16th Oct 1917: Germans drench Anzacs with mustard gas

For four nights between the 14^th & 19^th October the Germans drenched the valleys behind the Australian lines with mustard gas, causing 116 casualties in I Anzac Corps area on the 16^th alone. The 43^rd Battalion in II Anzac Corps had to evacuate 40 men blistered and gassed after work on the railway near Zonnebeke.