CHAPTER III. Materiality of the Brain, and its subjection to the agency of physical causes.-It is the organ of mind, and will influence its manifestations.-It is liable to morbid action, according to the particular organ in a state of irritation :proofs of this position, arising out of simple, and morbid, and sympathetic excitement of the brain. It was stated in the last chapter, that the various phenomena of superstition, and especially alleged supernatural appearances, depend upon a morbid condition of the brain, in consequence of which it has escaped the due control of the presiding mind. In order to apply this proposition to the several forms of superstitious manifestation, it is necessary to describe the functions of the brain in a state of health and of disease. I. The brain is a material organ, and is liable to be acted upon by many physical causes. This is almost a self-evident proposition, since we see that it is possessed of extension, figure, solidity, and of a certain degree of invariable structural arrangement. It is true that we are unacquainted with the ultimate cerebral fibre, or with the reason why these fibres are assembled according to their present form; and it is also true, that we are unacquainted with the mode of their function: but we conclude, from very close analogy, that the brain is most perfectly adapted to its peculiarity of function, because we know that this is the case with other organs and functions of the body; and because we find, from observation, that this office is more or less perfectly performed, according to varying circumstances of original character, and physiological manifestation, as well as according to the phenomena of health or indisposition. Now, as such, the brain will require a due and regular supply of fine and healthy blood, exactly in proportion to the extent and importance of its agency in the animal economy; and its functions will be feebly and irritably carried on if that supply be defective in quantity, or less highly animalized than in its most perfect state. On the contrary, it will be oppressed, if the supply should exceed the demand of ordinary expenditure and it will be variously irritated and disturbed, if that blood shall not have undergone its proper purifying change in the lungs; and, more especially, if it shall have been charged with any noxious qualities; according to the extent of its deterioration, the intensity of the consequent morbid impression, and the disordered changes with which it is associated. But, since the brain also forms the centre of nervous sympathy, it is intimately connected with many other viscera, whose functions cannot be carried on without the assistance derived from this organ, and whose infinitely varied disturbances are all propagated by a reflex action to this common centre. Thus, disorder of stomach will interfere with the integrity of brainular action, and head-ache, languor, and inaptitude for mental exertion, are the consequence. This state continuing a certain length of time, or being frequently repeated, will, in a constitution so predisposed, give rise to hypochondriasis: and, in a still more aggravated form of impression, this hypochondriasis may be exchanged for deeper mental aberration: and thus the due functions of the brain will be suspended-perhaps irrecoverably destroyedby the reflex action of disorder, whose first point of irritation was in the stomach. : Again the skin is an important organ; and a simple morbid impression made upon it will sometimes occasion a degree of cerebral disturbance. Even in common catarrh, the earliest symptoms will very generally be those of unwonted drowsiness and oppression: these will be followed by chills, and a certain wandering of intellectual manifestation, which indicates that the brain is not under the usual control of the will; and when the subsequent re-action has occurred, it will be accompanied by pain in the head, excited susceptibility to sensorial impression, and general disposition to over-action. When this first impression may have been more intense, particularly if it shall have resulted from the invasion of fever of a specific character, the cerebral disturbance will be more distinctly characterized; and the deviations from correct, congruous, coherent, and consecutive thought, will be more apparent. This is so manifestly the case, that some authors have placed the seat of fever exclusively in the brain, because that organ always suffers more or less; forgetting that, although it has to bear its own peculiar burdens, it is also callupon to sympathize, when any other organ of the body is affected with morbid irritation; thus proving that it is eminently the organ ed which is most under the influence of physical disturbance. Again: every person may have remarked the unwonted irritability which attaches to convalescents. And, be it remarked, that it is unwonted: they who have borne long, submissively, and patiently, with great suffering, become impatient and irritable as soon as they begin to recover; and this, not from a feeling of having exhausted a long-tried stock of patience, but from a peculiar state of the brain, which it requires a great mental effort to control. Every person who has experienced this return from sickness to health, knows this to be the fact: and it is manifest in children, who would not be subjected to these effects, if they arose from an exhaustion of the influence of patience and submission, as moral motives; but who do equally experience this irritability, which takes its origin from a purely physical condition, and which observers actually hail as the harbinger of returning health; because, even to the observation of those who reason not upon its causes, this indication has been associated by experience with the setting in of a new train of healthy actions. Nor let the sincere Christian be fearful of avowing his belief in the physical origin of a |