XX 



CONTEXTS. 



§249. 

 §250. 



§251. 

 §252. 

 §253. 



The course taken by sugar . 

 The course taken by proteids 



PAGE 



414 

 415 



The Mechanism of Absolution. 



The mechanism of the absorption of the fats 417 



The pumping action of the villi 419 



The mechanism of the absorption of diffusible substances and of 

 water. Relations of the process to diffusion. Action of the 

 cells. The two stages of the act of absorption ; their nature . 420 



CHAPTER II. 



§ 254. Respiration 



SECTION I. 



The Mechanics of Pulmonary Respiration. 



§ 255. The entrance and exit of air into and from the lungs ; tidal and 

 stationary air 



§ 256. Complemental, reserve or supplemental, and residual air. Results 

 of an opening into the pleural chamber 



§ 257. The lungs before birth and the changes at birth .... 



§ 258. The pressure exerted in breathing and the quantity of air moved . 



§ 259. The graphic records of the respiratory movements ; pneumatograph 



§ 260. The curve of respiratory movements 



The Respiratory Movements. 



§ 261. The visible movements 



§ 262. The movements of inspiration. The movements of the diaphragm 



§ 263. The elevation of the ribs . 



§ 264. The muscles which move the ribs 



§ 265. The muscles of laboured inspiration . 



§ 266. Expiration. The expiratory muscles 



§ 267. Facial and laryngeal respiration 



SECTION II. 

 i 

 The Changes of the Air in Respiration. 



§ 268. The changes in temperature 



§ 269. The aqueous vapour in expiration 



§ 270. The gaseous changes .... 



§ 271. The diminution in volume . 



§ 272. The organic impurities in expired air 



424 



425 



426 

 427 

 427 

 428 

 432 



433 

 433 

 434 

 435 

 436 

 437 

 438 



440 

 440 

 440 

 441 

 442 



SECTION III. 



The Respiratory Changes in the Blood. 



§ 273. The gases of arterial and venous blood. The mercurial gas pump . 443 



