On Sense And The Sensible   

For the object of Smell exists not in air only: it also exists in

water. This is proved by the case of fishes and testacea, which are

seen to possess the faculty of smell, although water contains no air

(for whenever air is generated within water it rises to the

surface), and these creatures do not respire. Hence, if one were to

assume that air and water are both moist, it would follow that Odour

is the natural substance consisting of the Sapid Dry diffused in the

Moist, and whatever is of this kind would be an object of Smell.

That the property of odorousness is based upon the Sapid may be seen

by comparing the things which possess with those which do not

possess odour. The elements, viz. Fire, Air, Earth, Water, are

inodorous, because both the dry and the moist among them are without

sapidity, unless some added ingredient produces it. This explains

why sea-water possesses odour, for [unlike 'elemental' water] it

contains savour and dryness. Salt, too, is more odorous than natron,

as the oil which exudes from the former proves, for natron is allied

to ['elemental'] earth more nearly than salt. Again, a stone is

inodorous, just because it is tasteless, while, on the contrary,

wood is odorous, because it is sapid. The kinds of wood, too, which

contain more ['elemental'] water are less odorous than others.

Moreover, to take the case of metals, gold is inodorous because it

is without taste, but bronze and iron are odorous; and when the

[sapid] moisture has been burnt out of them, their slag is, in all

cases, less odorous the metals [than the metals themselves]. Silver

and tin are more odorous than the one class of metals, less so than

the other, inasmuch as they are water [to a greater degree than the

former, to a less degree than the latter].

Some writers look upon Fumid exhalation, which is a compound of

Earth and Air, as the essence of Odour. [Indeed all are inclined to

rush to this theory of Odour.] Heraclitus implied his adherence to

it when he declared that if all existing things were turned into

Smoke, the nose would be the organ to discern them with. All writers