Joseph Rucker Lamar,
Studley v. Boylston National Bank of Boston…
“ The banker's lien on deposits, the right of retention and set-off of mutual debts, are frequently spoken of as though they were synonymous, while in strictness, a set-off is a counterclaim which the defendant may interpose by way of cross-action against the plaintiff. But, broadly speaking, it represents the right which one party has against another to use his claim in full or partial satisfaction of what he owes to the other. That right is constantly exercised by business men in making book entries whereby one mutual debt is applied against another. ”
