How Did Lead Get Into Our Gasoline Anyway?

In my article about lead and crime, I didn't spend any time talking about the history of lead as a gasoline additive. Why? Because the piece was already 6,000 words long and I figured that adding to its length with a history lesson would detract from the primary point I wanted to make. Nonetheless, the history of tetraethyl lead (TEL) has lessons to teach us. Its origins as a gasoline additive began in the 1920s, when it was perfected by GM as an anti-knock compound for high-compression engines....