What is a plate or slip of glass on which is a picture or delineation to be exhibited by means of a magic lantern, stereopticon, or the like; a plate on which is an object to be examined with a microscope called?

slide — A plate or slip of glass on which is a picture or delineation to be exhibited by means of a magic lantern, stereopticon, or the like; a plate on which is an object to be examined with a microscope. (Webster's 1913.)

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