D. RESPIRATION. 



IX. a. External respiratory movements, b. Intra=thor 

 acic pressure, c. lntra=abdominal pressure. 



/. Appliances. Operating case; clippers; rabbit board; 

 rabbit; cone for anaesthesia; ether; kymograph; cardio- 

 graph, which may, in this case, be called a rabbit stetho- 

 graph; three recording tambours; 10 cm. of glass tubing, 

 3 mm. lumen; rubber tubing to match; chronograph. 



2. Preparation. 



(1) Fix and anaesthetize rabbit. 



(2) Clip ventral aspect of rabbit's thorax and abdomen. 



(3) Prepare thoracic and abdominal cannulae by drawing 

 the glass tube slightly in the center, cutting diagonally 

 at the middle, smoothing diagonally on an emery stone. 



(4) Join a 30cm. piece of rubber tubing to each cannula 

 at the larger end, and clamp it near the cannula. 



3. Operation. 



a. External respiratory movements. 



Place the button of the rabbit stethograph upon the 

 ventral surface of the rabbit as near as possible over the 

 junction of the diaphragm with the body wall, and a lit- 

 tle to the right or left of the median line. So adjust the 

 stethograph as to obtain the maximum excursion of the 

 recording lever. The stethograph may be held in posi- 



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