In 1665, an infectious disease swept through the British capital and claimed the lives of tens of thousands of people. The Great Plague of London haunted the memories of those who survived it. But it would take another two hundred years for the cause of this illness to be discovered: a small but powerful bacterium called Yrsina pestis. In those centuries, our understanding of diseases was transformed.

So Very Small is a brilliant journey through the epic history of bacteria, microbes and germs. Spanning centuries and continents, it draws on significant world events – the recurrent outbreaks of plague in Europe and Asia, the 1721 Boston smallpox outbreak, the great cholera pandemics of the nineteenth century – as well as the pioneering scientific discoveries that have furthered our understanding of bacteria. The compelling narrative culminates in a great medical breakthrough, the development of antibiotic treatment that has been the salvation of much of humanity in the twentieth century. Levenson also describes the medical and conceptual prejudices that so often delayed scientists’ ability to conquer infectious diseases. We still race today to stay ahead of strains of bacteria that are rapidly evolving.

Fascinating and immersive, So Very Small is an entertaining, well written and deeply researched history of the scientific quest to understand how tiny organisms have impacted the wider world.