LXVII. Strychnin. 



/. Material. One dog; two frogs; sulphate of strychnin. 



2. Preparation. Make a solution of sulphate of strychnin 

 0.01 gm. to 10 c. c.; also concentrated solution, 0.2 gm. 

 to 10 c. c. Pith frogs. Do not fasten the dog to the 

 dog-board. Set up electrical apparatus to obtain tetaniz- 

 ing current. 



3. Experiments and Observations. 



(1) Hypodermic injection of 0.01 gm. strychnin to the 

 dog. 



(a) Record the condition before, and symptoms as 

 they arise after exhibition of the drug, especially 

 with reference to : 



(I) Muscular activity. Describe convulsions. 



(II) Respiration. How affected by reflexes. 



(III) Circulation. Rapidity and rhythm of heart. 



(IV) If death occurs, which stops sooner, the 

 circulation or respiration ? 



(<) Formulate results. 



(2) Ligate thigh of frog, except sciatic nerve, at junc- 

 tion with body. Sever all structures except nerve 

 and femur, just below ligature. Separate cut surfaces 

 with rubber tissue to prevent diffusion of the drug. 

 Turn the frog over and make a median abdominal 

 incision. Pressing viscera aside, pick up the sacral 

 plexus of nerves going to the uninjured leg. The 

 sacral plexus may be readily recognized, lying on each 

 side of the median line. Pass a thread loosely around 

 the nerves, so as to quickly find them when wanted. 

 Inject into dorsal lymph space, 0.0001 gm. strychnin. 



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