Rock Doc

A good friend of mine checks each morning on the web for the final “Jeopardy” question. It’s the last question on the taped “Jeopardy” program to be broadcast later that day. I don’t go to movies or follow sports, so I’m often at a loss when it comes to many quiz show questions. But recently I was in a position to answer the “Jeopardy” question because of my early training in geology.

The category of the question I got right was “to ‘dum’ it up.” That means, in Jeopardy-speak, that the answer will have the syllable “dum” in it. The clue mentioned that there is a substance a chemist would call...