xvi CONTENTS. 



SECTION IX. 

 A Review of some of the Features of the Circulation. 



PAGl 



§ 165. The constant and variable factors . . 299 



§ 166. The influence of the venous inflow and of the distension of the 



cavities of the heart 300 



§ 167. The heart beat influenced by the quantity and quality of the blood 



flowing through the heart 300 



§ 168. The causes of an irregular heart beat 301 



§ 169. The causes of the sudden cessation of the heart beat and of sudden 



death 302 



§ 170. Instances of the working of the vaso-constrictor mechanism . . 303 



§ 171. The influence of bodily exercise on the vascular mechanism . . 304 



§ 172. The influence of food on the vascular mechanism .... 306 



§ 173. The vascular mechanism and the nervous system .... 307 



BOOK II. 



THE TISSUES OF CHEMICAL ACTION WITH THEIR RESPECTIVE 



MECHANISMS. NUTRITION. 



CHAPTER I. 



The Tissues and Mechanisms of Digestion. 



§ 174. Food-stuffs. The several stages of digestion 311 



SECTION I. 

 The Characters and Properties of Saliva and Gastric Juice. 



Saliva. 



§ 175. The chemical characters of saliva. Mucin 313 



§176. The properties of saliva. The action of saliva on starch. Characters 



of starch, dextrins, dextrose, maltose 314 



§ 177. The nature of the amylolytic action of saliva. The amylolytic 



ferment 316 



§ 178. The characters of parotid, submaxillary, sublingual, and mixed 



saliva 318 



Gastric Juice. 



§ 179. The chemical characters of gastric juice 320 



§ 180. The action of gastric juice on proteids. Artificial gastric juice. 

 The characters of the more important proteid bodies. Forma- 

 tion of acid-albumin 321 



