196 



EXPERIMENTAL PHARMACOLOGY 



into the lumen of the artery pointing toward the animal's 

 head. This should be done with great care and no chloro- 

 form should be emptied out in the wall of the vessel. The 

 assistant now takes hold of the ligatures (hemostats) that 



Fig. 186. Brass tube (//,. inches long and J4 inch in diameter) with (separable) 

 spear point to be passed through the chest for recording lung volume changes. The 

 holes cover a space about 2 I / 2 inches long. 



control the jugular veins and gets ready to close off (by 

 pressure) these vessels. It is advisable for a second as- 

 sistant to put a bull-dog clamp on the left carotid at this 

 moment. The operator then injects the chloroform (one 



To recording 

 tambour 



Requlatmq by pass 



I 

 Perforated brass tube 



- 6t /n fere 05 fa/ space 



Fig. 187. Arrangement of animal for recording lung volume changes. (For descrip- 

 tion see text.) 



or two cubic centimeters) into the vertebral artery. This 

 chloroform quickly reaches the brain and destroys all parts 

 with which it comes in contact. The blood-pressure falls 



