If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.




October 2, 2017 | A version of this story appeared in Volume 95, Issue 39


Letters to the editor


Rare earths

Credit: Peggy Greb/USDA/Science Source
Rare-earth oxides (clockwise from top center): praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium.
A photo of six mounds of powders colored black, tan, off-white, gray, yellow, and white.
Credit: Peggy Greb/USDA/Science Source
Rare-earth oxides (clockwise from top center): praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium.

The recent article about rare earths (C&EN, Aug. 28, page 30) reminded me of my work at Ames during the early 1950s. From 1951 to 1953, I worked for Frank Spedding, who was director of both Iowa State University’s Institute for Atomic Research and the Ames Laboratory of the Atomic Energy Commission (now the U.S. Department of Energy). His earlier work in support of the Manhattan Project is well-known. In addition, his interest in the chemistry of rare earths led to the development of ion-exchange procedures that made it possible for us to produce some of the first multigram quantities of high-purity rare-earth oxides by a relatively simple process.

Our first work was with 1-inch-diameter, 48-inch-long [2.54-cm-diameter, 121.92-cm-long] glass columns filled with Dowex-50 resin. The distribution of the resin in the columns and the elution rates required careful control to maintain horizontal boundaries between the rare earths as they moved down the column.

Initially, the eluant was collected at a drops-per-minute rate into 10-mL flasks, and one of us was in attendance 24 hours a day to change flasks and to make sure no problems occurred. When it was established that high-purity material was being obtained by the procedure, some was converted into metal by Harley Wilhelm in the lab’s metallurgy facility. By 1953 the columns had grown to 8 inches [20.32 cm] in diameter and 10 feet [3.05 meters] in length, and proportionally more rare earths were being produced.

Even then we had no sense of the elements’ future importance, and it is interesting to read of their many applications today.

(The picture of colored rare earth oxides in the article could also have included erbium, which is pink, as I recall.)

Jack L. Evans
Sun Lakes, Ariz.

From the web


Re: Retraction of paper

Readers commented online on the retraction of a 15-year-old paper.

“This is the way science is supposed to work—correcting itself.” I completely disagree. This is how publishing is supposed to work, giving the chance to verify results from other researchers. Science is supposed to develop our understanding of the world, and it does so by publishing results that are accurate. I do not wish to criticize Orvig, but the scientific community. There are just a few journals which actually reproduce an experiment in some of their editors labs before accepting the manuscript. And this is exactly what should have been done here, 15 years earlier. Experiments have to be reproducible. And submissions have to be specific, with an editorial board that takes its responsibility for accurate science seriously and has the equipment or contacts to do so. Especially with such [low-molecular-weight] compounds.

In reply to Richard, a noble proposition, but to invoke the old fable, “Who’s going to bell the cat?” Reproducing experiments, on commission, is a volunteer function. Same applies to refereeing. The only publication I know of that uses checkers to rerun the preps submitted is Organic Synthesis. The checkers must support the efforts, both for materials and labor, on their own grants. For doing that one gets a preview of the prep and a “publication.” Do you do this work of reproducing?
Robert Buntrock

If the error led others astray or upset a principle of chemistry, then it would have been short-lived. If others found the compound useful for a purpose that would require the dimeric structure, they would have discovered the error. Once it’s out there, the world of chemistry becomes the fact-checker. If no one caught it, how did that happen? There is little value in being the person who corrects someone else’s mistake, but if we do, we should appreciate that we could be making the next mistake ourselves. Be sympathetic, even if you wasted your time and resources. And if you correct your own error, tell C&EN about it.
Ron Kluger


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.