Cobalt Therapy, 1951

Canadian scientists have helped to banish the darkness, to feed people better, to view the smallest objects, and to cure once fatal diseases. Scientists have treated cancer with radiation since 1896. Radium provided the necessary radiation until, with Cobalt 60, scientists discovered a source 300 times more powerful and 6000 times less expensive. The forerunners of today's Cobalt 60 therapy units were developed by Dr. Harold Johns in Saskatoon, and by Atomic Energy of Canada Ltd. These stamps, designed by Roger Hill of Toronto, mark the end of the three-year stamp series on Canadian Innovations in Science and Technology. The scientific achievements being honoured have been accurately rendered in a pleasing and precise illustrative style. Like the previous two issues which focussed on the themes of Transportation and Communications, this year's stamp designs features notes, drawings and diagrams on the development of each innovation on their backgrounds.