Know your chemical weapons

Direct link <a href="http://www.slate.com/blogs/the_vault/2013/05/24/chemical_weapons_wwii_posters_taught_soldiers_to_identify_gasses_by_smell.html?wpisrc=obinsite" rel="nofollow">http://www.slate.com/blogs/the_vault/2013/05/24/chemical_wea...</a>