We have become used to the type of history book that focuses on one particular commodity, material or scientific discovery and declaims how it has “changed the world”. In contemporary times, perhaps the first to do this was Longitude, Dava Sobel’s work that examined how the ability to measure distance at sea fundamentally transformed man’s ability to trade and wage war, and thus altered history. Since then, we have seen books claiming that their subject matter is singularly responsible for changing the world. Mark Kurlansky’s books Salt and Cod spring to mind, but there are others, and sooner or later some enterprising author will no doubt write 200 pages on the historical importance of “Dust”. But I digress.
However, many years ago, Hans Zinsser had a similar idea. In 1934, this scientist decided to write a long book which, amongst other things, touched on the shaping of history by Rats and Lice (in particular through their ability to carry and pass on diseases such as Typhus). Zinsser describes his work as a biography of Typhus. But Zinsser is far from a scientist who is limited by his scientific subject. The book starts with a gentle discussion of the ability of scientists to discuss subjects not related to science. It’s an important discussion – should scientists touch the realms of history for instance. Zinsser concludes that they both should and must and energetically goes about doing so, quoting such literary greats as Joyce, Shelley and Eliot along the way.
Zinsser’s style is a wonderful blend of poetic writing and simple science. But he is also very funny. At one point a footnote to the word “saprophyte” tells us that “if the reader does not understand this word, it is too bad” .
To understand the history of Typhus we need to learn a little about the spread of disease, how certain diseases love the dirty cramped conditions of human existence and how the medicines that fight them work. We learn also how humans can get disease from animals, and how animals (or insects) can carry these diseases, but not succumb. We also learn how terrible an epidemic really is. This book was written shortly after millions died in the First World War. Millions more died in the great influenza epidemics that followed that conflict.
More interestingly the non-biologist like myself learns that diseases like Typhus have a history of themselves and Zinsser, in those pre-DNA testing times shows us how scientists can show that the disease had evolved down different paths. The different variants having different effects, and different victims. Part of this discussion looks at epidemics in history and Zinsser examines the evidence for whether certain mass deaths described by Pliny or other ancient historians can be attributed to various “modern” diseases.
This is a fabulous work. Science as it should be written, by an author who clearly didn’t think that one should never stray from one’s area of special understanding. But one who also believed that knowledge was important to combat disease. I’ll leave the last words to Zinsser himself:
About the only genuine sporting proposition that remains unimpaired by the relentless domestication of a once free living human species is the war against those ferocious little fellow creatures, which lurk in the dark corners and stalk us in the bodies of rats, mice, and all kinds of domestic animals; which fly and crawl with the insects, and waylay us in our food and drink and even in our love. The Chambers Scientific and Technological Dictionary actually defines it as “an organism living heterotrophically  and osmotrophically on dead organic matter”
 if the reader does not understand this word, it is too bad
Davis - The Monster at Our Door - The Global Threat of Avian Flu
Wallace - Dead Epidemiologists: On the Origins of Covid-19
Quammen - Ebola: The Natural and Human History