promethium

Promethium, a chemical element in the lanthanide series with atomic number 61 and the symbol Pm, may very well be the element with the dubious honor of having the most names attached to it. It is radioactive and extremely rare in nature. Only one isotope of promethium has uses beyond pure research. Because it has a relatively long half-life (2.6 years) and does not emit strong gamma rays, making it relatively safe as radioactive materials go, promethium-147 is used in atomic batteries and as a phosphor in luminous paint.

In 1902, chemist Bohuslav Brauner recognized that there should be an element between neodymium and samarium in the lanthanide series. Then it was off to the races with a variety of scientists claiming to have discovered element 61, giving it a name, and then having their hopes dashed when other scientists showed they were wrong.

A group of scientists from the University of Illinois claimed to have isolated the element in 1926, dubbing it illinium, after the university. An Italian team claimed to have isolated the element, dubbing it florentium (after the city of Florence) in 1924, but they did not publish their find until after the Illinois group had made their announcement. It didn’t matter, because both were shown to be wrong, the spectral lines they saw ending up belonging to other elements. In 1938, a team at the Ohio State University claimed to have produced the element in their cyclotron, dubbing it cyclonium, but their experiment could not be replicated.

Element 61 was finally and definitively produced at the Oak Ridge National Laboratory in 1945, under the auspices of the Manhattan Project. Because of wartime secrecy, the announcement was not made until July 1947, however. This initial announcement did not offer a name for element 61. The team did not publicly proffer a name until the September 1947 meeting of the American Chemical Society.

The earliest use of the name promethium that I have found is in the Chicago Tribune with a dateline of 15 September 1947. The article is about B. S. Hopkins, a member of the University of Illinois team who was still maintaining his primacy in the element’s discovery:

He said no one thought of contesting his claim until atomic energy was developed during the war and enabled man to create illinium and other elements artificially thru the use of cyclotrons (atom smashing machines) and atomic furnaces.

Dr. Hopkins said two atomic physicists in 1942 claimed they had isolated illinium by the cyclotron method and suggested that the element be renamed cyclonium.

Now three investigators from the Massachusetts Institute of Technology say they have created the same material in an atomic furnace and want to rename it promethium, Dr. Hopkins said.

(Marinsky and Glendenin had moved on from Oak Ridge to M.I.T. following the war.)

The issue of Newsweek dated 29 September 1947 lists a few other names for element 61 that had been proposed:

Since the artificial 61 was produced in the course of atomic-energy research, names tentatively discussed by the Oak Ridge group reflected the Manhattan project: promethium (Pm) for the legend of man getting fire from the gods; thanium (Tn) for death; and grovesium (Grr) for General Groves. A group at Ohio State University suggested cyclonium (Cy), for the cyclotron.

And in addition to the names for the real-world element, the name promethium was used even earlier in fiction. The fictional metal is a MacGuffin in her 1942 novel Murder in the O.P.M.:

He interrupted me. “Have you ever heard of promethium?”

“I’ve heard of Prometheus in Greek mythology.”

“That’s where the word comes from. Just as titanium comes from Titan. Promethium is a metal like titanium, iridium and beryllium. It’s used chiefly as an alloy to harden softer metals like copper and aluminum.”

And a few pages later there is this this rather misogynistic description of a woman:

“‘Diane’s twenty-two, almost twenty-three. She looks like a Fragonard, and she’s all violet and pale gold, except, unfortunately, a little promethium dropped into the ladle when the angels were pouring her out——’”

I stopped and looked at Colonel Primrose. Apparently I had heard of promethium.

He smiled. “In a two-per-cent promethium alloy, copper cuts the toughest steel in existence, Mrs. Latham,” he said blandly.

“She . . . does sound awful,” I said. I went back to Agnes’ letter.

“‘——so that “difficult” isn’t quite strong enough and her family don’t like to call her any of the more modern terms.’”

That’s a lot of names for one rather rare element.

Sources:

“Chemistry’s Full Table.” Newsweek, 29 September 1947, 58–60 at 59. ProQuest Magazines.

Ford, Leslie (pseud. Zenith Jones Brown). Murder in the O.P.M. New York: Charles Scribner’s Sons, 1942, 6, 8. Archive.org.

Gibbons, Roy. “U. of I. Scientist Out to Prove He Found Element” (15 September 1947). Chicago Daily Tribune, 16 September 1947, 23/2. ProQuest Historical Newspapers.

Marinsky, J. A., L. E. Glendenin, and C. D. Coryell. “The Chemical Identification of Radioisotopes of Neodymium and of Element 61” (16 July 1947). Journal of the American Chemical Society, 69.11, November 1947, 2781–85. DOI: 10.1021/ja01203a059. (Announcement of discovery, but no name for element 61 is proffered.)

Oxford English Dictionary, third edition, June 2007, s.v. promethium, n.

Photo credit: Unknown photographer, 2006. Louvre Museum, Paris. Wikimedia Commons. Public domain photo.