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
Actions of 30 September – 4 October 1917 were to be replaced by a policy of fighting for every piece of ground. Armin thought that even if counter-attacks failed to recapture ground, the British would keep more troops in the front line and that German infantry casualties were no worse in counter-attacks than under British barrages. On 30 September, the 4th Army issued an operation order for more field artillery bombardments between British attacks and that at least half of the heavy artillery ammunition was to be used for observed fire on captured pill-boxes, command posts and machine-gun nests, duckboard tracks and field railways. Gas bombardments were to