Mel,
re gas in eastern-Med, see
http://wih.sagepub.com/cgi/content/abstract/12/3/278and in particular pages 316/317
quote: "In mid-March 1917, a month before the EEF’s gunners subjected the Gaza defenders to poison gas, the Germans conducted a chemical bombardment on British trenches at the Salonica front.... ... ... In the course of three nights the Germans fired about 15 000 asphyxiating shells on a small sector of British trenches, inflicting about 113 casualties, of whom only one died. Apparently, the advanced gas masks that replaced an older model only a month earlier had done their job. German and Bulgarian chemical harassment fire, with deadly poison and tear gas, directed mainly against artillery batteries, continued to the end of the war, causing their temporary neutralization.... ... ... on 14 September 1918, with the decisive Anglo-French offensive (several days prior to the final EEF offensive in Palestine). On that night British artillery fired no fewer than 37 000 chemical shells, most of them of a deadly asphyxiating kind. This was an impressive amount, even by Western Front standards, and it achieved significant results by silencing Bulgarian artillery and neutralizing enemy troops in their trenches (the hundreds of prisoners taken suffering from chemical symptoms testified to the bombardment’s efficiency). The offensive, much assisted by the poison gases, ended successfully with a truce after two weeks, followed by Bulgaria’s retirement from the war"
regards
Michael