’m not a chemist, I only pretend to be one when I’m on TV or write as if I am. Today I’m going to write about “skin,” a four-letter word used to describe all sorts of multi-letter reaction residues that may develop on a coin’s surface over a long period of time or much quicker with a little dubious help. Now, I’ll encourage readers who know much more than I care to know about chemistry to write in and educate
