_Of_ PASTURE _of_ PLANTS.
Cattle feed on Vegetables that grow upon the Earth’s external Surface;
but Vegetables themselves first receive, from within the Earth, the
Nourishment they give to Animals.
The Pasture of Cattle has been known and understood in all Ages of
the World, it being liable to Inspection; but the Pasture of Plants,
being out of the Observation of the Senses, is only to be known
by Disquisitions of Reason; and has (for ought I can find) pass’d
undiscover’d by the Writers of Husbandry[8].
[8] When Writers of Husbandry, in discoursing of Earth and
Vegetation, come nearest to the Thing, that is, the _Pasture_
of _Plants_, they are lost in the Shadow of it, and wander in a
Wilderness of obscure Expressions, such as _Magnetism, Virtue, Power,
Specific Quality, Certain Quality_, and the like; wherein there is no
manner of Light for discovering the real Substance, but we are left
by them more in the Dark to find it, than Roots are when they feed on
it: And when a Man, no less sagacious than Mr. _Evelyn_, has trac’d
it thro’ all the _Mazes_ of the _Occult Qualities_, and even up to
the _Metaphysics_, he declares he cannot determine, whether the Thing
he pursues be _Corporeal_ or _Spiritual_.
The Ignorance of this seems to be one principal Cause, that
Agriculture, the most necessary of all Arts, has been treated of by
Authors more superficially than any other Art whatever. The Food or
_Pabulum_ of Plants being prov’d to be Earth, where and whence[9] they
take that, may properly be called their Pasture.
[9] By the _Pasture_ is not meant the _Pabulum_ itself; but the
_Superficies_ from whence the _Pabulum_ is taken by Roots.
This Pasture I shall endeavour to describe.
’Tis the inner or (internal) Superficies[10] of the Earth; or which
is the same thing, ’tis the Superficies of the Pores, Cavities, or
Interstices of the divided Parts of the Earth, which are of two Sorts,
viz. _Natural_ and _Artificial_.
[10] This Pasture of Plants never having been mentioned or described
by any Author that I know of, I am at a loss to find any other Term
to describe it by, that may be synonymous, or equipollent to it:
Therefore, for want of a better, I call it the inner, or internal
Superficies of the Earth, to distinguish it from the outer or
external Superficies, or Surface, whereon we tread.
Inner or internal Superficies may be thought an absurd Expression,
the Adjective expressing something within, and the Substantive
seeming to express only what is without it; and indeed the Sense of
the Expression is so; for the Vegetable Pasture is within the Earth,
but without (or on the Outsides of) the divided Parts of the Earth.
And, besides, Superficies must be joined with the Adjective Inner (or
Internal) when ’tis used to describe the Inside of a thing that is
hollow, as the Pores and Interstices of the Earth are.
The Superficies, which is the Pasture of Plants, is not a bare
Mathematical Superficies; for that is only imaginary.
By Nature, the whole Earth (or Soil) is composed of Parts; and,
if these had been in every Place absolutely joined, it would have
been without Interstices or Pores, and would have had no internal
Superficies, or Pasture for Plants: but since it is not so strictly
dense[11], there must be Interstices at all those Places where the
Parts remain separate and divided.
[11] For were the Soil as dense as Glass, the Roots or Vegetables
(such as our Earth produces) would never be able to enter its Pores.
These Interstices, by their Number and Largeness, determine the
specific Gravity (or true Quantity) of every Soil: The larger they are,
the lighter is the Soil; and the inner Superficies is commonly the less.
The Mouths, or Lacteals, being situate, and opening, in the convex
Superficies of Roots, they take their _Pabulum_, being fine Particles
of Earth, from the Superficies of the Pores, or Cavities, wherein the
Roots are included.
And ’tis certain, that the Earth is not divested or robb’d of this
_Pabulum_, by any other Means, than by actual Fire, or the Roots of
Plants.
For, when no Vegetables are suffer’d to grow in a Soil, it will always
grow richer. Plow it, harrow it, as often as you please, expose it to
the Sun in Horse-Paths all the Summer, and to the Frost of the Winter;
let it be cover’d by Water at the Bottom of Ponds, or Ditches; or if
you grind dry Earth to Powder, the longer ’tis kept exposed, or treated
by these or any other Method possible (except actual Burning by Fire);
instead of losing, it will gain the more Fertility.
These Particles, which are the _Pabulum_ of Plants, are so very
minute[12] and light, as not to be singly attracted to the Earth, if
separated from those Parts to which they adhere[13], or with which
they are in Contact (like Dust to a Looking-Glass, turn it upwards, or
downwards, it will remain affixt to it), as these Particles do to those
Parts, until from thence remov’d by some Agent.
[12] As to the Fineness of the _Pabulum_ of Plants, ’tis not
unlikely, that Roots may insume no grosser Particles, than those on
which the Colours of Bodies depend; but to discover the greatest
of those Corpuscles, Sir _Isaac Newton_ thinks, it will require a
Microscope, that with sufficient Distinctness can represent Objects
Five or Six hundred times bigger, than at a Foot Distance they appear
to the naked Eye.
My Microscope indeed is but a very ordinary one, and when I view with
it the Liquor newly imbibed by a fibrous Root of a Mint, it seems
more limpid than the clearest common Water, nothing at all appearing
in it.
[13] Either Roots must insume the Earth, that is their _Pabulum_,
as they find it in whole Pieces, having intire Superficies of their
own, or else such Particles as have not intire Superficies of their
own, but want some Part of it, which adheres to, or is Part of the
Superficies of larger Particles, before they are separated by Roots.
The former they cannot insume (unless contained in Water); because
they would fly away at the first Pores that were open: _Ergo_ they
must insume the latter.
A Plant cannot separate these Particles from the Parts to which they
adhere, without the Assistance of Water, which helps to loosen them.
And ’tis also probable, that the Nitre of the Air may be necessary to
relax this Superficies, to render the prolific Particles capable of
being thence disjoin’d; and this Action of the Nitre seems to be what
is call’d, Impregnating the Earth.
Since the grosser Vegetable Particles, when they have pass’d thro’
a Plant, together with their moist Vehicle, do fly up into the Air
invisibly; ’tis not likely they should, in the Earth, fall off from the
Superficies of the Pores, by their own Gravity: And if they did fall
off, they might fly away as easily before they enter’d Plants, as they
do after they have pass’d thro’ them; and then a Soil might become the
poorer[14] for all the Culture and Stirring we bestow upon it; tho’ no
Plants were in it; contrary to Experience.
[14] But we see it is always the richer by being frequently turned
and exposed to the Atmosphere: Therefore Plants must take all their
_Pabulum_ from a Superficies of Parts of Earth; except what may
perhaps be contained in Water fine enough to enter Roots intire with
the Water.
It must be own’d, that Water does ever carry, in its Interstices,
Particles of Earth fine enough to enter Roots; because I have seen,
that a great Quantity of Earth (in my Experiments) will pass out of
Roots set in Rain-water; and tis found that Water can never be, by
any Art, wholly freed from its earthy Charge; therefore it must have
carry’d in some Particles of Earth along with it: But yet I cannot
hence conclude, that the Water did first take these fine Particles
from the aforesaid Superficies: I rather think, that they are exhal’d,
together with very small Pieces to which they adhere, and in the Vapour
divided by the Aereal Nitre; and, when the Vapour is condens’d, they
descend with it to replenish the Pasture of Plants; and that these
do not enter intire into Roots, neither does any other of the earthy
Charge that any Water contains; except such fine Particles which have
already pass’d thro’ the Vegetable Vessels, and been thence exhal’d.
This Conjecture is the more probable, for that Rain-Water is as
nourishing to Plants set therein as Spring-Water, tho’ the latter have
more Earth in it; and tho’ Spring-water have some Particles in it that
will enter intire into Roots, yet we must consider, that even that
Water may have been many times exhal’d into the Air, and may have still
retain’d a great Quantity of Vegetable Particles, which it received
from Vegetable Exhalations in the Atmosphere; tho’ not so great a
Quantity as Rain-water, that comes immediately thence.
These, I have to do with, are the Particles which Plants have from the
Earth, or Soil; but they have also fine Particles of Earth from Water,
which may impart some of its finest Charge to the Superficies of Roots,
as well as to the Superficies of the Parts of the Earth[15] which makes
the Pasture of Plants.
[15] If Water does separate, and take any of the mere _Pabulum_ of
Plants from the Soil, it gives much more to it.
Yet it seems, that much of the Earth, contain’d in the clearest Water,
is there in too large Parts to enter a Root; since we see, that in a
short time the Root’s Superficies will, in the purest Water, be cover’d
with Earth, which is then form’d into a terrene Pasture, which may
nourish Roots; but very few Plants will live long in so thin a Pasture,
as any Water affords them. I cannot find one as yet that has liv’d a
Year, without some Earth have been added to it.
And all Aquatics, that I know, have their Roots in the Earth, tho’
cover’d with Water.
The Pores, Cavities, or Interstices of the Earth, being of two Sorts,
_viz._ _Natural_ and _Artificial_; the one affords the Natural, the
other the Artificial Pasture of Plants.
The natural Pasture alone will suffice, to furnish a Country with
Vegetables, for the Maintenance of a few Inhabitants; but if
Agriculture were taken out of the World, ’tis much to be fear’d, that
those of all populous Countries, especially towards the Confines of the
frigid Zones (for there the Trees often fail of producing Fruit), would
be oblig’d to turn _Anthropophagi_, as in many uncultivated Regions
they do, very probably for that Reason.
The artificial Pasture of Plants is that inner Superficies which is
made from dividing the Soil by Art.
This does, on all Parts of the Globe, where used, maintain many more
People than the natural Pasture[16]; and in the colder Climates, I
believe, it will not be extravagant to say, ten times as many: Or
that, in Case Agriculture were a little improved (as I hope to shew is
not difficult to be done), it might maintain twice as many more yet, or
the same Number, better.
[16] The extraordinary Increase of St. Foin, Clover, and natural
Grass, when their Roots reach into pulveriz’d Earth, exceeding the
Increase of all those other Plants of the same Species (that stand
out of the Reach of it) above One hundred Times, shew how vastly the
artificial Pasture of Plants exceeds the natural. A full Proof of
this Difference, (besides very many I have had before) was seen by
two Intervals in the middle of a poor Field of worn-out St. Foin,
pulveriz’d in the precedent Summer, in the manner describ’d in a
Note on the latter Part of Chap. XII. relating to _St. Foin_. Here
not only the _St. Foin_ adjoining to these Intervals recover’d its
Strength, blossom’d, and seeded well, but also the natural Grass
amongst it was as strong, and had as flourishing a Colour, as if
a Dung-heap had been laid in the Intervals; also many other Weeds
came out from the Edges of the unplow’d Ground, which must have lain
dormant a great many Years, grew higher and larger than ever were
seen before in that Field; but above all, there was a Weed amongst
the St. _Foin_, which generally accompanies it, bearing a white
Flower; some call it _White Weed_, others _Lady’s Bedstraw_: Some
Plants of this that stood near the Intervals, were, in the Opinion of
all that saw them, increased to a thousand Times the Bulk of those
of the same Species, that stood in the Field three Feet distant from
such pulveriz’d Earth.
_Note_, These Intervals were each an Hundred Perch long, and had
each in them a treble Row of Barley very good. The Reason I take
to be this, That the Land had lain still several Years after its
artificial Pasture was lost; whereby all the Plants in it having only
the natural Pasture to subsist on, became so extremely _small_ and
_weak_, that they were not able to exhaust the Land of so great a
Quantity of the (vegetable) nourishing Particles as the Atmosphere
brought down to it.
And when by Pulveration the artificial Pasture came to be added
to this natural Pasture (not much exhausted), and nothing at all
suffered to grow out of it for above Three Quarters of a Year, it
became rich enough, without any Manure, to produce this extraordinary
Effect upon the Vegetables, whose Roots reached into it. How long
this Effect may continue, is uncertain: but I may venture to say, it
will continue until the Exhaustion by Vegetables doth over-balance
the Descent of the Atmosphere, and the Pulveration.
And what I have said of any one Species of Plants in this Respect may
be generally apply’d to the rest.
The natural Pasture is not only less than the artificial, in an equal
Quantity of Earth; but also, that little consisting in the Superficies
of Pores, or Cavities, not having a free Communication[17] with one
another, being less pervious to the Roots of all Vegetables, and
requiring a greater Force to break thro’ their Partitions; by that
Means, Roots, especially of weak Plants, are excluded from many of
those Cavities, and so lose the Benefit of them.
[17] None of the natural Vegetable Pasture is lost or injured by the
artificial; but on the contrary, ’tis mended by being mix’d with it,
and by having a greater Communication betwixt Pore and Pore.
But the artificial Pasture consists in Superficies of Cavities, that
are pervious to all Manner of Roots, and that afford them free Passage
and Entertainment in and thro’ all their Recesses. Roots may here
extend to the utmost, without meeting with any Barricadoes in their Way.
The internal Superficies, which is the natural Pasture of Plants, is
like the external Superficies or Surface of the Earth, whereon is the
Pasture of Cattle; in that it cannot be inlarg’d without Addition of
more Surface taken from Land adjoining to it, by inlarging its Bounds
or Limits.
But the artificial Pasture of Plants may be inlarg’d, without any
Addition of more Land, or inlarging of Bounds, and this by Division
only of the same Earth.
And this artificial Pasture may be increas’d in proportion to the
Division of the Parts of Earth, whereof it is the Superficies, which
Division may be mathematically infinite; for an Atom is nothing;
neither is there a more plain Impossibility in Nature, than to reduce
Matter to nothing, by Division or Separation of its Parts.
A Cube of Earth of One Foot has but Six Feet of Superficies. Divide
this Cube into Cubical Inches, and then its Superficies will be
increas’d Twelve times, _viz._ to Seventy-two Superficial Feet. Divide
these again in like Manner and Proportion; that is, Divide them into
Parts that bear the same Proportion to the Inches, as the Inches do to
the Feet, and then the same Earth, which had at first no more than Six
Superficial Feet, will have Eight hundred Sixty-four Superficial Feet
of artificial Pasture; and so is the Soil divisible, and this Pasture
increasable _ad Infinitum_.
The common Methods of dividing the Soil are these; _viz._ by _Dung_, by
_Tillage_, or by both[18].
[18] For _Vis Unita Fortior_.