2x15 - Tennessee Tuxedo and His Tales

When Tennessee and Chumley are ordered by Stanley Livingston to get back the rare coin with which they accidentally paid the paper boy, they trace the coin's path to a bakery and then to a cookie from that bakery that Chumley ate. How shall they recover the coin? Tennessee and Chumley turn to Phineas J. Whoopee, who tells them about x-rays.