Four Tales of George de Hevesy
Tale One: Getting the Lead Out
Ernest Rutherford often boasted, "[I have] never given one of my students a hopeless problem" (Wilson 1983). Had he been in a humorous mood, he might even have made this comment in the presence of George de Hevesy.
January 1911. George de Hevesy had good reason to regret crossing the English Channel - the resulting seasickness laid him up in bed for two weeks before he could continue his journey. His destination: the University of Manchester’s Institute of Physics. His intent: to learn what he needed about electrical conductivity measurements in gases and return home. But the Hungarian-born chemist was entering the domain of Ernest Rutherford, and while there it was Rutherford who would control his fate.
And Rutherford had a problem that Hevesy might help solve. He had recently acquired a considerable quantity of Radium D, a valuable byproduct of radium he hoped to make use of. The problem was that the Radium D was mixed up in a large quantity of lead, and the latter made it exceedingly difficult to investigate the radiations from the Radium D.
So one day, by design or happenstance, Rutherford and his newly arrived chemist found themselves together in the laboratory basement where the radioactive lead was stored. Perhaps with a friendly arm on Hevesy’s shoulders, Rutherford issued a challenge, "My boy, if you are worth your salt, you separate Radium D from all that nuisance lead." (Levi 1985).
And Hevesy might have smiled as he accepted the assignment. For as he later recalled, "Being a young man, I was an optimist and felt sure that I should succeed in my task" (Hevesy 1962). But all the optimism in the world couldn’t change the fact that, unbeknownst to anyone, radium D was a form of lead (Pb-210 to be specific) - chemically inseparable from the stable lead with which it was associated!
Struggling with the impossible task, hampered by recurrent bouts of bad health, and intimidated by the English language, Hevesy labored in vain for over a year. Finally, his intellectual and emotional resources deleted, Hevesy conceded "Entire failure."
But in that moment of despair came inspiration! "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 activity," (Levi 1985) i.e., spike ordinary lead with pure radium D, which could be obtained from radon, and use this "radioactive indicator" to study the properties of the lead! The radiotracer method was born! A technique that would reshape 20th century science! A victory snatched from the jaws of defeat!
Eager to begin, Hevesy left for the Institute for Radium Research in Vienna - the place to go if you wanted Radium D in quantity. While there, he and Fritz Paneth implemented Hevesy’s concept of radioactive indicators and coauthored1 "The Solubility of Lead Sulphide and Lead Chromate" (Hevesy and Paneth 1913), the first published account of the radiotracer technique.
But Hevesy and Paneth’s paper wasn’t an account of the first investigation to utilize radiotracers - Hevesy never published that study. He did talk about it however, and here’s his story:
Tale Two: Hevesy and the Landlady
During his trying experiences at Manchester, Hevesy grew distinctly unhappy with the boardinghouse he stayed at (it couldn’t have helped that the place had been recommended by Rutherford). Perhaps his bouts of indigestion made him more picky than usual (Badash 1969). In any event, he became convinced that his landlady had a nasty habit of recycling food. His suggestion that she serve freshly prepared meat more than once a week was met with indignation - how could he, she insisted, accuse her of serving anything but the freshest of ingredients. But Hevesy wasn’t persuaded. At the next opportunity, the following Sunday, Hevesy secretly spiked the leftovers on his plate with radioactive material. A few days later, the electroscope he smuggled into the dining room revealed the presence of the tracer - radioactive hash! Confronted with the irrefutable evidence, all the landlady could do was exclaim "this is magic!" The first radiotracer investigation had successfully followed leftover meat from the Sunday meal to the kitchen meat grinder, into the hash pot, and back onto the dining room table. (Brecher and Brecher 1969, Myers 1979). To this day, it is doubtful if a successful radiotracer study has provided greater personal satisfaction!
Tale Three: A Cup of Tea
Springtime 1913. Hevesy was "indulging in a cup of tea at the Manchester Physics Laboratory" with the immortal Henry J.G. Moseley. In one of those moments of idle speculation the spring season seems to bring upon us, Hevesy expressed a desire to "determine the fate of the individual water molecules contained in the cup of tea consumed." Moseley was not inclined to engage in such flights of fancy and, as Hevesy commented, "even a man of the vision and outlook of ... H.J.G. Moseley considered this hope to be a highly utopian one." (Hevesy 1962). But Moseley was wrong, Hevesy would indeed learn the fate of those water molecules. Moseley never did - he was shot and killed by a Turkish sniper in the Battle of Suvla Bay in 1915.
The means to discover the mysterious fate of consumed tea came in 1933 when Harold Urey provided Hevesy with several liters of 0.6% deuterium oxide (a.k.a. heavy water). Whether or not Hevesy made tea from it is not recorded, but he and his new drinking buddy, E. Hofer, consumed the stuff in 150, 250, and for the sake of precision, 2000 ml aliquots. After "55 samples of urine and other excreta were investigated and more than 1000 distillation operations carried out" (Hevesy and Hofer 1934), simple gravimetric measurements revealed that half of the body’s water turned over every 9 days - a measurement that represents the first application of isotopic tracers in the clinical sciences. And in the first use of isotopic dilution in the biological sciences, Hevesy and Hofer estimated the body’s water content at 43 liters. Although not given to sentimentality, Hevesy fondly recalled the springtime cup of tea with his late friend Henry Moseley in the opening sentence of the paper in which he and Hofer reported their findings.
Tale Four: Hevesy and the Saint
The aforementioned study paved the way for Hevesy’s later investigations that would prove that biological systems exist in a dynamic equilibrium. Hevesy first and unambiguously postulated this concept in "Radioactive Indicators in the Study of Phosphorous Metabolism in Rats" (Chievitz and Hevesy 1935). Today, it is hard to appreciate the revolutionary nature of the paper - a paper that "figuratively shook the earth of biology" - a paper that "at least one person has memorized...as many another has a great poem"(Huggins 1965).
Harry Truman once said, "the only new thing in the world is the history you don’t know." And as Hevesy would learn to his shock and amazement, he wasn’t the first to realize that biological systems are in a constant state of turnover (Arrhenius 1996). St. Thomas Aquinas had come to this conclusion 700 years earlier! The Italian philosopher had been struggling with a perplexing theological issue: what would happen on the day of resurrection to a man who had been a cannibal? How could the body of someone be reconstituted if its parts had also belonged to several others? St Thomas’s conclusion was eminently logical: "the identity of the body is not dependent on the persistence of the same material particles," "[that] during life, by the process of eating and digesting, the body undergoes perpetual changes."
Hevesy might have been disappointed that he could no longer claim priority to a theory that once "shook the earth," but he would henceforth make a point of giving the saint full credit. (Hevesy 1962).
Footnote
- During this collaboration, Paneth and Hevesy joined Victor Hess in the pioneering balloon ascents in which the unexpected increase in background radiation levels lead to the discovery of cosmic rays.
References
- Arrhenius, G. Personal communication; 1996.
- Badash, L. Rutherford and Boltwood, letters on radioactivity. Yale University Press, New Haven; 1969.
- Brecher, R.; Brecher, E. The rays - A history of radiology in the United States and Canada. Baltimore, MD: Williams and Wilkins Company; 1969.
- Chievitz, O. ; Hevesy, G. Radioactive indicators in the study of phosphorous in the metabolism in rats. Nature 136: 754; 1935.
- Hevesy, G.; Paneth, F. The solubility of lead sulphide and lead chromate. Z. Anorg. Chem. 82: 322; 1913.
- Hevesy, G. and Hofer, E. Elimination of water from the human body. Nature 134: 879; 1934.
- Hevesy, G. Adventures in radioisotope research. Vol I. Pergamon Press, New York; 1962.
- Huggins, C. A valentine for George Hevesy. Int. J. App. Radiation and Isotopes 16(9): 507; 1965.
- Levi, H. George de Hevesy. Adam Hilger Ltd. Bristol; 1985.
- Myers, W.G. Georg de Hevesy: The father of nuclear medicine. J. Nuc. Med. 20 (6): 590-594; 1979. #