Bertram Boltwood
Bertram Borden Boltwood was an American pioneer of radiochemistry.
He graduated from Yale University, and taught there 1897-1900. He established that lead was the final decay product of uranium, noted that the lead-uranium ratio was greater in older rocks and, acting on a suggestion by Ernest Rutherford, was the first to measure the age of rocks by the decay of uranium to lead, in 1907. He got results of ages of 400 to 2200 million years, the first successful use of radioactive decay by Pb/U chemical dating. More recently, older mineral deposits have been dated to about 4.4 billion years old, close to the best estimate of the age of earth.
Boltwoodite is named after him. He was a member of the Connecticut Academy of Arts and Sciences.
In his later days, Boltwood suffered from depression and committed suicide on August 15, 1927.
