Element 87—Francium

One of the most remarkable things about element 87 is the number of times that people claimed to have discovered it after it was predicted by Mendeleev in 1871 and given the provisional name of eka-caesium . It was recognized early on that the periodic table more or less fizzles out after element 83, or bismuth. All subsequent elements are radioactive and therefore unstable, with a few exceptions like uranium and thorium. But this fact did not deter a number of scientists from searching for element 87 among natural sources and in many cases from claiming to have isolated it. For example, Druce and Loring in England thought they had identified the element by using the classic method developed by Moseley for measuring the K α and K β lines of any element’s X-ray spectrum. But it was not to be. In the 1930s, it was the turn of Professor Fred Allison from the Alabama Polytechnic Institute (now Auburn University). Allison developed what he called a magneto-optical method for detecting elements and compounds based on a supposed time lag in the development of the Faraday effect, whereby the application of a magnetic field causes a beam of polarized light passing through a liquid solution to be rotated. Allison mistakenly thought that every element gave a particular time lag, which he claimed was observed with the naked eye, and that this effect could be used to identify each substance. He boldly claimed in a number of journal articles, and even a special feature in Time Magazine, that he had observed elements 87 and also 85, both of which were still missing at the time. Literally hundreds of papers were published on this effect, including a number of studies arguing that it was spurious. But these days the Allison effect is often featured in accounts of pathological science, alongside the claims for N-rays and cold fusion.