GENERAL PHYSIOLOGY. 63 



(b) Qualitative variation of stimuli. Make and mount a 

 gastrocnemius preparation for indirect stimulation. 



(5) Study the response to the following variations of 

 mechanical stimuli : cutting, pinching, tapping, 

 pricking. 



(6) Study the responses to the following variation of 

 thermal stimuli : ice, hot wire. 



(7) How does the muscle respond to indirect stimula- 

 tion with glycerine, alcohol ? 



(V) Quantitative variation of stimuli. Use gastroc- 

 nemius preparation. 



(8) Mechanical stimuli : light tapping, heavy tapping. 



(9) Thermal stimuli : Touch the nerve with the wire 

 which has been held in boiling water, i.e., 100 C. 



Touch the nerve with a wire which has been 

 heated to redness in a gas flame. 



(10) Chemical stimuli : Put the end of the nerve into 

 0.6 % solution of common salt. Follow this with y^ 

 saturated solution of common salt. Compare the 

 results with those obtained when a saturated solu- 

 tion was used. 



((T) Variation in the length of time of applying stimulus. 

 Use gastrocnemius preparation. 



(11) Cut off, or pinch off the nerve very slowly. This 

 may be done so slowly and with such a gradual in- 

 crease of pressure as to cause no contraction of the 

 muscle. 



(12) Put the central end of the sciatic into tepid 

 0.6 % NaCl solution, and . gradually bring to a 

 boil, protecting the muscle and that part of nerve 

 not in the solution, with absorbent cotton moistened 

 in normal saline solution. 



The nerve may be functionally destroyed without 

 causing a contraction of the muscle. 



