CHAPTER IV. 



RESPIRATION. 

 I. THORACIC MOVEMENTS. INTRATHORACIC PRESSURE. 



1. Appliances necessary for these exercises are: Kymograph; 

 physiological operating case; clippers; stethograph; -thoracic cannula. 

 (See Appendix, 12.) The stethograph consists of two tambours; 

 the recording tambour is the same as used in other analogous 

 experiments (Fig. 56), while the receiving tambour, joined to 

 the recording tambour through a J-metre length of No. % pressure 

 tubing, is provided with a cork button which may be placed upon 

 the rabbit's thorax and receive and communicate its movements to 

 the air in the tambour system. 



FIG. 56 



Recording tambour. (Described in Appendix, 12.) 



2. To Study the Movements of the Rabbit's Thorax. The 



problem is to take a graphic tracing or stethogram of the movements 

 of the thoracic walls, and from this tracing to determine the rate 

 and the character of the movements, particularly the latter. 



To record a stethogram, fasten the rabbit upon its board and hold 

 the button of the receiving tambour upon the thorax, tracing the 

 movement of the lever upon the kymograph. 



Study the characteristics of this curve. 



Anaesthetize the rabbit with ether. How does the stethogram vary 

 as the anaesthesia progresses? Is the stethogram of full anaesthesia 

 different in any essential feature from the normal one? 



