On the basis of magnetic measurements and comparison with artifacts that were known (using other techniques) to be up to 2500 years old, the group showed that the mass of lead corrosion products is directly proportional to an object's age (New Journal of Physics, 2003, 5, 99) ↑ M. Jacoby, "Chemistry in the Holy Land", Chemical & Engineering News, 5 March 2007, page 20, published by American Chemical Society ↑ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997).