Modus Operandi: Tax Everything of Any Value, but Especially the Real Revolutionary Ones

I've heard this is an urban legend, but Gary Becker recently recounted the event during a lecture at Brown University:

Michael Faraday, the man given credit for the first electric motor, once sought an audience with the British Prime Minister, William Gladstone. So Faraday took the crude model of his electric motor and showed it to the statesman. However, Gladstone did not seem very impressed. "This is all very nice, but really, what good is it?" the prime Minister asked puzzled. The scientist Farraday answered, in a response particularly pleasing to an economist: "Someday, you will want to tax it!"

A long list of insidious taxes currently imposed on a docile (please look it up) and woefully complacent public would normally follow, but I am sorry, I must manage my blood pressure.