ADVANCED EXPERIMENTAL PHYSIOLOGY 163 



the rabbit the depressor runs separately on both sides. In the 

 dog it is bound up in the vago-sympathetic trunk. 



The trachea is opened and a tracheal cannula inserted. This is 

 connected by a side tube with a recording tambour. The writing 

 styles of the manometer float and of the tambour are brought to 



FIG. 153. Mercurial manometer fitted with float and writing style. 



write on the kymograph exactly beneath one another. A clock 

 marking seconds and an electric signal placed in the primary circuit 

 are also brought to write on the kymograph. The primary circuit 

 is arranged to give tetanising shocks, and shielded electrodes are 

 connected with the secondary coil by means of a Du Bois key, and 

 are placed in position under the peripheral end of the vagus nerve. 



