CHAPTER X 



WHAT HARVEY WAS TAUGHT CONCERNING THE HEART 



Until now we have been examining the locomotive 

 machinery of the human body — its muscles or engines, 

 its levers or bones, and its joints or bearings. These 

 structures make up a large part of the human machine. 

 My learned friend, the late Prof. Alex. Macalister 1 of 

 Cambridge University, has estimated that in a man of 

 middle size the locomotive system should weigh about 

 80 lb. The bones, 200 in number, make up 20 lb. of 

 that amount, while the muscles, of which Prof. Macalister 

 counts 260 pairs, make up the remaining amount — 60 lb. 

 Thus the locomotive system represents about three-fifths 

 of the total weight of the human machine. Now, we 

 have seen that this mass of machinery can be kept going 

 only if it is supplied with certain materials ; the muscular 

 engines need to be continually stoked, while the masons in 

 the bones and the lubricators at the joints must have their 

 stores constantly replenished. Nature has met that need by 

 adopting another contrivance — one which man discovered 

 for himself long ago and with which we are all familiar — 

 the pump. The heart of the human body is a pump — one 

 which in the ingenuity of its construction, the delicacy 

 of its regulation, and the effectiveness of its work far 

 surpasses any model of man's invention. 



It seems difficult for us to believe that there ever was 

 a time when men did not know that the heart was a 

 pump. Yet such was the case. The story of that dis- 

 covery is a romance of real life — the story of adventure 



1 Man Physiologically Considered. Present Day Tracts, 1891. 

 89 



