Page:Dan McKenzie - Aromatics and the Soul.pdf/123

Rh spectrum, but to the overpowering influence of a single odour.

Indeed, none of the other senses shows the same phenomenon. If we happen to catch a momentary glimpse of the noonday sun, we plainly see a disc of intense light (it is pale blue in colour to my eye), surrounded by a fiery halo, before it blinds us. In the same way, when a gun is fired close to the ear, we hear the sound before we are deafened by it.

It is for such reasons that perfumers never sniff at a bottle of scent ; they take a little, rub it on the back of the hand, and then wait until the spirit has evaporated before they proceed to smell it.

The exquisite delicacy of the sense might lead us to suppose that the olfactory organ must be quick at responding to its proper stimulus. But such is not the case. It is, on the other hand, relatively “slow in the uptake.”

Gleg has estimated that the reaction time for auditory sensation is from 0’12 to 0’15 of a second, whereas the reaction time for smell is as much as 0’5 of a second, only one sensory stimulus being slower, that of pain, namely, which occupies 0’9 of a second.

Odours are conveyed to the olfactory end-organ in the air we breathe. Before they can rise into