1881.J 



On the Physiological Action of /3 Lutidine. 



169 



(4.) The effect of the poison might also be thought due to its action 

 upon the muscles themselves, causing them to lose their irritability 

 and cease to respond to stimuli reaching them from the nerve. The 

 last experiments would go strongly against this, but to be perfectly 

 sure we performed the following : A frog, whose brain had been de- 

 stroyed, received urari up to a point at which no reflex action occurred, 

 and no contraction of the leg muscles on stimulation of the sciatic 

 nerve. The animal was placed in a moist chamber, and by means of 

 the pendulum myograph tracings were taken of the contractions of the 

 gastrocnemius, caused by direct stimulation. A number of these 

 tracings of the muscular contraction was taken before application of 

 the poison, and then from time to time ft lutidine was injected into the 

 dorsal lymphatic sac, commencing withO"l cub. centim. of 10 per cent, 

 solution, and finally using as much as two drops of the pure alkaloid ; 

 but there was no alteration of a decided character in any of the curves, 

 either upon the latent period, contraction, or relaxation. 



It may be mentioned that after acting on frogs retaining their spinal 

 cord with ft lutidine, destruction of the spinal cord with a wire, causes 

 little or no movement of the limbs, as is the case under ordinary 

 conditions. 



From all these results it cannot but be evident that the disappear, 

 ance of reflex action is due alone to the effect of the poison on the nerve 

 cells of the spinal cord. 



Strychnine and ft Lutidine. — Such being the action of 6 lutidine upon 

 the spinal cord, we were naturally led to ascertain whether it was 

 antagonistic in its action to strychnine. If a frog, whose brain has 

 been destroyed, be treated with a small quantity of strychnine solution, 

 the slightest stimulus is sufficient to throw the animal into strong 

 tetanic convulsions. 



Various experiments were tried ; as examples we will give the 

 following : — 



(1.) A frog whose reflex action was good (the brain having been 

 destroyed in the usual way) had sufficient ft lutidine solution given it, 

 to cause this reflex action to disappear. A drop of 0*5 per cent, 

 strychnine was injected into its dorsal lymphatic sac, a quantity 

 which injected into another frog similarly prepared brought on the 

 strongest convulsions. Still no effect was produced, neither did any 

 change appear when another large drop was injected. 



(2.) As an example of another method, a frog (whose brain had 

 been destroyed) was thrown into strong 'convulsions by the use of 

 strychnine, then 0*5 cub. centim. of 10 per cent, ft lutidine were 

 injected into the dorsal lymphatic sac, also a drop of the pure alkaloid ; 

 in fifteen minutes the strychnine tetanus was passing off and in 

 twenty-five minutes had quite gone. The same effect happened with 

 smaller quantities of the alkaloid. 



N 2 



