E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Lupine.
He does not know a libel from a lupine. In Latin: “Ignorat quid distent æra lupinis,” “He does not know good money from a counter, or a hawk from a handsaw.” The Romans called counters lupines or beans. A libel was a small silver coin the tenth part of a denarius = the as.
