[61] A Tree of any Sort will spoil Corn all round it, in a large Circle; half an Acre of Turneps has been spoil’d by one: Hereby ’tis plain, that Trees rob as Weeds; because ’tis not by their Shadow, there being as much Damage done by them on the South-Side, where their Shadow never comes, as on their North-Side: Nor can it be by their dropping; for ’tis the same on the Side where a Tree has no Boughs to drop over the Plants, when they are also at a very great Distance from all Parts of the Tree, except its Roots. Let three Beds of the same Soil, equal, and equally prepared, be sown with the same Sort of Corn. Let the first of these Beds be kept clean from Weeds: In the Second, let a Quantity of Weeds grow along with the Corn; and in the Third, stick up a Quantity of dead Sticks, greater in Bulk than the Weeds. It will be found, that the Produce of the Corn in the First will not exceed that of the Third Bed; but in the Second, where the Weeds are, the Corn will be diminish’d in Proportion to the Quantity of Weeds amongst it. The Sticks, having done no Injury to the Corn, shew there was room enough in the Bed for Company to lodge, would they forbear to eat; or else (like Travellers in _Spain_) bring their Provision with them to their Inn, or (which would be the same thing) if Weeds could find there some Dish so disagreeable to the Palate of the Corn, and agreeable to their own, that they might feed on it without robbing; and then they would be as innocent as the Sticks, which take up the same Room with the Weeds. The Quantity of Nourishment Weeds rob the Corn of, is not in Proportion only to their Number and Bulk, but to the Degrees of Heat in their Constitution; as appears by the Instance of Charlock and Turneps, mention’d in the Chapter _Of Change of Species_. ’Tis needless to go about to compute the Value of the Damage Weeds do, since all experienc’d Husbandmen know it to be very great, and would unanimously agree to extirpate their whole Race as intirely, as in _England_ they have done the Wolves, tho’ much more innocent, and less rapacious than Weeds[62]. [62] If we consider the Crops they utterly destroy, and those they extremely diminish; and that very few Crops escape without receiving Injury from them; it may be a Question, whether the Mischief Weeds do to our Corn, is not as great as the Value of the Rent of all the Arable Lands in _England_. But alas! they find it impossible to be done, or even to be hoped for, by the common Husbandry; and the Reasons I take to be these.