LECTURE V. g^5 



appear like impervious chords. This hap- 

 pened, indeed, in young patients. Yet, 

 Mr. Hunter never attempted to demonstrate 

 muscular fibres in arteries ; he says there 

 is a reddish substance surrounding the tube 

 near the internal coats, which he believed 

 to be the structure possessing irritability. 

 Specimens of arteries thus contracted, and 

 contrasted with others of the same size, but 

 of their natural dimensions, are exhibited 

 in the Museum. Mr. Hunter must have 

 been acquainted, from his brother's lectures, 

 with the inconclusive experiments of Hal- 

 ler, relative to the irritability of different 

 parts of the body. He adopted another 

 and a better mode of determining, whether 

 parts possessed a power of vital contraction. 

 Observing that this power in muscles pro- 

 duced contraction after the ordinary func- 

 tions of life had ceased, he tried whether, 

 and for what length of time, parts could 

 contract in this manner. Thus did he sa^ 

 tisfy himself, that the arteries of the funis 

 umbilicalis had vital energies remaining in 

 them sixty hours after its detachment. 



Q 



