The Cerebro-Spinal Nervous System is concerned with the activities arising from the conscious activities of the mind, including those of the five senses. It controls the muscles by which we speak, walk, move our limbs, and pursue the ordinary activities of outer life. But, while these are very important to the individual, there is another set of activities--inner activities--which are none the less important. The Sympathetic System controls the involuntary muscles by means of which the heart throbs, the arteries pulsate, the air is conveyed to the lungs, the blood moves to and from the heart, the various glands and tubes of the body operate, and the entire work of nutrition, repair, and body-building is performed. While the Cerebro-Spinal System, and the Conscious Mind are able to rest a considerable portion of the twenty-four hours of the day, the Sympathetic System and the Subconscious Mind must needs work every minute of the twenty-four hours, without rest or vacation, during the life of their owner. Dr. E. H. Pratt, in his valuable "Series of Impersonations" published in the medical magazines several years ago, and since reproduced in book form, makes "The Sympathetic Man" speak as follows: "The entire body can do nothing without me; and my occupation of supplying the inspiration for our entire family is so constant and engaging that I am compelled to attend strictly to business night and day from one end of life to the other, and have no time whatever for observation, education, or amusement outside of my daily tasks. As a rule, I perform my work so noiselessly that the rest of the family are scarcely conscious of my existence, for when I am well everything works all right, each organ plays its part as usual, and the entire machinery of life is operated noiselessly and without friction. When I am not well, however, and am not quite equal to the demands made upon me, I have two ways of making it known to the family. One is by appealing to self-consciousness through the assistance of my cerebro-spinal brother, with whom I am closely associated, thereby causing some disturbance of sensation or locomotion (the most frequent disturbance in this direction being the instituting of some form of pain); or I sometimes take it into my head to say nothing to my cerebro-spinal brother about my affairs, but simply shirk my duties, and my inefficiency becomes manifest only when some one or all of the organs suffer from some function poorly performed."