Was cleaning some of the wheats I found yesterday and noticed one in particular. I could clearly see a 19*4 and a "bump" on the bottom (d?). Was not visible but how to clean in case it was a "d" and 1914? I decided to mix some vinegar and salt to see if it would do the trick. Did not leave it long , maybe 2-3 minutes while I put the rest of the pennies in my small bucket and went to rinse it out with water. Got my loupe and looked again. Dang it now there was no "4" or "bump" . completely melted away. Stupid stupid!!!