This book is a scientific biography of Louis Harold ( Hal ) Gray, FRS (1905 65), a pioneer in radiobiology a little known science that is nevertheless extremely important since it constitutes the basis of radiotherapy. Hal Gray s work also played a vital role in ensuring that radiography would be a safe procedure for the hundreds of millions of persons in whom X-ray pictures have been taken. The book offers fascinating insights into both the history of radiobiology and the life of Hal. It contains much unique biographical material made available to the author over the past 35 years by Hal...