A Devotion to Their Science Pioneer Women of Radioactivity MARELENE F. RAYNER-CANHAM AND GEOFFREY W. RAYNER-CANHAM SENIOR AUTHORS AND EDITORS Chemical Heritage Foundation Philadelphia McGill-Queen's University Press Montreal & Kingston • London • Buffalo Contents Preface ix Acknowledgments xi Foreword xii MARIANNE AINLEY PART ONE THE OVERVIEW 1 i Early Years of Radioactivity 3 2 Pioneer Women of Radioactivity 12 PART TWO THE FRENCH GROUP 29 3 Marie Curie: Time Only for Science and Family 31 HELENA M. PYCIOR 4 Ellen Gleditsch: Professor and Humanist 51 ANNE-MARIE WEIDLER KUBANER AND GRETE P. GRZEGOREK 5 May Sybil Leslie: From Radioactivity to Industrial Chemistry 76 6 Catherine Chamie: Devoted Researcher of the Institut de Radium 82 vi Contents 7 Stefania Maracineanu: Ignored Romanian Scientist 87 MIRUNA POPESCU, MARELENE F. RAYNER-CANHAM, AND GEOFFREY W. RAYNER-CANHAM 8 Alicia Dorabialska: Polish Chemist 92 STEPHANIE WEINSBERG-TEKEL 9 Irene Joliot-Curie: Following in Her Mother's Footsteps 97 E. TINA CROSSFIELD 10 ... And Some Other Women of the French Group 124 PART THREE THE BRITISH GROUP 127 11 Harriet Brooks: From Research Pioneer to Wife and Mother 129 12 Fanny Cook Gates: A Promise Unfulfilled 138 13 Jadwiga Szmidt: A Passion for Science 145 14 Ada Hitchins: Research Assistant to Frederick Soddy 152 15 ... And Some Other Women of the British Group 156 PART FOUR THE AUSTRO-GERMAN GROUP l6l 16 Lise Meitner: The Foiled Nobelist 163 SALLIE A. WATKINS 17 Stefanie Horovitz: A Crucial Role in the Discovery of Isotopes 192 18 Marietta Blau: Discoverer of the Cosmic Ray "Stars" 196 LEOPOLD E. HALPERN 19 Elizaveta Karamihailova: Bulgarian Pioneer of Radioactivity 205 SNEZHA TSONEVA-MATHEWSON, MARELENE F. RAYNER-CANHAM, AND GEOFFREY W. RAYNER-CANHAM 20 Elizabeth Rona: The Polonium Woman 209 21 Ida Tacke Noddack: Proposer of Nuclear Fission 217 FATHI HABASHI 22 ... And Some Other Women of the Austro-German Group 226 vii Contents Epilogue: The End of an Era and a New Generation 229 Appendix: Dates of Selected Events in the History of Atomic Science (1895-1940) 235 Contributors 237 Notes 239 Index 303 7 Stefania Maracineanu: Ignored Romanian Scientist MI RUNA PO PESCU, M A RELENE F. RA YNER-CAN I-I AM, ,nd GEOFFREY W. R AYNER- C AN H AM As we look baek in time, it is d iffieu lt to appredatc the chal1enge that face<! Ihe young women scicntists who dccided 10 leave Iheit home­ lands to pursue research with one of the stars of rad ioactivity. 5tcfa­ nia Maracineanu travel1ed wesl from Roman ia aU Ihe way to Paris 10 work with Curie. Het work was outside Ihe mainstf\'am of reseilrch in radioaeilivity, bul during the 19JOS het results wcre quite oontroversial. Mosi of Ihe women who devoted Ihcit jives to Ihe stud y of radio­ ilctivity relieei on rorrespondence and visits for mutual support ilnd cnooufilgement. Maracineanu, however, sceffiS to have been isolatcd from Ihe group of women scholaT'S. Stefania (S tl! phanie) Mara­ dneanu was born in Bucharest on 18 June 1882.' She had a bleak childhood aboul which she did noi !ike 10 lalk. After obtaining a degree in Ihe physical and chemical sciences in 1910, she became a leacheT al the Central 5chooJ fo r Gi rls in Bucharest. It was in 1922, with the financial support of the Romanian minister of Science, Ihal she arrived in Paris 10 pursue grad uate resea~h with Marie Curie. Her firsl task was 10 dNermine the precise half-lifc of polonium! Ihe clemenl disoovered by Curie hcrself. Maracineanu found thal the half-life of polonium secmed to depend upon Ihe identily of Ihe metal on which the polonium laycr had been depos­ ilcd. She oonsidered that Ihe alpha rays from the polonium had par­ tiaU )' transformcd some atoms of Ihe metal into radioactive isotopcs. Had Ihis observation becn ve rified, it would have becn the firsl e~ ample of artificial radioactivity, a discovery for which the JoHot- 88 Th.., French Group Curies would later I\.>ceive credit. As part of her study, she devised a mcthod for the measurement of thc intcnsity of strong a-ray emil­ ters.' On Ihe hasis of s uch promising research work, she was awardcd il doctorale degree in 1924.4 Marilcîneanu then applied for a posilion in her homeland to TUn the proposed Romanian Laboratory for the measurement of radioac­ livity. Curie wrote a reference for her. "1 have great cstccm for the work that shc ha s accomplished. In particular, shc has acquired a perfect knowlcdge of precise elcctrometric mea s urement s.~5 It is not dear whether shc was unsuccessful or whether the position did not materialize, for she continued to work in Paris with Curie for one more ycar, and then at the Meudon and Paris Astronomical Obscr­ vatori es with H. Deslandres until 19)o. Maracîneanu bc<ame convinced thal solar radiation had an effect on the radioac\ivity of substanccs, and this became the focus of her research. In part icular, she nolt.>d that the half-life of polonium was differcnt when the polonium was dcposited on lcad, if th e deposilion was pcrfomed in sunlight.6 5he argued Ihat Ihe sun's rays had caus...'<1 the lead, then known 10 be the end of Ihe radioactive decay serics, ilself 10 become radioactive. In 1925 while al Meudron, she reporte<! that lead exposed to sun1ight produced scintil1ations on a zinc sulfide screen similar 10 that of alphaparticlcs.7 Thi s rildiation, she noted, lash..>d as long as a month. It is important to note thal Maracîneanu was not alone in heT convictions thal sunlight could induce materials 10 become radioacIÎ\'e. Three yea rs earlier, A. Nodon had proposcd that the sun and the uppcr atmosphere emitted pcnctrating radiation, enough 10 discharge elcctroscopcs and darken sealcd photographic film (this may have becn the effect of cosmic rays).! The following year, he d aimed Ihal Ihe rate of radioactive decay was affected by the sun.9 Maradneanu then lumed hcr attention 10 the measuremenl of Ihe level of radio."lctivily in ancient lcad roofs. Her studies suggested that south-facing roofs showed higher levels of radioactivity than north­ facing roofs. 'O H. Deslandrcs, who prcsented her result5, supportcd her findings, himself concluding thal the induced radioactivity musl be due to some unknown fonn of radiation frorn the sun that he desig­ natcd ultril x." Gcnnan scientist5 became involvcd in the controversy over the sourre of this radiation from Ihe sun, atmosphere, ar both. {)ne of her fonner colleagues at the Institut de Radium, Franz Behounek. daimed that it was simply natural radioactivity that was being found, '2 while W. Kolhorster argued in support of Maracineanu. 'l Elizilbeth R6na '4 became involved in the debale, finding no evi­ dence that Ihc polonium in Maracineanu's earlier experiment5 could 89 Stefania Maracineanu rapidly have diffused inlo the lead 10 cause Ihe SUpposed radioactiv­ ity of the lead itsclf. '5 However, Maracineanu may have been observ­ ing decay fragments Ihal had become imbedded in the lead as a result of the Temil from partide emission, the phenomenon first observed by Harriet Brooks. ,6 Maradneanu had thought Ihal the solar radialion had oonverled lead back to polonium, but by 1928 she had decided that radium 0, the radioactive isotope of lead, lead-l10, was actuaJly being formcd. '7 In 1929 she found evidenc:e of mercury, gold, and helium in the sun­ exposed lead, suggesting that Ihe lead had becn transmuted into the two other melal s.'" A flurry of papers on this subject appeared in 19JO, mosi, but not ali, attacking Maracincanu's claims. Fabry and Debreuil rcportcd that they had found no evidcnce of nuclear trans­ formations in old lead roofing as Maracineanu had claimcd. '9 Mara­ cineanu responded by suggesting that they had not obtained pmper samples.'" She had some supporters: the German scientist G.I. Pok­ rowsky had rcportcd thal x- rays and gamma rays had cause<! ele­ menls inc1uding lead to become radioactive," while the Frcnch scientist RebouJ maintaincd that even non-radio.1ctive metaJs actu­ aUy emittcd soille form of radiation.ll Thrcc papcrs upheld the contention that the sun-eKposed lcad roofs showcd evidenc:e of radioacti vity. Howevcr;. the three pairs of al,1.tF.QN - Sroi t.s (I.D.d. Mlle M(I.cG iIl3.vry:J Bo\!.taric (Ind RQY,""' 'il. .I,.d Lepape and GesJin'5 - werc circumspect about the cause of the radi­ alion. Moreover, Smits and MacGillavry objecte<! to Maracineanu citing their preliminary and confidential res ul ts. Boutaric and Roy dccided subscquently that the trares of radioactivity originated with exposurc to rainwater rather than sun.- Maradneanu wrote a strong response to these papers, challenging Iheir doubts aboul the soun::e of the radioactivity.>7 Meanwhile, in the German literature Mara­ cineanu and Behounek had a lively exchange on the topic of the quality and interpretation of Maradneanu's lIleasurcment.s ..!I This markcd the end of Maradneanu's ill-fatcd series of publica­ Hons on the possibility of the sun's rays causing radioacti ve tranSrOf­ mations. Neverthelcss, Maracineanu was convinced that she had bcen the first to observe Ih e phenomenon of artificial radioactivity. That is, through the bombaroment of a stable isotope wi th radiation she had generated a different, radioactive subslanc:e. It is possible in her early experiment5, when a layer of radioactive polonium was placed on different metal surfaces, some of the nuclei of the under­ Iying metal atoms oould have becn affectcd by the alpha rays in a nuclear reaction.