ACTIOX OF VEEATEIXE 



435 



the left thigh tightly. Under the skin of the back inject two 

 cubic centimeters of veratrine solution (five cubic centi- 

 meters equal one milligram) and attach the animal to the 

 frog board as illustrated. Connect the secondary wires to 

 the tendo Achillis and to the carpet tack. Do not stimulate 

 Hie muscle as the first contraction is the one which will in 



Fig. 344. Frog heart tracing showing the action of veratrine. The vagus trunk was 

 stimulated as indicated. Inhibition occurred before but not after veratrine was applied. 

 What action did the drug have here? How would you prove your conclusions? 



all likelihood show the action of the drug the best and this 

 one should be recorded. Adjust the inductorium connec- 

 tions for single shocks and use only the break shock to 

 stimulate the muscle. About ten or fifteen minutes should 

 be allowed for absorption of the drug. When everything 

 is entirely ready start the drum (medium speed) and when 



