The Traveling Quack, an image from 1889, by Tom Merry
What's a quack?
"While the origins of the term are obscure, the term "quack" probably came from the Dutch Quacksalber, a charlatan, mountebank, empiric or itinerant seller of medicine. It may also have been derived from the sounds made by a duck, the term applied to the hawker of nostrums whose excessive zeal in describing the merits of his or her cure may well have sounds similar to the squawking of a duck..."From William H. Helfand's book Quack Quack Quack.
Relating to Quacks, Quackery and Nostrums, Part 1, from Ephemera Assemblyman>>