Part 2

What put me upon this Method was an Observation of two Lands (or Ridges) drill’d with _Turneps_ in Rows, a Foot asunder, and very even in them; the Ground, at both Ends, and one Side, was hard and unplow’d; the _Turneps_ not being ho’d, were very poor, small, and yellow, except the Three outside Rows, _B_, _C_, _D_, which stood next to the Land (or Ridge) _E_, which Land being plow’d and harrow’d, at the time the Land _A_ ought to have been ho’d, gave a dark flourishing Colour to these three Rows; and the _Turneps_ in the Row _D_, which stood farthest off from the new-plow’d Land _E_, received so much Benefit from it, as to grow twice as big as any of the more distant Rows. The Row _C_, being a Foot nearer to the new-plow’d Land, became twice as large as those in _D_; but the Row _B_, which was next to the Land _E_, grew much larger yet[2].

[2] A like Observation to this on the Land E, has been made in several Turnep Fields of divers Farmers, where Lands adjoining to the Turneps have been well tilled; all the Turneps of the contiguous Lands that were within three or four Feet, or more, of the newly pulveriz’d Earth, received as great, or greater increase, in the Manner as my Rows B C D did; and what is yet a greater Proof of the Length of Roots, and of the Benefit of deep Hoing, all these Turneps have been well Hand-ho’d; which is a good Reason why the Benefit of the deep Pulveration should be perceivable at a greater Distance from it than mine, because my Turneps, not being hoed at all, had not Strength to send out their Roots through so many Feet of unpulveriz’d Earth, as these can through their Earth pulveriz’d by the Hoe, tho’ but shallowly.

This Observation, as ’tis related to me (I being unable to go far enough to see it myself) sufficiently demonstrates the mighty Difference there is between Hand-hoing and Horse-hoing.

_F_ Plate 6. is a Piece of hard whole Ground, of about two Perch in Length, and about two or three Feet broad, lying betwixt those two Lands, which had not been plow’d that Year; ’twas remarkable, that during the Length of this interjacent hard Ground, the Rows _B_, _C_, _D_, were as small and yellow as any in the Land.

The _Turneps_ in the Row _D_, about three Feet distant from the Land _E_, receiving a double Increase, proves they had as much Nourishment from the Land _E_, as from the Land _A_, wherein they stood; which Nourishment was brought by less than half the Number of _Roots_ of each of these _Turneps_.

In their own Land they must have extended a Yard all round, else they could not have reach’d the Land _E_, wherein ’tis probable these few Roots went more than another Yard, to give each _Turnep_ as much Increase as all the Roots had done in their own Land.

Except that it will hereafter appear, that the new Nourishment taken at the Extremities of the Roots in the Land _E_, might enable the Plants to send out more new Roots in their own Land, and receive something more from thence.

The Row _C_ being twice as big as the Row _D_, must be suppos’d to extend twice as far; and the Row _B_, four times as far, in proportion as it was of a Bulk quadruple to the Row _D_.

A _Turnep_ has a Tap-Root, from whence all these Horizontal Roots are deriv’d.

And ’tis observable; that betwixt these two Lands there was a Trench, or Furrow, of about the Depth of nine or ten Inches, where these Roots must descend first, and then ascend into the Land _E_: But it must be noted, that some small Quantity of Earth was, by the Harrowing, fall’n into this Furrow, else the Roots could not have pass’d thro’ it.

_Roots_ will follow the open Mould[3], by descending perpendicularly, and mounting again in the same manner: As I have observ’d the Roots of a Hedge to do, that have pass’d a steep Ditch two Feet deep, and reach’d the Mould on the other side, and there fill it; and digging Five Feet distant from the Ditch, found the Roots large, tho’ this Mould was very shallow, and no Roots below the good Mould.

[3] A Chalk-Pit, contiguous to a Barn, the Area of which being about 40 Perch of Ground, was made clean and swept; so that there was not the Appearance of any Part of a Vegetable, more than in the Barn’s Floor: Straw was thrown from thence into the Pit, for Cattle to lie on; the Dung made thereby was haled away about three Years after the Pit had been cleansed; when, at the Bottom of it, and upon the Top of the Chalk, the Pit was covered all over with Roots, which came from a Witch-Elm, not more than Five or Six Yards in Length, from Top to Bottom, and which was about Five Yards above, and Eleven Yards from the Area of the Pit; so that in three Years the Roots of this Tree extended themselves Eight times the Length of the Tree, beyond the Extremities of the old Roots, at Eleven Yards Distance from the Body: The annual-increased Length of the Roots was near Three times as much as the Height of the Tree.

I’m told an Objection hath been made from hence against the Growth of a Plant’s being in proportion to the Length of its Roots; but when the Case is fully stated, the Objection may vanish. This Witch-Elm is a very old decay’d Stump, which is here called a _Staggar_, appearing by its Crookedness to have been formerly a _Plasher_ in an old White-thorn Hedge wherein it stands: It had been lopped many Years before that accidental Increase of Roots happened; it was stunted, and sent out poor Shoots; but in the third Year of these Roots, its Boughs being most of them horizontally inclined, were observed to grow vigorously, and the Leaves were broad, and of a flourishing Colour; at the End of the third Year all these Roots were taken away, and the _Area_ being a Chalk-Rock lying uncovered, round the Place where the Single Root, that produced all these, came out of the Bank, no more Roots could run out on the bare Chalk, and the Growth of the Boughs has been but little since.

_Wheat_, drill’d in double Rows in _November_, in a Field well till’d before Planting, look’d yellow, when about Eighteen Inches high; at Two Feet Distance from the Plants, the Earth was Ho-plow’d, which gave such Nourishment to ’em, that they recovered their Health, and changed their sickly Yellow, to a lively Green Colour.

So in an Orchard, where the Trees are planted too deep, below the Staple or good Mould, the Roots, at a little Distance from the Stem, are all as near the upper Superficies of the Ground, as of those Trees, which are planted higher than the Level of the Earth’s Surface.

But the Damage of planting a Tree too low in moist Ground is, that in passing thro’ this low Part, standing in Water, the Sap is chill’d, and its Circulation thereby retarded.

One Cause of Peoples not suspecting Roots to extend to the Twentieth Part of the Distance which in reality they do, was from observing these Horizontal-Roots, near the Plant, to be pretty taper; and if they did diminish on, in proportion to what they do there, they must soon come to an End. But the Truth is, that after a few Inches, they are not discernibly taper, but pass on to their Ends very nearly of the same Bigness; this may be seen in _Roots_ growing in Water, and in some other, tho’ with much Care and Difficulty.

In pulling up the aforemention’d _Turneps_, their Roots seem’d to end at few Inches Distance from the Plants, they being, farther off, too fine to be perceiv’d by ordinary Observation.

I found an extreme small Fibre on the Side of a _Carrot_, much less than a Hair; but thro’ a Microscope it appear’d a large Root, not taper, but broken off short at the End, which it is probable might have (before broken off) extended near as far as the _Turnep_ Roots did. It had many Fibres going out of it, and I have seen that a _Carrot_ will draw Nourishment from a great Distance, tho’ the Roots are almost invisible, where they come out of the _Carrot_ itself.

By the Piece _F_ Plate 6. may be seen, that those Roots cannot penetrate, unless the Land be open’d by Tillage, _&c._

As Animals of different Species have their Guts bearing different Proportions to the Length of their Bodies; so ’tis probable, different Species of Plants may have their Roots as different. But if those which have shorter Roots have more in Number, and having set down the means how to know the Length of them in the Earth, I leave the different Lengths of different Species to be examin’d by those who will take the Pains of more Trials. This is enough for me, that there is no Plant commonly propagated, but what will send out its Roots far enough, to have the Benefit of all the ho’d Spaces or Intervals I in the following Chapters allot them, even tho’ they should not have Roots so long as their Stalks or Stems.

And this great Length of Roots will appear very reasonable, if we compare the Largeness of the Leaves (which are the Parts ordain’d for Excretion) with the Smalness of the Capillary Roots, which must make up in Length or Number what they want in Bigness, being destin’d to range far in the Earth, to find out a Supply of Matter to maintain the whole Plant; whereas the chief Office of the Stalks and Leaves is only to receive the same, and to discharge into the Atmosphere such Part thereof as is found unfit for Nutrition; a much easier Task than the other, and consequently fewer Passages suffice, these ending in an obtuse Form; for otherwise the Air would not be able to sustain the Stalks and Leaves in their upright Posture: but the Roots, tho’ very weak and slender, are easily supported by the Earth, notwithstanding their Length, Smalness, and Flexibility.

Plants have no Stomach, nor _Oesophagus_, which are necessary to convey the Mass of Food to an Animal: Which Mass, being exhausted by the Lacteals, is eliminated by way of Excrements, but the Earth itself being that Mass to the Guts (or Roots) of Plants, they have only fine Recrements, which are thrown off by the Leaves.

In this, Animal and Vegetable Bodies agree, that Guts and Roots are both injured by the open Air; and Nature has taken an equal Care, that both may be supply’d with Nourishment, without being expos’d to it. Guts are supply’d from their Insides, and Roots from their Outsides.

All the Nutriment (or _Pabulum_) which Guts receive for the Use of an Animal, is brought to them; but Roots must search out and fetch themselves all the _Pabulum_ of a Plant; therefore a greater Quantity of Roots, in Length or Number, is necessary to a Plant, than of Guts to an Animal.

All _Roots_ are as the Intestines of Animals, and have their Mouths or Lacteal Vessels opening on their outer spongy Superficies, as the Guts of Animals have theirs opening in their inner spongy Superficies.

The Animal Lacteals take in their Food by the Pressure that is made from the Peristaltic Motion, and that Motion caus’d by the Action of Respiration, both which Motions press the Mouths of the Lacteals against the Mass or Soil which is within the Guts, and bring them into closer Contact with it.

Both these Motions are supply’d in Roots by the Pressure occasion’d by the Increase of their Diameters in the Earth, which presses their Lacteal Mouths against the Soil without. But in such Roots as live in Water, a Pressure is constantly made against the Roots by the Weight and Fluidity of the Water; this presses such fine Particles of Earth it contains, and which come into Contact with their Mouths, the closer to them.

And when _Roots_ are in a till’d Soil, a great Pressure is made against them by the Earth, which constantly subsides, and presses their Food closer and closer, even into their Mouths; until itself becomes so hard and close, that the weak Sorts of Roots can penetrate no farther into it, unless re-open’d by new Tillage, which is call’d Hoing.

When a good Number of Single-Mint Stalks had stood in Water, until they were well stock’d with Roots from their two lower Joints, and some of them from three Joints, I set one in a Mint-Glass full of Salt Water; this Mint became perfectly dead within three Days.

Another Mint I put into a Glass of fair Water; but I immers’d one String of its Roots (being brought over the Top of that Glass into another Glass of Salt-water, contiguous to the Top of the other Glass: This _Mint_ dy’d also very soon.

Of another (standing in a Glass of Water and Earth till it grew vigorously) I ty’d one single Root into a Bag, which held a Spoonful of dry Salt, adjoining to the Top of the Glass, which kill’d this strong Mint also. I found that this Salt was soon dissolv’d, tho’ on the Outside of the Glass; and tho’ no Water reach’d so high, as to be within Two Inches of the Joint which produc’d this Root: The Leaves of all these were salt as Brine to the Taste.

Of another, I put an upper Root into a small Glass of Ink, instead of a Bag of Salt, in the Manner above-mention’d; this Plant was also kill’d by some of the Ink Ingredients. The Blackness was not communicated to the Stalk, or Leaves, which inclin’d rather to a yellowish Colour as they died, which seem’d owing to the _Copperas_.

I made a very strong Liquor with Water, and bruised Seeds of _Wild-Garlick_, and, filling a Glass therewith, plac’d the Top of it close to the Top of another Glass, having in it a Mint, two or three of whose upper Roots, put into this stinking Liquor, full of the bruised Seeds, and there remaining, it kill’d the Mint in some time; but it was much longer in dying than the others were with Salt and Ink. It might be, because these Roots in the _Garlick_ were very small, and did not bear so great a Proportion to their whole System of Roots, as the Roots, by which the other Mints were poison’d, did to theirs.

When the Edges of the Leaves began to change Colour, I chew’d many of them in my Mouth, and found at first the strong aromatic Flavour of Mint, but that was soon over; and then the nauseous Taste of _Garlick_ was very perceptible to my Palate.

I observ’d, that when the _Mint_ had stood in a Glass of Water, until it seem’d to have finish’d its Growth, the Roots being about a Foot long, and of an earthy Colour, after putting in some fine Earth, which sunk down to the Bottom, there came from the upper Joint a new Set of white Roots, taking their Course on the Outside of the Heap of old Roots downwards, until they reach’d the Earth at the Bottom; and then, after some time, came to be of the same earthy Colour with the old ones.

Another _Mint_ being well rooted from Two Joints, about Four Inches asunder; I plac’d the Roots of the lower Joint in a deep Mint-Glass, having Water at the Bottom, and the Roots of the upper Joint into a square Box, contriv’d for the Purpose, standing over the Glass, and having a Bottom, that open’d in the Middle, with a Hole, that shut together close to the Stalk, just below the upper Joint; then laying all these upper Roots to one Corner of the Box, I fill’d it with Sand, dry’d in a Fire-shovel, and found, that in one Night’s time, the Roots of the lower Joint, which reach’d the Water at the Bottom of the Glass, had drawn it up, and imparted so much thereof to those Roots in the Box above, that the Sand, at that Corner where they lay, was very wet, and the other three Corners dry. This Experiment I repeated very often, and it always succeeded as that did.

And for the same Purpose I prepar’d a small Trough, about two Foot long, and plac’d a Mint-Glass under each End of the Trough; over each Glass I plac’d a Mint, with half its Roots in the Glass, the other half in the Trough: The Mints stood just upon the Ends of the Trough. Then I cover’d these Roots with pulveriz’d Earth, and kept the Glasses supply’d with Water; and as oft as the white fibrous Roots shot thro’ the Earth, I threw on more Earth, till the Trough would hold no more; and still the white Fibres came thro’, and appear’d above it; but all seem’d (as I saw by the Help of a coarse Microscope) to turn, and when they came above-ground, their Ends enter’d into it again. These two _Mints_ grew thrice as large as any other _Mint_ I had, which were many, that stood in Water, and much larger than those which stood in Water with Earth in it: They being all of an equal Bigness when set in, and set at the same time. Tho’ these two, standing in my Chamber, never had any Water in their Earth, but what those Roots, which reach’d the Water in the Glasses, sent up to the Roots, which grew in the Trough. The vast Quantity of Water these Roots sent up, being sufficient to keep all the Earth in the Troughs moist, tho’ of a thousand times greater Quantity than the Roots which water’d it, makes it probable, that the Water pass’d out of the Roots into the Earth, without mixing at all with the Sap, or being alter’d to any Degree. The Earth kept always moist, and in the hot Weather there would not remain a Drop of Water in the Glasses, when they had not been fresh supply’d in two Days and one Night; and yet these Roots in the Glasses were not dry’d, tho’ they stood sometimes a whole Day and Night thus in the empty Glasses. These two Mints have thus liv’d all one Summer.

_Remarks on the_ Mints, _&c._

Tho’ the Vessels of Marine Plants be some ways fortify’d against the Acrimony of Salt, as Sea-fish are, yet the Mints all shew, that Salt is poison to other Plants.

The Reason why the Salts in Dung, Brine, or Urine, do not kill Plants in the Field or Garden, is, that their Force is spent in acting upon, and dividing the Parts of Earth; neither do these Salts, or at least any considerable Quantity of them, reach the Roots.

I try’d Salt to many Potatoes in the Ground being undermin’d, and a few of their Roots put into a Dish of Salt-water, they all died sooner or later, according to their Bigness, and to the Proportions the Quantity of Salt apply’d did bear to them.

By the Mints it appears, that Roots make no Distinctions in the Liquor they imbibe, whether it be for their Nourishment or Destruction; and that they do not insume what is disagreeable, or Poison to them, for lack of other Sustenance; since they were very vigorous, and well fed in the Glasses, at the time when the most inconsiderable Part of their Number had the Salt, Garlick, and Ink offer’d to them.

The sixth _Mint_ shews, that when new Earth is apply’d to the old Roots, a Plant sends out new Roots on Purpose to feed on it: And that the more Earth is given it, the more Roots will be form’d, by the new Vigour the Plant takes from the Addition of Earth. This corresponds with the Action of Hoing; for every time the Earth is mov’d about Roots, they have a Change of Earth, which is new to them.

The seventh _Mint_ proves, that there is such a Communication betwixt all the Roots, that when any of them have Water, they do impart a Share thereof to all the rest: And that the Root of the lower Joint of this Mint had Passages (or Vessels) leading from them, through the Stalk, to the Roots of the upper Joint; tho’ the clear Stalk (through which it must have pass’d) that was betwixt these two Joints, was several Inches in Length.

This accounts for the great Produce of long tap-rooted Plants, such as _Lusern_ and _St. Foin_, in very dry Weather: for the Earth at a great Depth is always moist. It accounts also for the good Crops we have in dry Summers, upon Land that has a Clay Bottom; for there the Water is retain’d a long time, and the lower Roots of Plants which reach it, do, like those of this Mint, send up a Share to all the higher Roots.

If those Roots of a Plant, which lie at the Surface of the Ground, did not receive Moisture from other Roots, which lie deeper, they could be of no Use in dry Weather. But ’tis certain, that if this dry Surface be mov’d or dung’d, the Plant will be found to grow the faster, tho’ no Rain falls; which seems to prove, both that the deep Roots communicate to the shallow a Share of their Water, and receive in Return from them a Share of Food, in common with all the rest of the Plant, as in the Mints they did.

The two last _Mints_ shew, that when the upper Roots have Moisture (as they had in the Earth in the Trough, carried thither first by the lower Roots) they impart some of it to the lower, else these could not have continu’d plump and fresh, as they did for 24 Hours in the empty Glass. And I have since observed them to do so, in the cooler Season of the Year, for several Weeks together, without any other Water, than what the upper Roots convey’d to them, from the moist Earth above in the Trough[4]. I know not what Time these Roots might continue to be supply’d thus in the hot Weather, because I did not try any longer, for fear of killing them.

[4] ’Tis certain, that Roots and other Chyle Vessels of a Plant have a free Communication throughout all their Cavities, and the Liquor in them will run towards that Part where there is least Resistance; and such is that which is the most empty, whether it be above or below; for there are no _Valves_ that can hinder the Descent or Ascent of Liquor in these Vessels, as appears by the growing of a Plant in an inverted Posture.

But it must be noted, that the Depth of the Glass protected the Roots therein from the Injury of the Motion of the free Air, which would have dry’d them, if they had been out of the Glass.

In this Trough is shewn most of the Hoing Effects; _viz._ That Roots, by being broken off near the Ends, increase their Number, and send out several where one is broken off.

That the Roots increase their Fibres every time the Earth is stirr’d about them.

That the stirring the Earth makes the Plants grow the faster.