A scientist argues that chemical weapons merit sober evaluation and preparedness rather than moral rejection, tracing their historical antecedents and legal restrictions, summarizing World War I experience, classifying agents by physiological effect and protective measures, and critiquing pacifist and political responses. He emphasizes scientific study of war's causes, discusses Hague Convention limits and methods of deployment, explains differences among respiratory poisons, lachrymators, and arsenical smokes, and considers their military utility and ethical implications while urging national readiness and technical understanding to inform policy.