There was nothing to be seen in the air, yet suddenly, and without any apparent cause, we were overpowered by a smell exactly like nasturtium, but infinitely stronger and more pungent. The similarity noticed is remarkable, for doesn’t nasturtium come from Latin words which really mean a nose-twister? Anyway, there we were in our trenches, unexpectedly overpowered by a horrible acrid smell and an invisible gas. A lot of the boys--fine, splendid, honest fellows, who did not understand the meaning of any kind of warfare that is not honourable and aboveboard, were utterly unable to fathom the mystery, and they seemed to think that it was the kind of pest that had to be taken with the other discomforts of campaigning in the Low Country. “What the deuce is it?” they asked. It was not until the whole unspeakable visitation was over that most of the men realised what had happened, and that the Germans had tried to blind us as a preliminary to annihilation. Like so many more of the German hopes, this did not develop on the lines that had been planned. This was the first poison-gas attack that we experienced, and I am thankful to say that on the whole it was a failure; but when you remember that we were utterly unready for such a filthy form of fighting, and that we had no means of combating it or nullifying its effects, you will realise the extreme disadvantage of the contest from the point of view of the Canadians. I have said that it was about four o’clock in the afternoon when we had our first experience of the poison-gas. Now that I am talking of the thing it strikes me as a strange coincidence that it was at about four o’clock in the morning when we had our second visitation. We had got into our stride and settled down to hard hammering and what you might call routine campaigning. Then came the morning of Saturday, April 24th, when the sun rose ten minutes before five o’clock, which means that at about four o’clock day was breaking. Most of us were asleep; but in war time there is no such thing as universal rest for men, and our sentries were posted and keeping watchful eyes upon the German lines. It is said that the darkest hour comes just before the dawn, and I think there is no doubt that man’s lowest vitality is reached at that particular period. At any rate, the Germans probably thought so, for they planned a specially fatal attack upon us in the grey hours of this April morning. While looking round in the cheerless dawn one or two of our sentries saw a yellowish kind of cloud coming towards us, over the hogback, and travelling pretty fast. The sight was unusual enough to be noticed, but no one who saw it had the slightest idea what it really was, until we were enveloped in the filthy folds; then we knew that it was poison-gas.