George Charles
de Hevesy (German: Georg Karl von Hevesy) (1 August 1885 – 5 July 1966) was a Hungarian
radiochemist and Nobel laureate, recognized in 1943 for his key role in the
development of radioactive tracers to study chemical processes such as in the metabolism
of animals. He also co-discovered the element hafnium.
Early Years
Hevesy György was born in Budapest, Hungary,
to a wealthy and ennobled Roman Catholic of Hungarian Jewish descent family,
the fifth of eight children to his parents Lajos (Louis) Bischitz and Baroness
Eugenia (Jenny) Schossberger (ennobled as "De Tornya"). Grandparents
from both sides of the family had provided the presidents of the Jewish
community of Pest. George grew up in Budapest and graduated high school in 1903
from Piarista Gimnázium. The family's name in 1904 was Hevesy-Bischitz, and
Hevesy later changed his own.
De Hevesy began his studies in
chemistry at the University of Budapest for one year, and at the Technical
University of Berlin for several months, but changed to the University of Freiburg.
There he came in contact with Ludwig Gattermann. In 1906 he started his Ph.D.
thesis with Georg Franz Julius Meyer, acquiring his doctorate in physics in
1908. In 1908 Hevesy got a position at the ETH (Eidgenössische Technische Hochschule in Zurich, Switzerland).
Research
In 1922 de Hevesy co-discovered hafnium
(72Hf) (Latin Hafnia for "Copenhaghen",
the home town of Niels Bohr),
with Dirk Coster. Mendeleev’s periodic
table in 1869 put the chemical elements into a logical system, however there
was missing a chemical element with 72 protons. On the basis of Bohr's atomic
model Hevesy came to the conclusion that there must be a chemical element that
goes there. The mineralogical museum
of Norway and Greenland in Copenhagen furnished the
material for the research. Characteristic X-ray spectra recordings made of the
sample indicated that a new element was present. This earned him the 1943 Nobel
Prize in Chemistry.
Hevesy was offered and accepted a
job from the University
of Freiburg. Supported
financially by the Rockefeller Foundation, he had a very productive year. He
developed the X-ray fluorescence analytical method, and discovered the Samarium
alpha-ray. It was here he began the use of radioactive isotopes in studying the
metabolic processes of plants and animals, by tracing chemicals in the body by
replacing part of stable isotopes with small quantities of the radioactive
isotopes. In 1923, Hevesy published the first study on the use of the naturally
radioactive 212Pb as radioactive
tracer to follow the absorption and translocation in the roots, stems and
leaves of Vicia faba, also known as the broad bean.
World l War II and Beyond
When Nazi Germany occupied
Denmark from April 1940, during World War II, de Hevesy dissolved the gold Nobel
Prizes of Max von Laue and James Franck with aqua regia; it was illegal at the
time to send gold out of the country, and were it discovered that Laue and
Franck had done so to prevent them from being stolen, they could have faced
prosecution in Germany. He placed the resulting solution on a shelf in his
laboratory at the Niels Bohr Institute. After the war, he returned to find the
solution undisturbed and precipitated the gold out of the acid. The Nobel
Society then recast the Nobel Prizes using the original gold.
In 1943 Copenhagen
was no longer seen as safe for a Jewish scientist and de Hevesy fled to Sweden, where he worked at the Stockholm University
College until 1961. In
Stockholm de Hevesy was received at the department of German by the Swedish
professor and Nobel Prize winner Hans von Euler-Chelpin, who remained strongly
pro-German throughout the war. Despite this, de Hevesy and von Euler-Chelpin
collaborated on many scientific papers during and after the war.
During his time in Stockholm, de Hevesy
received the Nobel Prize in chemistry. He later was inducted as a member of the
Royal Society and received the Copley Medal, of which he was particularly
proud. De Hevesy stated: "The public thinks the Nobel Prize in chemistry
for the highest honor that a scientist can receive, but it is not so. Forty or
fifty received Nobel chemistry prizes, but only ten foreign members of the
Royal Society and two (Bohr and Hevesy) received a medal-Copley." George
de Hevesy was elected a foreign member of the Royal Swedish
Academy of Sciences in
1942, and his status was later changed to Swedish member. He received the Atoms
for Peace Award in 1958 for his peaceful use of radioactive isotopes.
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