Sylva Sylvarum, 6th edition published in 1651, p. 176 where Bacon talks of God's promise, rainbows:
"It hath been observed by the Ancients, that when a Raine Bow seemeth to hang over or to touch, there breaketh forth a sweet smell. The cause is, for that this happenth but in certain matters which have in themselves some sweetnesse, which the Gentle Dew of the Raine Bow doth draw forth. And the like doe soft showers; for they also make the ground sweet. But none are so delicate as the Dew of the Raine Bow, where it falleth. It may be also that the water itself hath some sweetnesse: for the Raine Bow consisteth of a glomeration of small drops which cannot possibly fall but from the Aire that is very low. And therefore may hold giving sweetnesse of the herbs and flowers, as a distilled water."