ITS VALUE AND LIMITS. 61 



and have the delicious pleasure of enjoying their 

 effects whenever he chose. We often neglect it, 

 but we absolutely have a mine of wealth in those 

 ten fingers, which the longest and most observant 

 life cannot exhaust. Exhaust ! the use of it is 

 the very reverse ; for we absolutely multiply it in 

 the same proportion as we use it; and the hand 

 which can do the most is the readiest in the suc- 

 cessful performance of any thing new. 



But still, exquisite as is the discrimination of 

 the hand, it can take note only of that which has 

 the most obvious properties of matter. It has, 

 indeed, a sensibility to heat and cold, but that is 

 vague and variable, inasmuch as it is only the dif- 

 ference between the touching body and the sub- 

 stance touched, and the body gives no information 

 as to its own temperature, and but a shadowy one 

 of the relative temperatures of other things. The 

 real offices of the hand, or rather of that muscular 

 feeling of which the hand is one of the most 

 perfect instances, are acting as a balance to mea- 

 sure" pressure and resistance, and as a line to 

 measure space ; and though its sensibility in both 

 these respects is exquisite almost to infinitude, we 

 can collect the little differences until their sum is 

 of such magnitude as that we can recognize and 

 cross-examine it by the eye, so as to make the 

 one organ of observation establish the truth of 

 the other. 



But exquisitely fine as the discrimination of 

 the hand can be rendered, arm's length bounds 

 the range of its knowledge ; and muscular power 

 can take heed of nothing save that which resists 

 it by contact ; so that if our observation were 

 limited to the hand or the muscular feeling, it 

 G 



