In Chap. LIII Porta denies “that the diamond doth hinder the loadstone’s vertue.” “Some pretend,” says he, “there is so much discord between the qualities of the loadstone and the diamond, and they are so hateful, one against the other, and secret enemies, that if the diamond be put to the loadstone, it presently faints and loses all its forces. (Pliny.) The loadstone so disagreeth with the diamond, that if iron be laid by it, it will not let the loadstone draw it; and if the loadstone do attract it, it will snatch it away again from it. (St. Augustine.) I will say that I have read of the loadstone: how that, if the diamond be by it, it will not draw iron; and, if it do when it comes neer the diamond, it will let it fall” (Marbodeus, of the Loadstone ... Marbodei Galli ... de lapidibus pretiosis Enchiridion ... Freiburg, 1530, 1531): “All loadstones by their vertue iron draw; But of the diamond it stands in awe: Taking the iron from’t by Nature’s Law.” “I tried this often, and found it false; and that there is no truth in it.” With reference to the above, see Plat (at A.D. 1653), who also alludes to the fact of the softening of the diamond with Goat’s blood. This is alluded to by Porta in the next chapter. Chapter LIV contains extracts from Castianus in Geoponic. Græc., Marbodeus and Rhenius, the interpreter of Dionysius. In 1560 there was established at Naples, by the versatile Giam. della Porta, the first Academy of Sciences--Academia Secretum Naturæ--to which were admitted only those who had contributed to the advancement of medicine or to scientific studies in general (“Science,” December 19, 1902, p. 965). REFERENCES.--Libri, “Hist. des Sc. Mathém.” Vol. IV. pp. 108–140, 399–406; Houzeau et Lancaster, Vol. II. p. 229; The Fourth Dissertation of the “Encycl. Brit.,” p. 624; Sarpi, at A.D. 1632; Poggendorff, “Geschichte der Physik,” 1879, pp. 133, 273–274; “Encycl. Brit.,” the article on “Optics”; “Journal des Savants” for September 1841. =A.D. 1575–1624.=--Boehm--Böhme--Behmen (Jacob), a mystical German writer, known as the theosophist _par excellence_, is the author of “Aurora,” etc. (1612), “De Tribus Principiis” (1619) and of many other treatises, which were reprinted under the title of “Theosophia Revelata,” and which contain his many very curious observations concerning astrology, chemistry, theology, philosophy and electricity. REFERENCES.--“Notice sur J. Boehm,” La Motte-Fouqué, 1831; “Notes and Queries” for July 28, 1855, p. 63; Ninth “Britan.,” Vol. III. p. 852; J. Ennemoser, “History of Magic,” Vol. II. pp. 297–328.