14 ADVENTURES IN RADIOISOTOPE RESEARCH 



school to learn the handling of short-lived substances. I later became 

 engaged with the study of the electrochemical properties of radioele- 

 ments of unknown chemical character and the measurement of their 

 valency from diffusion data. 



The early origin of the famous Geiger- counter goes back to those 

 Manchester days as well. Rutherford and Geiger counted a-particles by 

 making use of a galvanometer which registered the arrival of each 

 a-particle. The ionization produced was magnified by using the principle 

 of production of ions by collision. The much more difficult task of 

 counting /3-particles was solved later, after the first World War, by 

 Geiger, then at Kiel. 



When I was in Manchester, Rutherford was much interested to come 

 into the possession of a strong radium D sample. Large amounts of 

 radium D were stored in the laboratory, but imbedded in huge amounts 

 of lead. The great German chemist Haber intended to pay Germany's 

 war debts after the first World War by extracting gold from the ocean. 

 First he undertook to check the correctness of the available gold analyses 

 of sea water. He found the gold content of the ocean to be very much 

 lower than previously found. He summarized the depressing results 

 of his expedition by stating : "Dilution is the death of all value". Ruther- 

 ford could have made the same remark when glancing at the hundreds 

 of kilograms of lead chloride extracted from pitchblende and presented 

 to him by the owner of the Joachimsthal mines, the Austrian govern- 

 ment. 



Radioactive Tracers 



One day I met Rutherford in the basement of the laboratory where 

 the lead chloride was stored. He addressed me by saying : "If you are 

 worth your salt, you separate radium D from all that nuisance of lead." 

 Being a young man, I was an optimist and felt sure that I should succeed 

 in my task. Trying during a year all sorts of separation methods and 

 making the greatest efforts, it looked sometimes as if I succeeded, but 

 I soon found out that it was radium E, the disintegration product of 

 radium D, a bismuth isotope, which I separated. The result of my efforts 

 was entire failure. To make the best of this depressing situation, I thought 

 to avail myself of the fact that radium D is inseparable from lead, and 

 to label small amounts of lead by addition of radium D of known acti- 

 vity obtained from tubes in which radium emanation decayed. From 

 such tubes pure radium D can be obtained. 



It was the Vienna Institute for Radium Research which owned in 

 those days by far the greatest amount of radium and, correspondingly, 

 of radium emanation. This fact induced me to interrupt my stay in 

 Manchester and to proceed to Vienna. In the Vienna Institute there were 



