It is this shared view of Kripke and Putnam that I wish to discuss, putting aside the second claim as to the metaphysical or ontological character of the necessity of such claims as 'Water is H2 O'. In the two sections which follow I shall argue that Kripke and Putnam are wrong in their shared view of the scope of metaphysical necessities; I shall argue that there is a possible world in which to introduce the example I shall use for the rest of my arguments gold fails to have atomic number 79, despite the agreement on the part of Kripke and Putnam, that it is, if true, metaphysically necessarily true that gold have atomic number 79. It is crucial to an acceptance of the metaphysical necessity of such claims