Since the middle of the nineteenth century psychology has gradually come to be recognised as a branch of biological science. This is due to the influence of the works of Darwin and Herbert Spencer, of the Clinical and Neurological School of Meynert, Golgi, Cajal, Flechsig, and others, and recent developments in the Psychometric School of Fechner and Wundt on the other. The Alienistic School can render powerful aid to this movement; and though there are indications of the current in the proper direction, as shown more particularly in the work of Mercier (1) and Bevan Lewis (2), the end, however, cannot as yet be said to have been achieved, nor the movement to have become general. Psychology still lingers on the borderland of metaphysics; it has not yet been established on the firm rock of natural science. And while it thus lingers progress in knowledge is slow and restricted.