The Belgians still held the flooded Yser Canal up to the neighbourhood of Bixschoote. There the line was carried on by the French Eighth Army, now commanded by General Putz in the place of General d'Urbal. His troops seem to have been all either Colonial or Territorial, two classes which had frequently shown the utmost gallantry, but were less likely to meet an unexpected danger with steadiness than the regular infantry of the line. These formations held the trenches from Bixschoote on the canal {46} to the Ypres-Poelcapelle road, two thousand yards east of Langemarck, on the right. At this point they joined on to Plumer's Fifth Corps, the Canadian Division, Twenty-eighth and Twenty-seventh British Divisions, forming a line which passed a mile north of Zonnebeke, curling round south outside the Polygon Wood to the point where the Fifth Division of the Second Corps kept their iron grip upon Hill 60. The average distance from Ypres to all these various lines would be about five miles. Smith-Dorrien, as commander of the Second Army, was general warden of the district. ------------------------------------------------------------------- {47} [Illustration: Ypres] ------------------------------------------------------------------- [Sidenote: The coming of the poison gas. April 22.] Up to the third week of April the enemy opposite the French had consisted of the Twenty-sixth Corps, with the Fifteenth Corps on the right, all under the Duke of Würtemberg, whose headquarters were at Thielt. There were signs, however, of secret concentration which had not entirely escaped the observation of the Allied aviators, and on April 20 and 21 the German guns showered shells on Ypres. About 5 P.M. upon Thursday, April 22, a furious artillery bombardment from Bixschoote to Langemarck began along the French lines, including the left of the Canadians, and it was reported that the Forty-fifth French Division was being heavily attacked. At the same time a phenomenon was observed which would seem to be more in place in the pages of a romance than in the record of an historian. From the base of the German trenches over a considerable length there appeared jets of whitish vapour, which gathered and swirled until they settled into a definite low cloud-bank, greenish-brown below and yellow above, where it reflected the rays of the sinking sun. This ominous bank of vapour, impelled by a northern breeze, drifted {49} swiftly across the space which separated the two lines. The French troops, staring over the top of their parapet at this curious screen which ensured them a temporary relief from fire, were observed suddenly to throw up their hands, to clutch at their throats, and to fall to the ground in the agonies of asphyxiation. Many lay where they had fallen, while their comrades, absolutely helpless against this diabolical agency, rushed madly out of the mephitic mist and made for the rear, over-running the lines of trenches behind them.