Indeed, the dragon to this day hates mankind and has such a nature and such diabolical arts in itself that sometimes when it emits its fiery breath, the spirits of the air disturb the air.[375] This illustrates a common feature of Hildegard’s natural history and pharmacy; namely, the association of natural substances with evil spirits either in friendly or hostile relationships. In the preface to the first book of the _Subtleties_ she states that some herbs cannot be endured by demons, while there are others of which the devil is fond and to which he joins himself. In mandragora, for example, “the influence of the devil is more present than in other herbs; consequently man is stimulated by it according to his desires, whether they be good or bad.”[376] On the other hand, the holm-oak is hostile to the spirits of the air; one who sleeps under its shade is free from diabolical illusions, and fumigating a house with it drives out the evil spirits.[377] Certain fish, too, have the property of expelling demons, whether one eats them or burns their livers or bones.[378] Finally, stones and metals have their relations to evil spirits. It is advisable for a woman in childbirth to hold the gem jasper in her hand, “in order that malignant spirits of the air may be the less able to harm her and her child; for the tongue of the ancient serpent extends itself towards the perspiration of the child, as it emerges from the mother’s womb.”[379] Not only does the touch of red-hot steel weaken the force of poison in food or drink, but that metal also signifies the divinity of God, and the devil flees from and avoids it.[380] [Sidenote: Stars and fallen angels: sin and nature.] It is perhaps not very surprising that we should find in Hildegard’s works notions concerning nature which we met back in the Enoch literature, since some of her writings take the same form of recorded visions as Enoch’s, while one of them, the _Liber vitae meritorum_, is equally apocalyptic. At any rate, in the _Scivias_ in the second vision, where Lucifer is cast out of glory because of his pride, the fallen angels are seen as a great multitude of stars, as in the _Book of Enoch_, and we are told that the four elements were in harmony before Lucifer’s fall.[381] The disturbing effect of sin, even human, upon nature is again stated in the _Causae et curae_, where it is said that normally the elements serve man quietly and perform his works. But when men engage in wars and give way to hate and envy, the elements are apt to rage until men repent and seek after God again.[382] In the _Liber vitae meritorum_, too, the elements complain that they are overturned and upset by human depravity and iniquity.[383] [Sidenote: Nature in Adam’s time: the antediluvian period.]