Sentence:  ... If you draw, Sir, there's one prospect up the river, by the mills—upon my conscience—but you don't draw?'/ No answer./ 'A little, Sir, maybe? Just for a <WSD>maggot</WSD>, I'll wager—like "my" good lady, Mrs. Toole.' 
Meaning of the word marked with <WSD> tags:  A whimsy or fancy.