When we think of World War One we picture weary soldiers ‘coughing ... a dying man and almost taste the ‘green sea’ of lethal mustard gas. These vivid impressions sprang from the pen of ...

Europe fell silent today to honour the centenary of the Battle of Passchendaele, one of the bloodiest battles of World War One and the first in which mustard gas was used effectively as a weapon.

But the most infamous - and deadliest - was mustard gas, in reality an oily vapour first used by the Germans in July 1917, again near Ypres. Known as the “King of Battle Gases”, it acted by ...