Mustard or Yellow Cross gas--Not deadly but a dangerous pest--Its troublesome persistence--Cleaning it out by fires--Sneezing of Blue Cross gas--Another pest--Its violent effect--The limit of gas shell effectiveness--The need for constant vigilance and disciplinary training 169 CHAPTER X Liquid fire--First used by Germans in July 1915--A great surprise and success--German hopes from it--Construction of a flame projector--Flammenwerfer companies--Their perilous duties and incidents of desertion from them--Improved types of projectors--Co-operation of machine-gun fire--Failure of liquid fire--Its short duration and short range--Ease of escape from it 185 GAS AND FLAME GAS AND FLAME CHAPTER I The first rumours of German gas attacks--Sceptically received--First attack in 1915--Canadian pluck under gas--Nernst and Haber the inventors of German gas--The difficulties of getting practicable gases--The technic of gas attacks--A German prisoner’s account. In the early part of April, 1915, we were in the trenches opposite Messines. We enjoyed the usual morning and evening “hate”; we sniped and were sniped at; we patrolled and wired and attempted to drain away the superfluous water, and there was much mud and humour and expectancy. It is true there were no Mills grenades or Stokes mortars or tin hats, but trench warfare was not so very different then from what it is now--with one great exception: There was no gas. And there were consequently no respirators to carry day and night. It is almost impossible now to remember the time when one did not carry a respirator in the trenches. Somehow it makes you feel quite naked to think of it--and yet there we were, imagining we knew what war really was like! The newspapers we got at that time were generally a good many days old, and censored at that, and our chief source of news about the war in other people’s parts of the line was a summary of so-called information issued from headquarters, which percolated down to the battalion and, like every other summary before and since, went by the name of “Comic Cuts.” Somewhere about the middle of the month we heard that in somebody else’s summary had appeared a paragraph to the effect that a deserter from the German lines up in the salient had told a cock-and-bull story of how they intended to poison us all with a cloud of gas, and that tanks full of the poison gas were already installed in their trenches.