crystal, rock, 48, 52, 59, 111 Curtius, Nicolaus, 35. Cusan (Michael Khrypffs), Cardinal de Cusa, 3, 64, 108. Cynosure, the, or Pole-star, 14, 81, 117, 222, 235. Dean, Forest of, loadstone found in the, 11. decay of the magnetick virtue, 18, 37, 124, 138, 149. declination, the, or dip, 184. denarius of Antony, 110. diamond, an electrick, 48, 50, 59, 111. alleged power to attract iron, 109, 112. alleged antipathy to magnet, 2, 7, 109, 143. experiments upon, 143. Diego Alfonso, 178. Differences between electricks and magneticks, 47, 60, 65. Dioscorides, 1, 2, 9, 32. dip, the, also called declination, 8, 46, 184-204. dipping-needle, or declination instrument, 185, 203. direction, or directive force, 41, 46, 115, 119. dividing a loadstone, 16, 72, 100, 121, 122, 127, 130, 136, 145, 146. Dominicus Maria Ferrariensis, 212, 213. Doria, Andrea (Admiral), 4. Drake, Sir Francis, *iij _bis_, 117. Du Puys (also called Puteanus), 3, 63. Earth, the, a great magnet, 38, 39, 40, 41, 44, 119, 211. _echeneis_ (the sucking fish), 7, 63, 110. Ecphantus, 214. effluvia, electrical, 52, 53, 59, 66. magnetical, 61. electrical attraction, 50, 51, 111. electrick force, definition of, 52. electricks, *vj, 46-60. _electrum_ ([Greek: êlektron]), 47. emerald is non-electrick, 51. emery, 22, 51. Empedocles, 208. Encelius (or Entzelt, Christoph.), 3, 111. Epicurius, 61, 62. Erasmus Rheinholdus, 213. Erastus, Thomas, 3, 22. errors in navigation, 166, 177. Evax, King of Arabia, 111. Euripides, 9, 11, 18. {243} Fallopius, Gabriellus, 3, 34, 35, 112. Fantis, Antonius de, 107. Fernelius, Joannes Franciscus, 4. Ficinus, Marsilius (or Marsiglio Ficino), 3, 7, 116 153. filings of iron, 37, 69, 90, 91, 92, 104. Filippo Costa. _See_ Costa. fire destroys magnetick properties, 66, 67, 91, 124. flame destroys electrification, 59. flame hinders not magnetick attractions, 66. Flavius Blondus. _See_ Blondus. flies in amber, 47. form _versus_ matter, 52, 65. Fra Paolo, 6. Fracastorio, Hieronymo, 5, 50, 67, 71, 91, 110, 113, 152. Franciscus Maurolycus. _See_ Maurolycus. Franciscus Rueus. _See_ Rueus. Gagates. _See_ jet. Galen, 2, 9, 32, 35, 39, 46, 49, 61, 62, 63. Gallus, Marbodæus, 2, 7. garlick, its reputed antagonism to magnetism, 2, 32, 64. Gartias ab Horto, 32. Gaudentius Merula, 7. Gauricus, Lucas, 7. Geber (J[=a]bir ibn Háiyán, _Al-Tarsus[=i]_) 21. Gemma, Cornelius, 63. gems, electrick properties of, 48, 51. _geniter_, 47. Georgius Agricola. _See_ Agricola. Gilbert, Adrian, 11. Gilgil Mauritanus, 19. Gioia, or Goia, of Amalfi, 4. Giulio Cæsare, 141. glass, an electrick by friction, 48, 54, 59. use of loadstone in making, 111. goat's blood, 7. Gonzalus Oviedus, 4. Goropius, Henricus Becanus, 4. Grotius, Hugo, 167, 168.