One night companies H and I of the 108th Infantry were almost completely wiped out by gas. They were in low lying trenches by the side of the canal under a constant fire of gas shells, while the damp weather kept the dangerous fumes near the ground. They had no orders to evacuate to a safer post and no human being can live forever in a gas mask, so one after another the men yielded to temptation, took off their masks for momentary relief, and inhaled the gas-laden air. All evening and night they kept coming in by twos and threes to our aid post, the stronger ones walking, the rest on stretchers. Their clothing reeked of the sickeningly sweet odor. The room was soon full of it, so that we had to blow out the candles and open the door for a few minutes to avoid being gassed ourselves. There were three ambulances running that night to the Main Dressing Station, and I made it my task to meet each car, notify the doctor and bring the gassed and wounded men out to the ambulance. Most of them were blinded for the time being by the effect of the gas. No light was possible, as that would have drawn fire at once. Every ten minutes through the night our village was shelled, and in walking the forty or fifty yards through the park to the gate, I had to make two detours with my blinded men to avoid fresh shell-holes made that very afternoon. I admit feeling an occasional touch of panic as I led the big helpless fellows around those fresh shell holes and helped them into the ambulances. The final touch came when a youngster of perhaps seventeen entered the aid post alone, walking painfully. "What outfit are you from, sonny?" was my natural greeting. "I am the last man left in Company H," was the proud reply. This was the sort of fatal blunder which seemed to occur once in every command before the lesson was learned that gas-filled trenches need no defending, and that troops, safely withdrawn a hundred yards or more, can be moved forward again quickly enough the moment the gas lifts. The English had had the same lesson more than once until they learned it thoroughly; so had the Germans; now our armies, with their examples before us, had to learn it again through the suffering of our own soldiers. Our division was not the only one in which the same or a similar blunder cost the men so dearly, for I have read the same incident of more than one unit on other parts of the American line, and have had them verified by officers who were present at those other catastrophes. In the art of war the instruction of the generals costs the lives of the soldiers.