Flickr links: Mustard Gas | Phosgene
Yes, Minnesotastan has posted about the Otis Historical Archives of the National Museum of Health and Medicine's photo collection on Flickr before on Neatorama, but I found these posters telling the public how to distinguish various poison gases through their distinct smells to be utterly fascinating!
I mean, whodathunk that mustard gas would smell like garlic? (Shouldn't they just call it garlic gas?). Or that phosgene can result in "increased dopey feeling"? Link