A Pellucid is not ſeen, but percieved by the privation of Colour. So vve ſee not Air in Air, VVater in VVater, Glaſs in Glaſs, and every Pellucid in an equal Pellucid; and becauſe vve knovv they are not coloured, vve count them to be diaphanous, viz. that may be ſeen, or ſhone thorough.