Plutarch, De Iside et Osiride
Goodwin, Ed.

These then are the things that may be uttered without doors and in public, they containing nothing but matters of common cognizance. But now the most learned and reserved of the priests do not term the Nile only Osiris, and the sea Typhon; but in general, the whole principle [p. 94] and faculty of rendering moist they call Osiris, as believing it to be the cause of generation and the very substance of the seminal moisture. And on the other hand, whatever is a-dust, fiery, or any way drying and repugnant to wet, they call Typhon. And therefore, because they believe he was of a red and sallow color when he was born, they do not greatly care to meet with men of such looks nor willingly converse with them. On the other side again they report that Osiris, when he was born, was of a black complexion, because that all water renders earth, clothes, and clouds black, when mixed with them; and the moisture also that is in young persons makes their hair black; but grayness, like a sort of paleness, comes up through over much draught upon such as are now past their vigor and begin to decline in years. In like manner, the spring time is gay, fecund, and very agreeable; but the autumn, through defect of moisture, is both destructive to plants and sickly to men. Moreover the ox called Mnevis, which is kept at Heliopolis (and is sacred to Osiris, and judged by some to be the sire of Apis), is of a coal-black color, and is honored in the second place after Apis. To which we may add, that they call Egypt (which is one of the blackest soils in the world) as they do the black part of the eye, Chemia. They also liken it to the heart, by reason of its great warmth and moisture, and because it is mostly enclosed by and removed towards the left (that is, the southern) part of the earth, as the heart is with respect to a man's body.