TASTE. 485 



other properties, belonging to various articles of food, which belong 

 really to the class of ordinary physical qualities and are appre- 

 ciated by the ordinary sensibility of the tongue, though we usually 

 speak of them as being perceived by the taste. Thus a starchy, 

 viscid, watery, or oleaginous taste is merely a certain variety of con- 

 sistency in the substance tasted, which may exist either alone or in 

 connection with real savors, but which is exclusively perceived by 

 means of the general sensibility. So also with a pungent or burning 

 taste, such as that of red pepper or any other irritating powder. 

 The quality of piquancy in the preparation of artificial kinds of 

 food is alwa}^s communicated to them by the addition of some such 

 irritating substance. The styptic taste seems to be a combination of 

 an ordinary irritant or astringent effect with a peculiar taste, which 

 we always associate with the former quality in astringent sub- 

 stances. 



There is also sometimes a liability to confound the real taste of 

 certain substances with their odorous properties, or flavors. Thus 

 in most aromatic articles of food, such as tea and coffee, and in 

 various kinds of wine, a great part of what we call the taste is in 

 reality due to the aroma, or smell which reaches the nares during 

 the act of swallowing. Even in many solid kinds of food, such as 

 freshly cooked meats, the odor produces a very important part of 

 their effect on the senses. We can easily convince ourselves of this 

 by holding the nose while swallowing such substances, or by recol- 

 lecting how much a common catarrh interferes with our perception 

 of their taste. 



The most important conditions of the sense of taste are the fol- 

 lowing : 



In the first place, the sapid substance, in order that its taste may 

 be perceived, must be brought in contact with the mucous mem- 

 brane of the mouth in a, state of solution. So long as it remains 

 solid, however marked a savor it may possess, it gives no other 

 impression than that of any foreign body in contact with the sensi- 

 tive surfaces. But if it be applied in a liquid form, it is then spread 

 over the surface of the mucous membrane, and its taste is imme- 

 diately perceived. Thus it is only the liquid and soluble portions 

 of our food which are tasted, such as the animal and vegetable 

 juices and the soluble salts. Saline substances which are insoluble, 

 such as calomel or carbonate of lead, when applied to the tongue, 

 produce no gustatory sensation whatever. 



The mechanism of the sense of taste is, therefore, in all proba- 



