A STUDY OF THE BLOOD 



123 



minute organisms multiply rapidly and produce poisons 

 called tox'ins, that cause the inflammation. 



As soon, however, as these inflammatory processes begin, 

 great armies of white cor- 

 puscles are hurried to the 

 spot and proceed to attack 

 the invading bacteria. If 

 the 



FIG. 44. - White Corpuscles. 



number of germs is 

 relatively small, and if the 

 corpuscles are in a healthy 

 condition, the latter seize 

 upon and devour the bac- 

 teria in the same way that a = a w hite corpuscle devouring a bac- 

 an amoeba takes in its food. terium. 



Under these conditions lit- & = a white corpuscle destroyed by bac- 



tie if any pus is formed. 



But if the bacteria get the upper hand in the struggle, many 

 of the corpuscles are killed, and it is the dead white cor- 

 puscles that form the pus. 



Amount of Blood in the Body Blood constitutes about one 

 thirteenth of the weight of the body; hence, in an adult 

 weighing one hundred and fifty pounds there would be a 

 little less than twelve pounds of this tissue. Ordinarily the 

 blood is distributed about as follows : 



one fourth in the heart, lungs, large arteries, and veins, 

 one fourth in the liver, 



one fourth in the muscles attached to the skeleton, 

 one fourth in the other organs of the body. 



4. THE HYGIENE OF THE BLOOD 



Conditions Affecting the Red Corpuscles. Since supplying 

 oxygen to the various tissues is the function of the red 

 corpuscles, it . is very important that their number be suffi- 

 cient and that they be kept in a healthy condition. To this 

 end, an abundance of sleep, exercise, fresh air, and nutritious 



