396 Prof. Christison on the Poisonous Properties oj Hemlock, 



tery, back again to the heart by the pulmonary veins, and, lastly, 

 by the general arterial system to the spine. If a correct view of 

 the facts be here taken, there scarcely seems any refuge for the 

 physiologist, except in the novel, and, at first, startling doctrine,* 

 that conia acts by entering the blood, and producing on the in- 

 ner membrane of the bloodvessels a peculiar nervous impression, 

 which is instantly conveyed by sympathy along the nerves to the 

 organ remotely and ultimately affected. 



After these remarks on the properties of conia, it remains to 

 be seen whether they coincide with what is known of the proper- 

 ties of hemlock itself. On this question hangs the ulterior one, 

 whether conia is the true active principle of the plant. 



I have in vain attempted to settle the point by reference to 

 the existing descriptions of the effects of hemlock by toxicolo- 

 gical authors. Passing by, for the present, the statements of an- 

 cient authors, which will be reverted to afterwards, and proved 

 not to be confidently referrible to the modern hemlock ; we come 

 first to the older modern writers, such as Ma tthioli and Kircher. 

 The former says, a vine-dresser and his wife, who ate hemlock 

 roots for parsnips, became so delirious, that they ran about the 

 house, frantically knocking themselves against every thing in 

 their way ;f and the latter says, two monks from the same cause 

 became raving mad, plunged into a pond, taking themselves for 

 geese, and suffered long after from incomplete palsy and muscu- 

 lar pain.^: It is difficult, certainly, to connect these narratives 

 with the preceding details of the action of conia. As little con- 

 nection can be traced with the matter of fact narratives of cases 

 in more recent times, which all point at delirium, coma, and con- 

 vulsions, as the leading symptoms. These cases, however, are li- 



* Lately advanced by Messrs Morgan and Addison in regard to the action of poisons 

 generally. 



f Petri Andreas Matthioli Commentarii in sex libros Dioscoridis, p. 73G. Edit. Ve- 

 neris 1582. 



+ Wibmer, die Wirkung der Arzneimittel und Gifte. i. 172. 



