Sentence:  ... it may be some kinde of Prophecy, of the continuance, and <WSD>lasting</WSD> of these "Letters," that having been scattered, more then Sibyls leaves, I cannot say into parts, but corners of the "World," they have recollected and united themselves ... 
Meaning of the word marked with <WSD> tags:  The action or state of persisting; the time during which something or someone persists.