=Cloud Gas.= The fact that the gas cloud looked like smoke is responsible for the name “cloud gas.” Really all gases are nearly or wholly invisible, but those which volatilize suddenly from the liquid state so cool the air as to cause clouds of condensed water vapor. The cloud obscured everything behind and in front of it. It led the German to put off fake smoke clouds and attack through them, thus taking the British at a tremendous disadvantage. Then and there began a realization of the value of smoke. Cloud gas was also the real cause of the highly organized raid that became common in every army during the World War. The real purpose in the first raids, carried out by means of the box barrage, was to find out whether or not gas cylinders were being installed in trenches. These raids finally became responsible, in a large measure, for driving the old cloud gas off the field of battle. It did not, however, stop the British from putting off cloud gas attacks in 1918 by installing their gas cylinders on their light railway cars and then letting the gas loose from the cylinders while still on the cars. This enabled them to move their materials to the front and put off gas attacks on a few hours’ notice when the wind was right. =Toxic Smoke Candles.= To-day we have poisonous smokes that exist in solid form and that are perfectly safe to handle until a fuse is lighted. The so-called candles will be light enough so that one man can carry them. With these, cloud gas can be put off on an hour’s notice when wind and weather conditions are right, no matter how fast the army may be moving and whether on the advance or in retreat. Cloud gas will usually be put off at night because the cloud cannot be seen, because then men are tired and sleepy, and all but the most highly trained become panicky. Under those conditions the greatest casualties result. The steadiness of wind currents also aids cloud gas attacks at night. =Value of Training in Peace.= And this brings up the value of training in peace. We are frequently asked, “Why do you need training with masks in peace; why do you need training with actual gas in peace; cannot these things be taught on short notice in war?” The answer is, “No!” Nothing will take the place of training in peace. All of us recall that early in the war the Germans spread broadcast charges that the Allies were using unfair and inhumane methods of fighting because they brought the Ghurka with his terrible knife from Asia and the Moroccan from Africa. And we all know that after a time the Germans ceased saying anything about these troops. What was the cause? They were not efficient. Just as the Negro will follow a white officer over the top in daylight and fight with as much energy and courage and many times as much efficiency as the white man, he cannot stand the terrors of the night, and the same was true of the Ghurka and the Moroccan.