They were foreign--old French and English coins.

Here's one of them that I kept." He took from his pocket a gold coin and handed it to Gabriel.
Lane rose to his feet with an exclamation: "Why, this is like the louis-d'or that grandfather saved through the war and gave to father." Uncle Sylvester took the coin back, placed it in his left eye, like a monocle, and winked gravely at the company.
"It is the SAME!" he went on quietly.

"I was interested, for I had a good memory, and I remembered that, as a boy, grandfather had shown me one of those coins and told me he was keeping them for old Jules du Page, who didn't believe in banks and bank-notes.

Well, I traced them to a trader called Flint, who was shipping gold dust from Stockton to Peter Gunn & Sons, in New York." "To whom ?" asked Gabriel quickly.
"Old Gunn--the father of your friend!" said Uncle Sylvester blandly.

"We talked the matter over on our way to the station this morning.