184 Human Physiology. 



that odours are perceived as flavours. If a man hold his nose 

 tightly, and shut his eyes, he cannot, by tasting, distinguish 

 brandy, gin, whiskey, and rum from each other, The moment 

 the odour is permitted to enter the nose, the taste of each 

 becomes perfectly distinct. 



To enable the tongue to taste articles of food so quickly as 

 to give pleasure in eating, or guard by disgust against swallow- 

 ing acrid or impure substances, it is provided abundantly with 



nerves whose office it is to convey 

 to the mind a sense of flavours. As 

 a nerve of touch carries the sense 

 of cold, heat, dryness, hardness, &c., 

 a nerve of taste carries a sense of 

 sweetness, sourness, bitterness, and 

 all the thousand modifications of 

 flavour to be found in the vege- 

 Fig. 34. -SMALL PAPILLA OF table and animal kingdom. These 



OF - *-'p ed * P-P*- 



the tongue, as on the fingers, and 

 the looped nerves, and looped blood-vessels attending and 

 nourishing the nerves, make up the substance of these papillae. 

 The blood-vessels are shown in Fig. 34, as the nerves were in 

 the preceding figure. 



The uses of taste in warning us from danger are evident. 

 But every natural function is attended with pleasure. All food 

 natural and proper for man gives him delight through the sense 

 of taste. Fruit, the most natural food of man, is the most 

 delicious to the unperverted taste. The taste, however, in men, 

 and even in some animals, may be educated and perverted. 

 We learn to love things which were at first nauseous and dis- 

 gusting to us. Men smoke and even chew tobacco. The 

 excessive use of spices and condiments blunts the sensibility of 

 the nerves of taste, and the corrupted sentinel lets the enemy 

 pass into the stomach, and worry it into dyspepsia, while the 



