460 EXPERIMENTAL PHARMACOLOGY 



(1:1000) to the Ringer's solution. Perfuse this solution 

 through the animal and compare the outflow with that from 

 the other solutions. What conclusions can you draw ? How 

 do acids and alkalies compare with adrenaline and nitrites 

 as regards their effects on the arterioles ? 



EXPERIMENT CLXIV. 



Magnesium, Calcium. (Rabbit: Anesthesia, Antagonism. 



Meltzer and Auer.) 



1. Into a rabbit inject subcutaneously 1.7 grams of mag- 

 nesium sulphate (in twenty-five per cent solution) per kilo- 

 gram of weight. Watch the animal closely and observe 

 that in thirty or forty minutes deep anesthesia is produced. 



A ten cubic centimeter hypodermic syringe with a very 

 fine point is now filled with three per cent calcium chloride 

 solution. Place a bull-dog on the lateral margin of the 

 rabbit's ear near the head and block the flow of blood in 

 the marginal ear vein which will become engorged with 

 blood. Insert the syringe point into the vein (pointing to- 

 ward the heart), remove the bull-dog and inject about eight 

 cubic centimeters of the calcium chloride solution. Handle 

 the animal carefully and observe what effect the calcium 

 has. What conclusions can you draw ? What explanation 

 can you offer? Could you use magnesium chloride instead 

 of the sulphate? Would it simplify the conditions if cor- 

 responding salts (chloride) of the metals were used? 



EXPERIMENT CLXV. 



Arsenic. (Dog or Rabbit: Respiration, Blood-pressure, 

 Peristalsis, Renal Action, Blood.) 



1. Prepare a dog (or rabbit two grams of urethane) 

 for recording blood-pressure, respiration and intestinal con- 

 tractions. Insert a bladder cannnla (avoid hemorrhage into 



