on Mufcular Motion. 27 
being conftantly covered with mucus, which the vapour could 
not penetrate without diflolving it, which it had not time to 
do, and, if it had, would have united with it, fo as to form a 
foap, void of any Simulating power. 
Ir, therefore, the original motion began in the end of the 
nerves of the noftril, it muft be excited by a fubftance at a 
diftance from the end of that nerve, without any communica- 
tion of motion between the ftimulus, that is, application pro- 
ducing the motion, and the end of the nerve in which it is 
excited ; therefore, on any fuppofition, a ftimulus is capable 
of exciting a motion, in a part at a diftance, without any 
communication of motion ; and it is therefore not neceffary, 
that the nerves fhould be at all employed in the motions of the 
body excited by a ftimulus, as it can a Ct at a diftance without 
their intervening. Further, that the nerves are not employed in 
the motions excited by ftimuli, is evident from this experiment t 
take the heart out of a living animal, cut all the nerves off as clofe 
as poffible, lay it in nearly the heat of the body of the animal, 
it will continue to contract for fome time. As foon as it has 
ceafed contracting, prick a fibre in one of the ventricles ; both 
ventricles, and all their fibres, will contract inftantly, although 
there be now'' no communication by the nerves, between many 
of the contracting fibres, and the fibre ftimulated. It might 
be fufpeCted, that the motion of the fibre ftimulated might 
affeCt the others: in this cafe the contractions would be pro- 
gtefllve ; but, on the contrary, the whole contraCt at once. 
I cannot help bringing another inftance, where ftimuli 
produce aCtion in parts at a diftance, without any communica- 
tion of motion by the nerves. When infufion of cantharides 
is applied to the fkin, as we fay vulgarly, it is not applied im- 
mediately to the Ikin ; but in the firft inftance to the mucous 
E 2 and 
