ACTION OF ACOXIT1XE 429 



EXPERIMENT CXXXIV. 



Aconitine. (Frog: Heart Tracing.) 



1. Determine the action of aconitine on the heart and in- 

 hibitory apparatus of a frog. Lea re the medulla intact. 

 Inject the drug into the dorsal lymph sac with a hypodermic 

 syringe. The action on the heart is of some special interest 

 because of the peculiar behavior of the organ under the ac- 

 tion of the drug. This heart action has been thought to lie 

 of some value in identifying aconitine. What can you say 

 regarding the chemical tests for the identification of aconi- 

 tine? Do you know of any other drugs that act on the 

 frog's heart in a manner similar to that of aconitine? 



EXPERIMENT CXXXV. 

 Aconitine. (Turtle: Heart Tracing.) 



1 . Repeat the above experiment using a turtle instead of 

 a frog. Apply the drug directly to the heart. What gen- 

 eral conclusions can you draw .' 



EXPERIMENT CXXXVI. 



Aconitine. (Dog: Blood-pressure, Respiration, 



Temperature.) 



1. Arrange to record the blood-pressure, respiration and 

 temperature (rectal thermometer). After the experiment 

 starts make a record of the temperature reading every 

 three or five minutes. Place aconitine solution (aconitine 

 " potent, " ten cubic centimeters equal one milligram) in 

 the injecting burette. Isolate and ligate loosely (but do 

 not injure] both vagus nerves. When all is ready take a 

 normal tracing and then inject one-half cubic centimeter of 

 aconitine solution. Some samples of aconitine are exceed- 



