There are great things to come in the future, jet cars and all that. But the past held a few wonders too—for example, jars of mercury available at the corner apothecary. Just 50 years ago, people treated the shiny
liquid metal like a toy. Sadly, I’ll never experience the strange sensation of sticking my entire arm into a barrel of mercury, as kids once did during factory tours. Today mercury is considered a horrific poison, so bad that schools are evacuated for
a broken thermometer.