The Solar Plexus. William Walker Atkinson

      I

       The Four Brains of Man

       Table of Contents

      Man has four brains, and not merely one as is commonly believed to be the case. Man's four brains, each having its separate characteristics and distinctive ,offices and functions, are as follows: (1) the Cerebrum; (2) the Cerebellum; (3) the Medulla Oblongata; and (4) the Solar Plexus, or Abdominal Brain. The structure, and the respective offices and functions of each of these four brains of Man, are as follows:

      (1) The Cerebrum. The Cerebrum is the higher and front portion of "the brains" located in the cranium or skull. It consists of two symmetrical halves, which are connected by a broad band of white substance. Each hemisphere is composed of a centre of white substance. surrounded by a gray border, following the convolutions which constitute its external form. The offices and functions of the Cerebrum are as follows: (1) the anterior portions of the cerebral hemispheres are the chief centres of voluntary motion, and of the active outward manifestations of Intelligence: (2) the individual convolutions constitute separate and distinct centres; and in certain groups of convolutions are localized the centres for various physical movements, i.e., the motions of the eyelids, face, mouth, tongue, ear, neck, hand, foot, etc.

      The Cerebellum. The Cerebellum is the hinder and lower part of "the brains" located in the cranium of skull; it is situated beneath the posterior lobes of the Cerebrum, and is about one-seventh the size of the latter. It is composed of white matter in the interior, and of gray matter on the surface. It is divided into two hemispheres, separated on the upper surface by an anatomical process, and on the lower surface by a deep fissure corresponding in form to the Medulla Oblongata, The white centre of the Cerebellum takes on the form of a miniature tree, with trunk, branches, twigs, and leaves—this is known as the "arbor vitæ." The offices and functions of the Cerebellum are as follows: (1) it is concerned with the powers of motion in various ways and forms, in various degrees; and (2) it is held by some authorities to perform certain important offices in connection with the physical phase of the Sexual functions and organism.

      The Medulla Oblongata. The Medulla Oblongata is the upper and enlarged end of the spinal cord—the extension and prolongation of the latter into the cranium or skull. Its substance resembles that of the spinal cord in its structure of gray and white matter; but it possesses a peculiar and different arrangement of the strands of the cord before it enters into and forms a connection with the brain. In the substance of the Medulla Oblongata are situated the great ganglionic centres which control respiration. deglutition, vomiting, etc. Pressure of the Medulla Oblongata, and not simple strangulation, is held to be the actual cause of death in the process of judicial hanging. From the interior portion of the Medulla Oblongata, and the under surface of the Cerebrum, arise the Cranial Nerves, which emerge from the cranial cavity through openings in the base of the skull; these are distributed to various parts of the head'and neck; to the organs of special sense; and to some of the thoracic and abdominal organs. In the posterior and lowermost portion of the substance of the Medulla Oblongata, are located the original sources of certain nerves which indirectly control the organs and functions of respiration.

      The Solar Plexus, or Abdominal Brain. The Solar Plexus, or Abdominal Brain, the functions and offices, the powers and activities, of which constitute the chief subject matter of this book, is, as the name indicated, situated in the abdomen. Some of its filaments, however, accompany the branches of the aorta (the great artery) which are distributed to the stomach, intestines, spleen, pancreas, liver, and certain other organs, but not to the lungs. It is situated in the upper part of the abdomen, behind the stomach, in front of the aorta or great artery, and in front of the pillars of the diaphragm. Its place is popularly known as "the pit of the stomach," or back of the point where the ribs begin to separate and spread to each side.

      The Solar Plexus is the great plexus, i.e., network of nerve-fibres, mass of nerve-substance, etc., of the great Sympathetic Nervous System. It is composed of both gray and white nervous substance, or brain-matter, similar to that of the other three brains of Man. It receives and distributes nerve-impulses and currents to all of the abdominal organs, and supplies the main organs of nutrition, assimilation, etc., with their nervous energy. It performs most important offices in the so-called "vegetative life" of the body, supplying the nerve-energy which is required for the processes of nutrition, assimilation, growth, etc. In fact, it is the great power-house of physical life-energy. The bodily functions cannot be performed without it; when it is injured the entire physical well- being is at once seriously affected; and when it receives a severe shock, death often ensues, a fact which the history of prize-fighting amply illustrates.

      Its name, "solar," was bestowed upon it by reason of (1) its central position; (2) the fact that its filaments extend in all directions to the important abdominal organs, like the rays of the sun; and (3) the fact that it is recognized as being the power-house, and great reservoir of "life force," just as the sun is the great power-house and reservoir of material energy of our solar system.

      The Sympathetic Nervous System, over which it presides, is that great division of the nervous system which regulates and energizes the important functions of the organs upon which physical life depends, and by which it is sustained. Bichet terms this division of the nervous system, "the nervous system of organic life," because, as he pointed out, "it seems to regulate—almost or quite independently of the will—the due performance of the functions of the organs of respiration, circulation, and digestion."

      Bailey says: "Functionally, the Sympathetic System is quite distinct from the Cerebro-Spinal System. It has been called the system of vegetative existence, because of its presiding over the processes of nutrition and growth, the so-called 'vegetative functions,' in contra-distinction to the Cerebro-Spinal System, which presides over such distinctly animal faculties as sensation, motion, and intellect. The Sympathetic System controls the so-called automatic mechanisms of the body, the rhythmical beating of the heart, contraction and dilation of the arteries, the peristaltic action of the gastro-intenstinal tract, the contraction of smooth muscle wherever found, and the control of the secretions of various glands, etc." So, it may be seen, the Solar Plexus presides over a very important region of physical life.

      The Solar Plexus both receives