54 77/7'; HUMAN 7iOJ)Y. 



puscles, a little larger, and spherical in shape, in the pro- 

 portion of one white one to three or four hundred red. 



6, The red globules have the property of attracting 

 oxygen to themselves. They take it from the air in the 

 lungs, and carry it to all parts of the body. 



7, These globules give the blood its red color. If they 

 were all taken out, it would be transparent and color- 

 less. When there is a plenty of red blood in the blood- 

 vessels, there is a rosy hue in the cheeks, and the lips are 

 cherry red. This we call a healthy color. It is healthy 

 because it indicates that there is blood enough, and that 

 it is well supplied with globules. As these are the car- 

 riers of oxygen, a good number of them means plenty 

 of oxygen in the tissues; and that is necessary to good 

 health. On the other hand, colorless lips and skin indi- 

 cate a lack of red globules, scanty oxygen, and ill health. 



8, The watery part of the blood, in which the globules 

 float, is called the plasma. This contains many sub- 

 stances dissolved in it, some of which are derived from 

 the food, and nourish the body; and some are waste mat- 

 ters, which the blood is carrying away to be discharged. 



9, When blood flows out of the blood-vessels, it soon 

 thickens into a jelly. This is called the coagulation of 

 the blood. 



10, Blood does not coagulate in the blood-vessels during 

 life if they are sound. If the blood is flowing very fast, 

 it will not coagulate until the flow is checked. If the air 

 is extremely cold, it does not coagulate quickly. 



11, It is this coagulation of the blood that saves us 

 from bleeding to death when we are wounded. The clots 

 which form, stop up the mouths of the cut vessels. 



12, In case of a wound, the blood should be helped to 



