224 EXPERIMENTAL PHARMACOLOGY 



Why is this so import ant? The injecting burettes contain 

 adrenaline and strychnine sulphate (one cubic centimeter 

 equals one-half milligram). 



Adjust all writing points (so they will pass each other) 

 on the drum. Keep the anesthesia moderately deep and 

 as even as possible. The oncometer tracing should be the 

 upper record, the blood-pressure next below, then the res- 

 piration, and at the bottom of the drum should be the base 

 line and time marker. The student (and the instructor) 

 should make careful observations in each experiment to 

 determine about what sized tambour bowls and what mag- 

 nification should be used for each organ from which rec- 

 ords are obtained. This will necessarily vary largely with 

 different types of tambours and must be determined in 

 each laboratory from experience. 



Take about one inch of satisfactory tracings and then 

 inject one cubic centimeter of strychnine. What is the 

 result? Note the time of day. After the pointers return 

 to normal (which should be in a short time) inject one 

 cubic centimeter of strychnine again. When the records are 

 again back to normal inject one-half cubic centimeter of 

 adrenaline. Do you get satisfactory records? What is 

 the action of small (therapeutic) doses of strychnine on 

 the heart and circulation? Slowly, from time to time, in- 

 ject one cubic centimeter doses of strychnine and allow 

 the animal to lie perfectly quietly. Is there any change in 

 the blood-pressure as the action of the drug comes on 

 slowly? After a time there will be a sudden reaction. Be 

 sure the drum is going and that you record the result well. 

 Do not give any more drug for a while then and wait for 

 further developments. How is the oncometer record af- 

 fected? How do you account for this? Be sure you are 

 ready to give artificial respiration if it is needed. Observe 

 carefully the actions of the face and mouth muscles when 

 the animal shows most marked symptoms. What is meant 

 by the expression "risus sardonicus"? Are there any spe- 



