Ghosts of radioactivity past

Frederick Soddy's radioactive samples are no longer kept within the Soddy Box, which was built to house them in the 1950s.

The box, minus its radioactive contents, now lives in the Hunterian Museum at the University of Glasgow.

However, although the box is non-radioactive (or at least, no more radioactive than any normal material), it does bear witness to its former radioactive occupants.

Within the wooden, lead-lined chest, the samples were kept in glass jars.

The jars are now empty. However, they carry the scars from their former, intensely radioactive contents:

Sample 1 was effectively non-radioactive, and the jar looks like a normal glass sample jar. However, other jars, such as that containing sample 3, have developed a distinct smoky tint. Aluminosilicate materials exposed to ionising radaiation often develop smokiness (this is the cause of the colour in the quartz gemstone "cairngorm").

The intensity of the smokiness is a record of the how much radiation the glass has been exposed to.

Open the box!!

What do Frederick Soddy's radioactive materials from the first decade of the 20th century look like?

The samples are all in small sealed glass tubes containing small quantities of powders, or in one case, a metal tube. The maximum dose the samples deliver  varies from insignificant (Sample 1, labelled actinium), to 29 millisieverts per hour (No 4, encased in lead). Many of the glass tubes are smoky, violet or purple, but this is due to radiation damage to the glass - the actual contents are pure white.

The most significant sample may well be No 6, which is labelled "Mesothorium" in Soddy's own hand. Soddy's work which lead to his concept of isotopes involved mixing radium (Marie Curie's 226Ra derived from the uranium decay series) with barium salts, and "mesothorium" (now known as 228Ra derived from the thorium decay series) and trying to separate these mixtures by chemical means. Others had also tried this, but Soddy decided that the failure to separate them was not due to inadequate chemical techniques, but rather because mesothorium and radium were the same chemical element, occupying the same place in the periodic table. This insight, and the word isotope, were pubished in his letter to Nature on 4th December 2013.

It is almost certain that this is one of the samples Soddy used in developing this key concept.
 

The Soddy Box!

Most of the radioactive materials used by the pioneers of radioactivity are now lost.

As we grew increasingly aware of the dangers of radioactivity during the 20th century,  people grew uneasy about having these powerful sources lying around in their offices and laboratories, and in most cases, they were disposed of.

However, in Glasgow Soddy's samples were not simply treated as radioactive waste.  In the late 1950s John Lloyd of the University's Natural Philosophy department, designed a special mock-medieval, lead-lined treasure chest to house what he saw as historical jewels. The box was built in the University works department, and quickly became known as "The Soddy Box":

Although lead-lined, the box was not a significant barrier to the powerful radium-rich sources within, and the box itself had to be kept away from people. At various times it lived in a hut on the roof of the Joseph Black building, in an old coal-mine adit underneath the building, and in disused toilets within the building, among other places. The mythical Soddy Box became an invisible, but notorious part of the University's science heritage.

Eventually, the box and its radioactive contents came under the care of the University's Radiation Protection Service, and were properly logged and registered as required by the evolving laws and regulations.

However, around 2011, the Scottish Environmental Protection Agency carried out a review of unused radioactive materials in Scotland. The Soddy Box contents were identified as orphan materials, with no clear function, or reason for being held, and their fate was in the balance. Options for their disposal as radioactive waste were costed, but the episode made people aware of these rare survivors from the dawn of the nuclear age. Voices from within the University, and from isotope scientists all over the UK argued for their preservation as key historical artifacts, and this argument prevailed.

Although the radioactive materials remain physically in the custody of the Radiation Protection Service, they are now part of the University's Hunterian museum collections. The samples are no longer housed in the box, and the box (non-radioactive) is now in the care of the Hunterian, where it will play a leading role in the forthcoming exhibit "Born in Glasgow:100 years of Isotope Science", opening on December 5th 2013.

But what was in the box?

Was it in the study, or the dining room?

Isotopes will be 100 on December 4th 2013.

 The word first appeared in the scientific literature on December 4th 1913, when University of Glasgow radiochemist, Frederick Soddy published a letter in the journal Nature:

The first appearance of the I-word!

Although the science was Soddy's, the word itself had been suggested to him by a Glasgow doctor, Margaret Todd, partner of the pioneer of female medical education, Sophia Jex Bake.


Frederick and his wife Winifred lodged with Winifred's parents at 11 University Gardens, Glasgow.  George and Emma Beilby were wealthy from his work as an industrial chemist, but were also keen advocates of women's rights, and other progressive social causes.

The event definitely took place on evening in 1913 in 11 University Gardens, but there are two slightly different accounts of how the word was suggested.  The best known version, as recalled around 1950, by Soddy's colleague, Alexander (later Lord) Fleck, has it that the word was suggested over dinner one evening. However, Soddy himself towards the end of his life in the 1950s,  recalled that Margaret had suggested it to him one evening in the study.

 The two versions might not be mutually exclusive: maybe there was a dinner, and afterwards, conversation in the study.

One way or the other, the word "isotope" was born in this Glasgow building.