Science blog

Exploring science at the British Library

Introduction

Find out about social sciences at the British Library including collections, events and research. This blog includes contributions from curators and guest posts by academics, students and practitioners. Read more

19 July 2022

Gold - why is it so valuable?

Our current Gold exhibition explores the use of gold in books and documents around the world. This blogpost looks at gold from a scientific perspective, and why it has the properties that have caused it to be so valued throughout human history.

Gold is probably the first metal to be known to humans. Unlike other metals, which need to be extracted from their ores, gold exists in the environment as the metal itself, from tiny specks up to large nuggets. This is because it rarely reacts with other chemicals, which also explains why it does not tarnish in air like silver or rust like iron. The oldest gold items in the exhibition are two gold plaques, with shelfmarks Or 5340 A and Or 5340 B, with inscribed Buddhist scriptures in Pali. They were discovered buried at the base of a stupa in Maunggan in Myanmar and are dated to the 5th or 6th centuries CE.

Two strips of gold inscribed in Pali, with a ruler for comparison showing them to be around 25cm and 35cm long.
The Buddhist gold plaques



Because of its lack of corrosion, gold has been seen as mystically special, and used for objects of high prestige and to make coins. One notable object in our exhibition is the treaty between the rulers of the Indian city of Calicut (now Kozhikode) and the Dutch, which was inscribed into a two-metre-long strip of gold. Gold was used to symbolise the importance of the treaty but also for practical reasons, as a material that would not rot or decay in a tropical climate.


The reason why gold is so unreactive is because of the number of electrons in each atom. This is the same as the number of protons, and it is this which decides which element an atom is. Within atoms, electrons are arranged in layers called "shells", and gold is particularly unreactive as its outermost shell is full of electrons, which is a particularly stable state for an atom.


Unlike some atoms with full outermost shells, like helium and neon, gold can react with some other chemicals. This is because gold can lose one to three electrons if the reaction can release enough energy to strip them off - called "oxidation", and it can also share electrons with other atoms, without giving up any of its own.


The first material to be discovered by medieval alchemists which can react with gold is the famous aqua regia, Latin for "king's water". Despite the appetising-sounding name, this is very dangerous and you should not try this at home - it is a very corrosive mixture of concentrated hydrochloric acid and nitric acid in water. Because of the hydrochloric acid, the mixture contains chloride ions, which are chlorine atoms which have received an extra electron from the hydrogen atoms in the water. The chloride atoms can share their electrons with the gold atoms to create what are called complexes, and this makes it easier for the nitric acid, which is an oxidising agent, to strip electrons away from the gold atoms, creating gold chlorides which dissolve in the water. Gold compounds do have some uses, such as treating arthritis and in some kinds of traditional silver-based photography.
Fortunately aqua regia doesn't occur naturally, so our gold exhibits are perfectly safe.


Our Gold exhibition is open from Friday 20th May 20 Sunday 2nd October 2022, and you can book tickets online to visit.

Supported by:

The logo of BullionVault shows an isometric gold cube inside a larger transparent cube.

The exhibition is supported by the Goldhammer Foundation and the American Trust for the British Library, with thanks to The John S Cohen Foundation, The Finnis Scott Foundation, the Owen Family Trust and all supporters who wish to remain anonymous.

13 May 2022

Healthy Cities - How do we make London happier and healthier after Covid-19?

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After longer than two years Covid-19 is still with us, and while we are doing our best to live with it, many questions remain about its long-term impacts. The negative impacts are all to evident in our daily lives, from the personal loss for those who have lost the loved ones, to long-term physical and mental health impacts, which we are still grappling to understand, the state of economy, the impact on educational outcomes for young people, the rise in poverty and so on. Yet, if there is a sunnier side of things, there is a hope that we have learned some important lessons that can help us improve the way in which our society and our cites work.

There is no doubt that London has become livelier in the recent months, but we know that it is not quite like it used to be. On the other hand, many would say that there are many things that we do not want to be the way they used to be – just consider the return to daily commute on the crowded tube trains!

This Sunday, we are welcoming the Med Fest to the British Library, to celebrate all things medical, but also to discuss how London can become happier and healthier place after Covid-19. We will discuss how past pandemics have shaped the London we know, how the city's health coped during COVID-19 and how we can prepare for the next pandemic. We will also look at the real-life examples of how communities have become healthier and improved their lives.

To help us engage with these urgent questions affecting us all, we will be welcoming the following speakers:

  • Dame Carol Black, Chair of the British Library and the UK Government's high-level policy adviser on health and work, and the misuse of illegal drugs
  • Kieron Boyle, Chief Executive at Impact on Urban Health, and Chief Executive of Guy’s and St Thomas’ Foundation
  • Martin Gorsky, Professor of History at the Centre for History in Public Health, The London School of Hygiene & Tropical Medicine
  • Rita Issa, GP and planetary health academic, London’s Sustainable City Public Sector Changemaker 2022
  • Layla McCay, Director of the Centre for Urban Design and Mental Health, and Policy Director at NHS Confederation
  • Ashley McKimm, Director of Innovation at the British Medical Journal, and Editor-in-Chief, BMJ Innovations
  • Audrey de Nazelle, Senior Lecturer at the Centre for Environmental Policy, Imperial College London
  • Richard Watson, Futurist-in-Residence, Entrepreneurship Centre at Judge Business School, Cambridge University
  • Kirsten Watters, Director of Public Health at London Borough of Camden

Everyone is welcome. Join us by signing up here for your free place.

23 November 2021

Climate change resources at the British Library

The British Library main building in St Pancras, seen over a hedge with a small tree to the left
(Photograph by Tony Antoniou)


The COP26 conference in Glasgow has ended, but the real work of reducing carbon emissions must now begin. The science staff and the British Library Green Network have created a collection guide now available on our website, which includes key items to provide information on the problems and potential solutions.

The guide includes books, journals and online databases that you can only access within the British Library if you have a Reader Pass, but there are also many links to trustworthy websites that contain a wealth of information on climate change, the Earth's climate, and the wider issues.

We will be keeping it up to date so that it will continue to be useful into the future.