Elements and birthdays have been intertwined for me since boyhood, when I learned about atomic numbers. At eleven, I could say “I am sodium” (element 11), and now at seventy-nine, I am gold. A few years ago, when I gave a friend a bottle of mercury for his eightieth birthday—a special bottle that could neither leak nor break—he gave me a peculiar look, but later sent me a charming letter in which he joked, “I take a little every morning for my health.”
