A salesman tried to dupe Twain. His response? A turn-of-the-century burn of the century.

via The Library of Congress/Wikimedia Commons Prostitution may be the “world’s oldest profession,” but quackery can’t be too far behind. In the 19th century, American medical doctors began to take a scientific approach to practicing medicine, but it didn’t stop the growing number of con artists pushing fake medical cures, elixirs, tonics, and serums across the countryside. These traveling sales people would set up tents and make fire-and-brimstone speeches touting the unbelievable benefits of their products that were said to cure everything from tuberculosis to baldness. These displays were often accompanied by confidence tricks and fake testimonials. via Carol M. Highsmith/Wikimedia commons By the time the people who bought the medicine realized it was fake, the con artists were off …