One feels, on reading this, that here is information of value to the enemy, for much of it is news to the civilian reader. However, doubtless Col. Waitt, authority on chemical warfare in the U.S. Army, has touched only the fringe of what promises to be one of the decisive factors in the present war. He supports the view that -- frightful as it might be, chemical warfare in the end causes fewer fatalities, fewer casualties, and less destruction than the present form of warfare. He does not dramatise the possibilities, but presents a matter of fact statement of historical backgrounds from the days of the Spartans and Athenians, to the present, and an analysis of the basic types of gases, their characteristics, operation, value, dangers, and preventatives. The most interesting part of the book, to me, was that dealing with the new trends resulting from mechanized and aerial warfare, and the trial in Abyssinia, proof that it is practicable. There is detailed discussion of the strategy of chemical warfare, the imperative necessity of preparedness, drill, cooperation between chemical defense squads and other parts of the service, rigid protection of individuals, and of groups, and knowledge of types of gas, behaviour, recognition and treatment. He discusses gas masks, gas proof shelters, protective clothing, military and civilian. Packed with information, but with stress on military aspects primarily.