideration.