LECT. VI. RESPIRATION. 117 



LECTURE VI. 



RESPIRATION. GASEOUS ENDOSMOSE. 



ARGUMENT. Phenomena of respiration. Respiratory organs in different 

 class of animals. Mechanism of respiration ; inspiration ; expiration. 



Changes produced in the air by respiration; changes effected by fishes in 

 the air dissolved in the water in which they live. Respiration is both 

 pulmonary and cutaneous. 



Changes produced in the organism by respiration; arterialization of the 

 blood. Respiration of gases. 



Physico-chemical nature of the process of respiration ; changes produced 

 by atmospheric oxygen in venous blood drawn from an animal ; nature 

 of the changes ; experiments of Magnus ; atmospheric oxygen acts on 

 blood through membrane ; the process is, perhaps, gaseous endosmose ; 

 diffusion of gases ; Valentin and Brunner's researches. 



Conclusions. 



Phenomena of Respiration. THE action of the oxygen of 

 the atmospheric air on venous blood ; the changes pro- 

 duced in the air by its introduction into the pulmonary 

 cells ; and the modifications effected in the blood which 

 traverses the capillary network, on the delicate walls of the 

 bronchial vesicles ; are the principle phenomena which 

 constitute the function of respiration, and which will form 

 the subject of the present lecture. 



Organs of Respiration. No animal exists, even amongst 

 those possessing the lowest degree of organization, whose 

 life is not essentially connected with those modifications 

 which atmospheric oxygen produces in its substance. The 

 organs, by means of which this action takes place, are more 



