Vocabularies do not develop in order that structural and functional facts may be recorded for the information of forthcoming scientists. Words arise in response to the demands of practical life. It is practically more important that some substances “taste good,” and others “taste bad,” than that there are just four elementary taste qualities. Hence for certain primitive circumstances two taste words are all that are needed in ordinary conversation. It by no means follows from this that the salt, sour, and bitter, which all fall in the “bad taste” category, are not discriminable from one another by the taste organs of the savage. It would be just as cogent to insist that, since we have only one word for the taste of various sour things, all of these various tastes must be indistinguishable to us.
Nor is the argument safe that those sense qualities for which specific names exist must be more ancient than those qualities for which names are borrowed. Many of our color names are not primarily color names at all,—as violet, rose, olive, turquoise, lemon, straw, orange, and, perhaps, pink and green. Red, blue, and yellow seem to be more essentially color names. Yet, it is difficult to suppose that an organism sensitive to red and yellow should not also be sensitive to orange, which may be produced by a mixture of red and yellow light.
In the case of the odors, which we have every reason to believe are extremely ancient sense qualities, we have in our own language almost no exclusively olfactory names. Smells are designated by the objects with which they are associated,—as lilac, lavender, musk; or names are borrowed from other sensory modes, as sweet, sour, heavy; or still more descriptive and perceptual names are used, such as fresh, flat, rancid, foul, nauseating. Interesting as the vagaries of vocabulary may be, they yield very little information concerning the primitiveness, elementariness, sensitiveness, or distribution of the various taste qualities.
CHAPTER II
The Organization of the Tastes
System and Organization in Other Senses
In the case of some of the sensory modes it is possible to arrange the various elementary qualities in a schema or graph, representing in a diagrammatic way their relations to each other, the results of their combination, their influence on each other, etc.
Thus, in the case of vision the conventional “color pyramid” expresses the various relations between the different elementary colors and the different degrees of brightness. Red, yellow, green, and blue occupy the corners of the base of a double pyramid. The upper apex represents white and the lower apex black. On the side between red and yellow are found the various oranges which result from mixing red and yellow light in varying proportions. On the remaining sides are represented the combinations of yellow and green, green and blue, blue and red. Along the vertical axis range the different grays. Cross sections of the pyramid indicate, at different levels, the result of mixing the different colors with these grays, thus yielding the tints and shades of the colors. Along the base, the colors which are at the extreme ends of any diagonal passing through the center are complementary,—they neutralize each other when mixed and under other circumstances each tends to induce the other by contrast. The visual manifold may thus be adequately schematized on a three-dimensional figure.
In a similar way the various tones, in the case of hearing, may be arranged along a one-dimensional line, which represents the tonal scale. Is it possible to arrange in any such systematic way the elementary taste qualities so as to indicate their relationship to each other? Before suggesting such a diagram it will be well to have in mind just what relationships the various taste qualities do as a matter of fact display.