GUSTATION. 759 



It is undoubtedly true that we lose the delicacy of the sense of taste when the sense 

 of smell is abolished. The experiment of tasting wines blindfolded and with the nostrils 

 plugged, and the partial loss of taste during a severe coryza, are sufficiently familiar illus- 

 trations of this fact. In the great majority of cases, when there is complete anosmia, the 

 taste is sensibly impaired; and, in cases in which this does not occur, it is probable 

 that the savory emanations pass from the mouth to the posterior portion of the nasal 

 fossae, and that here the mucous membrane is not entirely insensible to special impres- 

 sions. 



It is unnecessary, in this connection, to describe fully the reflex phenomena which fol- 

 low impressions made upon the olfactory membrane. The odor of certain sapid sub- 

 stances, under favorable conditions, will produce an abundant secretion of saliva and even 

 of gastric juice, as has been shown by experiments upon animals. Other examples of the 

 effects of odorous impressions of various kinds are sufficiently familiar. 



Gustation. 



The special sense of taste enables us to appreciate what is known as the savor of cer- 

 tain substances introduced into the mouth; and this sense exists, in general terms, in 

 parts supplied by filaments from the lingual branch of the fifth and the glosso-pliaryngeal 

 nerves. 



It is somewhat difficult to define precisely what is meant by savory substances. The 

 word savory is frequently used so as to include the quality of odor ; and, indeed, the 

 senses of gustation and olfaction are quite closely connected. Almost all substances that 

 affect the sense of taste possess a certain odor, and taste and smell are thus simultaneously 

 impressed. Medicinal articles of a disagreeable taste may sometimes be swallowed with- 

 out making a very disagreeable impression, if the nares be closed. Again, when the 

 nares are closed or when the sense of smell is rendered obtuse by an affection of the 

 Schneiderian membrane, it is difficult to distinguish delicate shades of flavor, as the differ- 

 ences in wines. This is a matter of common observation and remark. There are, also, 

 certain articles which have a repulsive odor, the taste of which is not disagreeable, such 

 as some varieties of old cheese. As a rule, however, ' articles agreeable to the taste pos- 

 sess an agreeable odor, and the senses of taste and smell are not'easily separated from 

 each other. These facts have led to a distinction which cannot, however, be always 

 made with accuracy between true tastes and flavors. It is assumed by some physiolo- 

 gists, that the true tastes are quite simple, presenting the qualities which we recognize as 

 sweet, acid, saline, and bitter ; while the more delicate shades of what are called flavors 

 nearly always involve olfactory impressions, which it is difficult to separate entirely from 

 gustation. 



If we apply the term savor exclusively to the quality which makes an impression upon 

 the sense of taste, we recognize that the sensation is special in its character and different 

 from the tactile sensibility of the parts involved and from the sensation of temperature. 

 The terminal filaments of the gustatory nerves are impressed by the actual contact of 

 savory substances, which must, of necessity, be soluble. To a certain extent, there is a 

 natural classification of savors, some of which are agreeable, and others disagreeable ; but 

 even this distinction is modified by habit, education, and various other circumstances. 

 Articles that are unpleasant in early life often become agreeable in later years. Inasmuch 

 as the taste is, to some extent, an expression of the nutritive demands of the system, it is 

 found to vary under different conditions. Chlorotic females, for example, frequently 

 crave the most unnatural articles, and these morbid tastes may disappear under appro- 

 priate treatment. Inhabitant ; of the frigid zones seem to crave fatty articles and will 

 even drink rancid oils with avidity. Patients often become accustomed to the most dis- 

 agreeable remedies and take them without repugnance. Again, the most savory dishes 

 may even excite disgust, when the sense of taste has become cloyed, while abstinence 



