Aconitine, Sfc, in relation to their Chemical Constitution. 345 



Aconine is inoperative towards body temperature, except in very 

 large doses, which enfeeble respiration and cause a curare-like action 

 on motor nerve terminations. Even then the effect is relatively 

 slight, as the heart; remains active and the vaso-constrictor system is 

 still in play (lethal dose causing death (guinea-pig) in 60' reduced 

 the temperature by 1*7° C). 



Action on Skeletal Muscle. 



Aconitine does not in ordinary lethal doses materially affect irrit- 

 ability, capacity for work, or form of contraction of frog's muscle. 

 Exposure to the direct action of aconitine solutions causes fibrillation 

 and lengthening of the muscle curve (an effect resembling slight vera- 

 trine action has been described). Fibrillation is abolished by aconine 

 and curare, and is therefore not attributable to the action of aconi- 

 tine directly on muscular tissue, but to a stimulation of motor nerve 

 endings. 



Biacetylaconitine reduces the irritability of muscular tissue, the 

 muscle (after poisoning in situ) is more readily fatigued, the curve of 

 contraction therefore losing in altitude whilst increasing in length. 



Bevzaconine in large doses produces rapid fatigue with failure of 

 contractility which is, however, restored by rest. Contact of strong 

 solutions reduces excitability and capacity for w r ork. 



Aconine in doses sufficient to immobilise frogs is inoperative. 

 Larger quantities slightly reduce excitability and capacity for work, 

 but have not the action so characteristic of benzaconine. 



Lethal Doses. 



The results are stated in decimals of a gram per kilo, of the body 

 weight, and where two figures are given the lethal dose lies between 

 them. 





Cat. 



Kabbit. 



Gruinea pig. 



Frog (R. Temp.). 



Aconitine .... 



Diacetjl-aco- \ 

 nitine .... J 

 Benzaconine . . 



-000134 



-004—0 -00515 



-0245 

 0-166—0-4 



0-000139 



0-0042 

 0-0272 



-00012 j 



-0042 



0-0238—0-0293 

 0-275 



0-000586 (March) 

 0014 (July) 



0-039 



0-284 



1055—1-75 





General Conclusions. 



It would therefore appear from our study of the pharmacology of 

 these alkaloids, that the introduction of two additional acetyl groups 

 into the molecule of aconitine does not create any pronounced varia- 



