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LORD RUTHERFORD 391

Honored by Fifth Annual Nuclear Pioneer Lecture 11th Annual Meeting, Society of Nuclear Medicine

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LORD RUTHERFORDOF NELSON,1871-1937 392 LORD RUTHERFORD

Lord Rutherford of Nelson (1871-1937)

There are a thousand threads in nuclear medicine: energy, form and sub stance; devices for measuring, calibrating and for just plain every day detecting; queer elements and sometimes even new elements. All these threads interweave through the science of the past two centuries. In our science, at one point they all come together. Around the turn of the century, the triumvirate of Becquerel, Crookes and Rutherford approached each other's work as though they disagreed—and some times they did, but never for long. Each was surrounded by a group of excep tional chemists and physicists unraveling a tangled web of impossible evidence. If it were necessary to pick one of these men ( and this can't be done), probably Rutherford would be selected as the originator of nuclear medicine. Many per sons that later became important were students of Rutherford—Soddy, Hevesy, Geiger. Or they were following the ideas of Rutherford—Lawrence, Fermi, Oliphant. Or they were students of these students—Hamilton, Low-Beer. Every thing in nuclear medicine ultimately finds its way back to Rutherford.

NEW ZEALAND

Rutherford was born near Nelson, New Zealand, on August 30, 1871. He went to Nelson College where he was known as a prodigy because of awards not just in mathematics, physics and chemistry, but also in Latin, French, English Literature and History. He went to the University at Christchurch and distin guished himself in the transmission of electrical waves through the atmosphere and devised an ingenious magnetic detector. Because of this work, and the fact that he was such an outstanding student, he was the second choice for an an cient (1851) scholarship to England. The first choice got married and so Ruther ford went to Cambridge. In the fall of 1895 he arrived at the Cavendish Labora tory and was making a reputation in wireless physics when Roentgen announced a new kind of light. CAVENDISH LABORATORY

Professor J. J. Thomson, director of the Cavendish Laboratory, was akeady investigatingthe queer eventsthatWilliam Crookes demonstratedwith an elec tric current in a (well, it was almost a vacuum). Thomson had dis covered that air through which X rays passed became a conductor of electricity. He called in Rutherford to be his personal assistant. They had a fairly good idea of what was going on, Thomson said a portion of molecules traveled in one di rection and had a negative charge, another portion traveled in the opposite di rection with a positive charge; the pair when separated he called “ions―.Ruther ford's job was to learn everything about ions. It was a full year's work and in the meantime Becquerel (also Crookes and Sylvanus Thompson) had shown that oxide and maybe some of the other very heavy metals did the same sort of thing, and so Rutherford shifted from X rays to uranium. FLVFH ANNUAL LECTURE—NUCLEAR PIONEER SERIES 393

We could follow the career of Rutherford year by year, until his death in 1937, discussing each major discovery. In 1897, ionization; in 1898, “non-deviable― and “deviable―rays from uranium which he renamed “alpha―and “beta―.With Owens at McGill, he discovered thoron; then the deflection of alpha particles, then thorium-X growing from thorium; in 1903, the exponential laws of decay and recovery; in 1903, in connection with radium; in 1904, the subject of geochronology. In 1905 he was primarily responsible for Boitwood's claim that lead was the end product of the radium disintegration series. But this can get awfully tedious, because there is often more than one and few years are without a major discovery. With some inevitable oversimplification, it is possible to summarize Ruther ford's career in four periods; Student, McGill, Manchester, Cambridge. From 1895 to 1898, he was a student of J. J. Thomson's. During this period he was primarily interested in electromagnetic phenomena and he probably preceded, or was at least contemporary with Marconi on questions of wireless transmission.

MCGILL

During 1898, the Curies were busy at work with polonium. At the same time, McGill University had an opening and was looking for a professor of physics. Rutherford was anxious to get married to a New Zealand girl and needed money and so applied for the position. With the enthusiastic backing of J. J. Thomson he got the job, but first “finished―his work on the rays from uranium. In September of 1898 he went to Montreal where he changed from student to professor over night. Rutherford was only 27 years of age. At McGill he met Robert Bowie Owens, another new professor (of Electrical Engineering). Rutherford got Owens to run down some trouble with the electrical measurements of thorium oxide. This material worked something like uranium but sometimes it behaved and some times it didn't. Owens did run down the trouble. The temperamental behavior of thorium oxide was due to drafts. This was a naive piece of stupidity to every body except Rutherford and Owens, there was a gaseous emanation that came offof the thorium.(Later Rutherfordfound the same thing with uranium). Rutherford worked out his own mathematics on a number of experiments to discover radioactive growth and decay. By September of 1899, Rutherford thought he had solved the problem of emanation (he hadn't, but it was a good start) and in another month thought he had explained how these emanations caused what he then called “excitedradio activity―. The Curies had already published a paper on the radioactivity “in duced― by radium but they knew nothing of Rutherford's work and he knew nothing of theirs. The activity had so short a life that the presence of a separate element was unsuspected unless you did the kind of experiment that Rutherford had invented. During the summer of 1900, Rutherford returned to New Zealand to get married. By the time he returned to McGill, a young (23 years old) laboratory instructor in chemistry had been hired and was looking for a research problem. 394 LORDRUTHERFORD

This was Frederick Soddy. Rutherford got him to look more carefully into the radium and thorium gases that were being formed. From 1898 to 1907, Rutherford was primarily concerned with the very intri cate phenomena of radioactive changes in the naturally occurring radioactive elements. It was during this period that the trend of study of radioactivity was bent towards electrical measurements. J. J. Thomson was an “electrical―physicist and he chose Rutherford as a student because Rutherford could make electrical measurements. Becquerel was a chemist but he chose Pierre Curie as a colleague because Curie was an “electrical―physicist. Sir William Crookes was a chemist, who felt much more at home with photographic measurements, but he recognized the quantitation that the “electrical―physicists were capable of. Probably be cause of the insistence by all three that measurements be quantitative as well as qualitative, the whole field of radioactivity, unlike roentgenology, was directed away from towards electrical phenomena.

MAN@HE5TER During the next few years the idea of a “transmutation―became fairly well accepted. During the early months of 1907, the professor of physics at the Uni versity of Manchester in England was anxious to retire. Professor Rutherford from McGill was selected to replace him. From 1907 to 1919, Rutherford was Professor of Physics at Manchester. By the time he arrived, he found already established a young German Ph.D. named Hans Geiger who was supposed to be neither teacher nor student, but only do research. Rutherford always had something that had to be done and so Geiger was given the job of developing an ionization method for measuring alpha particles. The chamber had already been worked out in Canada but not in the sense that it was a practical device (practical to a physics laboratory, the prac ticality in medicine comes much later). In 1908 the theory of transmutation was so obvious, though still undeveloped, that Rutherford received the Nobel prize for Chemistry. (It is all right for a physicist to receive the Nobel prize in Chemistry because Becquerel, who was very definitely a chemist, had received the Nobel prize in Physics in 1903.) During 1912, when Soddy had already given a name to and proved the theoretical necessity for “isotopes―,a Danish visiting physicist came to Ruther ford's laboratory at Manchester as a part of his year of study abroad. In those days study abroad was considered necessary for a Ph.D. degree. was dissatisfied with the atom-model that Rutherford had developed and so he im proved it. We now call this the Bohr atom, but it's really the Bohr modification of the Rutherford atom. (When you really get down to it, it's really the Bohr re modification of the Rutherford modification of the Thomson atom. And Thomson gives credit to Crookes, who gives credit to others before him.) George Hevesy was working in Rutherford's laboratory at the same time and here a separate thread in tracer techniques shifts from transmutation physics to chemistry and finally to biochemistry tracers and finally to a portion of nuclear medicine. Rutherford was knighted in 1914; his war work was on the transmission of sound under water, but he continued to work with the high energy alpha par FIFTH ANNUAL LECTURE—NUCLEAR PIONEER SERIES

tides from radium with the idea that he could produce a disintegration of nitrogen nuclei. As an important physicist, the British Military wanted him on “important― committees. The story is that in 1919 he kept one committee waiting while he finished an experiment which, if it worked, he said would make the committee's deliberations obsolete. This was the demonstration that he could willfully pro duce the disintegration of an atom. With one experiment he had found the Phi @ losopher's Stone, started the Cold War, won World War III and made nuclear medicine possible.

CAMBRIDGE In 1919, Rutherford's teacher at the Cavendish Laboratories, J. J. Thomson, retired to less arduous work and Rutherford returned, this time not as a student —as he had twenty-three years before—but as head of the Cavendish Laboratories. From 1919 to a few weeks before his death on October 19, 1937, Rutherford's concern was the nucleus of the atom. Perhaps the peak of this fourth period was in 1932 which saw the discovery of artificial disintegration by artfficial nuclear projectiles. ( Rutherford's earlier demonstration in 1919 was with the natural alpha particles of radium C. ) 1932 also saw the discovery of the positron which Rutherford had postulated, and of the neutron which he had talked about at con siderable length. Both the artificial disintegration and the discovery of the neutron were done at the Cavendish Laboratories under Rutherford's guidance. Ruther ford was highly prejudiced against theoretical scientists who did not get their hands dirty in a laboratory. In spite of this, he formed the basis upon which most current atomic theory rests.

HONORS Rutherford received twenty-three honorary doctorates in the days when the degree was given not for a contribution to the budget but for a contribution to science. He received seven medals, including most of those that are remarkable for their distinction in science—the Rumford Medal, the Bernard Medal, Copley, Franklin, Albert and Faraday Medals. In 1908, he received the Bressa prize and the Nobel prize.In 1914 he was knightedto become SirErnestRutherford;in 1931 he was honored by the BritishEmpire to become Baron Rutherfordof Nelson. He was President of the Royal Society for five years; President of the British Association; President of the Institute of Physics. He was a member of, an honorary member of, a corresponding member of, or a foreign associate of more than twenty-seven societies of the arts and sciences, and he was active in many of them (including, incidentally, the Royal Society of Medicine). Sir William Crookes was an honored guest at the 1897 meetings of the Roentgen Society in . Becquerel had actually performed some tentative radiological experiments. But Rutherford was never directly involved in medical work. He did influence the decision that the leftover radium from the British Air Force in 1919 go to the development of teletherapy under the direction of the Medical Research Council in England. He also was influential in the design, de velopment and use of Grimmet's enormous (five gram) radium beam therapy unit. This was the predecessor of much of the later development of teletherapy, 396 LORDRUTHERFORD

using radioisotopes as the source of energy. Rutherford had a medical interest but there was never sufficient material available. He died just as the accelerators were beginning to produce radioisotopes in sufficient quantity for medical investiga tion. If you had to select the name of one man who first conceived the idea of nuclear medicine, you would be in trouble. Sam Seidlin was obviously the first to apply radioiodine to a thyroid carcinoma metastasis in the early 1940's, but he wasn't first. Robert Ball had tried it on the first patient the day before Pearl Harbor. But this was just the adaptation of an idea of using radioiodine in thyroid physiology,which occurredin about 1938.But thiswas justan adaptationof an idea of using a radioisotope of a naturally occurring element—probably radio sodium about 1934. But this was just an adaptation of an idea around 1925 that an isotope of radium could be adsorbed onto a saline solution. But this was just an adaptation of an idea that Hevesy had in 1913 of separating one lead from another. But this was not an adaptation—it was the result of an accumulated fifteen years of scientific exploration by ten to twenty giants in physics and chem istry (it's hard to tell the difference between the sciences). it is not just incidental that all of the Pioneers honored by The Society of Nuclear Medicine were developing Rutherford's ideas. Ernest Lawrence made a machine to produce a more powerful projectile for Rutherford's disintegration. Hevesy, in Rutherford's laboratory, was trying to separate some radium D (Pb210) from a huge amount of lead. Hamilton investigated the metabolic be havior of any and every new radioactive isotope; Low-Beer was interested in their therapeutic potentialities. Fermi investigated a new kind of a projectile which had been suggested by Rutherford many years before. When Nuclear Pioneers are chosen for future meetings, the only way the selection committee will be able to avoid an intellectual descendant of , will be to choose a man whose major work was done before 1898. MARSHALL BRUCER, M.D.