The Second sort of Blight, _viz._ from light Ears, is that which is most frequent, and more general: This brings the greatest Scarcity of Wheat. The Cause is plainly Want of Nourishment to perfect the Grain, by whatever means that Want is occasioned. Several Accidents kill the Plants, or injure their Health, and then the Grains are not filled; as Lightning, the Effects whereof may be observed by the blackish Spots and Patches in Fields of Wheat, especially in such Years as have more of it than usual. Against this there is no Defence. The other Causes of the Blight, which are most general, and do the most Damage, may, in some measure, be prevented. One Cause is the lodging or falling of Corn; for then the Stalks are broken near the Ground, whereby many of the Vessels are so pressed, that the Juices cannot pass them; and then the free Circulation is hindered; the Chyle cannot mount in sufficient Quantity to be purified, and turned into Sap; the Defect whereof makes the Plants become languid, and only just able to live; they have Strength enough to linger on to the time of their Period, as in very old Age, but not to bring their Fruit, which is the Grain, to its natural Bulk, nor to fill it with Flour: and the sooner the Stalks fall, the less and thinner the Grain will be. Hence it often happens, that when Tillage, Dung, and good Land have brought a Crop of Wheat, that in the Months of _April_ and _May_ promise to yield the Owner Five or Six Quarters on an Acre, then in _June_ it falls down, and scarce affords Five or Six Bushels; and that perhaps is so thin and lank, that the Expence of reaping and threshing it may overbalance its Value. That the falling down of Wheat does cause the Ruin of the Crop, is well known; but what causes it to fall, is not so plain. And, without knowing the true Causes, ’tis not likely that a Remedy should be found against the Disease. I take this Weakness of the Stalks, which occasions their falling, to proceed from want of Nourishment, want of Air, want of the Sun’s Rays, or of all Three. One Argument, that it lodges for want of Nourishment, is, that a rich Acre has maintain’d a Crop of Five Quarters standing, when another poorer Acre was not able to support a Crop from falling, which was but large enough to have brought Three Quarters, if it had stood: and this in the same Year, and on the same Situation. And ’tis very plain, that if one Acre was twice as rich as the other, it must be able to nourish Five Quarters better than the other could nourish Three Quarters. Air is necessary to the Life and Health of all Plants, tho’ in very different Degrees: Aquatics, which live under Water, are content with as little Air, as their Companions the Fishes.