[To] explain the phenomena of the mineral kingdom … systems are usually reduced to two classes, according as they refer to the origin of terrestrial bodies to FIRE or to WATER; and … their followers have of late been distinguished by the fanciful names of Vulcanists and Neptunists. To the former of these Dr HUTTON belongs much more than to the latter; though, as he employs the agency both of fire and water in his system, he cannot, in strict propriety, be arranged with either.