INSPIRATION 



313 



FIG. 121. Pneumographic curve of a man, after Langendorff. To be read from left to right. 



E, expiration, 7, inspiration. 



plethysmograph (Gad). In Fig. 123 is reproduced a -respiratory curve made with 

 the apparatus pictured in Fig. 122. 



The variations of intrathoracic pressure also are used for registration of 

 the respiratory movements. 



Finally, the respiratory movements can be recorded with the plethysmo- 

 graph by placing the entire animal in a closed, air-tight box and allowing 



FIG. 122. Apparatus for registering the volume of the respired air. B, receiver; A, spirometer; 

 e, writing point. The trachea of the animal is connected with a. The openings at 6 and c 

 serve to ventilate the receiver. 

 20 



