On the Magnet/II-37
 until it is liquid, and from this a small mass of iron is cast. But if the loadstone draws the dust to itself quickly and readily, we conjecture that the iron ore is rich; if slowly, poor; if it seems altogether to reject it, there is very little iron in it or none at all. In like manner iron dust can be separated from another metal. Many tricks there are also, when iron is secretly applied to lighter bodies, and, being attracted by the motion of a loadstone which is kept out of sight, causes movements which are amazing to those who do not know the cause. Very many such indeed every ingenious mechanician will perform by sleight of hand, as if by incantations and jugglery.
The page and line references given in these notes are in all cases first to the Latin edition of 1600, and secondly to the English edition of 1900.
187 ^ Page 109, line 11. Page 109, line 13. halinitro.—Either native carbonate of soda or native carbonate of potash might be meant, but not saltpetre. Scaliger, in his De Subtilitate ad Cardanum (Lutet., 1557, p. 164), Exercitatio CIII., 15, under the title, Nitrum non est Salpetræ, says: "More tuo te, tuaque confundis. Salpetræ inter salis fossilis ponis hîc. Mox Halinitrum inter salis, & nitri naturam, speciem obtinere."
"Sal nitrum is salt which is boiled out of the earth, especially fat earth, as in stables, or any place of excrements." (A Chymicall Dictionary explaining Hard Places and Words met withall in the Writings of Paracelsus ..., Lond., 1650.)
188 ^ Page 109, line 20. Page 109, line 23. arte ioculatoriâ.—Edition 1628, joculatoriâ; edition 1633, jaculatoriâ.