ALL GAS.

If you get a choking feeling, and a smell of musty hay,
You can bet your bottom Dollar that there's phosgene on the way.
But the smell of bleaching powder will inevitably mean
That the enemy you are meeting is the gas we call chlorine.
When your eyes begin twitching, and for tears you cannot see,
t is'nt mother peeling onions, but a dose of C.A.P.
If the smell resembles pear drops, then you'd better not delay,
It's not father sucking toffee, it's that ruddy K.S.K.
If you catch a pungent odour as you are coming home for tea,
You can safely put your shirt on it, they're using B.B.C.
And lastly, while geraniums look pleasant in a bed,
Beware their smell in war-time; if its lewisite, you're dead.