226 LECTURE V. 



Mr. Hunter's notions of life were pecu- 

 liar. He thought that it was an active prin- 

 ciple, which, by operating in various modes 

 and degrees, produced the different phasno- 

 mena by which its existence is characterized. 

 He knew that parts, in which no muscular 

 structure was evident, were nevertheless 

 irritable, and that the modes of contraction 

 and relaxation of muscular parts were va- 

 rious. He seems by no means satisfied, 

 that all the phaenomena of muscular relaxa- 

 tion can be accounted for, on the supposi- 

 tion of the abatement or cessation of an 

 active power. Without, therefore, pretend- 

 ing to determine the modes of action of the 

 sanguiferous tubes, seeing that they have 

 a power of vital contraction upon the dimi- 

 nishing quantity of their contents, knowing 

 that vessels alone are capable of producing 

 a quick and forcible current of their con- 

 tained fluids, as is evident in the ascent of 

 sap of vegetables, and still more so in the 

 acceleration of the current of the fluids 

 contained in the absorbing vessels of ani- 

 mals, as they approach to the trunk of the 



