384 



Prof. J. T. Cash and Mr. W. E. Dmistan. 



is remembered that all applications of the aconitines, externally, are to 

 be considered dangerous if any abrasion of the skin is present. 



The chemical part of this inquiry has been conducted in the Labora- 

 tories of the Scientific Department of the Imperial Institute, with the 

 assistance and co-operation of the Government of India. Our thanks 

 are specially due to Dr. George Watt, C.I.E., Eeporter on Economic 

 Products to the Government of India, for the interest he has shown in 

 the investigation, and for the care he has taken in the collection of the 

 necessary material. 



The physiological experiments have been conducted in the Depart- 

 ment of Materia Medica and Pharmacology of the University of 

 Aberdeen, and have been assisted by a grant made by the Eoyal 

 Society from the Government Fund. The assistance of Drs. Esslemont 

 and Fraser has been very valuable in carrying out some of the obser- 

 vations entailed in this department of the research. 



" The Pharmacology of Pyraconitine and Methylbenzaconine con- 

 sidered in Eelation to their Chemical Constitution." By J. 

 Theodore Cash, M.D., F.E.S., Eegius Professor of Materia 

 Medica in the University of Aberdeen, and Wyndham E. 

 Dunstan, M.A., F.E.S., Director of the Scientific Department 

 of the Imperial Institute. Eeceivecl June 11, — Eead June 20, 

 1901. 



(Abstract.) 



In a previous paper* we have shown that an entire change in the 

 physiological action ensues on the withdrawal of the acetyl group 

 from aconitine as is seen in the action of benzaconine, the first 

 hydrolytic product of aconitine, from which it differs in containing 

 an atom of hydrogen in the place of one acetyl group. This 

 .alkaloid is devoid of the characteristic physiological action and 

 extraordinary toxicity of aconitine, whilst in respect of its action on 

 the heart it is in the main antagonistic to that of the parent alkaloid. 

 In order to study further the remarkable dependence of the physio- 

 logical action on the presence of the acetyl group, we have examined 

 the action of two derivatives of aconitine which we have obtained in 

 this research, viz., pyraconitine and methylbenzaconine. 



Pyraconitine was first prepared by one of usf by heating aconitine 

 at its melting point, when the acetyl group is expelled as one molecule 

 of acetic acid and the alkaloid pyraconitine remains. This compound 

 * ' Phil. Trans.,' B, 1893, vol. 190, p. 239. 



f Dunstan and Carr, ' Trans. Chem. Soc.,' 1894, vol. 65, p. 176. 



