CONTENTS. xxi 



The Relations of Oxygen in the Blood. 



PAGE 



274. The absorption of oxygen by blood is not according to ' the law of 



pressures ' 447 



275. The characters of hsemoglobin , . . 450 



276. The spectroscopic features of hsemoglobin 451 



277. The spectroscopic features of reduced hsemoglobin .... 453 



278. The oxygenation and reduction of hsemoglobin . . . ' . 455 



279. The colour of venous and arterial blood 455 



280. Carbonic-oxide-haemoglobin 457 



Products of the Decomposition of Haemoglobin. 



281. Hsemoglobin splits up into hsematin and a proteid .... 458 

 282. The features of hsematin. Hsemin. Methsemoglobin ... . 460 



The Relations of the Carbonic Acid in the Blood, 

 283. The carbonic acid of the blood not simply absorbed . , . 461 



The Relations of the Nitrogen in the Blood. 

 284. The nitrogen simply absorbed , 461 



SECTION XV. 

 THE RESPIRATORY CHANGES IN THE LUNGS. 



285. The relations of the oxygen of the blood to pressure. Association 

 of oxygen with, and dissociation from hsemoglobin. The 



problem stated 462 



286. The experimental evidence 464 



287. The relations of the oxygen in laboured breathing and asphyxia . 465 



The Exit of Carbonic Acid. 



288. The exit of carbonic acid from the blood into the pulmonary alve- 

 olus the result of ordinary diffusion 466 



SECTION V. 

 THE RESPIRATORY CHANGES IN THE TISSUES. 



289. The oxidations of the body take place mainly in the tissues and not 



in the circulating blood. The respiration of muscle . . . 467 



290. The respiration of other tissues. The taking in of oxygen separate 



from the giving out of carbonic acid 409 



291. A summary of respiration in its chemical aspects .... 470 



SECTION VI. 

 THE NERVOUS MECHANISM OF RESPIRATION. 



292. Respiration an involuntary act. The efferent nerves, the respiratory 



centre 472 



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