British war crimes September 1915 and continued their usage for the remainder of the war. This was done in retaliation for the use of chlorine by Imperial German Army the preceding April. Following the Imperial German Army's use of poison gas at Ypres, the commander of II Corps, Lieutenant General Sir Charles Ferguson, had said of poison gas: Mustard gas was first used effectively in World War I by the German army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name "Yperite" comes from its usage by the German army near the
Action of 25 September 1917 removing more guns from the Third Army and Fourth Army, which were further south in Artois and Picardy. The increased amount of heavy artillery was to be used to destroy German concrete shelters and machine-gun nests, which were more numerous in the German battle zones, than the outpost zones which had been captured in July and August and to engage in more counter-battery fire. Few German concrete pill-boxes and machine gun nests had been destroyed during earlier preparatory bombardments and attempts at precision bombardment before attacks had also failed. The and guns and howitzers in the Second Army on 31