Science.

Alexandra Herald and Central Otago Gazette, Issue 423, 2 June 1904, Page 7

Science.

HEALTH.

fIQCKHEBE is a great disparity between flyfAg the degree of health commonly Cjlks enjoyed and that which is possible

of attainment. The difference cannot well arise from want of knowledge, for the literature of to-day is liberally sprinkled with hints and suggestions on health, and if not attributable to lack of information ou the principles of hygiene, we fear it may be due to want of plunk in carrying those principles into practice. Depend upon it physical vigour will never come to us from the mere study cf hygiene, we must exert a force of will sufficient to mould our habits in accordance with the laws of health. A person who is inactive, indolent, or leading a purely sedentary life must not expect to enjoy robust health; he may earnestly desire it, but it will never come without effort on his part. Nature proffers the boon it is true, but only as a reward for active exertion. The exertion may be either the toiling of the labourer, the running of the athlete, or the varied exercises of the sporting „ gentleman, Physical exertion aids the promotion of good health through the effects it produces in the lungs, the heart, the skin, and the muscles. Its influence on respiration is a very important one, because the amount of air inspired, and the consequent expansion of the lungs are very much greater during exercise than during repose. In order to appreciate this point we compare the breathing of a man walking at the rate of fcur miles an hour with that which takes place when be is remaining at rest. The man, while at rest takes into his lungs 27 cubic feet of the atmosphere every hour. From thiß amount of air his blood will absorb 416 grains of oxygen, while by expiration he will breathe out 603 grains of carbonic acid. This is the condition of things which obtains daring a state of repose. Now note what an important increase occurs during active exercise, when, of course, there will be a considerable increate in the amount of both inspired and expired air. The amount he now takes in through quicker and deeper breathing enables his blood to absorb 1.829 grains of oxygen instead of '416 while he was at rest; and the carbonic acid he gives out is 2.501 grains against 608 during repoee. The enormous difference is at once apparent; and—because the oxygen is as necessary to life and health as the ordinary food, and since the carbonic acid acts as a poison while in the system, the advantages gained by this double increase becomes of the utmost importance, and of the greatest possible value, It is calculated that if 10 hours out of the 24 were devoted to fair bodily exertion, there would be an elimination of waste products amounting to nearly double the quantity thrown off when a person remained inactive. It is obvious, therefore, that so far as respiration alone is concerned, the gain from exertion very well repays the effort, and must certainly place a person in much more favourable circumstances with respect to his health. Again, physical exertion promotes a more vigorous and healthy action of the skin. The more a man exercises his body, the more reddened he notices Its surface has become. This colouration is due., to an increased fulness of the blood vessels of the skin, and their congested condition gives rise to a freer perspiration. Water leaves the body by three channels—the' kidneys, the lungs, and the skin; and in each case carries with it certain waste products, which if they were allowed to accumulate in the system would bring about death from poisoning. Hence the great importance of these outlets always being free and unobstructed. Daring a period of rest more water escapes by the kidneys than by the lungs ana skin together; but during active exercise the opposite is the case, for then a larger proportion leaves the body by the skin and lungs than by the kidneys. This in itself is a decided gain, because it saves the kidneys from being overworked, and renders them lees liable to attacks of disease. After a great deal of painstaking labour, it has been computed that there are 28 miles of perspiratory tubing in the ssin of a man of average height and size, If this be so, we can easily realise the immense importance of a regular and free actton of the skin. Even during rest this extensive drainage system is in action, but to nothing like the extent that is necessary to carry off the liquid refuse. Hence it is a common thing to hear people remark that a good sweating does them good.