224 ^'^ ^^^ Vital Principle. 



from other parts of his Pathology, that he meant 

 to exclude the nervous fyftem. Dr. Haller's 

 theory of the vis infita was formed from a variety 

 of experiments on living animals, by which he 

 found the irritability of mufcles to remain, long 

 after their connexion with the brain was de- 

 ftroyed*. But the experiments of Dr. Monro f. 

 Dr. WhyttJ, and Dr. Smith ||, prove that there is 

 no real diftindtion between the vis infita and the 

 nervous energy. This difpute is fo well known, 

 that a particular account of the arguments 

 and experiments is unneceflary ; and fome of the 

 ftrongeft will be produced in the courfe of our 

 inquiry. Galen, from fimilar obfervations with 

 Dr. Haller, had drawn the fame conclufion with 

 refpeft to the motion of the heart §. 



Dr. Whytt, with an inaccuracy furprizing in 

 fo acute a phyfiologift, fuppofes the foul to be 

 prefent in different parts of the brain at the fame 

 time, while he confiders the foul as immaterial 

 and unextendedf. Nay, he afferts that when 

 contradlion takes place, on the irritation of a 

 feparated mufcle, the aflion happens from the 

 influence of part of the foul contained in the fe- 

 parated part**. Yet he complains that Dr. 



• Phyfiolog. T. I. p. 426 to 466. Id. T, JV. p. 516. 



t Obf. on the Nerv. Syft. 

 J Obi", on Irritab. and Senftb. p. 310, (of the Quarto 

 edit.) II DifTert. Inaugural. 



§ Van Swieten Comment. T.J. p. 3, 4. 

 f Vit. & Inv. Mot. p. 202. ** lb. 



Haller 



