And Themistocles replied, that Chrysippus only proposed such things by the by, as instances to correct us, who easily assent and without any reason to what seems likely, and disbelieve everything that seems unlikely at the first sight.

But why, sir, are you concerned at this?
For if you are speculative and would inquire into the causes of things you need not want subjects in your own profession; but pray tell me why Homer makes Nausicaa wash in the river rather than the sea, though it was near, and in all likelihood hotter, clearer, and fitter to wash with than that?
And Theon replied: Aristotle hath already given an account for this from the grossness of the sea water; for in this an abundance of rough earthy particles is mixed, and those make it salt; and upon this account swimmers or any other weights sink not so much in sea water as in fresh for the latter, being thin and weak, yields to every pressure and is easily divided, because it is pure and unmixed and by reason of this subtility of parts it penetrates better than salt water, and so looseneth from the clothes the sticking particles of the spot.

And is not this discourse of Aristotle very probable?
Probable indeed, I replied, but not true; for I have observed that with ashes, gravel, or, if these are not to be gotten, with dust itself they usually thicken the water, as if the earthy particles being rough would scour better than fair water, whose thinness makes it weak and ineffectual.

And therefore he is mistaken when he says the thickness of the sea water hinders the effect, since the sharpness of the mixed particles very much conduces to make it cleansing; for that open the pores, and draws out the stain.

But since all oily matter is most difficult to be washed out and spots a cloth, and the sea is oily, that is the reason why it doth not scour as well as fresh and that it is oily, even Aristotle himself asserts, for salt in his opinion hath some oil in it, and therefore makes candles, when sprinkled on them, burn the better and clearer than before.