Sentence:  'I your Enemy, Sir!' ſays he, with much Amazement, and ſome Sternneſs in his Look. 'Nay, be not angry,' ſaid "Benjamin", 'for I promiſe you I am not. You are perfectly innocent of having intended me any Wrong; for you was then an Infant; but I ſhall, I believe, <WSD>unriddle</WSD> all this the Moment I mention my Name. Did you never hear, Sir, of one "Partridge", who had the honour of being reputed your Father, and the Misfortune of being ruined by that Honour?' 
Meaning of the word marked with <WSD> tags:  To solve (a perplexing problem).