The British chemist and physicist Francis William Aston (1877-1945) invented the mass spectrograph and discovered the isotopic complexity of the elements.

Francis Aston was born on Sept. 1, 1877, at Harborne, Birmingham, where his father was a metal merchant and ran a small farm. He studied chemistry at Mason College (which later became the University of Birmingham). In his spare time he trained himself in the various arts of apparatus construction, especially glassblowing. When his scholarship expired, he took a post with a brewery firm. After 3 years he returned to the University of Birmingham. In 1910 an invitation arrived from J. J. Thomson to join him at the Cavendish Laboratory, Cambridge.

Separation of the Isotopes

Thomson was examining positive "rays" produced in electric-discharge tubes at low pressure. These were in fact atoms stripped of some or all of their outer electrons and thus carried an overall positive charge. Thomson had obtained...