PILOCARPINE, ADRENALINE; ARECOLINE, ETC. 287 



do you observe? How do you account for it? Pilocarpine 

 acts very much like arecoline (as does also muscarine) but 

 arecoline is much more powerful. 



Does atropine counteract all the actions of pilocarpine 

 or arecoline? Do your records show this? Inject one-half 

 cubic centimeter more of atropine. Then empty the atro- 

 pine out of the burette and replace it with barium chloride 

 solution (one-half per cent). Arrange all writing points 

 and inject one cubic centimeter of arecoline to see if it acts 

 as it previously did. Empty out the arecoline and replace 

 it with adrenaline. If the dog weighs ten kilos or more 

 then inject five cubic centimeters of the barium solution (a 

 smaller dose for a smaller dog). It will take about one- 

 half minute for the action of the drug to become well 

 marked (if the animal was in fair condition when the drug 

 was injected). The reaction should be very marked. 

 When this occurs inject one and one-half cubic centimeters 

 of adrenaline. Does this counteract any of the actions of 

 barium? On what structures does barium act? Did the 

 previous administration of atropine affect this in any way ? 

 Kill the animal with a big dose of barium and just after 

 the death record is made quickly open the chest (with large 

 tinner's snips) and observe the heart action. What is delir- 

 ium cordis? What is fibrillation? 



EXPEEIMENT LXX.* 



Pilocarpine, Adrenaline, Arecoline, Atropine, Barium. 

 (Spinal Dog: Blood-pressure and Bronchioles.) 



1. Etherize a dog (ten kilos) and arrange for blood- 

 pressure records. Place injecting burettes in both femoral 

 veins and one in the left external jugular. These burettes 

 contain adrenaline (1:10,000), pilocarpine (one cubic cen- 

 timeter equals one milligram) and arecoline (one cubic 



*Cats may be used for this experiment, but dogs are greatly to be preferred. 



