194 EXPERIMENTAL PHARMACOLOGY 



ity? Pick up the right phrenic nerve. AVhat is the origin 

 of this nerve? If you do not find it readily open the chest 

 and locate it on the pericardium at the side of the heart. 

 Trace it from here back up into the neck. Could you cut 

 both phrenics in the neck icitlwut opening the chest? This 

 is sometimes done to stop movements of the diaphragm 

 when these interfere Avith certain records that are being- 

 made. 



EXPERIMENT XXIX. 



Morphine, Codeine, Pantopon, Heroine, Peronine, Dionine, 

 Narcotine or Thebaine. (Spinal Dog: Bronchioles.) 



1. This is a new field of experimentation for most med- 

 ical schools. Many drugs act vigorously on the bronchioles 

 and it is unfortunate for medical students not to have 

 some opportunity to perform experiments to bring out 

 these results, for the action of these drugs is often much 

 more striking on the bronchioles (and perhaps frequently 

 as important) than are the corresponding actions on the 

 heart or other organs. Several methods will therefore be 

 given in different experiments in order to give every lab- 

 oratory a chance to carry out such experiments. The best 

 (but perhaps the most complicated) method will be given 

 in Experiment LXX. For peripherally acting drugs it is 

 advisable to use spinal dogs. (Cats may also be used for 

 this work but dogs are better.) 



Before starting the experiment be sure to arrange for 

 a reliable source of artificial respiration. This should be 

 from an artificial respiration machine, but a hand-bellows 

 fixed to open only a given distance (to regulate the stroke) 

 may answer. 



Etherize a dog and arrange it for a blood-pressure trac- 

 ing. Place injecting burettes in connection with the fem- 

 oral veins. One burette contains adrenaline (1:10,000), 

 the other an opium alkaloid. Any one of those at the head 



