William Henry Bragg. (Source: Australian Dictionary of Biography)

In 1915 a unique father-son team, William Henry Bragg (1862–1942) and his son, William Lawrence Bragg (1890–1971), won the Nobel Prize in physics for their seminal roles in X-ray crystallography, which was necessary to study the structure of complex organic molecules and allow further progress in pharmaceuticals research.

William Henry's mother died when he was just seven years old, and he was sent to live with a bachelor uncle, whose place he regarded as home during his years away at school and at Cambridge University. At the university he studied mathematics, but his first academic appointment, to the University of Adelaide in Australia—in mathematics and physics—required that he learn much of physics on his own.

Not until 1903–1904, at the age of 41, did William Henry embark on studies of ionizing radiation—a rather late-in-life start on a topic that was to bring a Nobel Prize. On the basis of his early publications on radiation, he was named Cavendish professor at the University of Leeds in 1908. His eldest son, William Lawrence, who had begun his university studies in mathematics in Australia, transferred to Cambridge, where he changed his focus to physics.

In 1912, Max von Laue reported the diffraction of X-rays by a crystal. The elder Bragg and his son, who was by then a doctoral student with J. J. Thomson at Cambridge, began exploring this phenomenon immediately. They brought different interests and skills to the collaboration. William Henry's original interest was in what diffraction showed about the nature of X-rays, and he was a skilled experimenter and designer of instruments. William Lawrence was more concerned with what X-rays revealed about the crystalline state, and he possessed a powerful ability to conceptualize physical problems and express them mathematically.

In 1915, the same year William Henry received the Nobel Prize, he was appointed to University College, London. But the work on X-ray crystallography came to a halt during World War I, and both Braggs served as scientific advisers to the military.

In 1923 William Henry became head of the Royal Institution, a position in which he served 20 years and to which his son succeeded in 1954. In their various positions the Braggs continued their work in X-ray crystallography and built up programs for doctoral and postdoctoral students. Under their leadership the field moved on to such fields of study as the structure of metals and organic compounds and later to those of biochemical and pharmaceutical importance.

Further Reading

• American Chemical Society
• Chemical Heritage Foundation
• Society of Chemical Industry
• The Chemists' Club