and its Alkaloid Conia. 397 



mited in number ; few are minutely described ; several occurred 

 before physicians had learned to discriminate accurately the exter- 

 nal characters of the true hemlock, and other poisonous umbelli- 

 ferous plants resembling it ; in scarcely any of them is allusion 

 made to the risk of error from this cause, or any pains taken to 

 establish the identity of the poison ; and in some, including one 

 related by myself, which occurred twelve years ago, the symptoms 

 were taken at second hand, the individuals having died before 

 being seen by a competent observer.* The resemblance subsist- 

 ing between hemlock and various umbelliferous plants, such as 

 Cicuta virosa, Mthusa cynapium, CEnanthe crocata, Chtsrophyllum 

 temulentum, is alone sufficient to vitiate most of the modern de- 

 scriptions of the poisonous effects of the first species. We know 

 that they often have been confounded together ; and hence we 

 can have no certainty what the plant was in special cases of poi- 

 soning, where the name merely is given, and the narrative does 

 not contain internal evidence of its exact nature. Singular then 

 as it may appear, we are very imperfectly acquainted with the 

 real effects of one of our most familiar poisons on the human 

 body. 



For the like reasons, our knowledge of the effects of hemlock 

 on the lower animals is far from being precise or positive. The 

 only unequivocal experiments, indeed, are those of Professor Or- 

 FiLA,f and a few performed by Professor Schubarth ;\ and from 

 these we should infer, that, besides possessing irritant properties, 

 hemlock induces giddiness, convulsions, loss of sensibility, palsy, 

 and coma. This account does not agree with the account given 

 above of the action of conia, which does not seem to affect the 

 senses so long as the respiration goes on. But it is possible that 

 the difference is more apparent than real, and that hemlock has 



* Gmelin's Pflanzengifte 605. Corvisarfs Journal de Medecine, xxix. 107. Philo- 

 sophical Transactions, xliii. 18. Wibmer, ut supra, i. 171. My Treatise on Poisons. 

 f Toxicologie Generate, ii. 303. 

 % Horn's Archiv fur Medizinische Erfahrung, 1 824. 



3e2 



