Of all the available resources of the Materia Medica, opium, in its beneficial efficacy, is probably surpassed by none. It calms irritability, it soothes pain, it assuages spasm, and restores sleep. And when, in the course of disease, these indications have to be fulfilled, there is no drug like opium upon which we can place such uniform reliance. It is no wonder, then, that its advantages have been solicited, and realised, in the practice of psychological medicine.