Part 3 (1/2)

In short, there may exist not only a difference in the const.i.tution of the different organs of the body, but these natural conditions are more or less changeful in their states, within certain limits, while still in a state of health. There may exist a condition of over-activity, or of under-activity, in any or all portions of the body, and from the operation of causes, the nature of which we are entirely ignorant, and concerning which persons do not much care, so long as they do not experience so much discomfort as to be unfitted for their usual occupations and pleasures.

Such experiences are common with many persons, who yet remain in a condition of health.

Pa.s.sing now to the conditions of the mental side of the human system, we find, in what are called healthy states, that there exists as broad a diversity of character as in the physical. While some apprehend any thing a little abstruse with great difficulty, or fail to do so at all, others understand it with a readiness which we are accustomed to call intuition; while many occurrences seem merely to impinge upon and glance off the minds of some persons never to be remembered again, they pa.s.s from the minds of others only after long years, or remain through life.

Some persons always look upon and judge of occurrences and results in an unusual way. They are odd or singular in their mental const.i.tution, and are accustomed to do odd and out-of-the-way things just as naturally as others would do the same things in such a manner as to attract no attention. Some persons see, hear, taste, touch, and smell so much more quickly and delicately than others, that we must conclude there exists a radical difference in the perfection of the organization of the nerve-cells of these various organs of special sense.

Again, there are periods in the experience of some persons, when they see, hear, touch, taste, and smell with much greater readiness and delicacy than at other times, even in a state of so-called health. Musical sounds are more delicate and pleasing; harsh and rough sounds are more harsh and rough; certain articles of food produce a keener sense of relish, and colors a greater sense of pleasure: all of which would indicate temporary changes in the structure or function of the nerve element comprising these special organs of sense.

The same is true to even a larger extent of the emotional nature. Persons, in certain states of the nervous system, are pleased with persons, objects, and sensations, which afford them no pleasure at other times; they are displeased and pained, while in other conditions, with sentiments which would at other times produce no such effect. They sometimes feel that the world and its possessions and pleasures are so great and grand that they can never leave them, and the thought of doing so causes the keenest anguish; while in another state all these pleasures and possessions appear as empty and valueless as a bubble of air, and the thought of leaving them, and throwing off the burdens and cares of life, which are usually so much enjoyed, seems almost pleasurable.

Again, some persons have periods of being irritable, restless, nervous; they cannot bear much; little incidents which, in other conditions of the nervous system, they would think little or nothing of, turn them into a pa.s.sion of excitement, which can hardly be controlled for the time being.

In other states they may long to weep, or to be in solitude where they cannot be disturbed; or they may shout, and laugh, and talk, while thoughts come coursing through the brain so fast that words fail in their expression.

The same changes occur among the impulses; these are at times almost irresistible. Nearly every one, while standing on a high cliff or house-top, has felt an impulse to jump off or push his friend off, reckless of the consequences.

In the usual condition of the nervous system persons love their children and relatives, and are ready to do and suffer and at times even to die for them, if need be, while at other times all these sentiments fade away, so that they are unconscious of them, and even the opposite sentiment of dislike or hatred takes their place.

Periods of mental lethargy come over many persons at times, so that they care neither to talk nor engage in any of their usual intellectual or physical pursuits; and such stimuli as are usually sufficient to rouse the brain into action appear to have very little effect. They feel and say that there is a state of only partial brain-activity. At other times the brain acts with the greatest freedom; occurrences which took place long years before, and which, perhaps, have not been thought of since, come back with all the freshness of yesterday. Thoughts come rapidly. Keen flashes of wit, bright scintillations of thought, forms of expression of unusual felicity, pour forth spontaneously, while the mind apprehends and retains many kinds of knowledge with the greatest readiness. Similar variations take place in reference to courage and its opposite, timidity; truthfulness and suspicion; and, in fact, the whole range of mental endowments.

Now all this grand play of diverse emotions and conditions in the psychical functions takes place in a state of health; still, there can be no doubt that it comes from an unstable condition of the nervous elements of the brain, or from changes produced in some manner in these varied and delicate structures. It may be from varying states which are constantly occurring in the blood, in the processes of reception and elimination; or from those delicate chemical operations which must be forever going on in the nerve elements of the brain hemispheres, affecting their recipient and sensitive capacities; or it may be from other unknown causes: and these changes occur much more readily and frequently in some persons than in others.

Bearing in mind, now, these conditions of the physical and mental systems, the tendencies to which are inherited, and more or less changeful in character, we may proceed a step farther.

This unstable condition, both physical and mental, may exist not only as an inherited condition, but it may be produced, or become greatly increased by causes external to the system, which are brought into contact so as to influence it.

A few ill.u.s.trations may serve to make this more clear:

1. When a person who has not been accustomed to use the muscles of the arm in active and vigorous exercise, lifts, or makes a strong effort to lift, a heavy weight, if the effort is continued any considerable length of time, two conditions result therefrom:

First, a state of tremulousness, or spasm of the arm, hand, and especially of the fingers. The largest effort the individual can make toward controlling this irregularity of movement, is insufficient, and these parts remain in a condition of more or less spasmodic action, until the nervous energy is restored.

Second, there results a sensation of pain, more or less severe, according to the time the exertion has continued. This would indicate positive injury, to some extent, in the nerve filaments of the muscles which have been so unusually exercised. The degree of effect will be dependent upon the condition of the nerves of the hand and arm at the time the effort is made, and upon the amount of force expended.

If the effort is repeated soon, there will result a similar condition, and ultimately the nerve would cease to respond to the call for action in any degree,--the arm would be paralyzed.

2. All are more or less familiar with that condition which is usually termed the _writer's cramp_. Sometimes persons of a peculiar nervous organization, who have been accustomed to spend many hours a day in the mechanical process of writing, experience such a loss of nervous energy that the arm fails to respond to the will power. There results spasmodic and irregular movements in the arm, and more especially in the fingers, indicating that some morbid condition of the median nerve has been produced. If the case is neglected, and the exciting causes continue in operation, after awhile the nerve will become less and less responsive to the call of the will, and the arm may become seriously affected, after a longer or shorter period of more or less pain. In this case, as in the former one, there may exist all degrees of impairment of nerve function, from that of slight unsteadiness or instability, up to entire failure.

3. The condition of the nervous system in ch.o.r.ea presents another ill.u.s.tration. Between the ages of ten and fifteen years, in some children, there may occur such changes in the condition of the nervous element, from the altered character of the blood, as to render it more or less unstable in some portion. One arm or one leg, or a hand, or some of the muscles of the face or neck, cannot be kept long at rest by any effort which can be exerted by the individual, and this may be so slight as scarcely to attract attention, or it may be so great as to cause extreme suffering for a long time, and ultimately destroy life.

Now the primary condition in the above cases is one of _instability of nerve function_. Such a change has occurred in the elemental tissue of the nerve, as to injure its power of activity so far as it is under the control of the will. The nerve has been stimulated to over-activity, or its energy impaired by other causes arising within the system itself.

These ill.u.s.trations have related to those portions of the nervous system which are more immediately connected with motion, and which, consequently, are located in the muscular system. If, now, we pa.s.s from these portions of the nervous system up to its grand centre, or that part of it whose function is connected with mental operations, we shall find similar effects resulting from like causes.

If a person experiences a sudden mental shock, occasioned, it may be, by sad intelligence of some kind, or if he pa.s.ses suddenly through some great personal peril, or if he has made unusual mental effort in some abstruse study, or in the conduct of business, which has been long protracted, he becomes conscious of what is called mental fatigue. The brain refuses to respond to any calls which may be made upon it for further action, or partially refuses; it becomes confused and bewildered, and unsteady in its action; it is difficult to force it to further application, or to connected lines of thought, and if, by a strong effort of the will, this is done during a short time, it is inclined soon to wander from the subject, and there exists a more or less distinctly recognized sensation of pain as well as inability to regulate its action.

In this case, also, as in the others, there may result any degree of effect, from a sensation of fatigue up to mental spasm, and the amount will depend on the condition of the brain during the time the effect continues, and its intensity. The two conditions of instability and pain may be less marked in the case of the brain than in the nerves of motion, but there can be little doubt there has resulted something of a similar character in both.

Precisely in what this change which has taken place consists, may not be easily determined. There may have occurred actual lesion of nerve element, or only impairment or exhaustion of functional power without lesion; probably the latter condition only, in the primary stages of the operation. Certain portions of the brain have been over-stimulated in action, and consequently their power of normal activity and stability is impaired, as was seen in the cases of nerves distributed to the muscles of the arm and other portions of the body.