BREATH AND BREATHING 



913 



BRECKINRIDGE 



breaths make it considerable. When the chest 

 is expanded, the air rushes in to fill the vacuum 

 caused by the expanding lungs. The act of 

 respiration is usually mechanical, except when 

 a person deliberately tries to expel as much 

 of the air from the lungs as possible. 



Frequency of Breathing. No definite state- 

 ment can be made as to how many times a 

 person breathes in a minute, for the variations 

 are considerable. In general, however, the 

 number of respirations is in a fairly definite 

 proportion to the number of heart beats one 

 to four and one-half or five. A full-grown man 

 or woman in good health may breathe nor- 

 mally from sixteen to twenty times in a min- 

 ute the average is eighteen but exercise, ill- 

 ness or certain personal characteristics may 

 increase this range. There have been known 

 cases of hysteria during which the patient 

 breathed over 100 times a minute. 



Lung Capacity. The quantity of air that is 

 changed in each act of breathing, known as 

 breathing, or tidal, air, is from twenty to thirty 

 cubic inches, but this is increased during physi- 

 cal exertion of any kind. Over and above this 

 normal thirty cubic inches, complemental air to 

 the amount of about 100 cubic inches may be 

 drawn into the lungs by the deepest possible 

 inspiration, and about the same amount, known 

 as reserve air, may be driven out by a forced 

 expiration. But no matter how hard a person 

 tries, he cannot expel all the air from his 

 lungs. There remains always about 100 cubic 

 inches, known as residual air. All in all, about 

 686,000 cubic inches of air pass through the 

 lungs of an adult person every twenty-four 

 hours; this may be doubled by continued exer- 

 tion of any sort. 



What Breathing Accomplishes. In passing 

 through the lungs the air gives up oxygen to 

 the blood and receives in exchange carbon 

 dioxide, or carbonic acid gas, a waste, the 

 exchange taking place in the tiny, thin-walled 

 blood vessels of the lungs. The amount of 

 carbon dioxide carried out varies with the 

 temperature and moisture of the air, the age, 

 sex, muscular development, state of health and 

 the nature and quantity of food and exercise. 

 In both sexes it increases to about the thirtieth 

 year, and is greater in strong, healthy persons 

 than in frail, slender ones. If this gas were 

 not carried off, asphyxiation would result, just 

 as surely as it does from escaping illuminating 

 gas. By a remarkable provision of nature the 

 proportions and supply of oxygen and carbonic 

 acid gas are always assured. Plants breathe 

 fig 



out, or exhale, oxygen, and they inhale car- 

 bonic acid gas, to them a life-giving principle. 

 Oxygen is the fuel needed by man to keep the 

 fires of life going. Thus do plants and animals 

 help each other. 



Breathing in Relation to Health. Breathing 

 is an instinctive act that is, a person does not 

 have to think or plan in order to breathe; and 

 if conditions were always the best this natural 

 breathing would supply plenty of pure air. 

 But many people find themselves under artifi- 

 cial conditions which are harmful in crowded 

 cities where smoke makes the air impure, or 

 in heated rooms where the ventilation is not 

 good. First of all, care should be taken to 

 have the air as pure as possible. Out-of-door 

 air is always better than that which has grown 

 heavy and dead within a room, even when the 

 former is damp, or perhaps dusty. In the 

 second place, deep breathing should be prac- 

 ticed. If as much air as possible is drawn into 

 the lungs, and is then completely exhaled, the 

 whole circulatory system is benefited. Five 

 minutes of deep breathing each day will be 

 found helpful, for such exercises warm up the 

 body and exercise certain accessory breathing 

 muscles. The air so breathed in should be 

 fresh air, however. No matter how cold a room 

 may be, such exercises should never be taken 

 with the windows closed. 



Bad Breath. This most troublesome condi- 

 tion may arise from any one of various causes 

 either from decayed teeth, catarrh, adenoids 

 or bad tonsils, diseases of the stomach, or con- 

 stipation. In any case breath perfumes or even 

 mouth washes do little good. If it is the 

 teeth that are at fault, a dentist should be con- 

 sulted; if any of the other organs, a physician 

 should be visited. Occasionally, where the 

 case is not extreme or of long standing, a sim- 

 ple laxative and a gargle, as listerine or hydro- 

 gen peroxide, will be effective. W.A.E. 



Related Subjects. All of the articles in the 

 following list will be found to contain informa- 

 tion related to some phase of the question of 

 breath or breathing: 



Adenoids 

 Catarrh 

 Circulation 

 Drowning 



Lungs 

 Pulmotor 

 Stomach 

 Teeth 



BRECK'INRIDGE, JOHN CABELL (1821- 

 1875), an American soldier, statesman and 

 Vice-President of the United States during 

 Buchanan's term as President. He was born 

 near Lexington, Ky., and was a descendant of 

 a long line of notable men. After graduating 



