“The first cylinders of German chlorine gas were released on Allied soldiers during the Second Battle of Ypres, in northwestern Belgium, on April 22, 1915. The soldiers were Algerian and Moroccan, colonial forces fighting for France. The Germans — this is how sophisticated chemical weapons were in the first year of World War I — used the wind as their delivery mechanism; they simply opened several thousand containers of the poison and let the breeze convey it toward the enemy. When combined with water, chlorine gas turns to acid. If you inhale it, first you smell pineapple, then your lungs burn away from the inside. If it gets in your eyes — well, you can imagine. It’s heavier than air, so at Ypres a dense yellow fog of it settled in the French trenches. The soldiers crawled out onto the field to escape the gas. The field was being strafed with German machine gun fire.” Grantland