ROBERT (called in Latin DE FLUCTIBUS), a person of some celebrity in his time, was the son of Sir Thomas Fludd, treasurer of war to Queen Elizabeth in France and the Low Countries, and was born at Milgate, Kent, in the year 1574. He received his education at St John's College, Oxford, and afterwards spent six years in travelling through France, Spain, Italy, and Germany. He acquired a strong attachment to the Rosicrucian philosophy, which consisted chiefly of a mystic or cabalistical jargon, and those who were initiated therein had certain secrets communicated to them analogous to those of free-masonry. On his return home Fludd took the degree of doctor of medicine, settled in the city of London, and became a fellow of the College of Physicians. His piety was of an enthusiastic kind, and the seeming depth of his knowledge gained him much admiration, and procured him temporary celebrity. It is said that he employed a kind of unintelligible cant when speaking to his patients, which sometimes contributed to their recovery, as it operated on their faith, and through it on the imagination. But he is chiefly known as an adept in philosophy, not as a physician. Blending the incomprehensible reveries of the Cabalists and Paracelsians, he formed a new physical system, replete with mystery and absurdity, and believed in two universal principles, the northern or condensing, and the southern or rarefying power. Innumerable genii, as he conceived, presided over these powers, and committed the charge of diseases to legions of spirits collected from the four winds of heaven. In his estimation, a harmony subsisted between the macrocosm and the microcosm, or the world of nature and the world of man. It is impossible to enumerate all his fancies and whims, which, however absurd and extravagant, being supported by mysterious gravity and the semblance of erudition, attracted the notice of the philosophers of that age. Even Kepler himself thought the preposterous jargon of Fludd worthy of refutation, and Gassendi with the same view wrote his Examen Philosophiae Fluddiana, 1629. Fludd wrote two books against Mersenne, the first entitled Sophia cum Moria cer- tamen, in quo lapis Lydius, a falsa structore Patre Marino Merseno monacho reprobatus, celeberrima voluminis sui Babylonicis in Genesim figmenta accurate examinat, Fran- fort, 1629, folio; and the second, Summum Bonorum, quod est verum Magiae, Cabala, Alchymiae, Fratrum Rosae Crucis Verorum, Subjectum, etc., 1629, folio. His other works were, 1. Utriusque Cosmi, majoris et minoris, Technica Historia, Appenheim, 1617, in 2 vols. folio; 2. Trac- tatus Apologeticus integritatem Soc. de Rosae Cruce defendens, Leyden, 1617; 3. Monochordon Mundi symphonia- cum, seu Replicatio ad Apologiam Joannis Kepleri, Fran- fort, 1620; 4. Anatomiae Theatrum triplici effigie designa- tum, ibid. 1623; 5. Philosophia Sacra et vere Christiana, seu Meteorologia Cosmica, ibid. 1626; 6. Medicina Catho- lica, seu mysticum artis medicandi sacrarium, ibid. 1626; 7. Integrum Morborum mysterium, ibid. 1631; 8. De Mor- borum Signis, ibid. 1631; 9. Clavis Philosophiae et Alchy- mie Fluddiana, ibid. 1633; 10. Philosophia Mosonica, Gouda, 1638; and, 11. Pathologia Daemonica, ibid. 1640.