Jaroslav Heyrovský
(1890-1967)
It does not happen very often for a scientist to find his life-long field of study, let alone receive the Nobel Prize for it, during a final exam. Jaroslav Heyrovský certainly was the exception to this rule by discovering polarography.
His youth
Jaroslav Heyrovsky was born in Prague on December 20th, 1890 as a fifth child to Klara Heyrovska and Leopold Heyrovsky, a law professor at the Charles University. Even in his youth, Jaroslav Heyrovsky was interested in sciences: together with his brother they have been collecting fossils, have built a simple astronomical telescope and, using an X-ray lamp, made X-rays of their hands and sent them to their friends as New Year's cards. During the high school, his favorite subjects were chemistry, physics and math.
His studies
In 1910, he started studying physical chemistry at the University College in London, England. After gaining the Bachelor of Sciences degree in 1913, he was working as a demonstrator to Frederick G. Donnan, researching the electrochemical properties of aluminium. The first world war has caught Heyrovsky in Prague, from where he was commanded to a medical unit. During the war, he didn't get an opportunity to progress with his experiments in electrochemics, however, he had plenty of time to reflect upon the results of his work in England. Shortly after the World War I, he has finished his thesis, named The Electroaffinity of Aluminium. Now there was nothing except the final examination standing between him and his PhD degree. This examination - especially in a case of such an outstanding student - was not some kind of test, but rather a scientific dialogue. One of the examiners was prof. Bohumil Kucera, who was at the time studying the electrocapilarity of mercury. He has devised a method by which he has measured the surface tension of mercury: a dropping electrode (drops of mercury flowing from a capillary tube). However, this method gave different results than those obtained by Lippmann and Gouy using a differend method. At that point, the other examiner said: "It would take a physical chemicist to solve this puzzle."
His invention
From the next day, Heyrovsky joined the dropping electrode project; at first weighing the drops, then measuring the time between them, yet those methods didn't throw any light on the discrepancy in results. In February 1922 he came to the idea of measuring the electrical current flowing through the electrode. He has observed that characteristic waves form on the current/voltage graph, corresponding to presence of various metallic ions in the mercury, even at minute quantities. He has realised that this is an important breakthrough. During the time that followed, Faraday's motto: Work, finish, publish! became his. He was so focused on the work that he even made errors in dates (for example writing down February 3rd instead of March 3rd); he dedicated all of his time to his new discovery. His brother said:
When he had to spend some time at some social event, even against his own will, he would always hurry back to his lab, saying "I've lost a lot of time, I must move on!"
The polarograph
At the beginning of the next school year, a group of young scientists has formed, studying the discovery. In 1924, Heyrovsky and one of his pupils, M.Shikata have constructed a device that would automatically increase the voltage and measure the changes in current. By that time, automatical measuring was quite new, except maybe measuring temperature and/or pressure over time.
The machine was powered by a clockwork which turned a large wheel and a smaller one. To the large wheel a wire was attached so that the voltage in the circuit was rising at a constant rate. The wire has led through a galvanometer and the dripping electrode. A lamp shone on the galvanometer (G), from which the light it was reflected at an angle according to the level of current. It fell on photographic paper, which was wound on the smaller wheel, thus creating a graph. They called the device polarograph and the "electrolysis with mercury drop method" was dubbed polarography.
---an attempt to draw the polarograph scheme in ASCII---
+------------+ +-- light reflected light
| | v | photographic paper on the small wheel
| +-----(G) <==<==LAMP | |
| | \ | | ______
| | \ <-----------+ | | | <- big wheel
| (E) ___\______________ <-+ | | ____
| | | | | | | |
| | ==| |======| |====| |========= <- wheel axis
| | |________________| | | | |__||
| | | | | =| |=
| | battery -v | |____| |_| <- clockwork
| +------------------(B)------+ ^
| |
+--------------------------------------+ <- electrical circuit
The polarographic method has quickly spread to other countries and fields of study, for it was soon discovered that the method may be used to analyze not only metal content but content of other, even
organic molecules in the sample.
The rewards
For the invention of polarography, prof. Heyrovsky was awarded an Honorary Doctor's degree at the universities of Dresden, Warsaw and Paris. A few years before his death he became a Foreign Member of the British Royal Society. However, the highest honour of all was the Nobel Prize for Chemistry in 1959.
Biographical data
1890 born in Prague
1910 begins to study at University College in London
1918 becomes a Doctor of Philosophy at Charles University
1920 becomes a docent; Doctor of Science at London University
1922 discovers electrolysis by mercury drop method (=polarography)
1924 constructs a polarograph (together with M.Shikata)
1926 becomes a professor
1950 becomes the director of the newly founded Polarographic Institute
1959 receives Nobel Prize in Chemistry
1963 retires
1967 dies (June 27)
Sources cited
- J. Heyrovský. Polarographie. Wien 1941
- J. R. Kavanová.Jaroslav Heyrovský. Prague: Orbis, 1972
- Jirí Koryta.Jaroslav Heyrovský. Prague: Horizont, 1976
- Vaclav Podany, Hana Barvikova.Jaroslav Heyrovský Archives ASCR. Czech Republic Academy of Sciences. July 6th, 2003
http://www.cas.cz/aa/pages/heyrovsk.htm
For more Nobel Prize laureates, check out Everything Quests: The Nobel Prize winners.