SENSE OF TASTE. 237 



through the manner in which the air reacts on their surface. It is curious 

 that the instance which (so far as we at present know) is most analogous to 

 this, should be met with among the inhabitants of the deep. It is a fact well 

 known to Whale-fishers, especially to those who pursue the Spermaceti Whale, 

 that these animals have the power of communicating with each other at great 

 distances. It has often been observed, for example, that, when a straggler is 

 attacked, at the distance of several miles from a shoal, a number of its fellows 

 bear down to its assistance, in an almost incredible short space of time. It can 

 scarcely be doubted, then, that the communication must be made through the 

 medium of the vibrations of the water, excited by the struggles of the animal, 

 or perhaps by some peculiar movements especially designed for this purpose, 

 and propagated through the fluid to the large cutaneous surface of the distant 

 Whales; and this idea is fully confirmed by the fact, that the nerves which 

 proceed to the skin, pass through the inner layers of blubber with scarcely 

 any subdivision, but spread out into a network of extreme minuteness, as soon 

 as they arrive at the surface. 



III. Sense of Taste. 



3*21. That this sense may be really considered as a peculiar modification of 

 that of Touch, appears from several considerations. In the first place, the 

 actual contact of the object of sense, with the organ through which the impres- 

 sion is received, is here necessary ; and this is the case in regard to no other 

 sense. Moreover the intimate structure of the organ is nearly the same in 

 both instances. Again, it appears from the considerations formerly alluded to 

 ( 228), that there is no special nerve of taste; the gustative impressions nuulc 

 upon the front of the tongue being conveyed by the lingual branch of the 

 fifth pair; whilst those made upon the back of the organ are conveyed by the 

 glosso-pharyngeal. The first of these nerves also ministers to ordinary tactile 

 sensibility; the second appears to convey the impressions which produce 

 nausea.* The papillae of the tongue are essentially the same in structure 

 with those of the skin ; and although Anatomists have classified them, accord- 

 ing to their differences of form and situation, there is no definite physiological 

 evidence that they possess corresponding varieties of endowment, although 

 this is quite possible. As a general rule, it is a necessary condition of the 

 sense of Taste, that the object should either be in a state of solution, or should 

 be soluble in the moisture covering the tongue ; if this be not the case, or if 

 the tongue be dry, a simple feeling of contact is all that is produced. As in 

 the case of touch, the idea of the character of the sapid body is very imperfect, 

 unless it is made to move over the gustative surface ; and thus the taste is very 

 much heightened by the compression and friction of the substance between 

 the tongue and the palate. From all these circumstances it appears indis- 

 putable, that a very strong analogy exists between Taste and Touch ; indeed 

 it may be questioned whether they are not in reality more closely allied than 

 is the sense of Temperature with that of Resistance. 



322. Although the tongue seems to be the chief seat of Gustative sensibility, 

 yet this is also possessed, though in a less degree, by the palate. But it is to 

 be remarked that the sensations produced by most sapid substances are of a 

 complex kind ; and are in great part due to the organ of Smell. Of this any 

 one may convince himself, by closing the nostrils, and inspiring and expiring 

 through the mouth only, when holding in the mouth, or even rubbing between 



* Indeed it may be questioned whether the glosso-pharyngeal is really a nerve of taste 

 at all; since the experiments which would indicate that it is so, may be explained upon 

 the supposition that nausea, rather than real gustative sensibility, was induced by the 

 substances applied to the tongue after division of the lingual branch of the fifth pair. 



