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 at