276 THE SPECIAL SENSES 



28. The muscular sense, by some considered distinct from 

 touch, gives rise to the sensations of weight, and other forms 

 of external resistance. That this feeling exists, is shown by 

 the following simple experiment : if the hand be placed flat 

 upon a table, and a somewhat heavy weight be put into it, 

 touch alone is exercised, and a feeling of pressure results ; but 

 if the hand be raised, a certain amount of muscular effort must 

 be put forth, and thus the sensation of w r eight is recognized. 

 Through the muscular sense, precision of effort is rendered pos- 

 sible ; for by it we learn to adjust the force exerted to the 

 weight of the object to be lifted, moved, or carried. Without 

 it all our movements would necessarily become ill-regulated 

 and spasmodic. In cases of disease, where the sensibility of 

 the lower limbs is lost while power of motion remains, the 

 patient is able to stand erect so long as he can see his limbs ; 

 but just as soon as his eyes are closed, he begins to waver, and 

 will fall unless supported. 



29. The Organ of Taste. The tongue is the special organ 

 of the sense of taste ; but the back part of the mouth always 

 possesses this faculty. The tongue is a muscular organ, the 



skin. The skin, in like manner, protects the body against the approach 

 of a hurtful degree of heat. Thus, you see, the skin has certain quali- 

 ties of sensation. Just as the eye, in looking at a wafer, perceives 

 that it is both red and circular, distinguishing both the color and form 

 of bodies, so the sensitive skin by contact with an object distinguishes 

 the qualities of form, firmness, hardness, liquidity, pressure, and tempera- 

 ture. * * * Weber has discovered the interesting fact that warm 

 bodies feel lighter than cold ones : if a cold coin be placed upon the 

 forehead of some person, whose eyes are shut, and then upon the same 

 spot two warm coins, the weight would seem to him the same, whilst 

 he could distinguish correctly in the case of cold weights. * * * If 

 we place the elbow in hot water, we experience heat only in the part 

 immersed, not in the whole arm, although the nerve just under the skin 

 runs throughout the arm and hand. What we feel is a dull sense of 

 pain in the whole arm if the water is too hot. So, too, if the elbow 

 is placed in ice- water the pain is just the same in the arm ; proving 

 that the nerve trunk can feel neither warmth nor cold." Bernstein 1 s 

 Five Senses of Man. 



28. The muscular sense? State what is said to illustrate the subject, 



29. The organ of taste ? The tongue ? Its powers of motion ? 



