on Mufcular Motion . j ~ 
and the ftomacli; and if the fpice were to aft by touching 
thefe fibres, it would be the fame, whether it was applied to 
the Ik in over the flomach, or to the Ik in of the arm; for in 
both cafes it muft be abforbed by the lymphatics, and carried 
to the left fide of the heart, and there and in the lungs be 
blended univerfally with the whole blood, and carried by the 
arteries to the moving fibres of the ftomach. Nay more, that . 
it would be equal, whether it was applied to the inner furface 
of the flomach itfelf, or to the external lkin, or any other 
membrane, of any other cavity : for the flomach is covered 
with mucus, and lined with a membrane which is perfectly 
impervious, and totally prevents any thing contained in the 
flomach from being any way applied to the moving fibres ; it 
muft in this cafe, therefore, be likewife taken up bv the 
lymphatics, or laCteals, and carried to the heart before it 
could touch the moving fibres of the flomach. The maxim 
then, arifing from our knowledge of the lymphatics, would 
be, that it was of no confequence where we applied a fpice in 
cafes of flatulency ; which is not true. By fimilar reafons it 
might be eafily fhewn, were it not for tiring my learned 
Audience, that all the knowledge of the properties of the 
fluids, which has been acquired by modern and accurate expe- 
riments, hardly contributes any thing to the knowledge of 
applying medicines for the cure of difeafes ; and that the ftudy 
of the laws of the attraction of life, or what has been called 
mufcular motion, is of confiderable importance. 
One more obfervation I have only to make, viz. that all 
original motions are by their nature perfectly unintelligible as 
to their caufe ; who can tell the caufe of gravity, chemical 
attraction, &c. ? and fo undoubtedly the attraction of life, in 
its caufe can never be inveftigated, being, like all other attrac- 
F 2 tion. 
