9 o 



THE VITAL PROCESSES 



that taking place between the blood and the air. This 

 exchange is known as internal, or cell, respiration. By 

 internal respiration the oxygen reaches the place where it 

 is to serve its purpose, and the carbon dioxide begins its 

 movement toward the exterior of the body. This 

 " breathing by the cells " is, therefore, the final and 

 essential act of respiration. Breathing by the lungs is 

 simply the means by which the taking up of oxygen and 

 the giving off of carbon dioxide by the cells is made 

 possible. 



HYGIENE OF RESPIRATORY ORGANS 



The liability of the lungs to attacks from such' dread 

 diseases as consumption and pneumonia makes questions 

 touching their hygiene of first importance. Consumption 

 does not as a rule attack sound lung tissue, but usually 

 has its beginning in some weak or enfeebled spot in the 

 lungs which has lost its "power of resistance." Though 

 consumption is not inherited, as some suppose, lung weak- 

 nesses may be transmitted from parents to children. This, 

 together with the fact, now generally recognized, that con- 

 sumption is contagious, accounts for the frequent appear- 

 ance of this disease in the same family. Consumption 

 as well as other respiratory affections can in the majority 

 of cases be prevented, and in many cases cured, by an in- 

 telligent observation of well-known laws of health. 



Breathe through the Nostrils. Pure air and plenty of it is 

 the main condition in the hygiene of the lungs. One nec- 

 essary provision for obtain ing pure air\s> that of breathing 

 through the nostrils. Air is the carrier of dust particles 

 and not infrequently of disease germs. 1 Partly through 



1 The amount of dust suspended in what we ordinarily think of as pure air is 

 shown when a beam of direct sunlight enters an otherwise darkened room. 



