Among Colours of the same kind, that which is nearest the Eye will undergo the least Alteration; The Reason of this is Evident, for the Air interposed between the Eye and the Object, has always some Effect upon it, and alters its Colour, either in a greater or less Degree; when the interposed Air, therefore, is found in a small Quantity, it must needs communicate a less share of its own Azure to the Species transmitted through it, and therefore will discolour it less, than when the said Air, being in a greater Quantity, has both a greater share of Colour, and makes more Resistance to the Species, in their Passage.