Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

     A point remains, besides,
Which best it seems to tell of, ere I go
To telling of the fact at hand itself.
Since to the varied things assigned be
The many pores, those pores must be diverse
In nature one from other, and each have
Its very shape, its own direction fixed.
And so, indeed, 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.