virtue. A number of demons, he said, ruled over the human frame, whom he arranged in their places in a rhomboid. Every disease had its peculiar demon who produced it, which demon could only be combated by the aid of the demon whose place was directly opposite to his in the rhomboidal figure. Of his medical notions we shall have further occasion to speak in another part of this book, when we consider him in his character as one of the first founders of the magnetic delusion, and its offshoot, animal magnetism, which has created so much sensation in our own day.
As if the doctrines already mentioned were not wild enough, he joined the Rosicrucians as soon as they began to make a sensation in Europe, and succeeded in raising himself to high consideration among them. The fraternity having been violently attacked by several German authors, and among others by Libavius, Fludd volunteered a reply, and published, in 1616, his defence of the Rosicrucian philosophy, under the title of the Apologia compendiaria Fraternitatem de Rosea-cruce suspicionis et infamiæ maculis aspersam abluens. This work immediately procured him great renown upon the Continent, and he was henceforth looked upon as one of the high-priests of the sect. Of so much importance was he considered, that Keppler and Gassendi thought it necessary to refute him; and the latter wrote a complete examination of his doctrine. Mersenne also, the friend of Descartes, and who had defended that philosopher when accused of having joined the Rosicrucians, attacked Dr. à Fluctibus, as he preferred to be called, and shewed the absurdity of the brothers of the Rose-cross in general, and of Dr. à Fluctibus in particular. Fluctibus wrote a long reply, in which he called Mersenne an ignorant calumniator, and reiterated that alchymy was a profitable science, and the Rosicrucians worthy to be the regenerators of the world. This book was published at Frankfort, and was entitled Summum