CHAPTER XXVII. PHYSIOLOGY OF THE SOUL-THE SYMPATHETIC NERVE. WE have already seen that the brain and spinal nerves are the chief residence of the spirit, and that by means of the two columns which pass upwards to the brain, the spirit receives intelligence from external nature, and is able to act upon external nature by means of the muscles. But there is another system of nerves in the body, quite distinct from the cerebro-spinal system, which neither conveys impressions to the spirit nor volitions from the spirit, but deals exclusively with the interior arrangements of the body. This is what is called the great sympathetic nerve, or ganglionic system. The cerebro-spinal system is, as it were, the husband, who attends to business and deals with the world, who fights for his wife and family when they are in danger, and provides for their sustenance by collecting supplies. The ganglionic system, on the other hand, is like the wife, who gives herself entirely to domestic duties, receiving the supplies provided by her husband, and preparing them for food, keeping the house in order, sweeping out the refuse, and patching, mending, and nursing wherever accident or disease may render it necessary or desirable. This great system of nerves is distributed over the trunk, without having any great central mass like the brain it has, however, numerous patches, or ganglia, as they are called, in different parts, in which the nerve is connected with small masses of nerve cells, so that whatever may be the use of the brain in the cerebrospinal system, these ganglia perform corresponding duties in this. The advantage of this arrangement is evident: in the cerebro-spinal system, unity of thought and concentration of attention are necessary, therefore a single brain forms the metropolis of its operations; but in the other system, where the operations are so numerous and so varied, and where all must be going on at the same time, instead of a single brain the cares of office are distributed among many ganglia, which, like the municipal courts of a country, adapt their labours to local circumstances, and perform their subordinate functions without having to engage the attention of the central government. The ganglionic system may be said to attend to all the household work of the body, the secretion of the glands, the preparation of the food, and the formation of the tissues, besides co-operating with a branch of the cerebrospinal system (the vagus) in the pulsation of the heart, the breathing of the lungs, and the action of the stomach. These are but part of its duties, so that we may form some idea of the endless variety and amazing multiplicity of its functions. There is one other peculiarity which distinguishes the ganglionic system of nerves. It never rests nor grows weary from the cradle to the grave. In regard to the other system it is not so; it requires not only to rest every night, but to obtain relief from the intensity of labour every seventh day, as well as at longer intervals; but the sympathetic nerve is always on the stretch, its silver cord is never relaxed, until the golden bowl is broken, and the pitcher is broken at the fountain (Eccles. xii. 6). We cannot but admire the wisdom of these arrangements, by which the mind is relieved of all care over those important functions, which require to be continually in action. They go on under the influence of the ganglionic system, without troubling the mind in regard to any of them: it is, therefore, left free to perform its own duties, which otherwise would be impossible. There are, indeed, several important exceptions to this rule, in the case of those actions which might become useful under the guidance of the mind. Thus, the lungs may be made useful for other purposes besides aërating the blood, such as speaking, blowing, &c., therefore the mind is allowed to exercise a certain amount of power over them; but even this is limited. The sympathetic nerve will allow the use of the lungs for speaking, &c., only on condition that the breathing shall not be unduly interrupted; and when the mind has finished all that was wanted, the sympathetic nerve resumes its control, and conducts the operation of breathing, without the mind being conscious of the act. A somewhat similar arrangement has been permitted in regard to a few other economic functions of the body, but only in so far as an advantage may be gained by their being placed for a season under the direction of the mind. Cases have even occurred in which the mind had power over the action of the heart, so as voluntarily to produce a state of body in many respects the same as death; the heart ceased to beat, and the person continued in that state for a considerable length of time, and then revived again. These cases have been well authenticated, though, happily, they are rare; and they may be explained by supposing that some monstrosity or malformation of the nervous system existed, so that the sympathetic nerve became, to a certain extent, subject to |