254 



HITCHCOCK'S ANATOMY 



and expiration is about twenty cubic inches, and the amount 

 passed through them in twenty-four hours about 860 cubic * 

 feet, or, as others estimate it, from 3,000 to 5,000 gallons 

 every day. This varies greatly. In the first place, the lower 

 the temperature the greater the amount of animal heat to be 

 generated, and consequently the greater the quantity of air 

 to be consumed. Also a person laboring in the open air 

 breathes more deeply than one confined to the house. Again, 

 the capacity of the lungs modifies the quantity of air inhaled. 

 And this capacity depends more upon the height of the indi- 

 vidual than any other physical feature. From a series of 

 5,000 observations made by Dr. Hutchinson, the following 

 principle is deduced. " For every inch of stature from 

 five to six feet, eight additional cubic inches of air are given 

 out at a forced expiration after a full inspiration." That is, 

 if a person five feet and six inches in height can expire 422 

 cubic inches, a person five feet and seven inches can expire 

 430 cubic inches. 



449. E f fret of Corpulence on Capacity of Lungs, — 

 Another fact of importance is deduced by the same experi- 

 menter — that if a person exceed the average weight on ac- 

 count of corpulence, the capacity of the lungs decreases in a 

 marked ratio, as is stated in these words : u When the man 

 exceeds the average weight (at each height) by 7 per cent, the 

 vital capacity decreases one cubic inch per pound for the next 

 thirty-five pounds above that weight.' 7 



450. Function of the Red Corpuscles. — The red cor- 

 puscles of the blood seem to be the carriers of oxygen from 

 the lungs to the various parts of the body. The prominent 

 reason for this belief is that the serum and salts of the blood 

 have but a very slight power of absorbing oxygen, while the 

 discs condense this gas at once. 



44S. How much air is used in each act of inspiration, and how much each day ? Hot 

 does temperature and exposure to the open air affect the amount respired ? Upon what 

 does the capacity of the lungs depend ? Give the law and its example. 449. How does 

 corpulence affect the capacity of the chest? Give the formula. 450. What is the prob- 

 able function of the red corpuscles of the blood ? 



