[Illustration: THE ACTION OF WATER; THE HANDS ARE CLENCHED AND THE JAW SET; THE SUBJECT CAN NEITHER SWALLOW NOR SPEAK.] For some time past the doctor had established that when a magnet is presented to a hypnotic subject in one of the phases of trance, the effect produced varies, according as the north or south pole, that is to say, the negative or the positive end of the magnet, is offered. The north pole in all cases produces a state of intense delight, expressed by gestures and outcries of pleasure. The subjects in this case declare that they see at the end of the magnet emanations of a beautiful blue light. When the bar is reversed the greatest horror and disgust at once affect the subject. If asked what it is that causes this dismay the subject will answer that it is the sight of a fearful red light playing around the end of the magnet. [Illustration: EXPRESSION OF PLEASURE CAUSED BY PEPPER PRESENTED TO THE LEFT SIDE.] Investigating further in this direction the doctor has discovered that the same subjects can detect in the human face emanations corresponding to those seen at the ends of the magnetic bar. Thus from the left eye and left ear and left corner of the mouth in persons in a good state of health, blue emanations can be seen by the hypnotized person, according to the declarations of such subjects. In cases of persons, however, suffering from nervous disorders, or from the results of diseases or accidents, the colors vary. Thus, according to one of the subjects, the red light proceeding from the right eye of a person affected with shortsightedness and fatigue of the organ was largely spotted with violet. Violet is the characteristic color in all cases of great nervous fatigue. Black, green, and multi-colored flames have been described by the subjects as showing from persons suffering with various forms of nervous disorder. A man who had been wounded in the eye with a rapier was characterized, at an interval of three months, by two different subjects, who, according to Doctor Luys, had had no means of inter-communication, as emitting a green light from the injured organ. [Illustration: EXPRESSION OF ANXIETY CAUSED BY PEPPER PRESENTED TO THE RIGHT SIDE.] If it can be established that certain diseases produce in those suffering from them a variation in the color of the emanations, which are perceptible to the hypnotic subject, the existence and nature of the disease will be certified by the tint.