STRYCHNINE AND PICROTOXIXK I*.')! 



page 144) and record the subject's normal reaction time 

 for sight, touch and sound. 



3. Take two tubes of oil (or water color) paint, one 

 white, the other red (other colors may also be used), and 

 with a brush on a white tile surface (pill tile) make a series 

 of mixtures of white and red varying only the slightest 

 degree in color. Also make several just alike. Number 

 these and let the subject note all those between which he 

 can just distinguish a difference. Record these results. 



4. Now let the subject take a therapeutic dose of 

 strychnine. 



Caul ion. Strychnine is very poisonous. The average dose is oue-sixtielh 

 of a grain, but many physicians give doses as large as one-thirtieth of a 

 grain. The drug i s probably best taken in the form of tablets (one-sixtieth 

 grain) as mistakes are thus less liable to occur regarding the size of the dose. 



5. AVait fifteen or twenty minutes (or longer) for the 

 drug to be absorbed and then again test the acuteness of 

 hearing, the reaction time for sight, touch and sound, and 

 the acuteness of color sense with the painted spots on the 

 tile (be sure these have not changed their color or appear- 

 ance by drying the spots should be thoroughly dry be- 

 fore the subject sees them the first time). Has the strych- 

 nine affected any of these reactions! AYhere did the drug 

 act to do this! Is the reaction in the nature of a stimula- 

 tion or a depression? How does this compare with alco- 

 hol! 



EXPERIMENT XXXVII. 

 Picrotoxine. (Frog: Action on Medulla and Cord.) 



1. Examine the arrangement of the apparatus shown 

 in Fig. 208. Pith a frog (cerebrum only] and arrange it 

 thus for recording contractions of the gastrociiemius mus- 

 cle. Under the skin of the back inject one cubic centi- 

 meter of picrotoxine solution (one cubic centimeter equals 



