The Philosophy of Natural Magic, by Henry Cornelius Agrippa, L. W. de Laurence ed. , at sacred-texts.com
Now, if thou desirest to receive virtue from any part of the World, or from any Star, thou shalt (those things being used which belong to this Star) come under its peculiar influence, as wood is fit to receive flame by reason of sulphur, pitch and oil. Nevertheless, when thou dost do any one species of things, or individual, rightly apply many things (which are things of the same subject, scattered, amongst themselves, conformable to the same Idea and Star), presently, by this matter so opportunely fitted, a singular gift is infused by the Idea, by means of the Soul of the World. I say "opportunely fitted," viz., under a harmony, like to the harmony which did infuse a certain virtue into the matter. For although things have some virtues, such as we speak of, yet those virtues do so lie hid that there is seldom any effect produced by them. But, as in a grain of mustard-seed, bruised, the sharpness which lay hid is stirred up; and as the heat of the fire doth make letters apparent to the sight which before could not be read, being writ with the juice of an onion, or with milk; and as letters wrote upon a stone with the fat of a goat, and altogether unperceived, when the stone is put into
vinegar appear and shew themselves; and as a blow with a stick stirs up the madness of a dog which before lay asleep—so doth the Celestial Harmony disclose virtues lying in the water; stirs them up, strengtheneth them, and makes them manifest; and as I may so say, produceth that into Act which before was only in Power, when things are rightly exposed to it in a Celestial Season. As for example: If thou dost desire to attract virtue from the Sun, and to seek those things that are Solary, amongst vegetables, plants, metals, stones, and animals, those things are to be used and taken chiefly which in a Solary order are higher. For these are more available. So thou shalt draw a singular gift from the Sun, through the beams thereof, being seasonably received together, and through the Spirit of the World.