Choking agent
About four months later, the German Army used chlorine gas for the first time against French and Algerian soldiers.  These soldiers did not know about this new weapon, and they panicked and tried to run away.  However, running makes chlorine's effects worse.  In a few minutes, the gas killed more than 1,000 French and Algerian soldiers, and injured more than 4,000 others.  One soldier who survived said: