"Gas! GAS! Quick, boys!—An ecstasy of fumbling Fitting the clumsy helmets just in time, But someone still was yelling out and stumbling And flound’ring like a man in fire or lime.— Dim through the misty panes and thick green light, As under a green sea, I saw him drowning...."
https://www.poetryfoundation.org/poems/46560/dulce-et-decorum-est