I’ve written a lot about diatoms over the past few months, trying to illustrate their beauty and diversity, as well as their importance in aquatic ecosystems. They are extremely abundant in freshwaters and oceans around the world and make an important contribution to the total primary productivity on the earth. Just occasionally, in the past, they have become so abundant that their accumulated dead shells have formed distinct geological strata. These were first discovered in northern Germany in the 1830s and people quickly realised that this soft sedimentary rock, known as Kieselguhr or diatomite, when ground to a fine powder, had many uses. The mild abrasive properties, for example, led to its inclusion in toothpaste, and it can also be used as a natural pesticide (we have used it to control red mites on our chickens).
In the 1860s, the Swedish engineer Alfred Nobel was experimenting with a new explosive material, nitroglycerin, which he thought had many possible applications in mining and quarrying. However, nitroglycerin was extremely unstable and, therefore, dangerous to use. Nobel found that if he mixed three parts of nitroglycerin with one part of Kieselguhr, the result was all the explosive power but now in a much more stable form. He christened his new invention ‘dynamite’.
The rest, as they say, is history. Except that today is the anniversary of the end of the Great War which led me to the somewhat oblique realisation of the role of these tiny but fascinating organisms in the carnage of warfare. In 1914 Europe split into two factions and spent the next four years lobbing enormous quantities of high explosives at one another. Not all was dynamite but it is sobering to remember how Nobel’s original hope of creating an explosive that was safe to handle contributed unintentionally to the toll of death and destruction.