World War I: Germany uses poison gas against Russians

History books record that the first instance of Germany using poison gas was at the Western front at the second battle of Ypres. This is true — but there were earlier attacks using nonlethal gas. French forces fired grenades filled with xylyl bromide – tear gas – at German lines, hoping to incapacitate them long enough to take over their positions. Germany’s initial field-of-battle experiments began six months later, in the battle of Bolimov, near Warsaw, against the Russians.

On this day, January 31, in 1915, Germany fired the first liquid-gas-filled shells at the Russians. As before, it was only with xylyl bromide. But what worked in the European summer failed in the Russian winter: not only did the liquid carry back to the German lines, but much of it failed to vaporize — unsurprising, given the below-freezing temperatures on the field of battle.

While poison gas killed relatively few soldiers in WW I, its use caused a psychological fear large enough to warrant a convention of the major world powers in the years after the war, to agree on a ban of the use of all chemical weapons in warfare. That convention was largely followed throughout WW II and beyond.