"On April 22," the veteran answered.[20] "It was the Duke of Würtemberg's army which had the foul dishonor of being the first to employ the evil thing. About five o'clock in the evening, from the base of the German trenches and over a considerable stretch of the line, there appeared vague jets of whitish mist. Like the vapors from a witch's caldron they gathered and swirled until they settled into a definite low-hanging cloud-bank, greenish-brown below and yellow above, where it reflected the rays of the sinking sun. This ominous bank of vapor, impelled by a northeastern breeze, drifted slowly across the space which separated the two lines, just at the point where the British and French commands joined hands. The southernly drift of the wind drove it down the line. "The French troops, staring over the top of their parapet at this curious cloud, which, for the time being, ensured them a temporary relief from the continuous bombardment, 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, overrunning the lines of trenches behind them. Some never halted until they had reached Ypres, while others rushed westwards and put the canal between themselves and the enemy. "The Germans, meanwhile, advanced, and took possession of the successive lines of trenches, tenanted only by dead garrisons, whose blackened faces, contorted figures and lips fringed with blood and foam from their bursting lungs, showed the agonies in which they had died. Some thousands of stupefied prisoners, eight batteries of 75's and four British batteries were the trophies won by this disgraceful victory. [Illustration: _Courtesy of "The Graphic."_ THE ZOUAVE BUGLER'S LAST CALL. "... he tore off his protecting mask, sent his anguished appeal to his comrades in the rear, and then lurched forward to die an agonizing death."] "It was especially terrifying to the Africans. They were ready for any form of fighting, but brigades such as the Moroccans, born and brought up under a vivid primitive fear of sorcery, were--for the first time in their history--driven into panic. They were willing to charge against men, no matter what the odds, but not against magic, and our officers had great difficulty in rallying them, even two or three days afterwards. When, however, the Algerian and Moroccan troops became convinced that it was the work of men and not of afrits or djinns, they had but one desire--revenge.