A plea for defensive armes, or, A copy of a letter written by Mr. Stephen Marshall to a friend of his in the city, for the necessary vindication of himself and his ministerie, against that altogether groundlesse, most unjust and ungodly aspersion cast upon him by certain malignants in the city, and lately printed at Oxford, in their Mendacium aulicum, otherwise called, Mercurius Aulicus, and sent abroad into other nations to his perpetual infamie