As a chemical engineering student in the mid-1950s, Bill Helfand enrolled in an art appreciation course to expand his educational horizons. He was so taken with it that he would skip engineering courses to attend the art class instead, and he soon began collecting. At the time, he couldn’t afford paintings, so he began collecting prints.

Helfand went on to become an executive with Merck and a significant collector of medical and pharmaceutical prints from around the world. His amazing collection now contains 7,500 prints from artists like Leonetto Cappiello and Jules Chéret, the “father of the modern poster.”

Posters from the collection are on display through July 31, 2011 at the Philadelphia Museum of Art. Check out some of these beautiful, strange, and often dubious advertisements for medical products and treatments.

The captions are taken from the exhibition catalogue, Health for Sale: Posters from the William H. Helfand Collection, published by the Philadelphia Museum of Art (available here). Thanks to the museum and Mr. Helfand for sharing the images with us.

For more, read part of an interview with Helfand about his collection here.