Battle of Waterloo Reenactment

How Processors Turned Battlefield Bones into Raw Materials

May 3, 2024
Learn how bones from the Battle of Waterloo found their way into the burgeoning fertilizer and sugar industries, shaping agricultural and industrial innovations.

On June 18, 1815, the Battle of Waterloo in Belgium destroyed France’s attempts to dominate Europe and thwarted Napoleon’s imperial ambitions.

It also left up to 20,000 men and 10,000 horses slain on the battlefield.

However, modern archaeologists have found only two human skeletons, both since 2012, plus a handful of horse skeletons at the battlefield site. 

So where did all the bones go?

According to the authors of The Real Fate of the Waterloo Fallen. The exploitation of bones in 19th century Belgium in a recent issue of the Journal of Belgian History, they were used as raw materials by nascent fertilizer and sugar processing industries. 

The authors — Bernard Wilkin, senior researcher at the state archives of Belgium; German freelance historian Robin Schäfer; and University of Glasgow professor of battlefield archaeology, Tony Pollard — say this really took off in the mid-1700s following a breakthrough by chemists who discovered it was the calcium phosphate in bones rather than their organic content that acted as fertilizer. 

The emergence of bone mills swiftly followed, the first being commissioned in England around 1780.

The market boomed again in 1824 when a process for dissolving bones in sulphuric acid was patented. Dubbed “superphosphate,” the resulting fertilizer doubled the yield of important crops.

Now, step back to 1747 when a German chemist found that the sugar in sugar beet is the same molecule as the one in sugar cane — the latter being scarce because of Napoleon’s blockade of sea routes. 

This coincided with the discovery that bone meal phosphate both allowed beets to grow in poorer soils and increased its sugar content. Within six years, 200 sugar beet refineries had been commissioned in German states alone. 

At the same time, consumers (it was no longer just a luxury item) wanted their sugar to be brilliant white. So charcoal was used to filter sucrose-containing beet juice.

However, the authors note that the discovery by a French industrialist in 1811 that granulated bone char was an even better filter medium effectively sealed the fate of the Waterloo fallen.

Within four years, the entire beet sugar industry in Europe had switched to this new material, later known as spodium. 

Because superphosphate was a byproduct of sugar refining, the value of the industry increased further and demand for raw bones hit new heights. 

In fact, a gigantic national sugar refinery was set up a couple of miles from the Waterloo battlefield. Next, tales of bones retrieved from Waterloo began to emerge. 

A letter signed by “a living soldier” in The Times in London on Oct. 18, 1822, said that more than a million bushels of “human and inhuman” bones had been imported the previous year from the continent into the port of Hull – often from the sites of bloody battles including Waterloo. After grinding in steam-powered mills, they were sent to a nearby market to be sold to farmers as manure. 

The French press picked up on this and other stories of bone trafficking. For example, L’Indépendant, on Aug. 23, 1835, reported that a company of industrialists bought permission to excavate the battlefield of Waterloo to remove the bones of the dead to make bone char.

In the Journal des connais sances médicales pratiques in 1858, French author Dr. Caffe, who had lost a brother in the battle of Waterloo, wrote: “I do not forget to have seen the same excavations carried out at Waterloo, where I had the misfortune to lose a brother. And the bones, transformed into animal black [bone char], went to clarify the beet sugar of Belgium and the northern departments.”

On the other hand, explain the authors, local politicians had little interest in putting an end to the very lucrative trade enriching both their regions and their citizens. In 1837, 100 kg of raw bone sold for 14 Francs, up from just 2 Francs five years earlier. 

Large-scale extraction of bone from former battle sites seems to have stopped toward the end of the 19th century and Fritz Haber demonstrated synthesis of ammonia from its elements for the first time in 1909. Ironically, the first demonstration of ammonia production in the laboratory was achieved by Humphry Davy using electrolysis in 1807, the same Davy who was involved in discovering the fertilizer value of calcium phosphate. 

Bone char, often referred to as natural carbon, is still used as a decolorizing filter in some sugar manufacturing processes, although more for cane sugar than beet sugar.

The authors conclude that more substantial research is needed on the fate of battlefield casualties after the Napoleonic War. Waterloo, they write, is only the tip of the iceberg in the industrial-scale exploitation of war dead during that period.

For more on this interesting bit of history, see the book: Bones of contention: the industrial exploitation of human bones in the modern age. 

About the Author

Seán Ottewell | Editor-at-Large

Seán Crevan Ottewell is Chemical Processing's Editor-at-Large. Seán earned his bachelor's of science degree in biochemistry at the University of Warwick and his master's in radiation biochemistry at the University of London. He served as Science Officer with the UK Department of Environment’s Chernobyl Monitoring Unit’s Food Science Radiation Unit, London. His editorial background includes assistant editor, news editor and then editor of The Chemical Engineer, the Institution of Chemical Engineers’ twice monthly technical journal. Prior to joining Chemical Processing in 2012 he was editor of European Chemical Engineer, European Process Engineer, International Power Engineer, and European Laboratory Scientist, with Setform Limited, London.

He is based in East Mayo, Republic of Ireland, where he and his wife Suzi (a maths, biology and chemistry teacher) host guests from all over the world at their holiday cottage in East Mayo

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