“When it reached our first trenches, the men in these trenches were obliged to leave, and a number of them were killed by the effects of the gas. We made a counter-attack about fifteen minutes after the gas came over, and saw twenty-four men lying dead from the effects of the gas on a small stretch of road leading from the advanced trenches to the supports. He, himself, was much affected by the gas, and felt as though he could not breathe. “These symptoms and other facts so far ascertained point to the use by the German troops of chlorine or bromide for the purpose of asphyxiation. There also are facts pointing to the use in German shells of other irritant substances. Still, the last of these agents are not of the same brutality and barbarous character as was the gas used in the attack on the Canadians. “The effects are not those of any of the ordinary products of combustion of explosives. On this point the symptoms described left not the slightest doubt in my mind.” KIND OF GAS EMPLOYED Various have been the opinions of chemists as to the kind of gas employed. Sir James Dewar, President of the Royal Institution, was of the opinion that it was liquid chlorine. Dr. F. A. Mason, of the Royal College of Science, considered it to have been bromine. Dr. Crocker, of the South-Western Polytechnic, said it may have been either carbon monoxide or liquid peroxide. Dr. W. J. Pope, Professor of Chemistry, Cambridge, and Sir E. Rutherford, Professor of Physics, Manchester University, agreed in thinking the gas to have been phosgene, a compound of carbon monoxide and chlorine, largely used in dye production in Germany. “For some years,” stated Sir James Dewar, “Germany has been manufacturing chlorine in tremendous quantities. . . . The Germans undoubtedly have hundreds of tons available. If several tons of liquid are allowed to escape into the atmosphere, where it immediately evaporates and forms a yellow gas, and if the wind is blowing in a favorable direction, it is the easiest thing for the Germans to inundate the country with poison for miles ahead of them. “The fact that the gas is three times heavier than air makes escape from its disastrous effects almost impossible, for it drifts like a thick fog-cloud along the surface of the ground, overwhelming all whom it overtakes.” ALLIES FORCED TO USE SIMILAR METHODS Of the German attack on the allied front near Ypres, Secretary of War, Earl Kitchener, speaking in the House of Lords on May 18, said: “In this attack the enemy employed vast quantities of poisonous gases, and our soldiers and our French allies were utterly unprepared for this diabolical method of attack, which undoubtedly had been long and carefully prepared.” It was at this point that Earl Kitchener announced the determination of the Allies to resort to similar methods of warfare.