14 



PROFESSOR C. R. MARSHALL OK 



Rabbit, 950 grin. R = number of respirations per minute. T = rectal temperature. 



Time 





Time 





after 



Remarks. 



after 



Remarks. 



Injection. 





Injection. 









R = 60. T = 396°. 







R = 48. T = 395°. 





1'44 mg. tutin into marginal vein of 





0'24 mg. coriamyrtin into marginal vein 





ear. 





of ear. 



4' 



Breathing more rapidly. 



r 



Very rapid breathing. 



5' 



R = 108. 



H' 



R = 204. 



6' 



R = 168. Head-noddings apparently 



5' 



R = 204. Head-noddings. 





synchronous with respiration. Slip- 



7' 



Powerful clonic terminating in tonic 





ping down on venter. 





convulsion. Lasted one minute. 



8' 



R = 204. Laid on venter with hind 





Quickly recovered. Then R = 84. 





limbs partially out. 



12' 



R = 204. Some twitching of ears. 



25' 



Head-nodding less marked, but slight 



15' 



Slightclonic convulsion of head, followed 





general tremors. Afterwards assumed 





by early stage of somersaulting move- 





characteristic (exaggerated springing) 





ment. 





posture. This strained position was 



17' 



Clonic convulsion of head. 





maintained for one hour. 



19' 



Quiet. R = 96. 



90' 



R=160. 



25' 



R = 108. 



104' 



Moved very carefully for a few steps. 



45' 



R = 60. Not moved since last note. 





Hind-limb movements somewhat 





Apparently normal. 





inco-ordinate. 



60' 



R = 60. T = 380°. 



120' 



R = 108. T = 36-8°. Recovering. 







These experiments show that in similar physiological closes tutin takes longer to 

 act and exerts a more prolonged effect than coriamyrtin, but apart from these 

 differences the two substances produce almost identical symptoms. The difference in 

 time of action is important in relation to the question of tolerance, and it explains in 

 some measure why, on the one hand, a second injection of tutin, administered after a 

 long interval, should so rapidly induce the convulsions which failed to appear as a 

 result of the first injection ; and, on the other hand, why relatively large quantities of 

 coriamyrtin, if administered in divided doses at short intervals, can be given without 

 inducing convulsions. 1 hope to publish experiments on this point later. 



Summary. 



1. Tutin, the active principle of the toot plant, causes epileptoid convulsions in 

 various classes of animals. After large doses to rabbits the earliest convulsions 

 commence with a general tonic spasm which is followed by clonic movements. After 

 small convulsant doses the couvulsions begin with clonic spasms of the muscles of the 

 head. These extend to the fore and then to the hind part of the body, and may 

 terminate in a tonic spasm. The later convulsions after larger doses also assume this 

 form. After the initial convulsions following small doses, somersaulting movements 

 are not uncommon. 



2. The convulsions are mainly of cortical and pontine origin. Convulsive move- 



