28 ADVEXTURES IN HADIOSIOTOPE RESEARCH 



Bohr's institute.) I suggested that we should, bury the medal, but 

 Bohr did not like this idea as the medal might be unearthed. I decided 

 to dissolve it. While the invading forces marched in the streets of Copen- 

 hagen, I was busy dissolving Laue's and also James Frank's medals. 

 After the war, the gold was recovered and the Nobel Foundation gene- 

 rously presented Laue and Franck with new Nobel medals. 



The Nobel Prize 



In December, 1935, on their journey home from Stockholm, where 

 they were presented by King Gustaf V with the Nobel prize, for their 

 fundamental discovery of artificial radioactivity, Frederic Joliot-Curie 

 and his wife stayed for a while in Copenhagen. It was then that Joliot 

 mentioned that he, his wife, and the third French Nobel laureate, Jean 

 Perrin, proposed me for the Nobel prize and also that they failed to 

 obtain the adherence of the Paris Academy to their proposal — the 

 celtium- hafnium controversy was not yet forgotten. During the war 

 Niels Bohr with his extreme kindness remarked to one of his friends that 

 one of the numerous disturbances created by the war was that I could 

 not receive the Nobel prize. The shocking refusal of the acceptance of 

 the prize by Domagk, Butenandt, and Kuhn at the order of their ruler 

 made the Swedish Academy of Sciences reluctant to distribute further 

 prizes during the war. In 1944 the Academy decided, however, to award 

 me the prize for 1943. With the war going on, no festivities were held, 

 and the prize, contrary to the usual custom, was handed over to me in 

 a meeting of the Academy of Sciences by the president. 



Radioactive Tracers in Radiobiology 



In 1940 we got interested, with L. v. Hahn, in the formation rate of 

 desoxyribonucleic acid, DNA. While the incorporation of ^^p^ for ex- 

 ample, into adenosintriphosphate of the growing liver indicates mainly 

 renewal of these molecules and not an additional formation, the incor- 

 poration into desoxyribonucleic acid indicates the latter to at least a 

 very large extent. 



By investigation of the effect of ionizing radiation on the incorporation 

 of 32p into DNA, it should thus be possible to find out if irradiation 

 blocks DNA formation. Together with Professor Hans von Euler, we 

 studied in Stockholm the incorporation of ^^P into the DNA of the 

 Jensen sarcoma of rats and found in the investigated 100 rats 

 exposed to Roentgen rays a marked depression of ^^P incorporation, and 

 thus a marked depression in the rate of formation of DNA. Similar 

 results were obtained when investigating ^^p incorporation into the DNA 

 in the various organs of growing rats. Indirect radiation effects 'were 



