Here's an 1866 Shield Nickel bearing a patent medicine stamp. It’s counter-stamped “Oil of Ice”. This counter-stamp is best found on Two Cent Pieces as well as Indian Head Cents, but is considered rare on other coins from the 1860’s. Dave Bowers attributed this counterstamp. The issuer was Charles H. Goodwin from Exeter, New Hampshire. In 1856 he had a shop on Water Street. He was a pharmacist or an apothecary by trade, and he marketed and sold a variety of drugs and notions. It's thought that his “OIL OF ICE” may have been a byproduct of camphor, as there was a "camphor ice" product at that time. Brunk and Rulau documented about 60 known coins, with 1880 being the latest date recorded. The total of coins with this counter-stamp may well approach a hundred or more. This issue has been copied. The copies, produced with individual letter punches, have rounded O's. Note the squarish O's on this genuine piece. Charles H. Goodwin, better known as, the maker and purveyor of Goodwin's Grand Grease Juice (G. G. G.) and Goodwin’s Grand Glittering Gobules (G. G. G. G.) and other patent medicines from Exeter, NH. G. G. G., a tonic for the hair and G. G. G. G. was a breath perfume. It's likely his OIL OF ICE was a camphor in glycerin concoction. The coin itself with the counter-stamp “Oil of Ice”. Rotated to easily read the mark. The reverse of the coin. Notice the rim of the coin at the 2:00 position. It is a minting defect in the coin. I do not have any better photos than these.