396 Prof. Curistison on the Poisonous Properties of 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, suchas Marrurovi and KrRrcHer. 
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. 
+ Petri Andree Matthioli Commentarii in sex libros Dioscoridis, p. 736. Edit. Ve- 
netiis 1582. 
+ Wibmer, die Wirkung der Arzneimittel und Gifte. i. 172. 
