ndeed, in breathing creatures be
The several senses, of which each takes in
Unto itself, in its own fashion ever,
Its own peculiar object. For we mark
How sounds do into one place penetrate,
Into another flavours of all juice,
And savour of smell into a third. Moreover,
One sort through rocks we see to seep, and, lo,
One sort to pass through wood, another still
Through gold, and others to go out and off
Through silver and through glass. For we do see
Through some pores form-and-look of things to flow,
Through others heat to go, and some things still
To speedier pass than others through same pores.
Of verity, the nature of these same paths,
Varying in many modes (as aforesaid)
Because of unlike nature and warp and woof
Of cosmic things, constrains it so to be.

Wherefore, since all these matters now have been
Established and settled well for us
As premises prepared, for what remains
'Twill not be hard to render clear account
By means of these, and the whole cause reveal
Whereby the magnet lures the strength of iron.
First, stream there must from off the lode-stone seeds
Innumerable, a very tide, which smites
By blows that air asunder lying betwixt
The stone and iron. And when is emptied out
This space, and a large place between the two
Is made a void, forthwith the primal germs
Of iron, headlong slipping, fall conjoined
Into the vacuum, and the ring itself
By reason thereof doth follow after and go
Thuswise with all its body. And naught there is
That of its own primordial elements
More thoroughly knit or tighter linked coheres
Than nature and cold roughness of stout iron.
Wherefore, 'tis less a marvel what I said,
That from such elements no bodies can
From out the iron collect in larger throng
And be into the vacuum borne along,
Without the ring itself do follow after.
And this it does, and followeth on until
'Thath reached the stone itself and cleaved to it
By links invisible. Moreover, likewise,
The motion's assisted by a thing of aid
(Whereby the process easier becomes),--
Namely, by this: as soon as rarer grows
That air in front of the ring, and space between
Is emptied more and made a void, forthwith
It happens all the air that lies behind
Conveys it