0.^2 On the Vital Principle. 



veflels*. Befides, the experiments of Dr. l^ang- 

 rifli and Dr. Schwenke prove that tying up the 

 artery of a limb does not prevent the motion of 

 the limb; rnow by the confenr of all fupporters of 

 a vital principle, the charafter of that principle 

 is, that it enables a mufcle to contradl ; but in 

 this cafe a limb is moved long after circulation 

 is Hopped in it ; the blood therefore does not 

 appear to contain a vital principle. " Dr. Lang- 

 " rilh tied up, and cut afunder, the carotid and 

 *' both the crural arteries of a dog, without de- 

 *' ftroying the motion of any mufcle ; and Dr. 

 " Schwenke aflures us, that, after having tied up 

 ** the cruraj arteries of a dog clofe to the groin, 

 *' the animal continued to move his leg and foot 

 ** for a whole dayf ." 



While the particular dodrines of the vitalifts 

 are expofed to thefe objeclions, fome dire6t 

 arguments may be brought againft the general 

 fuppofition of an independent living principle : 

 the arguments are of two kinds; refutations of 

 the general proofs offered in fupport of the vital 

 principle, and inftances of the direft influence 



* This fympathy is moft obfervable in difeafes. Spaf- 

 modic afFe£tIons of the heart are often attended with {hoot- 

 ing pain in one or both of the hpmeral arteries. To this 

 caufe the pain felt in one arm, in cafes of hydrothorax, 

 jnuft piobably be afcribed. 



f Whytt, Vital and Invol, Motions, p. 6. 



of 



