Mental Diseases and Their Modern Treatment | Page 5

brain, and from it goes forth the order to the muscular guardians of the injured part to hold the fort, or to beat a retreat, as may seem best. A good illustration of nerve action is when a boy sits down upon a bent pin, and then gets up again.
Let us now attend to the localization of those functions of the brain which direct and influence the body. By applying the galvanic current to different portions of the exposed brain in the case of a monkey, and carefully noting the effects, it was observed and determined that the excitement of one part of the brain caused movements of the lower limbs of the opposite side, as in walking. By stimulating another portion of the brain, the muscles of the forearm became flexed, while stimulation of another part would cause protrusion of the tongue, etc. Repeated trials enabled the experimenters to mark out on the brain the exact limits of these physical functions, and within the circles thus described, by due stimulus, action in some particular part of the body was invariably excited. Thus were the functions of the brain in their relationships to the functions of the body discovered and localized.
It was also discovered that certain portions of the brain were not used in thus controlling the actions of the body. These unused portions are found in the fore and hind parts of the brain. It is generally believed that in the anterior portion of the brain the intellectual workings are carried on, while in the hind part of the brain are located the centers of the emotions, the passions, and the appetites.
It is an interesting fact that each portion of the brain has its specific and special duty to perform. This fact has been demonstrated by the experiments of Fleurens, Longet, Velpeau, Ferrier, Hitzig, and others. By removing successively portions of the brain in some of the lower animals, the powers of what remained were determined. When the upper lobes of the brain were removed from a pigeon, that bird was deprived of the powers of memory, and will; but it could fly when thrown into the air, it could be roused by a gentle push or pinch, by a light flashed before its eyes, by ammonia held near its nostrils, by a pistol discharged close to its head. By removing another layer of brain tissue the faculty of sight is destroyed, while hearing remains. By removing still another layer the faculty of hearing is destroyed; and again, the power of motion is paralyzed, and so on to the end of the chapter. When we come to excise that center from which the pneumogastric nerve springs, then the heart and lungs are paralyzed and the animal dies.
This is true in all cases except that of the frog. A frog can live for a short time by cutaneous respiration, for scientific purpose, of course. The frog may be decapitated, and all nerve centers removed except those located in the spinal cord, and then if a portion of the belly be irritated with a drop of acid, an attempt will be made by the frog to remove the irritating substance by rubbing it off with his right leg. Now cut off the right leg and you will see an attempt to reach the irritated spot by the stump. Not succeeding, the animal will pause and think it over with his spinal cord, and then you will see him try to remove the acid with his left leg.
We now pass to a consideration of the brain as a seat of mental power,-- the temporal kingdom of the mind, the earthly tabernacle of the immortal soul. Within the convolutions of the brain rest not only the power of guiding and propelling the physical forces, but, also, therein is the seat of a higher power which enables man to control not only his own actions, but to influence and direct the actions of others; to oppose successfully his intellectual vigor and prowess against the crude strength of the lower animals, and against the combative elements of earth and sea and air.
Man's brain, in the first place, takes cognizance of external things through perception or impression. Next he stores away the fruits of cognizance in the wine press and vaults of memory. From these come forth at last the rich essence of judgment, the final result of a subtle and mysterious process. The will executes the mandates of the judgment.
The ancients thought that the brain was but a useless mass of crude matter, a sort of overgrown clam, a mountain snow-cap to keep the rest of the body cool. The modern student finds that the brain, which the ancients despised, has become the chief and most important organ of the human body. The human mind,