Boltwood, Bertram Borden

Boltwood, Bertram Borden, 1870–1927, American chemist and physicist, b. Amherst, Mass., grad. Sheffield Scientific School, Yale, 1892. After graduate study at Leipzig and Yale (Ph.D., 1897), he taught at Yale until his death, serving from 1910 to 1927 as professor of radiochemistry. An expert in laboratory technique and apparatus, he gave much of his energy to planning and supervising the building of the Sloane Physics Laboratory and the Sterling Chemistry Laboratory, both at Yale. He did important research on radioactive elements (he discovered ionium, an isotope of thorium, but believed it to be a new element) and pioneered in the radioactive dating of geological strata.