Viewing Melville Davisson Post: "The Copper Bonds" (1912).
Reprising his role as guardian of the innocent against robber barons, Randolph Mason outwits a "copper emperor" who had duped the treasurer of a Michigan county into persuading landowners in the county to sell him their mineral rights. Those rights become valuable after vast deposits of copper are discovered. When the treasurer comes to New York to collect county real estate taxes, the tycoon offers to pay them with the bonds of his corporation. Mason advises the skeptical treasurer to accept the offer. The treasurer takes the bonds, signs a receipt that they are payment of the taxes, sells them, and uses the proceeds to pay the landowners who were cheated by the tycoon. In their final meeting, the treasurer, prepped by Mason, recites an "ancient, correct, accurate doctrine of law" while gleefully telling the copper king that he still owes the taxes.