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ADDITIONAL NOTES. II. 

 THE FACULTIES OF THE SENSORIUM. 



Next the long nerves unite their silver train, 



And young Sensation permeates the brain. CANT. I. 1. 250. 



I. THE fibres, which constitute the muscles and organs of sense, 

 possess a power of contraction. The circumstances attending the exer- 

 tion of this power of contraction constitute the laws of animal mo- 

 tion, as the circumstances attending the exertion of the power of 

 attraction constitute the laws of motion of inanimate matter. 



II. The spirit of animation is the immediate cause of the contrac- 

 tion of animal fibres, it resides in the brain and nerves, and is liable 

 to general or partial diminution or accumulation. 



III. The stimulus of bodies external to the moving organ is the 

 remote cause of the original contractions of animal fibres. 



IV. A certain quantity of stimulus produces irritation, which is an 

 exertion of the spirit of animation exciting the fibres into contraction. 



V. A certain quantity of contraction of animal fibres, if it be per- 

 ceived at all, produces pleasure; a greater or less quantity of con- 

 traction, if it be perceived at all, produces pain; these constitute 

 sensation. 



VI. A certain quantity of sensation produces desire or aversion; 

 these constitute volition. 



VII. All animal motions which have occurred at the same time, or 

 in immediate succession, become so connected, that when one of them 

 is reproduced, the other has a tendency to accompany or succeed it. 

 When fibrous contractions succeed or accompany other fibrous con- 

 tractions, the connexion is termed association; when fibrous contrac- 

 tions succeed sensorial motions, the connexion is termed causation; 

 when fibrous and sensorial motions reciprocally introduce each other, 

 it is termed catenation of animal motions. 



