187 [NAR. 
in common to the whole nervous system. This 
matter he maintained was * a subtle elastic fluid 
inherent in the medullary substance of the brain 
and nerves. upon the motions of which all sense 
and vital motions depend ; and by which, therefore 
motions are communicated from every one part to 
every other of the nervous system.” He believed 
that there were certain phenomena which evinced 
an excessive degree ora relative paucity of this 
fluid, at different times ; and that it was liable to 
be affected in these respects by external bodies 
applied to the nerves. He believed that narcotics 
diminished the mobility of this nervous power, and 
that in a certain quantity they destroyed it alto- 
ther. This is his theory of the operation of 
what he called ‘narcotic sedatives.” I hope I 
shall not startle you when I declare my belief in 
the existence of ‘narcotic sedatives’? which act 
in some inscrutable manner on the vital powers, 
and may be, in the manner so ingeniously accounted 
for in the beactiful hypothesis of Cullen. I would = 
incline however to the still: more philosophic and 
beautiful doctrine of complex and inter-sociated 
sympathies, to come at the same conclusion. The 
fact alone, however, is all which materially inter- 
ests us at this time ; and as I assume it as unde- 
niable, that cold water taken suddenly into the 
stomach of a person over heated, and prussic acid 
- given to one under any circumstances of ordinary 
existence, do produce effects not referable to the 
same mode of action belonging to the incitant nar- 
cotics, F shall dispose of the deleterious principle 
just named in a distinct class, in Murrays arrange 
ment modified, under the name of SEDATIVES. 
shall assume the prussic acid as the type of this as- 
_ gemblage, and it will be perceived [ am not with- 
aut legitimate resources to make a goodly number 
