THE INFLUENCE OF EXERCISE UPON HEALTH. 329 



While the lungs and heart are doing better work under the stimu- 

 lus of muscular exercise, the heart pumping the blood more certainly 

 to the farthermost tissue of the body and the lungs more rapidly pu- 

 rifying the blood, other organs are benefited. The diaphragm, that 

 muscle separating the lungs and heart from the stomach and liver, is 

 rising and falling, and, with the increased expansion and contraction 

 of the walls of the thorax, is moving all the contents of the abdomen 

 to activity. The liver, the great gland of the body, has not only 

 more blood sent to it, but is quickened to action. For bilious people 

 there is no medicine like exercise and fresh air. In malarial districts, 

 bilious people are most easily affected by the malarial poison. Though 

 in such districts a great many troubles are conveniently laid at the 

 door of that enemy of health which do not justly belong there, yet 

 of the fact that some are affected by it, and others equally exposed 

 are not affected by it, may not the explanation be, that an active cir- 

 culation in one person effects the elimination of the poison through 

 the excretory organs so rapidly that it can not collect in sufficient 

 quantities to cause disturbance of the system ? In the case of a per- 

 son affected by a stupefying poison, the first thing to be done is to 

 keep tbe individual moving ; that is, to keep the circulation going by 

 exercise till the poison can be eliminated. The laboring-man who 

 works at a sewer in front of a house seldom feels any ill effects from 

 the overturned soil and poisonous gas, while some dweller in the 

 house, apparently not so much exposed, is stricken with typhoid or 

 malarial fever. Causes of the immunity of the workman may be 

 found in his greater strength and feebler sensibility, and in his open- 

 air life ; but may not another reason be seen in the quickened action 

 of his lungs and the profuse perspiration of his skin ? As to the 

 effect of want of exercise on the liver, the following passage may be 

 quoted from an authority on the subject : "A want of exercise in 

 the open air leads to derangement of the liver in two ways : viz. 

 (a) By causing a deficient supply of oxygen to the system, as a result 

 of which the oxidizing processes, which go on in the liver and else- 

 where, are imperfectly performed, and there is a tendency to the accu- 

 mulation in the system of fat and the imperfectly oxidized products 

 of disintegrated albumen. Oxygen is, so to speak, the antidote for 

 the destruction of materies morbi (lithic acid, etc.) produced by im- 

 perfectly oxidized albumen, (b) By retarding the circulation of the 

 blood through the liver. Since the time of Haller (1764), physiolo- 

 gists have recognized the influence of the respiratory movements in 

 producing the circulation of blood through the liver ; but upward of 

 thirty years ago Mr. Alexander Shaw showed more clearly than ever 

 before that the circulation of blood through the liver was greatly in- 

 fluenced by the alternate expansion and contraction of the thorax dur- 

 ing respiration. Mr. Shaw called attention to the fact that the portal 

 vein, without any provision for increasing its power, * has to perform 



