VI CONTENTS. 



PAGE 



Chemical Composition of the Blood, ..... 64 



The Blood-Corpuscles, or Blood-cells, ..... 65 



Chemical Composition of Ked Blood-cells, .... 68 



Blood-crystals, 69 



The White Corpuscles, 71 



The Serum, 72 



Variations in the Principal Constituents of the Liquor San- 



guinis, .......... 73 



Variations in Healthy Blood under Different Circumstances, 76 

 Variations in the Composition of the Blood in Different 



Parts of the Body, 77 



Gases contained in the Blood, ...... 81 



Development of the Blood, 81 



Uses of the Blood, . 85 



Uses of the various Constituents of the Blood, . . .85 



CHAPTEK VI. 



CIRCULATION OF THE BLOOD, 88 



The Systemic, Pulmonary, and Portal Circulations, . . 89 



THE HEART, 91 



Structure of the Valves of the Heart, 92 



The Action of the Heart, 96 



Function of the Valves of the Heart, 99 



Sounds of the Heart, 105 



Impulse of the Heart, ........ 107 



Frequency and Force of the Heart's Action, . . . 108 

 Cause of the Rhythmic Action of the Heart, . . .111 

 Effects of the Heart's Action, . . . . . .114 



THE ARTERIES, 115 



Structure of the Arteries, 115 



The Pulse, . . . . .123 



Sphygmograph, 124 



Force of the Blood in the Arteries, 129 



Velocity of the Blood in the Arteries, . . . .131 



THE CAPILLARIES, 131 



The Structure and Arrangement of Capillaries, . . . 132 

 Circulation in the Capillaries, 135 



