296 POPULAR LECTURES AND ADDRESSES. 



which the metaphysicians who followed Dr. 

 Thomas Reid in the University of Glasgow, 

 taught. It was in the University of Glasgow that 

 I learned about the muscular sense, and I have not 

 seen it very distinctly stated elsewhere. What 

 is this " muscular sense " ? I press upon the desk 

 before me with my right hand, or I walk forward 

 holding out my hand in the dark and using this 

 means to feel my way, as a blind man does con- 

 stantly who finds where he is, and guides himself, 

 by the sense of touch. I walk on until I perceive 

 an obstruction by a sense of force in the palm 

 of the hand. How and where do I perceive this 

 sensation ? Anatomists will tell you it is felt in 

 the muscles of the arm. Here, then, is a force 

 which I perceive in the muscles of the arm, 

 and the corresponding perceptivity is properly 

 enough called a muscular sense. But now take 

 the tip of your finger and rub a piece of sand- 

 stone, or a piece of loaf sugar, or a smooth 

 table. Take a piece of loaf sugar between your 

 finger and thumb, and take a piece of smooth 

 glass between your finger and thumb. You per- 



