Aconitine, $e\, in relation to their Chemical Constitution. 341 



Aeonine, Cu^3^0 xo . 



Benzaconine, C 24 H 3s (G 6 H 5 CO)N'0 1 o. 



Acetylbenzaconine (aconiline), C 2 4H37(CH 3 CO)(C 6 H & CO)N'0 1 o. 



Diacetylaconitine, C s4 H3 5 (CH 3 CO) 3 (C 6 H 5 CO)N0 1 „. 



As aconitine has been so largely used by previous workers, its 

 action will be treated of in greater detail than will be necessary 

 when considering its derivatives or its allies obtained from other 

 varieties of aconite. 



The modes of action of aconitine, diacetylaconitine, benzaconine, 

 and aconine, respectively, have been tested with regard to the 

 following points : — 



1. Their effect upon the blood pressure, pulse, and respiration of 

 anaesthetised cats. 



2. Their general effect, and especially their action upon temperature 

 and respiration of rabbits, and (occasionally) of guinea-pigs. 



3. Their general toxic action towards frogs with their effect in 

 detail upon circulation, respiration, cord reflex, motility, and cutane- 

 ous sensation of these animals. 



4. Their lethal dose towards some or all of the various animals 

 employed. 



Whilst the scope of this paper will be limited to these alkaloids, 

 there are many other alkaloids and derivatives closely allied to 

 aconitine which have been under examination, and it is intended to 

 present a further communication concerning them with as little 

 delay as possible. Among them may be named pseudaconitine, the 

 alkaloid of A. ferox; japaconitine, the alkaloid of A. japonicum. or 

 Fischeri, as well as several derivatives of aconitine. 



The following is a summary of the pharmacological action of the 

 alkaloids. 



Action on the Circulation. 



Aconitine at first stimulates medullary centres slowing the heart, 

 acceleration follows, auricles and ventricles taking up an irregular and 

 (at one stage of toxic action) independent rhythm. Imperfect systole 

 (especially in the ventricles) develops. Irritability of ventricular 

 wall is much increased. Extensive variations of blood pressure accom- 

 pany the preceding phenomena. After great ventricular acceleration 

 with very imperfect systole, delirium of the ventricles supervenes. 

 The vagus (stimulated) continues to restrain speed of contraction 

 (especially acting upon the auricle), and may favour closer sequence 

 of ventricular upon auricular systole, so as to cause a rise in blood 

 pressure. For the same reason during a stage of sequence, it may 

 cause the usual effect (fall of pressure). In slow poisoning the 

 cardiac vagus on stimulation ceases to produce any effect. Atropine 

 is unfavourable to the independent rhythm of auricles and ventricles 



