Internal Respiration. i 1 1 



shows most plainly in the face of the habitual drunkard, 

 purple, not merely from the over-amount of blood, but from 

 the lack of oxygen in the blood. While this abnormal 

 color does not show in the moderate drinker, the same 

 condition is nevertheless present, though in a lesser 

 degree. 



Summary. I. In passing through the lungs air loses oxygen, and 

 gains water, carbon dioxid, and other wastes. 



2. Oxygen is carried chiefly by the colored corpuscles of the blood; 

 it unites with hemoglobin in the corpuscles, forming oxyhemoglobin, 

 and gives the blood its bright scarlet color. 



3. The energy of heat and motion in the body results from the 

 oxidations in the tissues. 



4. Air once breathed is unwholesome. The air of living and sleep- 

 ing rooms needs constant renewal. 



5. When we exercise more, the muscles need more oxygen, so the 

 heart must beat faster and we must breathe faster. 



6. The body is like a locomotive in producing heat and motion by 

 oxidation.- 



7. Air, once breathed, has one hundred times as much carbon 

 dioxid as before. 



Questions. I. In what part of the lungs is the best air? Where 

 the worst? 



2. Is it easy to determine by the color of blood flowing from a 

 wound whether it is arterial or venous? Why? 



3. How is the air of a room affected by having many lamps or gas 

 jets burning. 



4. How is air affected by gasolene or kerosene stoves? 



5. Could a locomotive be run by feeding it with bread and meat? 



