HYGIENE OF THE CIRCULATORY SYSTEM 191 



one of the most important things is to acquire "wind"; that 

 is, the ability to continue severe exertions without losing 

 breath. This is in fact a training, of the heart, as well as 

 a training in correct breathing habits. Under suitable direc- 

 tions one can strengthen his heart considerably by means of 

 graded exercises in walking, running, climbing, etc. Indeed, 



FIG. 71. Treating a cut 



When the pressure of the thumb is not sufficient to compress the blood vessels and 

 stop the flow, a tourniquet may be used, made by tying a handkerchief about the limb 

 and twisting it tight by means of a stick slipped under the handkerchief. Of course, 

 the tourniquet or the bandage applied in this way is to be considered an emergency 

 measure, and steps should be taken to have the wound attended to by a physician 



one of the dangers of the athletic enthusiasm is that a student 

 will overdevelop his heart. But occasional severe strain upon 

 the heart is not the same as training it for hard work, and a 

 person with a weak heart should not be engaged in work that 

 strains this organ severely. 



221. Cuts and wounds. Small wounds will usually stop 

 bleeding in a short time because of the clotting of the blood 

 (p. 181). In view of our modern knowledge about the wide 



