ETHER ANESTHESIA 53 



A salt solution (Locke, Ringer, Tyrode, etc.) will be 

 placed in a large supply bottle in the laboratory. (Fig. 45.) 

 Sodium citrate solution for blood pressure work will be 

 supplied by the technician as needed. Unnecessary ivastage 

 ic III lie charged at cost. 



Specific detailed directions are given in the text for the 

 performance of each experiment, but both students and 

 instructors should be constantly on the watch for oppor- 

 tunities to improve the methods and technic given or to 

 introduce new and better experiments. The writer believes 

 this to be the best test of the vitality, spirit, and progress 

 of any course and he never teaches the same set of experi- 

 ments twice, but, on the contrary, he is constantly trying 

 to improve or drop the old experiments and to add newer 

 and better ones. This is even more true for apparatus, and 

 the writer sincerely hopes that all students and teachers 

 into whose hands this book may come will gladly contribute 

 all that they can toward devising better, simpler, and 

 cheaper apparatus. 



More experiments are given in this book than the class 

 will probably be able to perform. The instructor will se- 

 lect those best suited for the class and for the facilities of 

 tlie laboratory. Experiments entirely different from those 

 in the text may be substituted at any time. 



Not more than fifteen minutes should be occupied in 

 checking apparatus. Immediately thereafter proceed as 

 follows : 



EXPERIMENT I. 



Ether, (Action on the Central Nervous System. Cere- 

 brum.) 



1. Under an inverted battery jar (Fig. 31) place a full 

 grown normal frog. Take a small piece of absorbent cot- 

 ton and pour a few cubic centimeters of ether on it. Raise 

 the edge of the battery jar a little and slip the cotton under 



