Those Objects view'd through the greatest extent of gross Air, appear the most tinged with its Azure; so that the Air communicates a greater share of its Colour to a Body seen at two Miles distance from the Eye, than to the same Body when seen at half that distance: Here some one may Object, that in Landskips the Trees near at hand, appear brighter than those at a greater distance, which seems to overthrow our proposition; but this Objection is usually false, when understood of Trees ranged at equal distances; and does only hold true, where the nearest Trees are placed so wide from each other, that between them you see the Light of the Air, and of the Intermediate Fields, the more remote at the same time being closer and more compact, as is often observ'd on the Banks of Rivers, where the Trees are seen so near to each other, that they join their Shadows, and prevent either the Verdure of the Fields, or the Brightness of the Air from appearing. It must be observ'd however, that as the Shadow'd part of a Tree is more large than the part illumined, its Image will be stronger, and will preserve it self better, than that of the other; for which reason, a far distant Tree may happen to appear more obscure than a near one, notwithstanding the Azure brightness communicated by the Air to the latter.