Science blog

Exploring science at the British Library


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

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.

17 November 2021

Bloodletting and leeches, not so ancient.

Hippocrates (c. 460 BC - 377 BC), the ancient Greek physician, was the first to apply humorism to medicine. In ancient medicine, “humor” refers to a fluid or semifluid substance. According to Hippocrates, the body was made up of four humors; blood, phlegm, black bile, yellow bile. Moreover, that health and disease occurred naturally when these humors were imbalanced, either in deficiency or excess. Thus, if someone was unwell, it was a product of imbalance in their body. To cure a patient of an illness, the excess of the relevant humor had to be removed. A common treatment was bloodletting and the instrument used…leeches. Leeches were used for a wide range of ailments including headaches, gout, bruising, and brain disorders among others.



A decorated initial from an illuminated manuscript, showing two people in medieval clothing. One is cutting the arm of the other so that their blood runs down into a bowl.


Although by modern standards, most people would squirm at the thought of leeches sucking their blood and deem this tradition completely archaic, the use of leeches for medical purposes has not become wholly obsolete in the 21st century.

The medical leech is known as hirudo medicinalis. Leeches have remarkable properties that make them useful medical tools. They improve blood flow in areas with poor blood circulation. Their saliva contains anticoagulants preventing clotting, and as they suck they reduce tension and remove blood clots. Leeches release a natural antiseptic as they bite, therefore preventing infection. Due to these properties, the medical leech has had a revival and is now farmed in the UK to aid treatment.

Medical leeches are used for microsurgery, and reconstructive and plastic surgery.  In the case of plastic surgery, when tissue is reattached, blood clots can form as blood can get congested. Leeches are used to remove this tension and reduce clotting. Microsurgery is surgery that requires an operating microscope. One of the main purposes of microsurgery is to transplant tissue from one part of the body to another and to reattach amputated parts in what is known as free flap surgery. A major part of this process is repairing small blood vessels. Leeches have become a valuable tool for microsurgery recovery, salvaging surgically irreparable venous insufficiency occurring after free flap procedures. The leech can help the blood flow in small blood vessels and prevent tissue from dying.

Tracing the history of medicine can be full of surprises, especially when treatments date as far back as ancient Greece. No wonder Hippocrates is known as the father of modern medicine.


References and further reading:

  • NHS, University Hospitals Coventry and Warwickshire, Plastic Surgery Department, Leech Therapy.
  • Royal College of Surgeons of England, Why you should love a leech: bloodletting to microsurgery, 2018.
  • NHS, Oxford University Hospitals, Leech Therapy.
  • Green, P. A.|Shafritz, A. B. (2010). Medicinal Leech Use in Microsurgery. The Journal of Hand Surgery., 35(6), 1019-1021. Shelfmark: 4996.620000
  • Soucacos, P. N.|Beris, A. E.|Malizos, K. N.|Kabani, C. T. (1994). The use of medicinal leeches, Hirudo medicinalis, to restore venous circulation in trauma and reconstructive microsurgery. International Angiology., 13(3), 251. Shelfmark: 4535.770000
  • Bloodletting zodiac man