VIII. INTEMPERANCE.—Every one knows that alcoholic drinks are the cause of a vast amount of disease, crime, and misery in all civilized countries. No one knows how this is to be prevented, for no one knows how to make the great mass of the people wise and contented. The effects produced by excessive use of alcohol are well known to all physicians, and the remedy is self-evident. I see no use in adding to the heap of useless rubbish which exists in the shape of the great mass of existing popular literature on this subject, and therefore leave the subject to the reader, who is quite sure to know all that is really important on this subject.
IX. CLOTHING.—The hygiene of clothing is also a subject which may be treated summarily in this paper. People wear what they can afford, made according to the prevailing style. Diseases due to insufficient, excessive, or badly-fitting clothing occur most frequently in women and children, and the use of such clothing is for the most part due to poverty or fashion, either of which is beyond the power of the physician to successfully cope with. Here and there, in individual and exceptional cases, he may be able to do a little good by advising against tight lacing, high-heeled shoes, insufficient covering for the chest or legs, etc., and he will find that a knowledge of the peculiarities of the various styles of modern under-clothing will sometimes be very useful. Men are, as a rule, comfortably and sensibly dressed to suit their business and surroundings, and require no advice on this subject.
X. EXERCISE.—The ease and completeness with which the functions of an organ or of an organism are performed depend to a great extent upon the frequency and regularity with which such functions are exercised. Hence comes the importance of bodily exercise for the preservation of health, and every physician meets cases of disease due largely to want of work.
The term "exercise," or "bodily exercise," is commonly used as if it referred only to the muscles, and the amount of exercise which a man should take in a day is stated as equal to a certain number of foot-pounds. The mere giving work to muscles is not, however, exercise in the sanitary sense. A better definition is that of Du Bois Reymond—viz. that "exercise is the frequent repetition of a more or less complicated action of the body with the co-operation of the mind, or of an action of the mind alone, for the purpose of being able to perform such actions better." From this point of view it will be seen that exercise relates quite as much to the nervous system as to the muscles. When, for example, a student takes a walk over ground with which he is familiar, and is at the same time so deeply engaged in thought as to be practically unconscious of what he is doing, only being recalled to himself, it may be, by arriving at his own door, the exercise which he has had is but partial and insufficient. Going to the extreme, we can, as Du Bois Reymond remarks, conceive of a man with muscles individually exercised until they were like those of the Farnese Hercules, and yet who would be unable to walk, much less execute more complicated movements; for the proper co-operation of the muscles, which is effected through the nervous system, is quite as necessary as the force of their contraction.
The amount of exercise which is necessary for health varies with the individual and with age, season, etc., so that it is difficult to state any general rule upon this subject; but if stated in terms of muscular force only, the estimate of Dr. Parkes seems a fair approximation—viz. that every healthy man ought to take daily an amount of exercise equivalent to 150 tons lifted 1 foot, or a walk of about nine miles. The majority of trades and bodily occupations demand at least this amount of work, but in some of them the greater part of the exertion is made only by certain groups of muscles, and they are carried on in crowded and ill-ventilated shops. Such workmen, as well as all who are engaged in sedentary pursuits, require exercise in the open air—exercise which will bring into play the unused muscles and will break the train of thought of the professional man.
One of the most important questions with regard to physical exercise is the extent to, and manner in, which it should be provided for in a proper system of education. One of the latest and most instructive articles on this subject is that by Du Bois Reymond in the "Physiology of Exercise," a translation of which is given in the Popular Science Monthly for July and August, 1882. He divides the physical training which is more and more becoming a part of modern systematic education into three classes: The first, the turning, or gymnastics of the Germans; the second, the Swedish system, in which the exercises are limited to very simple though varied movements; and the English system, or rather want of system, consisting largely of athletic games and contests of various kinds. His objection to the Swedish system is that, while it strengthens the muscles, it does not increase the power over composite movements; in other words, it does not exercise the nervous system. Naturally, he prefers the German system to any other, although admitting that the English meets better the demands arising from our structure. "Were the end masterhood in running, jumping, climbing, in dancing, fencing, riding, in swimming, rowing, or skating, then nothing could be more advisable than to practise equally the necessary concatenations in the actions of the ganglion cells, without pausing at the not practically applicable preliminary and intermediate steps of the German turning."
From a sanitary point of view, the gymnasium, as usually located and managed, is by no means equivalent to out-of-door sports and contests, although it is often the best substitute for them. The form of exercise most used by men whose occupation does not involve bodily labor is walking, and next to this riding. Whatever mode be selected, it is very desirable that it should be taken for some other object than that of the mere making muscular exertion, or otherwise it will soon come to be looked upon as an unpleasant task, the time spent upon which is given grudgingly; and it will be partially or wholly abandoned as soon as the immediate discomfort which induced its use has ceased.
It is not an uncommon error among men engaged in mental work to suppose that they can, and ought to, take the same amount of exercise which gives good results in those whose occupations involve physical rather than mental effort, or to think that the more exercise they take the more study or writing they are equal to. This is a grave mistake. Expenditure of brain-tissue is not to be repaired by muscular exertion, but by sleep and food, and exercise in the fresh air sufficient to produce appetite and sufficient weariness to ensure restful sleep is all that is necessary. For a time it is true that the student or writer who has a well-developed body can continue to burn the candle at both ends, and win literary honors while also standing high as an athlete; but this surely leads to physiological bankruptcy in the end.
It is to be remembered that good muscular development is not necessarily synonymous with health, and that strength is not a guarantee against disease. And, while it is true that in this, as in most other matters of individual hygiene, each man must to a great extent be a law to himself, and learn by experience what kind of exercise and how much of it he requires, yet the physician can often supply the motive which was wanting, or check undue effort. Exercise for the sake of health and comfort is not an end, but a means; yet if this means can be made to secure to the patient an end agreeable and pleasant in itself, so much the better.
XI. CONTAGION AND DISINFECTION.—By "contagion" we mean the communication of disease from one person to another, either by direct contact or through some medium, such as air, water, etc. It therefore includes "infection," which is now generally used as a synonym for it. The so-called infective diseases of modern German writers (Infections-Krankheiten) include, besides what are commonly termed in English, contagious diseases, the so-called miasmatic diseases.