5. It seems that the period is of immense antiquity, from which a nation, the most learned of all others[40], as Theophrastus says, and who inhabit the most sacred region made by the Nile, began first, from the vestal hearth, to sacrifice to the celestial Gods, not myrrh, or cassia, nor the first-fruits of things mingled with the crocus of frankincense; for these were assumed many generations afterwards, in consequence of error gradually increasing, when men, wanting the necessaries of life, offered, with great labour and many tears, some drops of these, as first-fruits, to the Gods. Hence, they did not at first sacrifice these, but grass, which, as a certain soft wool of prolific nature, they plucked with their hands. For the earth produced trees prior to animals; and long before trees grass, which germinates annually. Hence, gathering the blades and roots, and all the germs of this herb, they committed them to the flames, as a sacrifice to the visible celestial Gods, to whom they paid immortal honour through fire. For to these, also, we preserve in temples an immortal fire, because it is especially most similar to these divinities. But from the exhalation or smoke [εκ δε της θυμιασεως] of things produced in the earth, they called the offerings θυμιατηρια, _thumiateria_; _to sacrifice_, they called θυειν, _thuein_, and _the sacrifices_, θυσιαι, _thusiai_; all which, as if unfolding the error which was afterwards introduced, we do not rightly interpret; since we call the worship of the Gods through the immolation of animals θυσια, _thusia_. But so careful were the ancients not to transgress this custom, that against those who, neglecting the pristine, introduced novel modes of sacrificing, they employed _execrations_[41], and therefore they now denominate the substances which are used for fumigations αρωματα, _aromata_, i.e. _aromatics_, [or things of an execrable nature.] The antiquity, however, of the before-mentioned fumigations may be perceived by him who considers that many now also sacrifice certain portions of odoriferous wood. Hence, when after grass, the earth produced trees, and men at first fed on the fruits of the oak, they offered to the Gods but few of the fruits on account of their rarity, but in sacrifices they burnt many of its leaves. After this, however, when human life proceeded to a milder nutriment, and sacrifices from nuts were introduced, they said _enough of the oak_.