mixture of vinegar and water, which he did not notice; I placed the glass under his nose without his perceiving the smell of the vinegar; I put it into his hand, and he drank it without complaining of any unpleasant sensation.” The conclusions which may be drawn from this remarkable history have been sufficiently expressed by Dr. Mesnet[85] in the following words: “The disturbance which these functional perversions of the nervous system bring into the course of life, extends not only to the organs of sense, and to intellectual actions properly so called, but it also sometimes awakens some instinctive excitation which surrenders the individual without any defence, and destitute of rational discernment, to the most deplorable impulses. He acts with the semblance of a freedom which he does not possess; he seems to prepare and to combine certain actions in the light of conscious volition, when he is in reality only a blind instrument, obedient to the irresistible mandates of an unconscious impulse.” The bearing of these conclusions upon the question of the moral responsibility of the somnambulist needs no further advertisement. The likeness of certain features of such cases to the phenomena of hypnotism is worthy of note. In this particular there is an evident likeness between the cerebral susceptibility of the ordinary dreamer, the somnambulist, and the hypnotised subject. All are alike in a condition which renders their imagination and their volition subservient to guiding sensations from without, so that their movements may be directed by the will of another. We have seen how the course of an ordinary dream may be modified by such suggestions. The history of the patient just related, illustrates the manner in which the actions of a somnambulic dreamer may be controlled by the will of a spectator. The ordinary phenomena of hypnotism exhibit the same subjection to the will of another. It is probable that a considerable part of the superior notoriety which belongs to this feature of hypnotism, is due merely to the fact that natural somnambulism is rarely made the object of such experiments and observations as are daily applied to the subjects of artificial somnambulism.