98 GENERAL PROPERTIES OF LIVING TISSUES 



decomposition by a small crystal of thymol. The 

 bottle should be shaken before the curare is with- 

 drawn. The curare should be injected at the 

 beginning of the laboratory day, so that there 

 may be time for its action in a dilute solution. 

 The motor nerves are paralyzed first and the 

 effect should, if possible, be limited to them. 

 Strong solutions paralyze other nerves, the heart, 

 and probably other muscles. 



Opening and closing Contraction. Place two 

 non-polarizable boot electrodes in rubber holders 

 upon a mounting-rod. Fill the boots half full 

 of saturated solution of zinc sulphate. Fill the 

 well in the toe of each boot with normal saline 

 solution. Place well amalgamated zincs in the 

 boots and connect them through an open simple 

 key with the poles of a battery. Prepare a 

 sartorius muscle (Fig. 25) from a curarized frog, 1 

 preserving the pelvic and tibial attachments. 

 Lay the muscle upon the toes of the boot 

 electrodes. Close the key. 



The muscle will twitch when the current is 

 made and probably when it is broken, but during 

 the passage of the current there will be normally 

 no contraction. 



1 Be sure to cut off the head or otherwise destroy the brain 

 of curarized frogs before operating on them. 



