He used non-persistent gases up to the very moment when his own men reached the British lines, thereby reducing the efficiency of British rifle and artillery fire and saving his own men. And this is just a guide to the future. A recent writer in the _Field Artillery Journal_ states that gas will probably not be used in the barrage because of its probable interference with the movement of our own troops. In making that statement he forgot the enemy and you cannot do that if you expect to win a war. =Gas in Barrages.= In the future we must expect the enemy to be in a measure as well prepared in chemical warfare as we are. Let us consider the special case of our own men advancing to the attack behind a rolling barrage. We will consider also that the wind is blowing toward our own troops. Obviously under those conditions the wind will blow our own gas back onto our troops. Will we use gas in that barrage? We certainly will! Because with the wind blowing toward our own troops we have the exact ideal condition that the enemy wants for his use of gas. He will then be deluging our advancing troops with all the gas he can fire, in addition to high explosives and shrapnel. Our men must wear masks and take every precaution against enemy gas. How foolish it would be not to fire gas at the enemy under those conditions. If we did not fire gas we would leave him entirely free from wearing masks, and entirely free from taking every other precaution against gas while our own troops were subject to all the difficulties of gas. No, we will fire gas at him in just as great quantities as we consider efficient. And that is just a sample of what is coming on every field of battle—gas used on both sides by every method of putting it over that can be devised. =World War Lessons Only Guide Posts. Example of Book Worms.= Every lesson taught by the World War must be taken as a guide-post on the road to future success in war. No use of gas or other materials in the past war must be taken as an exact pattern for use in any battle of the future. Too much study, too much attention to the past, may cause that very thing to happen. A certain general commanding a brigade in the Argonne told me just recently that while the battle was going on a general staff officer called him on the telephone and asked him what the situation was. He gave it to him. The staff officer then asked, “What are you doing?” and he told him. The staff officer replied, “Why, the book doesn’t say to do it that way under such conditions.” There you have the absurd side of too much study and too close reliance on details of the past.