No More Learning

Yea, I've seen
Those Samothracian iron rings leap up,
And iron filings in the brazen bowls
Seethe furiously, when underneath was set
The magnet stone. So strongly iron seems
To crave to flee that rock. Such discord great
Is gendered by the interposed brass,
Because, forsooth, when first the tide of brass
Hath seized upon and held possession of
The iron's open passage-ways, thereafter
Cometh the tide of the stone, and in that iron
Findeth all spaces full, nor now hath holes
To swim through, as before. 'Tis thus constrained
With its own current 'gainst the iron's fabric
To dash and beat; by means whereof it spues
Forth from itself--and through the brass stirs up--
The things which otherwise without the brass
It sucks into itself. In these affairs
Marvel thou not that from this stone the tide
Prevails not likewise other things to move
With its own blows: for some stand firm by weight,
As gold; and some cannot be moved forever,
Because so porous in their framework they
That there the tide streams through without a break,
Of which sort stuff of wood is seen to be.
Therefore, when iron (which lies between the two)
Hath taken in some atoms of the brass,
Then do the streams of that Magnesian rock
Move iron by their smitings.

Yet these things
Are not so alien from others, that I
Of this same sort am ill prepared to name
Ensamples still of things exclusively
To one another adapt. Thou seest, first,
How lime alone cementeth stones: how wood
Only by glue-of-bull with wood is joined--
So firmly too that oftener the boards
Crack open along the weakness of the grain
Ere ever those taurine bonds will lax their hold.
The vine-born juices with the water-springs
Are bold to mix, though not the heavy pitch
With the light oil-of-olive. And purple dye
Of shell-fish so uniteth with the wool's
Body alone that it cannot be ta'en
Away forever--nay, though thou gavest toil
To restore the same with the Neptunian flood,
Nay, though all ocean willed to wash it out
With all its waves. Again, gold unto gold
Doth not one substance bind, and only one?
And is not brass by tin joined unto brass?
And other ensamples how many might one find!
What then? Nor is there unto thee a need
Of such long ways and roundabout, nor boots it
For me much toil on this to spend.
More fit
It is in few words briefly to embrace
Things many: things whose textures fall together
So mutually adapt, that cavities
To solids correspond, these cavities
Of this thing to the solid parts of that,
And those of that to solid parts of this--
Such joinings are the best. Again, some things
Can be the one with other coupled and held,
Linked by hooks and eyes, as 'twere; and this
Seems more the fact with iron and this stone.
Now, of diseases what the law, and whence
The Influence of bane upgathering can
Upon the race of man and herds of cattle
Kindle a devastation fraught with death,
I will unfold. And, first, I've taught above
That seeds there be of many things to us
Life-giving, and that, contrariwise, there must
Fly many round bringing disease and death.
When these have, haply, chanced to collect
And to derange the atmosphere of earth,
The air becometh baneful. And, lo, all
That Influence of bane, that pestilence,
Or from Beyond down through our atmosphere,
Like clouds and mists, descends, or else collects
From earth herself and rises, when, a-soak
And beat by rains unseasonable and suns,
Our earth hath then contracted stench and rot.
Seest thou not, also, that whoso arrive
In region far from fatherland and home
Are by the strangeness of the clime and waters
Distempered? --since conditions vary much.
For in what else may we suppose the clime
Among the Britons to differ from Aegypt's own
(Where totters awry the axis of the world),
Or in what else to differ Pontic clime
From Gades' and from climes adown the south,
On to black generations of strong men
With sun-baked skins? Even as we thus do see
Four climes diverse under the four main-winds
And under the four main-regions of the sky,
So, too, are seen the colour and face of men
Vastly to disagree, and fixed diseases
To seize the generations, kind by kind:
There is the elephant-disease which down
In midmost Aegypt, hard by streams of Nile,
Engendered is--and never otherwhere.
In Attica the feet are oft attacked,
And in Achaean lands the eyes. And so
The divers spots to divers parts and limbs
Are noxious; 'tis a variable air
That causes this. Thus when an atmosphere,
Alien by chance to us, begins to heave,
And noxious airs begin to crawl along,
They creep and wind like unto mist and cloud,
Slowly, and everything upon their way
They disarrange and force to change its state.
It happens, too, that when they've come at last
Into this atmosphere of ours, they taint
And make it like themselves and alien.
Therefore, asudden this devastation strange,
This pestilence, upon the waters falls,
Or settles on the very crops of grain
Or other meat of men and feed of flocks.
Or it remains a subtle force, suspense
In the atmosphere itself; and when therefrom
We draw our inhalations of mixed air,
Into our body equally its bane
Also we must suck in.