The concentration of the tear gas was so small that when thrown it was barely noticed. Overtime, more lethal gasses were produced. A more lethal method called phosgene, was introduced by Victor Grignard in France of 1915 (“Chemical weapons in World War I”). Phosgene was colorless and had an odor that was hard to detect; leading to a more effective weapon. It was sometimes mixed with chlorine and when it was, the Allies called this combination White Star. More importantly, phosgene was a deadly killing agent because it could take up to twenty-four hours before symptoms were noticeable. Over the timespan of the war, over 36,000 pounds of phosgene were manufactured; making it second to chlorine in quantity manufactured (“Chemical weapons in World War I”). One of the last manufactured gasses of World War I was mustard gas. It was introduced by Germany in July of 1917 right before the Third Battle of Ypres. Mustard gas gave soldiers mustard-colored blisters and blind eyes while it made them fight for air until their throats would eventually close (“Chemical weapons in World War I”). While it was not great at killing soldiers instantly, the after effects were what made it so