The geologic history of China and its influence upon the Chinese people / by Eliot Blackwelder.

  • Blackwelder, Eliot, 1880-1969.
Date:
1914
Catalogue details

Licence: In copyright

Credit: The geologic history of China and its influence upon the Chinese people / by Eliot Blackwelder. Source: Wellcome Collection.

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    lungs not only oarl)on dioxide, hut also heat and moisture. I’ldess the air be warme*- than the body, it is ahvay.s warmeil during tlie proeess of inspiration and expiration, and is expired at about body temi)erature. Air whieh is inspired at a toinperatun' of (1° t'eutigrade below freezing is wanned to 24'r)° Centigrade during its passage through the nos(> alone. Chest Expansion and Mobility. Many people imagine that a big chest is a good chest, and they devote much time and trouble to the increase of their chest measurement hy means of various breathing and mu.scular exercises. But a big chest is not always a good chest. Mobility, or the power of expansion of a ehest, is always more im])ortant than mere size, and the methods adopted to increase the size of a chest often impair its mobility. We hear of chests increased .so many inches in so many weeks, but the increase often, indeed usually, means merely that the chest is pouted out and the ribs rigidly fixed in a position of forced inspiration. Dr. Harry Campbell found that the champion weight-lifter of the world had a very immobile chest, though its size was tre- mendous, and he found, on the other hand, the most mobile chest he had ever measured in a man of 6 ft. 4 in. in height, with a small chest measui’ing only .‘55 inches. Many ehests have been permanently damaged as organs of respiration by an ignorance of these facts. Up till a few years ago soldiers were made to pout their chests and hold their shoulders stiffly back, and the rigid protuberant chest became in time fixed in that position, and was considered an example of development. It was really an example of ignorant stupidity on the ])art of the trainer, and considerably reduced the soldiers’ breathing and working capacity. Chest Capacity. Mobility being equal, of course, the ca,pacious chest has more respiratory value than the smaller one, but most of the examples that are brought forth of great increases in chest measurement are instances of muscle increase, together vfith an unnatural fixation in an elevated position of ribs and collar-bones. An increase in chest mea.surcment. to be a true increase, must be a matter of growth, and this is a matter of food, as well as a matter of exercise, and it must take time. By reason- able and pidicious breathing, and by athletic exercises which do not involve fixing the muscles or holding the breath, it is possible to increa.se the mobility of the chest, and if the chest is fixed —as is sometimes the case—in a position of extreme expiration, it is po.ssible to raise and separate the ribs so as at once to increase its capacity and mobility, but no very rapid increase in cither res[)cct is possible or desirable. In judging the mobility and expansion of a chest by mea.suring it at full ins))iration and at full expiration, one must be careful not to be misled by incrca.se in measurement caused merely by contraction and consequent bulging of the mu.sclcs around the chest. A strong, muscular man, hy contracting and relaxing the big muscles on his chest and under his arms, can increa.se his chest measurmuent by several inches, and instances of twelve; or twenty inches expansion are of this fictitious nature. The chest wall is m.adc of bone, not of indiarubber; ami the amount it can expand is limited by the attachments and movements of the ribs ami breast-l)one. How to Breathe. By suitable breath- ing exercises the mobility of the chest may la; l)rcserved and increased, and there are juany ))rofes.sors of breathing ready to teach the })ublic exactly how to breathe. \Vc arc told we must inspire through the left nostril and expire through the right, and that we must alternately use our uj)per and lower ribs, and nonsense of that sort. But the best way to breathe is as Nature makes one breathe, aiul the best way to devcIo[) the chest and increase its mobility is to talce such exercises in the ojicn air as automatically deepen respiration. Breathing, after all, is an automatic reflex action. From birth to death, hour after hour, day after day, year after year, we breathe at the average rate of fifteen or sixteen breaths a minute, and breathing is quickened or slowly rendered deeper or shallower just as the regu- lating reflexes of the body direct. We have nothing to do with it; it is regulated by the physiological necessities of the case, by many varied and ingenious reflexes. A ten-mile walk, a half-mile run, a set at tennis, a game of football, wilt do more to develop the breathing capacity of the lungs than many hours of patient and painstaking exercises. And to breathe deeply just as an exercise is like raising and lowering a bucket down an empty well. It is largely waste of time and waste of energy. If we think, because we are breathing more oxygen, that therefore we are giving the tissues of the body more oxygen, we are making a great mistake. The Demand for Oxygen. When the tissues require more oxygen they ask for it in various ways; and reflex juessages sent to the respiratory centre dpe])en or quicken the breath- ing and accelerate the circulation. But merely to offer oxygen to the blood in the air-vesicles is vain, and the effort of deep breathing, so far as oxidation is concerned, is almost wholly wasted. Far better take exercise till the ti.ssues them- selves require oxygen; then the breathing'will rise to the occasion, and the heart and red blood eorpuscules will do their ))art. For it must be understood that respiration is a matter of circula- tion as well as of respiration. It is no use to bring cargo to the docks unle.ss there are ships to take it, and there is no u.se bringing oxygen to the lungs unless the little red blood-cells are there ready to load it and carry it to the tissues. Ev'en if ten minutes’ deej) breathing, by momentarily increasing the blood supply to the lung, do cause a little more oxidation, and in some form or other liberate or store a little more energy, what of that ? We take about 25,000 breaths a day, and it is absurd to think tliat a hundred or two dcaqi breaths can make much difference in the combustion or combustibilitv of the body.