(5.) _Lychnis._ Pliny and St. Isidore speak of a certain stone _lychnis_, of a scarlet or flame colour, which, when warmed by the sun or between the fingers, attracts straws or leaves of papyrus. Pliny puts this stone amongst carbuncles, but it is much more probably _rubellite_, that is to say, red tourmaline. (6.) _Diamond._ In spite of the confusion already noted, _à propos_ of _adamas_ (Note to p. 47), between loadstone and diamond, there seems to be one distinct record of an attractive effect having been observed with a rubbed diamond. This was recorded by Fracastorio, _De sympathia et antipathia rerum_ (Giunta edition, Venice, MDLXXIIII, chap. v., p. 60 _verso_), "cujus rei & illud esse signum potest, cum confricata quædã vt Succinum, & Adamas fortius furculos trahunt." And (on p. 62 _recto_); "nam si per similitudine (vt supra diximus) fit hæc attractio, cur magnes non potius magnetem trahit, [~q] ferrum, & ferrum non potius ad ferrum movetur, quàm ad magnetem? quæ nam affinitas est pilorum, & furculorum cum Electro, & Adamante? præsertim [~q] si cum Electro affines sunt, quomodo & cum Adamante affinitatem habebunt, qui dissimilis Electro est?" An incontestable case of the observation of the electrification of the diamond occurs in Gartias ab Horto. The first edition of his _Historia dei Semplici Aromati_ was publisht at Goa in India in 1563. In chapter xlviii. on the Diamond, occur these words (p. 200 of the Venetian edition of 1616): "Questo si bene ho sperimentato io più volte, che due Diamanti perfetti fregati insieme, si vniscono di modo insieme, che non di leggiero li potrai separare. Et ho parimente veduto il Diamante dopo di esser ben riscaldato, tirare à se le festuche, non men, che si faccia l'elettro." See also Aldrovandi, _Musæum Metallicum_ (Bonon., 1648, p. 947). Levinus Lemnius also mentions the Diamond along with amber. See his _Occulta naturæ miracula_ (English edition, London, 1658, p. 199). [119] PAGE 48, LINE 16. Page 48, line 18. _Iris gemma._--The name _iris_ was given, there can be little doubt, to clear six sided prisms of rock-crystal (quartz), which, when held in the sun's beams, cast a crude spectrum of the colours of the rainbow. The following is the account of it given in Pliny, book xxxvii., chap. vii. (p. 623 of the English version of 1601):