a ready means for producing such chemicals in bulk at practically
a moment's notice; further, that the safety of this country makes it
imperative that the study and investigation of the subject should be
continued and that our chemical and dye industry should be developed,
so that when an emergency arises we may have the necessary facilities
for supply ready to hand.

It is not for me to express any opinion here either as to the desirability
of using gas as a weapon or as to the possibility of preventing an enemy from
using it. But I am convinced that a decision come to without full knowledge
of the facts may involve grave danger and heavy preventable loss of life.
I am further convinced that Major Lefebure, by his special knowledge
and long experience as chemical liaison officer during the war, is well
qualified to speak, and that his opinion is entitled to full consideration.
For these reasons I think that his book will do a much needed public service.
I wish it every success, and the greatest possible number of readers.
HENRY WILSON, F.M.



CHAPTER 1

EXPLANATORY


The Riddle of the Rhine.--The Great War challenged our very existence.
But with the tension released, and the Allies victorious,
the check to the German menace appears crushing and complete.
Few realise that one formidable challenge has not been answered.
Silently menacing, the chemical threat remains unrecognised.