The gunners were among our chief sufferers from these gas shell, as their guns were so frequently placed in sunken roads and folds in the ground for protection against explosive shell and aërial observation, and these were just the kind of places that held the gas longest. In the open much less damage was done. I remember one night the first-line transport of a battalion of the Black Watch ran into a patch of country into which the boche was raining 77-millimetre Green Cross Shell, and came out with only three casualties, two of which were from a direct hit on one of the wagons, the driver being killed instantly. It seems particularly bad luck to be killed by a direct hit from a gas shell, for the bits of shell that fly about don’t do much damage in the ordinary way and don’t travel great distances. Indeed it is remarkable, even in the biggest gas-shell bombardments, how very few men are hurt by the fragments. The first week or two after the advent of the Green Cross the toll of gas-shell casualties was considerable if not alarming, but steps were immediately taken to get the situation in hand. It is in a case like this, where a surprise had been brought off, that Discipline, with a very big “D,” counts for so much. Fortunately the gas discipline of the British Army was pretty good, and it was not difficult to get new instructions carried out and orders obeyed. Once they got going their effect was most apparent and the gas-shell casualties dropped from week to week until they approached a minimum. Among the important steps that were taken were a revision of the methods of spreading the alarm, and the protection and clearing out of dugouts into which the gas had penetrated. Mention has already been made of the slight noise caused by the explosion of the gas shell, and instructions were accordingly issued that all shell that sounded like duds were to be regarded as gas shell, and the respirators adjusted accordingly. This got over one of the elements of surprise.