and its effects are felt 12 kilometres behind the front.
It is deadly stuff."

The accuracy of this reference to the long range effect of our gas
clouds is borne out in a number of other statements. For example,
we learnt from a prisoner examined by the French: "The men were thrown
into disorder and raised their masks because they were suffocated.
Many fell in running to the rear; a number did not become ill until
the next day. Vegetation was burnt up to a depth of 8 kilometres."
Again, prisoners taken at Maurepas stated that one of the English
gas attacks was effective 10 kilometres back.

There are also marked references to the surprise nature of our
gas attacks, which are an unconscious tribute to the successful
tactical developments which have already been referred to, and also
numerous other references to the "delayed" action of phosgene.
The prisoner mentioned above, taken at Maurepas, gave testimony
that some were only taken ill after several days, and one died
suddenly two days after, whilst writing a letter. One prisoner,
pointing to Les Ayettes on the map, stated that about the beginning
of September when gas came over suddenly in the late evening,
they thought it was from artillery fire because it was so sudden.
No one was expecting gas and very few were carrying their masks.
Another one stated: "The attack was a surprise and the cloud
came over and passed fairly quickly. The whole thing did not
occupy more than ten minutes." More than thirty per cent.
of the battalion was put out of action.

Finally, to show what a serious imposition this constant
cloud gas attack was upon the German Army, we will quote from