274 ON THE SENSES. 



finally, the greatest degree of obtuseness in the cuticle of the buck, the upper 

 arm, and the thigh. 



It is an old and well established usage to inquire into the design of all arrange- 

 ments in nature, and especially in our own wonderful an4 complicated or- 

 ganii^rn, and to judge all observed facts by the principle of conformity to that 

 design. This theological principle, which to the laity is almost indispensable 

 in their contemplation of the wonders of creation, and which, not without reason, 

 seems to them the surest guide to an understanding thereof, has in later times 

 been warmly attacked ; its value has been denied, and all employment of it in 

 scientific observation and inquiry been sedulously discarded. We shall not 

 here attempt to settle this troublesome controversy, nor to decide how much too 

 far, in one direction or the other, the views of the parties have carried them. 

 Our readers will not take it amiss, we are sure, if, with the aid of the above 

 principle, we seek to explain the unequal degree of delicacy of the sense of 

 place in different parts of the skin, and afford them the opportunity of admiring, 

 in this connexion, the adaptation and design which everywhere prevail in the 

 works of nature. We find, then, this sense in the highest perfection precisely 

 in those parts which, through their arrangement, situation and freedom of move- 

 ment, are best suited and most clearly destined to the operations of touch. 

 Observe the functions of your tongue, which you are accustomed only to regard 

 as an organ of speech and taste, during that most indispensable of acts, eating. 

 It indefatigably examines by touch the morsel which you are chewing and 

 separates what is not yet sufficiently comminuted fron^ that which is prepared 

 for swallowing, brings the former again under the molars for further reduction, 

 carefully removes from the mass whatever is unsuitable for deglutition, fish- 

 bones, fruit-Btones, &;c., and gives you accurate notice of the form and size of 

 the objects in the cavity of the moiith. All this, whose importance cannot be 

 mistaken even when it relates to so trivial an affiiir as mastication, would be 

 impossible without that exquisite delicacy of the sense of touch which resides 

 in the tongue. Still more evident perhaps will appear to you that nice discern- 

 ment of the place of external objects which pertains to the finger-ends, those 

 pre-eminently active organs of touch, with which you are accustomed to test 

 everything tangible, and whose services cannot, be replaced by any other portion 

 of the wide-spread surface endued with sensibility, because no other part is pos- 

 sessed of so much delicacy combined wifli such manifold mobility. You may 

 have often wondered at the accurate decisions of the groping finger of the blind, 

 in v/hom that organ seems to have replaced, as far as it can be replaced, the 

 priceless sense of vision, and you forget that your own finger has exactly the 

 same power, the same innate and delicate sense of place and position. This 

 sense, you say, is refined in the case of the blind ; but that is only true in so 

 far as the blind man has been compelled to consider in a more careful manner 

 the communications of the sense, to devote a more attentive study to the inter- 

 pretation of its tokens, the translation of the simple sensations into jdeas, and 

 has thence acquired greater practice and certainty in understanding its intima- 

 tions ; the sense itself has become no finer. In your own judgment of the 

 properties of objects which this sense, assisted by the muscular sense, is ca- 

 pable of ascertaining, you have been accustomed to allow the sight to interpose 

 and to modify through its perceptions the ideas derived, as has been shown 

 above, from the sense of touch. Take in your hand a three-cornered stick of 

 three inches length with two triangularx bases ; your sight informs you, at a 

 glance, if all these relations of shape and size. The blind judges of them with 

 equal accuracy through the sense of touch, as you yourself do if the trial is 

 made in darkness or with averted eyes. You first take the stick between the 

 thumb and forefinger, so that the two bases touch the skin of both, and per- 

 ceive at the moment that you hold a solid body with two triangular bases, 



