The Pharmacology of Pseudaconitine and Japaconitine. 383 



other two aconitines, but has been recognised as stronger than aconitine 

 by Langaard,* and in one series of observations by Harnack and 

 Meunicke. Kobert, on the other hand, does not separate japaconitine 

 from aconitine and pseudaconitine in toxicity. 



Dosage. — Based upon the observations made, the relative doses for 

 therapeutical purposes would be approximately, regarding that for 

 aconitine as the unit, for pseudaconitine 0*4 to 0*45, and for jap- 

 aconitine 0*8. 



Towards frogs the toxicity of these alkaloids is by no means so 

 great (per gramme body- weight) as it is towards the same unit of the 

 mammals and birds included in this research. Thus the lethal dose 

 per kilo, mammalian weight may only be lethal to 140 to 170 grammes 

 of frog weight, or even to less, according to the time of year. A 

 medium-sized rabbit may therefore be poisoned by a dose of aconitine 

 or japaconitine which would suffice to destroy six or eight frogs. 



Japaconitine is slightly more toxic towards both mammals and frogs 

 than is aconitine, but the higher toxicity of pseudaconitine towards 

 birds and mammals is not associated with an equal activity towards 

 frogs, for it exerts towards both R. esculenta and Pi. temporaria a 

 slightly lower toxicity than do either of the other alkaloids. 



There is no essential difference in the reaction of R. esculenta and R. 

 temporaria respectively to individual aconitines beyond a greater or less 

 accentuation of one or other symptom, as for example more excited 

 movement in the latter, more reduction of reflex in the former, but in 

 all parallel series of observations the resistance of R. esculenta has 

 proved to be slightly greater to all the aconitines examined. 



As concerns the local action of the aconitines upon sensory (cuta- 

 neous) structures in man, the differences are so trifling as to be 

 negligible. 



As regards the therapeutical employment of aconitine, japaconitine, 

 and pseudaconitine, the great similarity in their physiological actions, 

 amounting almost to a qualitative identity, which is established by this 

 investigation, justifies the employment of any one for internal ad- 

 ministration, provided that the dosage is properly regulated. Given in 

 the proportions mentioned above, the three alkaloids would exert 

 the same action. We strongly recommend the use of a pure alkaloidal 

 salt in preference to preparations made from the plants, since the 

 latter would be difficult to standardise, and even if this were done, the 

 action of the aconitines would be modified to a greater or less extent 

 by the other alkaloids present in the vegetable preparation. 



For local applications the three alkaloids may be introduced into 

 ointments in identical proportions. The greater toxicity of pseud- 

 aconitine need not prevent its use in this department of treatment if it 



* Langaard, 1 Arch. f. Path. Anat.,' 1880, 79, s. 229. 



