Is it now possible to apply a similar test to the various _qualities_ which comprise the _mode_ or _sense_ of taste, and thus arrive at an adequate classification and analysis of these qualities? The earliest attempts to analyze the tastes by this psychological method were often amusingly miscalculated. Thus Chatin, in 1880, presented a scheme in which the total manifold of taste was first divided into agreeable tastes and disagreeable tastes. The agreeable tastes were typified by those we call sweet, and the disagreeable by those we call bitter. It was, of course, at once necessary to indicate certain intermediate conditions in this scheme for a variety of tastes which were neither clearly agreeable nor markedly unpleasant. Moreover, it is a matter of common experience that a taste which is agreeable to one person (such as tobacco, olives, mustard) may be decidedly obnoxious to another person, or, indeed, even to the same person on a different occasion; so that such a classification cannot be said to represent in any fundamental way an analysis of tastes. There have been a great variety of classifications proposed on this direct descriptive basis, and a comparison of the various schemes at once suggests that the task is by no means as simple as it might seem. The number of elementary tastes ranges widely, some investigators enumerating five or six times as many fundamental taste qualities as others have recognized. Haller enumerated twelve different qualities—stale, sweet, bitter, sour, sharp, tart, spicy, salt, urinous, putrid, spirituous, nauseating. It is evident that this classification represents only a transition step toward a psychological analysis and that it is by no means free from the suggestion of provoking substances (spirituous, putrid) and the suggestion of effects produced (nauseating). Linnæus recognized somewhat fewer categories,—giving the following ten as fundamental,—sweet, spicy, oily, mucous, salt, styptic,[4] bitter, sour, aqueous, and dry. Footnote 4: Styptic,—causing contraction of tissues. Other authors have been content with indicating eight elementary tastes. Both Bain and Wundt have proposed a sixfold classification, as follows,—sweet, bitter, saline, alkaline, acid, and astringent or metallic. Most modern authorities reduce the number of elementary tastes to four,—sweet, salt, sour, bitter,—while at least three investigators have advocated a simple twofold classification, into sweet and bitter. _Taste Blends and Fusions_