220 Transactions of the American Institute. 



The process of respiration simply draws in the oxygen for purposes 

 of combustion. The whole respiratory, digestive, and circulatory 

 system is designed to provide for this combustion. The tissues of the 

 body are consumed by respiration. The blood vessels are the chan- 

 nels for communicating it to the most remote vessels, which ramify 

 through the muscles, and the heart is the great forcing pump, more 

 powerful than any engine. 



The quantity of blood in the whole body is only about three gal- 

 lons. The capacity of the heart is two ounces. At each pulsation it 

 expels half an ounce, and this is forced throughout the circulating 

 system. At each seventy beats thirty-five ounces of blood are forced 

 out by the heart, 120 pounds of blood every hour, and 2,880 pounds, 

 or 350 gallons, daily. All the blood in the body passes through the 

 heart every six or seven minutes, and the heart beats seventy times 

 per minute, 4,200 times an hour, and 100,000 daily, and 36,500,000 

 every year. If the heart stops beating — if the circulation of the 

 blood ceases — death ensues. 



The respiration simply draws in the oxygen, to be taken up at the 

 lungs by the blood, to be carried through the circulation to the 

 remote vessels into the capillaries, where the action of the oxygen 

 takes place. 



There are two sets of vessels, one going from the heart to the mus- 

 cles, nerves and brain, and the other back to the heart, connected by 

 their capillary vessels. The vessels going from the lungs and brain take 

 up the oxygen and carry it to the heart, which distributes it through 

 the body. The lungs are simply a mass of air passages. The cell 

 capacity of the lungs is 220 cubic inches ; but the minute cells of 

 the lungs expose 440 square feet of surface. So that every time we 

 inflate the lungs, we cause the air to come in contact with 440 square 

 feet of tissue, and the blood is thus rapidly oxygenized. It is sent 

 to the remote vessels, where it is carbonized. The oxygen is there 

 exhausted. If we should have this flow of blood to the muscles 

 interrupted they would become paralyzed ; if cut off from the brain, 

 we should become unconscious. 



I have already stated that a man consumes fourteen ounces of 

 carbon daily. Therefore one pound of carbon per day represents the 

 combustion in a man. It represents the muscular power which is 

 developed by the activity of a man. Three hundred pounds of carbon 

 represent a man's work in a year ! This is his muscular work in a 

 year. • 



