The Initiation and Development of Cellular Damage by Ionizing Radiations The Thirty—Second Silvanus Thompson Memorial Lecture

As members of the B.I.R., we have particular reason to be grateful that at the birth of our parent Society—The Röntgen Society—there was at hand a man of the stature of Silvanus Thompson to serve as the first President. Scientist, teacher, artist, man of letters, and translator of Gilbert's great work De Magnete, he was ideally fitted to impress on the small group who had been brought together out of the common interest in röntgen rays the true character of a learned society. On this occasion we meet to pay our respects to his memory. Thompson was an exceptionally versatile man. There was in his nature almost as strong a sense of the artistic as there was of scientific curiosity—a rare combination which made for lively lecturing and delightful reading. This combination of gifts is above all essential in a biographer, and lacking them I shall not attempt to add to what others have told us so well of Thompson's life and work (Russ, 1944). My subject tonight is “The initiation and development of cellular damage by ionizing radiations”. The disturbance suffered directly by a cell which is exposed to a moderate dose of ionizing radiation is, by any reckoning, almost infinitesimal. In terms of energy, one röntgen represents about 100 ergs/g of tissue, so that a dose of a few hundred röntgens, which will kill many cells, is comparable with the normal energy requirement of a cell to carry on vital processes for one second or less.