TASTE. ITS MEDIUM, OBJECT, ORGAN KINDS OF FLAVOUR
THE tasteable is a sort of tangible; hence, it is not perceptible through an extraneous body as medium, any more than the object of touch. And the body in which is savour, i.e. the tasteable, is in liquid as its material, which is tangible.§§ 501-4
Hence, if we were in water, we should taste a sweet thing put into it; not that the sensation would then operate through a medium, but because the savour would be mixed with the water, as in a drink. (Colour, however, is not thus seen because of any mixture or efflux.) There is then nothing corresponding to a medium [in tasting]. As colour is the visible, so savour is the tasteable.§§ 505-7
It causes no sensation of taste except in liquid; but it must be moist, actually or potentially; as [with] saliva which is very liquid and moistens the tongue.§ 508
As sight is of the visible and the invisible (for darkness is invisible, and sight discerns this also, as it does, in addition, the extremely bright, which is also invisible, but in quite another way); [and as] the same holds of hearing, which is of sound and silence, one being audible, the other inaudible, and [the latter includes] excess of sound, which is to hearing as brilliance is to sight; for as a feeble sound is in a way inaudible, so, in another way, is an extremely violent one. ('Invisible' indeed can mean either what is absolutely such, or [the term may also be used] as in other cases of 'the impossible' where [this concept] is applied both to what lacks what it ought to have by nature, and to what has this defectively,--as we say of a footless [animal] that it is motionless. So, in the same way, taste is of the savourable and the non-savourable, the latter being what has either only a faint savour, or one altogether destructive of the taste. It would seem that the principle of this is the drinkable or the non-drinkable; and taste is of both, but the latter has either a faint taste or one that destroys the sense: whilst the former is according to nature. The drinkable is common to taste and touch.§§ 509-11
Since what is tasteable is liquid, it is necessary that the sense-organ be neither liquid actually, nor incapable of becoming so. For taste is affected by the savourable thing as such. It is therefore necessary that the sensorium be moistened, yet in such a way that it keeps its potentiality thereto; the tasting sense being non-humid.§ 512
There is a sign of this in that the tongue cannot perceive taste either when it is dry or when it is too moist. In the latter case contact takes place with the original moisture; as when one who has first tasted a very strong flavour then tastes another, or those burdened [with fever] taste all things as bitter because the tongue is saturated in a liquid of that sort.§ 513
The species of savour are, like colours, the simple contraries; sweet and bitter. Adjoining these, however, are, with the former, the succulent, with the latter, the saline. Then there are the intermediary flavours: pungent, harsh, stringent and piquant. These seem to be about all the varieties of savour that exist; to which taste, as such, therefore, is in potency; the savourable being what reduces it to act.§§ 514-16