While upon this subject, it may be as well to state that there are no less than thirteen different flavours[1] belonging in common to the fruits and the various juices: the sweet, the luscious, the unctuous, the bitter, the rough, the acrid,[2] the pungent, the sharp, the sour, and the salt; in addition to which, there are three other kinds of flavours of a nature that is truly singular. The first of these last kinds is that flavour in which several other flavours are united, as in wine, for instance; for in it we are sensible of the rough, the pungent,[3] and the luscious, all at the same moment, and all of them flavours that belong to other substances. The second of these flavours is that in which we are sensible at the same instant of a flavour that belongs to another substance, and yet of one that is peculiar to the individual object of which we are tasting, such as that of milk, for instance: indeed, in milk we cannot correctly say that there is any pronounced flavour that is either sweet, or unctuous, or luscious, a sort of smooth taste[4] in the mouth being predominant, which holds the place of a more decided flavour. The third instance is that of water, which has no flavour whatever, nor, indeed, any flavouring principle;[5] but still, this very absence of flavour is considered as constituting one of them, and forming a peculiar class[6] of itself; so much so, indeed, that if in water any taste or flavouring principle is detected, it is looked upon as impure.

In the perception of all these various flavours the smell plays a very considerable[7] part, there being a very great affinity between them. Water, however, is properly quite inodorous: and if the least smell is to be perceived, it is not pure water. It is a singular thing that three of the principal elements[8] of Nature—water, air, and fire—should have neither taste nor smell, nor, indeed, any flavouring principle whatever.