After we thinned out we joined clouds
darkening cleared land and then
we were the shadows of those clouds
crossing open heaths.

Our green breath had to continue
till we were lingering
molecules causing mild headaches
among Flemish cattle.

When parts of our advancing front
united with water,
we converted damp wagon tracks
to pickling vats.

We had no wish other than to float
past tatters of swans
a half-mile above our objective
in the scored earth.

The one who housed us in metal
had a chemist wife
who shot herself with his pistol
upon our dispersal.

If only a huge ventilator, poised
to buoy us skyward,
could have been deployed
by top-flight sappers.

But wrists had to go awry as wind
stroked us northwest
through sandbagged parapets
into scorched lungs.

Note: 

“Song of the Canister’s Contents” contains a reference to Clara Haber (1870-1915) who shot herself not long after learning of her husband Fritz’s success at putting chlorine gas into cylinders and supervising its dispersal at the Second Battle of Ypres.