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.