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XLVIII. — On the Physiological Action of the Calabar Bean (Physostigma vene- 

 nosum, Balf.). By Thomas R. Fraser, M.D., Assistant to the Professor of 

 Materia Medica in the University of Edinburgh. Communicated by Professor 

 Christison, M.D., D.C.L., V.P.R.S.E. 



(Read 17th December 1866.) 



In 1855, the Professor of Materia Medica in the University of Edinburgh, in a 

 paper read before this Society, directed the attention of physiologists to some 

 of the remarkable properties of the Calabar bean.* In 1862,1 presented a 

 graduation thesis to the University of Edinburgh on the " Characters, Actions and 

 Therapeutic Uses of the Ordeal Bean of Calabar." The principal results I had 

 obtained at that time were that this substance causes death by either syncope 

 or asphyxia, the latter being due to an effect on the spinal cord and on the 

 respiratory centres ; that the symptoms resemble those of cardiac or pulmonary 

 embarrassment, according to the quantity of the poison administered, and to its 

 rate of absorption ; and, also, that the topical application of this agent to the 

 eyeball, or to its neighbourhood, produces a marked and rapid contraction of the 

 pupil and various disturbances of vision.-j- Since then, and more especially 

 because of the peculiarity of the last of these conclusions, a lively interest has 

 been taken in this substance. Its actions on the eye have been investigated by 

 nearly all the leading ophthalmologists of Europe and of America, and its general 

 physiology has occupied the attention of many distinguished students of biology. 

 Nor have these labours been barren of practical results. Ophthalmic medicine 

 has adopted this agent as one of its important remedies, and there can be little 

 doubt that general medical practice will soon include in its Pharmacopoeia a 

 drug of so great energy."! 



The present investigation was undertaken for the purpose of extending and 

 supporting my previous results, with some of which subsequent observers have 

 disagreed ; but I purpose to take an opportunity of examining these discrepancies 

 with some detail in a different place. The effects which follow the topical applica- 

 tion to the eyeball will be merely alluded to in this paper, as this portion of the 

 subject has not been completed. Enough has, however, been done to convince 



* Proceedings of the Royal Society of Edinburgh, vol. iii. p. 280 ; and Monthly Medical 

 Journal, vol. xx., 1855. 



f Edinburgh Medical Journal, 1863, and pamphlet. 



+ Since this sentence was written the Physo&tigmatis Faba has been admitted into the edition of 

 the " British Pharmacopoeia," published in 1867. 



VOL. XXIV. PART. III. 9 I 



