BRONCHIAL ACTION OF OPIUM ALKALOIDS 195 



of this section may be used, but either heroine, codeine or 

 dionine will probably give the best results. Be sure the 

 drug is fresh and of first-class quality. Codeine possesses 

 some advantages in this respect. The strength of the solu- 

 tion chosen should lie five milligrams to the cubic centi- 

 meter. 



With great care to avoid opening tlie chest at the apex 

 dissect down on the right side of the neck (see Experiment 

 XXVIII, 2; also Figs. 183 and 184), and pick up the right 

 vertebral artery. Place a ligature around the vessel and 

 tie the ligature once loosely. The ends of this ligature are 

 brought together and clamped with a hull -dog so it can 

 be found readily. Now with a large (five or six inch) 



Fig. 185. Large needles for sewing with heavy twine. 



needle (Fig. 185) pass a ligature of heavy twine through 

 the tissues in the side of the neck in such a manner that 

 both jugular veins will be included. The carotid artery 

 and vagus nerve must not be included. The ligature passes 

 out through the skin at the side of the neck. The two ends 

 of the ligature are brought together and tied once loosely 

 and clamped with a hemostat. Another ligature is simi- 

 larly placed on the opposite side so that in this way the 

 chief venous return flow from the head can be quickly 

 clamped off. Now fill a small syringe (two cubic centi- 

 meters) of good quality with chloroform. The point of the 

 syringe should be as small and as short as possible. A 

 cheap syringe is very liable to leak chloroform. Get all 

 apparatus properly adjusted and then lift up the vertebral 

 artery on an aneurism needle and insert the syringe point 



