GENERAL PHYSIOLOGY. 67 



(0) Close the key, i. e. "make" the current, and hold 

 the key down for several seconds. Note results 

 and take tracing. 



(.) Open the key, i. e. "Break the current." 

 Note results and take tracing. 



(V.) Make and break the current during one rotation 

 of the drum. If there is a response on both make 

 and break, so time the closing and opening of the 

 key that these will come in pairs with a consider- 

 able pause between. Before fixing the tracing, 

 (see Appendix A-7. ) mark each wave which was 

 the effect of making the current m., and each wave 

 which was caused by breaking the current, b. 



(5) Prepare and mount a sartorius from the curarized 

 frog. Bring the two poles into contact with the 

 muscle, and repeat the experiments suggested under 



(*) 



(6) In experiments (4) and (5) the observer has applied 

 electric stimulation of medium strength both directly 

 and indirectly to the sartorius and gastrocnemius 

 muscles. He is justified in formulating certain con- 

 clusions subject to subsequent modification. 



Formulate conclusions. 



(7) Describe minutely the chemical and physical proc 

 esses going on in the active Daniell cell. 



