For chemistry professionals today, it's sometimes difficult to believe that chemicals and chemistry were not always the subject of fear among the general public. In the 19th century, chemicals became the building blocks for effective drugs and for rapid advances in public health. Clean water, anesthesia, and painkillers -things we take for granted today - were and are the result of advances in chemistry. Chemists and chemical engineers made the bright future of the 20th century possible.
The reality of the 20th century turned out to be quite different. If one single event started the downhill slide in the image of chemistry, it was the first use of chemical warfare. On April 22, 1915, Captain Fritz Haber ordered German troops to open the valves on 6,000 pre-positioned cylinders of chlorine. Within minutes, Algerian and French troops in trenches near the Belgian village of Ypres saw a yellowish green cloud rolling toward their trenches. As the heavier-than-air gas filled their revetments, the troops, who could, ran; the rest writhed in agony as the gas burned their throats and eyes and finally drowned them in the fluid of their own lungs.
