Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

Now come, and I will indicate what wise
Impact of odour on the nostrils touches.
And first, 'tis needful there be many things
From whence the streaming flow of varied odours
May roll along, and we're constrained to think
They stream and dart and sprinkle themselves about
Impartially. But for some breathing creatures
One odour is more apt, to others another-
Because of differing forms of seeds and pores.
Thus on and on along the zephyrs bees
Are led by odour of honey, vultures too
By carcasses. Again, the forward power
Of scent in dogs doth lead the hunter on
Whithersoever the splay-foot of wild beast
Hath hastened its career; and the white goose,
The saviour of the Roman citadel,
Forescents afar the odour of mankind.
Thus, diversly to divers ones is given
Peculiar smell that leadeth each along
To his own food or makes him start aback
From loathsome poison, and in this wise are
The generations of the wild preserved.
     Yet is this pungence not alone in odours
Or in the class of flavours; but, likewise,
The look of things and hues agree not all
So well with senses unto all, but that
Some unto some will be, to gaze upon,
More keen and painful. Lo, the raving lions,
They dare not face and gaze upon the cock
Who's wont with wings to flap away the night
From off the stage, and call the beaming morn
With clarion voice- and lions straightway thus
Bethink themselves of flight, because, ye see,
Within the body of the cocks there be
Some certain seeds, which, into lions' eyes
Injected, bore into the pupils deep
And yield such piercing pain they can't hold out
Against the cocks, however fierce they be-
Whilst yet these seeds can't hurt our gaze the least,
Either because they do not penetrate,
Or since they have free exit from the eyes
As soon as penetrating, so that thus
They cannot hurt our eyes in any part
By there remaining.
     To speak once more of odour;
Whatever assail the nostrils, some can travel
A longer way than others. None of them,
However, 's borne so far as sound or voice-
While I omit all mention of such things
As hit the eyesight and assail the vision.
For slowly on a wandering course it comes
And perishes sooner, by degrees absorbed
Easily into all the winds of air;-
And first, because from deep inside the thing
It is discharged with labour (for the fact
That every object, when 'tis shivered, ground,
Or crumbled by the fire, will smell the stronger
Is sign that odours flow and part away
From inner regions of the things). And next,
Thou mayest see that odour is create
Of larger primal germs than voice, because
It enters not through stony walls, wherethrough
Unfailingly the voice and sound are borne;
Wherefore, besides, thou wilt observe 'tis not
So easy to trace out in whatso place
The smelling object is. For, dallying on
Along the winds, the particles cool off,
And then the scurrying messengers of things
Arrive our senses, when no longer hot.
So dogs oft wander astray, and hunt the scent.