(b) Defensive Information on the study of defensive measures is slight. It is known however that protective clothing, respirators, immunisation and the use of ethylene oxide as bactericide were all under active consideration before 1940. (c) B.W. Centres (i) Le Bouchet (ii) Trial grounds at Aubervilliers and possibly in Algeria. Poland 5. Research on B.W. was carried out in Poland prior to 1939, and successful use of B.W. sabotage during the German occupation has been claimed. Details are meagre, but there is some confirmation of the claims in the German allegations against the Poles.