Sulfur mustard later also against the French Second Army. The name Yperite comes from its usage by the German army near the town of Ypres. The Allies did not use mustard agent until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard shells. It took the British more than a year to develop their own mustard agent weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September 1918 during the breaking of the Hindenburg Line. Mustard agent was dispersed
Gas mask wearer to breathe the safer air found there. In addition, moist sponges were inserted at the end of the hoses in order to better filter the air. This was later modified to include its own air supply, leading to World War I era gas masks.<ref name="pbs.org/wgbh/theymadeamerica2"></ref><ref name="encyclopedia.com/topic/Garrett_Morgan2"></ref><ref name="biography.com/people/garrett-morgan2"></ref> The German army used poison gas for the first time against Allied troops at the Second Battle of Ypres, Belgium on 22 April 1915. As an immediate response was cotton wool wrapped in muslin issued to the troops by 1 May. This was followed by the Black Veil Respirator, invented by John