SENSE OF TASTE. 

 [Fig. 171. 



403 



A. Secondary papilla of the conical class, treated with acetic acid: a. Its basement membrane, b. 

 Its nerve-tube forming a loop. c. Its curly elastic tissue. The epithelium in this instance is not abund- 

 ant; but the vertical arrangement of its particles over the apex of the papilla is well seen, d, and illus- 

 trates the mode of formation of the hair-like processes described in the test. Mag. 160 diam. 



B. A similar papilla, deprived of its epithelium : a. Basement membrane. 6. Tubular fibre, probably 

 forming a loop, but its arch not clearly seen, c, c. Elastic fibrous tissue at its base and in its interior. 

 Magnified 320 diameters. 



c. Nerves of a compound papilla near the point of the tongue, in which their loop-like arrangement is 

 distinctly seen. Magnified 160 diameters.] 



528. 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 indisputable, 

 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. 



529. Although the Tongue seems to be the chief seat of Gustative sensi- 

 bility, 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 rub- 

 bing between the tongue and the palate, some sapid substance ; of which the 

 taste is then scarcely recognized, although it is immediately perceived, when 

 its effluvia are drawn into the nose. It is well known too, that, when the 



