A Dissertation on comets. [electronic resource] : Proving that the vulgar, and long-received notion, that they either cause or foreshew public calamities, is unphilosophical, absurd, and irreligious. Being the substance of the celebrated Mr Bayle's reflections on that subject, occasioned by the great comet in 1680, and revived with a view to that which has lately appeared. In a letter to a reverend professor. To which is prefixed, the theory of a comet, as given by Sir Isaac Newton and his followers.