PRELIMIjSTARY OPERATIONS 



207 



bulb. (See Figs. 198 and 199 for teelmic and apparatus; 

 also see Experiment XXVIII, page 189.) Use a large 

 bowled tambour to record the bladder contractions. If the 

 bladder is full of urine do not allow more of this to escape 

 than can be avoided. Arrange the mercury bulb as shown 

 in Fig. 199 and fill the bulb about two-thirds full of warm 

 salt solution. Insert the cork which carries a glass tube 

 to connect with the tambour. It is best not to connect the 

 tambour tube until the lung shield is inserted and the dog 



Air 



Mercury bulb 

 zso c.c. 



Salt solution 



Larqe bowled 



recording tambour 



Class or metal tube 

 orooved where tied 

 into bladder wall. 



Abdominal wall 



Fig. 198. Arrangement of apparatus for recording bladder contractions. A catheter 

 passed through the urethra may also be used sometimes to connect to the mercury bulb. 



is pithed, as the bladder tambour and tube would be in 

 the way of the operation. Place a hemostat on the penis 

 or vulva of the animal to prevent urination. 



By a median longitudinal incision open the thorax (start 

 artificial respiration at once) and expose the right lung 

 and the heart (do not open the pericardium). The anterior 

 mediastinum should, if possible, be gently turned over to 

 the left. Pick up both phrenic nerrc.s and cut iliem. 



