3
Certainly not, said the young man. My own opinion is that there must be something else that causes this, for the oil is thin, pure, and transparent, and the rust, when it encounters this, is most visible, but in the other liquids it becomes invisible.
3
Well done, my young friend, said Theon, and excellently said. But consider, if you will, the reason given by Aristotle. Not to be found in Aristotle’s extant works.
3
Very well, said he, I will.
3
Now Aristotle says that when the rust absorbs any of the other liquids, it is imperceptibly disunited and dispersed, since these are unevenly and thinly constituted; but by the density of the oil it is prevented from escaping and remains permanently as it is collected. If, then, we are able of ourselves to invent some such hypothesis, we shall not be altogether at a loss for some magic spell and some words of comfort to apply to this puzzling question.
4
Since, therefore, we urged him on and gave him his opportunity, Theon said that the air in Delphi is dense and compact, possessing a certain vigour because of the repulsion and resistance that it encounters from the lofty hills; and it is also tenuous and keen, as the facts about the digestion of food bear witness. So the air, by reason of its tenuity, works its way into the bronze and cuts it, disengaging from it a great quantity of rust like dust, but this it retains and holds fast, inasmuch as its density does not allow a passage for this. The rust gathers and, because of its great abundance, it effloresces and acquires a brilliance and lustre on its surface.
