Egyptologist Mimi Leveque removes salt deposits from the face of a 2,500 year-old mummy at Massachusetts General Hospital in Boston in 2003 -- a process the museum takes on every 10 years or so. (AP Photo/Josh Reynolds)
June 7, 2013: Mimi Leveque, a freelance conservator, cleans Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. Padihershef, who has made MGH his home since 1823, was a 40-year old stonecutter in the necropolis in Thebes, an ancient city on the west bank of the Nile. (AP Photo/Gretchen Ertl)
June 7, 2013: Mimi Leveque, a freelance conservator, cleans Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. (AP Photo/Gretchen Ertl)
June 7, 2013: Mimi Leveque, a freelance conservator, cleans Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. (AP Photo/Gretchen Ertl)
June 7, 2013: Mimi Leveque, a freelance conservator, cleans Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. (AP Photo/Gretchen Ertl)
June 7, 2013: Peter Johnson, director of the Mass General Hospital's Russell Museum, left, talks with Mimi Leveque, a freelance conservator, about Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. (AP Photo/Gretchen Ertl)
June 7, 2013: Mimi Leveque, a freelance conservator, cleans Padihershef, a 2,500-year-old Egyptian mummy at Mass General Hospital in Boston. (AP Photo/Gretchen Ertl)