https://www.warhistoryonline.com/guest-bloggers/dan-snow-second-battle-of-ypres-the-dawn-of-chemical-warfare.html
Dan Snow: Second Battle of Ypres - The Dawn of Chemical Warfare | War History Online
May 24, 2019 - 100 years ago this week my great grandfather was serving in the Ypres Salient. On 22 April at 5pm he noticed, 'a whitish blue mist to the north-east of us
second battle of ypres