x x x x x x x x x x x x x x x x x x x x x x x x x x x x x silver chromium zinc manganese iron cobalt Known forgery x x x x x x x x x x x x x x x x x x x x x x x x x x x x silver chromium zinc manganese iron cobalt _Match the patterns of these lead white “fingerprints”. Unknown painting A is_ not _a Rembrandt; it_ is _by the same forger who painted the known forgery at the bottom. Unknown painting B is either by Rembrandt, one of his fellow citizens, or one of his students using the same paint._ “It was thought of many times by many people. But, it’s never been used for identifying paintings. In 1964 in the Netherlands, two scientists, named Houtman and Turkstra, analyzed about 40 different samples of lead white, 20 of which came from Dutch and Flemish paintings. The rest were samples of lead white not taken from paintings but obtained directly from the manufacturers. They analyzed these samples for different elements. These included silver, mercury, chromium, manganese, tin, antimony, and a couple of others. “They found that the concentrations of these elements in the lead white from all the old Dutch and Flemish paintings were very similar. And the trace element concentrations were quite different in the modern lead white samples analyzed in the same way. At the time, they presumed that it was because the lead white in the paintings was manufactured so long ago. They may have been right to a certain extent.