334 EXPERIMENTAL PHARMACOLOGY 



The oxygen should be bubbling slowly but constantly 

 through the solution. This serves not only to oxygenate 

 the solution but also stirs it. Do you get a response to 

 the lobeline ? How do you explain the result 1 After a few 

 minutes slip the lower beaker out and replace the upper 

 one by another containing fresh warm salt solution. How 

 does the uterine strip respond to this? Take some more 

 normal tracings and then pour one or two (or more) cubic 

 centimeters of nicotine solution (one per cent) into the 

 beaker. Discuss your results fully. Change the beaker 

 again replacing it with one containing fresh warm salt 

 solution. Get some more records and then pour a small 

 amount of pilocarpine solution (one cubic centimeter equals 

 two milligrams) into the beaker. Discuss the results in 

 full. Add some atropine solution to the beaker and see if 

 this affects the uterine strip. (The size of the "dose" of 

 the drugs used in this experiment may have to be varied 

 a great deal in different experiments. The doses here 

 given will often be too large but the student can test this 

 out for himself.) 



EXPERIMENT LXXXIII. 



Adrenaline, Lobeline, Nicotine, Pilocarpine, Atropine. 



(Guinea Pig, Rabbit, Dog, Cat, Frog: 



Intestinal Segment.) 



(Consult the previous experiment to save animals.) 



1. Repeat the above experiment using a small ring cut 

 from the small intestine of one of the above mentioned ani- 

 mals. Do not injure the intestine if it can be avoided in 

 making your dissection. Be sure the intestinal ring is 

 properly weighted (try different weights to select the right 

 one) and then record some normal contractions. Add 

 some adrenaline (1:10,000) to the beaker and record the 

 results. How do you explain this? Change solutions and 



