RECORDING BRONCHIAL CHANGES 



L'S<) 



This apparatus works best when the air is intermittently 

 aspirated out of the chest (25 or 30 times per minute- 

 45 millimeters of mercury negative pressure with the by- 

 pass or inlet adjusted to give proper strength of suction 

 to fill the lungs well). In the absence of a machine capable 

 of giving negative interrupted pressure (see Fig. 360) pos- 

 itive artificial respiration may lie used in the ordinary 

 manner by blowing air into the trachea. Even a hand bel- 

 lows may be used for this, but a power driven machine is 



G/asi window 



'jjjj; -Removable cap 



Tube for 

 / aspiration 



Adjustable by-pass 



Diaphraqmotic 

 Surface 



Notch, for 

 ner/cardia/ sac 



Flanqe for sternum 

 Costal surface 



,:i 



Fig. 256. Another form of apparatus for insertion into the chest to record bronchial 

 changes. About one-third natural size. The three wings at the bottom are placed inside 

 the chest and are adjustable (by the thumb nuts) to fit various sized chests. When the 

 can (with a glass or celluloid window) is removed, the hand may be passed into the 

 chest to massage the heart, etc. The movements and changes in the lungs and heart 

 can be seen through the window. (For the method of use see text.) 



greatly to be preferred. The apparatus shown in Fig. 256 

 may also be used for the lungs. 



The chest of the animal is now opened by a median lon- 

 gitudinal incision, the apparatus is inserted as shown in 

 Fig. 257 and the edges are clamped around air tight with 

 liemostats. It is often advisable to sew one or two stitches 

 of heavy twine from side to side through the skin of the 

 upper end of the chest. The flange of the apparatus 

 catches the sawed edges of the sternum on each side and 



