De metallorum ortu & causis

-ro completing the word "Porrò", meaning furthermore all Natural Philosophers Physici, and those who are called rationalists, have so far divided metal as a genus into its species. But the Chemists Chemistæ alchemists have divided it differently. For some, in order to establish their Chemistry, divide metals into perfect and imperfect. They say there are only two perfect ones, namely gold and silver. The remaining four are imperfect, namely iron, copper, tin, and lead. From the definition of metal handed down by Geber Geber is the Latinized name of Jabir ibn Hayyan, an influential figure in the history of chemistry., it will become known to everyone how absurd this division of metals is. For thus in the third part of his book On the Sum of Perfection de summa perfectione he defines metal:
Chapter 31.

Metal (he says) is a mineral body, meltable, and extensible under the hammer in every dimension. This definition of metal applies no less to copper, iron, tin, and lead, than to gold and silver. Therefore copper, iron, tin, and