Smells like musty hay (WWII PSA Posters)

I'm always drawn to vintage images and design, and I have a special fondness for the tactics used in public service and propaganda posters, and how that imagery and messaging has changed over the years.

A friend just sent me a link to a blog entry about a massive archive of US Army medical illustrations and photos that the National Museum of Health and Medicine is making available on Flickr for public use. The whole collection is amazing but my eye was immediately drawn to these World War II poison gas warning posters:

(Images shown subject to Creative Commons License)