A preservative against popery, collected out of the writings of our most able divines : In answer to a book entituled fifty reasons or motives why the Roman Catholick apostolick religion ought to be prefer'd to all the sects this day in christendom, and which induced his most Serene Highness Anthony Ulrick, Duke of Brunswick Lunenburgh, &c. to abjure Lutheranism: and also to the papers annex'd to the said book. I. The decision of the Protestant University of Helmstadt, in favour of the roman catholick religion. II. Copies of two papers, written by the Late King Charles the IId. III. A copy of a paper, written by the Late Dutchess of York. These three papers were answer'd A.D. 1686, and the answer is now reprinted. By a Presbyter of the Diocess of Derry.