33.
chatochitis, 111.
chemists, the, 19, 20, 21, 24, 37, 66.
China, 4, 8, 9, 11, 17, 32, 119.
Chinocrates, 2.
circumpulsion, doctrine of, 3, 61.
clamps (open kilns), 26.
clay when burnt is magnetick, 26, 43, 97.
clepsydra, 231.
Coimbra, College of, 5.
coition (mutual attraction), 45, 46, 60, 65, 67, 68, 81, 98, 99, 103,
109, 131.
definition of, *vj, 68.
orbe of, *vj.
colours of loadstones, 9, 10, 27.
Como, 23.
compass, alleged invention of, by Amalfians, 4.
origin of the compass-card, 4, 165.
the mariners' (_pyxis_), 3, 115, 147, 165, 172.
the little (_pyxidula_), 181, 202.
different forms of, Italian, Baltic, Portuguese, English, 165, 166,
177, 181.
conduction, magnetick, 85, 104, 125.
consequent poles, 129, 142.
Copernican system, 231.
Copernicus, Nicolas, 212, 214, 216, 231, 237, 238, 240.
Cordus, Valerius, 10.
Cornelius Agrippa, 3.
Cornelius Gemma, 63.
Cornelius Tacitus, 25.
_corolla insorta_, or contorted circlet, 238, 240.
Cortes, Martin, 5, 116, 152.
Corvo, Island of, 167.
Costa, Filippo (of Mantua), 141.
Costaeus, Joannes, 3, 62, 227, 228.
_creagus_, the, or flesh-magnet, 110.
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, defi