The relish in the mouth is much more intense or acute than the feeling of the stomach, although this last may be more influential upon the general tone of the system by its amount. That the two interests are not altogether identical is shown by the circumstance that many tongue relishes are hard of digestion. But I am not aware of any case where what passes in the mouth is found nauseous to the digestion; on this point the two parts would seem to be in accord. 8. Relishes imply their opposite, disgusts. This sensation is constantly inspired by certain substances in consequence of their own nature; at particular times it may arise from any contact whatever, the alimentary surface being in a state of distemper. Oily substances seem to have a facility in causing disgust, from what cause I cannot say, seeing that they class also among relishes. Their mechanical form, when in the liquid or half liquid state, would appear to have an unfavourable action we are more ready to revolt at melted butter than at solid. Repletion renders any kind of food distasteful, and some kinds absolutely nauseous. In every point of view this feeling is much more dependent on the condition of the alimentary canal than on the material tasted. The different degrees of relish and nausea exhaust all that part of taste in sympathy with digestion; what remains belongs to the distinctive sensibility of the tongue, a sensibility that it shares with no other part of the body. The sensation of bitter, or sweet, or acrid, is a separate fact of the consciousness, and can be resolved into no other conscious condition whatsoever. It has influences on the emotional condition of the system very similar to the sensations of other senses; yielding pain or pleasure, and stimulating action and intelligence; but remaining nevertheless as a distinct and characteristic form of human feeling. An exhaustive enumeration of the pure tastes is impossible, but we may mention a few comprehensive classes. 9. Sweet tastes are a well recognised variety. At the head of these we must class the sugary taste as being the most prevalent of all forms of sweetness. The sweetness of SWEET TASTES. 155 every kind of fruit, of bread, and of milk, of alcoholic liquors, and of confectionary in general, is known to arise from sugar. Besides the relish that I attribute to this article of food, it undoubtedly acts upon the sense of taste in a remarkable way. We derive from it a highly pleasurable sensation in this limited sense; but no pleasure of mere taste can be compared in amount and influence to an agreeable alimentary feeling. We can lay it down as a rule that the pleasures of taste have as a whole a less influential action than the other class, and this must serve as a defining circumstance of every individual of them. The feeling of a sweet taste is keen and is dwelt upon with much satisfaction, but does not inspire the energy of the feeding action that follows up a savoury morsel. When digestion is satisfied there remains the enjoyment of sweets, and when the taste for these becomes cloyed by repetition it is by an independent effect on the gustatory nerves." But the great distinction of this feeling, and of all other feelings of taste proper, relates to the intelligence, or to the power of discrimination belonging to this organ, whereby a boundless number of substances can produce impressions recognised by us as totally different in character, which impressions of difference can remain or be recalled, after the original is gone, to compare with new cases that may arise, and to give that sense of agreement or disagreement whereon all our knowledge of the world is based. In the case of sweetness, for example, not only can we be affected with the pleasurable feeling or emotion belonging to it, but we can be distinctively affected by a great many substances possessing the quality; we can identify some and feel a want of identity in others; and we can so far retain the impression of a taste of yesterday as to compare it with a taste of to-day. This feature distinguishes the feelings of the mouth from organic feelings; it distinguishes in some degree tastes from relishes, although these last also possess considerable range of discrimination; and it is the point of superiority which sight, hearing, and touch, have to a still greater degree over organic sensations. * I shall remark upon sweetness again, under Smell. 10. Next to sweet tastes I may class bitter; the taste of quinine, gentian, or bitter aloes. This, and not sourness, is the proper contrast of sweet. Sweetness is the pleasure proper to taste, bitterness the peculiar or distinctive form of pain derived through this sense. Without having the bulk and influence of the massive forms of pain, this sensation is highly intense in its own limited region and sets on a wryness and contortion of the features, showing how repulsive and distasteful it is. A man may, however, have a great deal that is sound and pleasant about him notwithstanding a bitter taste in his mouth, and he may therefore be induced, for good reasons, to tolerate it. This does not mar the happiness in the manner of many of the feelings above discussed. Still it is sufficient to create acts of avoidance, and sentiments of aversion, leaving an impression behind it sufficient to keep up a selfprotecting impulse in the future. The sweet and the bitter express the two extremes of taste as regards pleasure and pain; the other varieties of the feeling involve qualities more important as means of discrimination than as sources of emotion, although not wholly devoid of this influence in either of its two opposite forms. 11. Perhaps we may be allowed to consider the saline as a class of tastes having something to distinguish it from the other great classes. The taste of a salt I hold to be more purely a taste than the sensation of an acid or an alkali for a reason that will presently be stated. Common salt may be taken as a good specimen of a saline taste, although very distinguishable from other salts, it being the glory of this sense to note a difference between almost any two substances that are capable of acting on it. Mineral waters, which contain salts of soda, magnesia, and lime, have a saline taste. This taste is rarely an agreeable one, in many cases it is very disagreeable, but we should be disposed to describe the feeling in most instances as singular and characteristic rather than as either pleasing or the reverse. The repulsive taste of Epsom salts would be termed a compound of the saline and the bitter. ALKALINE, ACID, ASTRINGENT, TASTES. 157 12. The alkaline taste is usually more energetic than the saline, as might be expected, seeing that a salt is a neutralized alkali. But if the remark above made be correct, namely, that salts owe their taste principally to their base, the alkali ought to have a considerable share of the saline in taste. Most alkalies and some earths and oxides of metals have characteristic tastes, rarely agreeable, and often not markedly the reverse. 13. The sour or acid taste is much more uniform in its nature than either the saline or the alkaline; which we may fairly ascribe to the influence of the acid quality itself, irrespective of the constituent elements. This is a sharp, penetrating, pungent action, having when very powerful more the pain of a burn, than of a repulsive taste; in diluted forms it is an agreeable pungent stimulus to the mouth; hence the liking for vinegar (the sour of cookery, as sugar is the sweet), and for acid fruits and vegetables. 14. The astringent is a distinct form of the sensation of taste; for an example we may refer to the effect of alum in the mouth. It is evident, however, that in the acid action, and still more in this of astringency, we depart farther and farther from the proper feeling of taste towards some grosser results of chemical and mechanical action. Astringent substances act on the skin and on the mucous membranes generally, and the influence lies in a kind of contraction or forcible shrinking of the part, to which we are sensitive whenever it occurs as a touch. The rough taste of tannin' may be put down under astringency. 15. The fiery taste of alcoholic liquors, camphors, and volatile oils, given in Gmelin's classification, seems to me to be happily designated. I am disposed to think that this too is more of a mechanical action than a gustative, although in some of the other substances entering with alcohol into wines, spirits, and malt liquors, there is a genuine stimulus of the taste. Gmelin's acrid taste may be looked on as a form of the fiery or astringent combined with some ingredient of the bitter. The pungency that marks all this class of sensations is a remarkable state of feeling deserving to be once for all discussed at length. This discussion, however, I prefer to take up under the sense of smell, the next in order in our arrangement. 16. With regard to the intellectual aspect of Tastes in general, Longet observes that these sensations are deficient as regards the power of being remembered; and he gives as a proof the fact that when we dream of being present at a repast we see the viands but do not taste them. This is an extreme comparison; it contrasts the most intellectual of all the senses, the most abiding of all sensations, with those that are least so. It is so far true that we do not recover sensations of taste so as to live habitually on the ideas of them, but they are slightly recoverable even as ideas, and for the purposes of identification and contrast, they may be recovered to a very great extent. A wine tasted to-day can be pronounced the same or not the same as a wine tasted a week ago, while well marked tastes may be remembered for years in this way. The intellectual character of the sense is also illustrated by its improveability. A wine-taster, a cook, or a chemist can acquire a delicate sensibility to differences of taste, which is not possible without some degree of permanence or retentiveness in the impressions made on the mind. SENSE OF SMELL. This sense is in close proximity to the organ of Taste, with which smell frequently co-operates; but we may consider the sense of Smell as placed at the entrance of the lungs to test the purity of the air we breathe. 1. The external objects of Smell, the material substances whose contact produces the sensations, are very numerous. They require to be in the gaseous state, in the same way that the objects of taste require to be liquified. Solids and liquids, therefore, have no smell except by being evaporated or volatilized. The greater number of gases and vapours are odorous. Of inodorous gases, the principal are the elements of the atmosphere, that is to say, nitrogen, oxygen, vapour of water |