Chlorine was discovered by Sir Humphry Davy in 1810 and was named from the Greek green-yellow. Like many of the elements, the properties of chlorine have been used for both healthful and harmful purposes as represented by the yin yang beads on this piece. Chlorine was used as a chemical weapon in World War I causing severe respiratory damage or death when chlorine gas combined with the moisture in the lungs creating hydrochloric acid. Its use in pesticides like DDT (dichloro-diphenyl-trichloroethene) caused serious environmental damage, including significant decline of eagles and other raptors due to the thinning of the birds’ egg shells. The poisonous properties of DDT take more than 15 years to break down. I chose to portray an eagle about to nest as I have enjoyed watching eagles on White Earth Lake and throughout the area since they have made the gradual and powerful come back once DDT was banned in the US in 1972. On the positive side, chlorine has provided safe drinking water for over a century and is widely used in manufacturing PVC, polyvinyl chloride pipes for water and waste.