RESPIRATION: THE GASEOUS INTERCHANGES 385 



ever augmentation of activity he may experience is the result of 

 the agreeable sensory stimulations coming to him, which arouse 

 his tissues to activity, either reflexly or voluntarily. Increased 

 oxygen consumption is, therefore, never the cause, but always 

 the result of augmented tissue activity. 



Coal Gas Poisoning. In the paragraph on asphyxia (Chap. 

 XXIII) the possibility of suffocation by carbon monoxid was 

 mentioned. This substance, which is an important constituent 

 of illuminating gas, has a greater affinity for hemoglobin than 

 has oxygen, and forms with it a very stable compound, carbon 

 monoxid hemoglobin. The result of breathing illuminating gas is, 

 then, the conversion of the hemoglobin of the blood into undis- 

 sociable carbon monoxid hemoglobin, and the consequent abol- 

 ishment of the oxygen-carrying function of the red corpuscles. If 

 the breathing of carbon monoxid has gone on long enough for 

 practically all the hemoglobin of the blood to be combined with 

 it, death from lack of oxygen is inevitable unless by the prompt 

 performance of blood transfusion a fresh supply of properly 

 functioning red corpuscles be introduced into the circulation. 

 Exposure to the gas for a shorter time, not enough to prove 

 fatal, but to the point of unconsciousness, is usually followed by 

 a long period, weeks or months, of serious functional impairment 

 of the tissues of the Body, due to the injury suffered by them 

 during the period of oxygen deficiency. 



