
“The steady drip of water causes stone to hollow and yield.”
Stilicidi casus lapidem cavat.
Book I, line 313 (tr. Stallings)
Variant translation: Continual dropping wears away a stone.
Compare: "The soft droppes of rain pierce the hard marble; many strokes overthrow the tallest oaks", John Lyly, Euphues, 1579 (Arber's reprint), p. 81
De Rerum Natura (On the Nature of Things)