.3»o ESSAYS AND OBSERVATIONS 



applied to the abdominal mufcles or vifcera 

 of a frog, would not put a ftop to the heart's 

 motion fooner, or indeed fo foon, as decol- 

 lation and the deftrudion of its fpinal mar- 

 tow, (N° 4. & 5. compared with N° 8. 

 & 10.). Opium therefore does not produce 

 its efteds, jolely^ by putting a flop to the 

 fqniftion of the brain and fpinal marrow,, 

 but its influence reaches to the fibres of the 

 mufcles themfelves, or to the extremities 

 pf th? nervous filaments which terminate in 

 them. 



^ When I fay the influence oi opium reaches 

 to the nervous filaments which terminate in 

 the mufcular fibre?, it is not meant, that 

 any effluvia or fubtile parts of the opium are 

 tranfmitted to them (See n &: above), 

 but that it deftroys their powers, by means 

 of that fympathy which they have, through 

 the brain or fpinal marrow, with the nerves 

 to which the opium is immediately ap- 

 plied. 



(J) From the above experiments we may 

 infer, that not only the power of voluntary 

 motion in the mufcles, but alfo their irrita- 

 bility or power of motion, when flimulated, 

 proceeds from the nerves, or is at leaft im- 

 mediately 



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