xiv RESPIRATION 



pressure of the mixed alveolar air, 148. With the same alveolar oxygen pres- 

 sure there is less anoxaemia at low atmospheric pressures than at normal atmos- 

 pheric pressure, 148. Anoxaemia due to hindered diffusion of oxygen into the 

 blood, 149. Poisoning by lung-irritant gases, 150. Arterial anoxaemia in 

 pneumonia, 150. Observations of Stadie, Harrop, and Meakins, 151. The 

 clinical administration of oxygen, 152. Description of apparatus for the pur- 

 pose, 154. Anoxaemia during muscular exertion, 156. Experiments of Briggs 

 on oxygen inhalation during muscular exertion, 157. Anoxaemia and 

 velocity of chemical reaction in the formation of oxyhaemoglobin, 158. 

 Anoxaemia due to defective oxygen-carrying power of the blood, 158. Evidence 

 that the symptoms of CO poisoning are due to anoxaemia, 160. CO is not 

 oxidized in the body, but passes in and out by the lungs, 160. Popular errors 

 as to the effects of CO poisoning and anoxaemia generally, 160. Relation be- 

 tween percentage of CO in air and percentage saturation of the blood with CO. 

 1 60. Relation between percentage saturation of the blood and symptoms, 161. 

 Causes of certain differences between the symptoms of CO poisoning and 

 those of anoxaemia produced in other ways, 162. Alteration of the dissociation 

 curve of oxyhaemoglobin in CO poisoning, 165. Acclimatization to CO poison- 

 ing, 1 66. Occurrence of NO haemoglobin in the body, 166. Methaemoglobin- 

 forming poisons, 166. Evidence that with these poisons death is due to anox- 

 aemia, 167. Recovery from methaemoglobin-forming poisons, 167. Hae- 

 molytic poisons, 168. Anaemia and anoxaemia, 168. Reasons why no anox- 

 aemia is present during rest in ordinary anaemia, 169. Anoxaemia due to de- 

 fective circulation, 169. Gum-saline injections in defective filling of the vessels 

 with blood, 170. 



CHAPTER VIII. BLOOD REACTION AND BREATHING 171 



Ordinary physiological indications of maintenance of a normal blood reaction, 

 *7i' Walter's experiments on acid poisoning and the defenses against it, 171. 

 Diabetic coma and acid poisoning, 173. "Titration alkalinity" and alkalinity 

 of the blood, 173. The "buffer substances" in the living body, 174. Modern 

 conceptions of alkalinity and acidity, 175. Osmotic pressure, molecular con- 

 centration, and molecular diffusion pressure, 176. lonization of molecules, 177. 

 lonization and reaction, 177. Electrometric measurement of reaction, 179. 

 Theories of acidosis and anoxaemia, 179. Hasselbalch's electrometric de- 

 terminations of relation of CO 2 pressure to reaction in blood, 182. Experiments 

 showing that variation of alveolar CO 2 pressure in the living body compensates 

 for variations in blood reaction which would otherwise occur, 183. Barcroft's 

 experiments on the Peak of Teneriffe, 183. Quantitative relation between varia- 

 tions of breathing and of blood reaction, 184. Extreme delicacy of regulation 

 of blood reaction, 185. Very small difference between the reactions of arterial 

 and venous blood, 185. Difference in reaction between oxygenated and fully 

 reduced normal blood, 186. Error in electrometric method, 188. Summary of 

 evidence as to the means by which blood reaction is regulated, 188. Dis- 

 turbance of blood reaction by anoxaemia, 189. Physiological evidence that the 

 blood becomes more alkaline, 189. Gradual, but incomplete, compensation for 

 this by the kidneys and liver, 192. This compensation mistaken for an 

 "acidosis," 192. Relief of the anoxaemia by the compensation, 193. Com- 

 pensatory blood changes brought about by exposure to excess of CO 2 , or by ex- 

 cessive removal by CO 2 from the body, 193. The amount of "alkaline reserve" 

 in the blood is no certain index of "acidosis" or "alkalosis," 194. Experiments 



