Of the incendiary materials the least valuable is the flame thrower. In the Chemical Warfare Service it has been the habit for a long while not to mention the flame thrower at all, unless questions were asked about it. It is mentioned here to forestall the questions. Even the German, who invented it and who, during the two years of trench warfare, had full opportunity for developing its use, finally came to using it largely as a means of executing people that he did not want to shoot himself. Men falling in that class were equipped with flame throwers and sent over the top. The German knew, as did the Allies, that each man with a flame thrower became a target for every rifle and machine gun nearby. The flame thrower is very quickly exhausted and then the one equipped with it has no means of offensive action, and in addition, is saddled with a heavy load, hampering all movements, whether to escape or to advance. INFLAMMABLE MATERIALS There will probably be some use for materials such as metallic sodium, spontaneously inflammable oils, etc., that will burst into flame and burn when exposed to the air, though white phosphorus is probably equal, and in most cases vastly superior to anything else so far suggested. Phosphorus burns with an unquenchable flame when exposed to the air, whether wet or dry. It is of great value for screening purposes, and for use against the enemy’s troops. The German did not use phosphorus simply because he did not have it, just as he did not use helium in his observation balloons because he did not have it. The value of phosphorus was just beginning to be realized slightly when the Americans entered the war, while its full value was not appreciated even by the American troops when the war closed. The work of the First Gas Regiment with phosphorus against machine gun nests proved how valuable it is against the enemy’s troops. It proved also its tremendous value as a screen. The Chemical Warfare Service was prepared to fill a great number of artillery shell with phosphorus, but due to the failure of our shell program to mature before the Armistice, phosphorus was not used by American artillery to any appreciable extent. SMOKE USED BY EVERYONE