ISO OUR BODIES AND HOW WE LIVE 



the time. Therefore we must keep making heat to make 

 up for this continual loss, known as "radiation." 



Besides this loss by radiation considerable heat is given 

 off in the moisture which is got rid of by the skin in 

 forming vapor, or sweat. The evaporation of this moisture 

 from the skin acts as a kind of regulator to keep down the 

 excess of heat. 



244. Effect of Alcohol upon the Lungs. We have learned 

 in previous sections that the most marked and immediate 

 effect of even a moderate amount of alcohol is upon the 

 nerves. This effect is evident, as we have read, in the 

 paralyzing action of alcohol upon the nerves which control 

 the muscular walls of the arteries. These muscles are 

 relaxed, and the blood vessels are dilated and filled with 

 an unusual amount of blood (Sec. 215). 



This action of alcohol also shows itself in dilating the 

 minute blood vessels, or capillaries, of the lungs. This 

 distension of the capillaries, if long continued, tends to 

 reduce the size of the air sacs and affords less space for 

 the air which is needed by the pulmonary tissues. The 

 result is that less oxygen is supplied to the blood. 



245. Relation of Alcohol to the Breathing Capacity of the 

 Lungs. When the capillaries of the lungs have been dis- 

 tended for a long time by the long-continued use of alco- 

 holic liquors, the walls may become thickened and hardened. 

 The result is that the breathing capacity of the lungs is 

 diminished. This loss in breathing space tends to prevent 

 the interchange of gases whereby the life-giving oxygen 

 is taken into the blood and carbon dioxide is cast out of 

 the body. 



The apparatus called the "spirometer," used by medical 

 examiners of life-insurance companies to test the breathing 



