SUNLIGHT.—The influence of the sun's rays upon the nervous system is very marked. [Footnote: The necessity of light for young children is not half appreciated. Many of their diseases, and nearly all the cadaverous looks of those brought up in great cities, are ascribable to the deficiency of light and air. When we see the glass room of the photographers in every street, in the topmost story, we grudge them their application to what is often a mere personal vanity. Why should not a nursery be constructed in the same manner? If parents knew the value of light to the skin, especially to children of a scrofulous tendency, we should have plenty of these glass house nurseries, where children might run about in a proper temperature, free from much of that clothing which at present seals up the skin—that great supplementary lung—against sunlight and oxygen. They would save many a weakly child who now perishes from lack of these necessaries of infant life.—DR. WINTER.] It is said also to have the effect of developing red disks in the blood. All vigor and activity come from the sun. Vegetables grown in subdued light have a bleached and faded look. An infant kept in absolute darkness would grow into a shapeless idiot. That room is the healthiest to which the sun has the freest access. Epidemics frequently attack the inhabitants of the shady side of a street, and exempt those on the sunny side. If, on a slight indisposition, we should go out into the open air and bright sunlight, instead of shutting ourselves up in a close, dark chamber, we might often avoid a serious illness. The sun bath is doubtless a most efficient remedy for many diseases. Our window blinds and curtains should be thrown back and open, and we should let the blessed air and sun stream in to invigorate and cheer. No house buried in shade, and no room with darkened windows, is fit for human habitation. In damp and darkness, lies in wait almost every disease to which flesh is heir. The sun is their only successful foe. (See p. 336.)
WONDERS OF THE BRAIN.—After having seen the beautiful contrivances and the exquisite delicacy of the lower organs, it is natural to suppose that when we come to the brain we should find the most elaborate machinery. How surprising, then, it is to have revealed to us only cells and fibers! The brain is the least solid and most unsubstantial looking organ in the body. Eighty per cent of water, seven of albumen, some fat, and a few minor substances constitute the instrument which rules the world. Strangest of all, the brain, which is the seat of sensation, is itself without sensation. Every nerve, every part of the spinal cord, is keenly alive to the slightest touch, yet "the brain may be cut, burned, or electrified without producing pain."
ALCOHOLIC DRINKS AND NARCOTICS.
ALCOHOL (Continued from p. 187).
EFFECT UPON THE NERVOUS SYSTEM.—In the progressive influence of alcohol upon the nervous system, there are, according to the researches of Dr. Richardson, four successive stages.
1. THE STAGE OF EXCITEMENT. [Footnote: The pupil should be careful to note here that alcohol does not act upon the heart directly, and cause it to contract with more force. The idea that alcohol gives energy and activity to the muscles is entirely false. It really, as we have seen (p. 183), weakens muscular contraction. The enfeeblement begins in the first stage, and continues in the other stages with increased effect. The heart beats quickly merely because the resistance of the minute controlling vessels is taken off, and it works without being under proper regulation. What is called a stimulation or excitement is, in absolute fact, a relaxation, a partial paralysis of one of the most important mechanisms in the animal body. Alcohol should be ranked among the narcotics.—RICHARDSON.]— The first effect of alcohol, as we have already described on page 144, is to paralyze the nerves that lead to the extreme and minute blood vessels, and so regulate the passage of the blood through the capillary system. The vital force, thus drawn into the nervous centers, drives the machinery of life with tremendous energy. The heart jumps like the mainspring of a watch when the resistance of the wheels is removed. The blood surges through the body with increased force. Every capillary tube in the system is swollen and flushed, like the reddened nose and cheek.
In all this there is exhilaration, but no nourishment; there is animation, but no permanent power conferred on brain or muscle. Alcohol may cheer for the moment. It may set the sluggish blood in motion, start the flow of thought, and excite a temporary gayety. "It may enable a wearied or feeble organism to do brisk work for a short time. It may make the brain briefly brilliant. It may excite muscle to quick action, but it does nothing at its own cost, fills up nothing it has destroyed, and itself leads to destruction." Even the mental activity it has excited is an unsafe state of mind, for that just poise of the faculties so essential to good judgment is disturbed by the presence of the intruder. Johnson well remarked, "Wine improves conversation by taking the edge off the understanding."
2. THE STAGE OF MUSCULAR WEAKNESS.—If the action of the alcohol be still continued, the spinal cord is next affected by this powerful narcotic. The control of some of the muscles is lost. Those of the lower lip usually fail first, then those of the lower limbs, and the staggering, uncertain steps betray the result. The muscles themselves, also, become feebler as the power of contraction diminishes. The temperature, which, for a time, was slightly increased, soon begins to fall as the heat is radiated; the body is cooled, and the well-known "alcoholic chill" is felt.
3. THE STAGE OF MENTAL WEAKNESS.—The cerebrum is now implicated. The ideal and emotional faculties are quickened, while the will is weakened. The center of thought being overpowered, the mind is a chaos. Ideas flock in thick and fast. The tongue is loosened. The judgment loses its hold on the acts. The reason giving way, the animal instincts generally assume the mastery of the man. The hidden nature comes to the surface. All the gloss of education and social restraint falls off, and the lower nature stands revealed. The coward shows himself more craven, the braggart more boastful, the bold more daring, and the cruel more brutal. The inebriate is liable to become the perpetrator of any outrage that the slightest provocation may suggest.
4. THE STAGE OF UNCONSCIOUSNESS.—At last, prostration ensues, and the wild, mad revel of the drunkard ends with utter senselessness. In common speech, the man is "dead drunk." Brain and spinal cord are both benumbed. Fortunately, the two nervous centers which supply the heart and the diaphragm are the slowest to be influenced. So, even in this final stage, the breathing and the circulation still go on, though the other organs have stopped. Were it not for this, every person thoroughly intoxicated would die. [Footnote: Cold has a wonderful influence in hastening this stage, so that a person, previously only in the first stage of excitement, on going outdoors on a winter night, may rapidly sink into a lethargy (become comatose), fall, and die. He is then commonly said to have perished with cold. The signs of this coma are of great practical importance, since so many persons die in police stations and elsewhere who are really comatose, when they are supposed to be only sound asleep. The pulse is slow, and almost imperceptible. The face is pale, and the skin cold. "If the arm be pinched, it is not moved; if the eyeballs are touched, the lids will not sink." The respiration becomes slower and slower, and, if the person dies, it is because liquid collects in the bronchial tubes, and stops the passage of the air. The man then actually drowns in his own secretions.]