on the occurrence of loadstone and of iron, 9,25.
on the dissolution of the earth, 91, 217, 218.
alleged relation of regions with the planets, 137.
on the elevation of the pole at different latitudes, 213, 214.
on the _Primum Mobile_, and the diurnal movement of the stars, 216,
228, 234.
on the anomalies of the earth's motion, 237.
Puteanus, Gulielmus (Du Puys), 3, 63.
pyrimachus (_i.e._, pyrites), 23.
Pythagoras, 57, 208.
_pyxidula_, 4, 181.
_pyxis_, 3, 115, 147, 165, 172.

Radius, the, of the earth's orbit, 218.
Rasis. _See_ Rhazes.
rays of magnetick virtue, 95.
Reinoldus, Erasmus (or Rheinholdus), 213.
_remora_, the (or sucking fish), 7, 63, 110.
resin becomes electrical by friction, 48, 52.
respective points, 5, 153, 161, 162.
reversal of polarity, 101, 137.
revolution of the globe, 46, 81, 91, 220.
repulsion, electrical, denied to exist, 113.
Rhazes (Muhammad ibn Zakar[=i]y[=a]), 34, 35.
rings, on the verticity of, 129.
Rodriguez de Lagos, 177.
Rosetius Calaber, Hannibal, 3.
Ruellius, Joannes, 7.
Rueus, Franciscus (de la Rue), 6.

Saffron of Mars, 34, 91, 93.
sagda, or sagdo, the, 111.
Sanuto, Livio, 5, 153, 167.
sapphire, the, 48.
scales of iron, 22.
Scaliger, Julius Caesar.
on cause of magnetick direction, 5, 64, 153.
on a fall of meteorick iron, 26.
on preservation of loadstones, 37.
on amber, 47.
on magnetick attraction, 70.
admits the loadstone to have a soul, 68.
on diamond attracting iron, 112.
scoria or slag of iron, 34, 35.
sealing wax is electrical, 48, 53.
Sebastian Cabot. _See_ Cabot.
Serapio, or Serapio Mauritania (Yuhanna ibn Sarapion), 2, 6.
Severtius, Jacobus, 5.
shielding, magnetick, by iron plate, 83, 85.
{246}
_siderites_ ([Greek: siderites]) 8, 11, 143.
_siegelstein_ 11.
silk suspension for magnetick iron, 29, 30.
Silvaticus, Matthaeus, 3.
silver, loadstone for, 109, 110.
similars, doctrine of attraction of, 50, 62.
Simon Stevinus, *v _bis_, 167, 168.
slate, magnetick properties of, 43.
smeargel (emery), 22.
Solinus, Caius Julius, 1, 9, 111.
Solomon the King, 4.
Sotacus, 9.
Stadius, 213.
stars are at various distances, 215.
steel, 23, 39, 69, 71, 93, 95, 147.
Stevinus, Simon, *v _bis_, 167, 168.
_stomoma_ ([Greek: stomoma]) 23, 33, 36.
Strabo, 25.
_succinum_. _See_ amber.
Sudini, or Sudavienses, 47.