Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

     Thus, too, those Birdless places must up-send
An essence bearing death to winged things,
Which from the earth rises into the breezes
To poison part of skiey space, and when
Thither the winged is on pennons borne,
There, seized by the unseen poison, 'tis ensnared,
And from the horizontal of its flight
Drops to the spot whence sprang the effluvium.
And when 'thas there collapsed, then the same power
Of that effluvium takes from all its limbs
The relics of its life. That power first strikes
The creatures with a wildering dizziness,
And then thereafter, when they're once down-fallen
Into the poison's very fountains, then
Life, too, they vomit out perforce, because
So thick the stores of bane around them fume.
     Again, at times it happens that this power,
This exhalation of the Birdless places,
Dispels the air betwixt the ground and birds,
Leaving well-nigh a void. And thither when
In horizontal flight the birds have come,
Forthwith their buoyancy of pennons limps,
All useless, and each effort of both wings
Falls out in vain. Here, when without all power
To buoy themselves and on their wings to lean,
Lo, nature constrains them by their weight to slip
Down to the earth, and lying prostrate there
Along the well-nigh empty void, they spend
Their souls through all the openings of their frame.
     . . . . . .