352 STUDIES IN LIFE AND SENSE. 



that number of pounds one foot high as the work performed at each 

 contraction of the left ventricle. The right ventricle's work measures 

 only one-third that of the left ; the right side of the heart being less 

 powerful than the left, and being occupied with driving blood simply 

 to the lungs, whilst the left side propels blood through the entire 

 system. The addition of the work of right and left sides, therefore, 

 gives us three " foot-pounds " as the total work of the heart at each 

 beat or contraction. But in an adult person of Caudal's physique 

 there are performed at least some seventy-five or seventy-six such 

 contractions per minute. At this rate, in twenty-four hours the 

 heart must perform a startling amount of work. If we could gather 

 all the force expended by the human heart in twenty-four hours into 

 one huge lift, it would suffice to raise at least 120 tons weight one 

 foot high. After such a revelation, it would be easy for us to accept 

 Caudal's hunger and thirst as the perfectly rational symptoms of a 

 lazy man. With the fact at hand of a bodily pumping engine con- 

 stantly at work within his frame, he would require no further proof 

 of his right to replenish the wear and tear of his body by regular 

 attendance at meals. The idle man must needs eat and drink for 

 common idleness has at least a physiological justification at its back 

 in the shape of the aphorism that whatever the hands find to do, the 

 bodily organisation knows no rest or cessation from its labour and 

 its toil. 



It can be shown that the work of the heart is not the only labour 

 which the ordinary processes of life entail. The function of breath- 

 ing is practically as incessant in its operation as that of the heart. The 

 rise and fall of the chest include, and are effected through, the work 

 of a multiplicity of structures, such as ribs, chest-muscles, midriff, 

 and lungs. When we read that there pass in twenty-four hours 

 through the lungs of an adult at rest some 686,000 cubic inches of 

 air a quantity increased in the same period to 1,568,390 cubic 

 inches in the hard-working subject we may judge that the work and 

 labour of breathing may fitly enough be ranked with that of the 

 heart in respect of its magnitude. There exists a large amount of 

 natural resistance offered by the elastic nature of the lungs and chest, 

 and which has to be overcome by the muscles employed in breathing. 

 It has been shown that the force which has to be overcome by these 

 muscles in the act of breathing in 200 cubic inches of air exceeds 

 450 pounds. In ordinary breathing, the elastic force we require to 

 overcome equals at least 170 pounds. With these details at hand, 

 there is little need to further emphasise the fact that the stillest of 

 lives is in reality a long spell of continuous work. In twenty-four 

 hours the muscles of breathing alone, perform an amount of work 

 equal to the raising of twenty-one tons one foot high. Adding this 

 amount to the force exerted by the heart, we may understand that 



