The Sorry Story of Nicolas Leblanc

A tragic tale, with all sorts of lessons for today

Nicolas Leblanc is not a household name. He wasn’t even a household name back in the 18th century, when he came up with the invention that changed the world. But it’s worth taking a moment to contemplate his story, if only because it provides some interesting lessons for today.

Leblanc was born in 1742, in central France, into what would today be considered a lower middle class family. His father was an official at a local iron works, but Nicolas had a good education and became a doctor. Working as a doctor in 18th century France wasn’t an especially lucrative occupation, so to make ends meet he became the surgeon to the Duke of Orléans, Louis Philippe II - a minor French royal.

Like many young, aspirational intellectuals, Leblanc used his spare time to carry out scientific experiments. This was the height of the enlightenment - the great era of the enthusiastic amateur, long before science or engineering were considered disciplines and occupations one could only aspire to courtesy of years at university.¹

So when, in 1783, Leblanc heard of a competition launched by none other than King Louis XVI, he could hardly contain himself. The prize in question (2,400 livres, which equates to hundreds of thousands of euros in today’s money) would be awarded to anyone who could come up with a way of turning salt into soda ash - a special alkali chemical which was hitherto made by burning wood ash or seaweed.

We don’t spend much time pondering soda ash these days but it’s one of the most important chemicals in the world. An alkali we use to make critical products: soaps, dyes, bleaches. Essential in the production of paper and glass. If you don’t have soda ash you’re in big trouble. And back in the 18th century France (and England and pretty much every other industrialising economy) was running desperately short of soda ash. This became known as the “soda crisis”.

Rapidly growing demand for glass, cloth, paper etc was outstripping the supply of soda ash, which was mostly made by burning wood or types of seaweed. Across Europe, there were fears about imminent deforestation, because of the sheer number of trees which might need to be chopped down to provide timber for buildings, masts for ships, charcoal for steel and, yes, ash to make soda ash. It was the great ecological panic of the day.

Scientists knew in theory that it should be possible to turn table salt (sodium chloride) into soda ash (sodium carbonate). It would mean a nearly infinite supply! The problem was, no-one could work out how to do it. So the King (also facing a dismal economy, desperate public discontent and the early sparks of revolution) launched his challenge.

Leblanc got to work. After some time, he came up with a way of using sea salt and sulphuric acid as raw materials for a chemical reaction. It was a dirty process, involving coal and limestone and a furnace running at 1000 degrees. But the end product was soda ash!

Actually there were lots of other side-products too. Billowing hydrogen chloride fumes which would kill anything close by, mounds and mounds of calcium sulphide (nasty stuff), not to mention the stench coming out the chimneys. Still, it did the trick.

With financing from the Duke of Orléans, in 1791 Leblanc built the world’s first plant turning salt into soda ash. He had won the challenge! However, by then the man who was supposed to provide the prize was on the run. France was in revolution. The King was about to lose his crown.

So despite having worked for years to come up with a solution to one of the biggest scientific challenges, and despite succeeding, Leblanc got no reward. Actually it was worse than that. His plant was seized by revolutionaries, because it had been financed by an aristocrat. The Duke was executed and Leblanc’s patent - for this method which he had slaved over and kept secret for years - was made public. Soda plants using the Leblanc process were built around the country. And worse, this French method soon made British industrialists millions.

The Leblanc plant in Glasgow - and Tennant’s Stalk

Leblanc himself received nothing. Not only did he never receive the prize money, he lost his plant and any hope of making his fortune. The rest of his years were miserable, spent in and out of the poorhouse. In 1806, poverty-stricken and desperate, he shot himself.

But the Leblanc process still changed the world - in more ways than one. It was one of the first great chemical processes of the industrial age. The pure soda ash it produced out helped firms produce brilliant glass, perfect paper and cleaning products that helped improve living standards

Ironically, it was not the French but the British who most benefited from it. In Glasgow a complex of Leblanc plants were built, including one with the tallest chimney in the worlds. The plants are long forgotten - I went looking for them recently but there’s no trace left.

Perhaps that’s to be expected. For while Leblanc’s process had (like Abraham Darby’s innovation of refining iron using coal rather than charcoal) helped save the forests, it ushered in its own environmental problems.

These plants were responsible for hideous pollution. Those tall chimneys were there to send the noxious vapours elsewhere. Even so, the impact on the local environment was terrible. So in the 19th century Britain imposed one of the first environmental regulations in history - the Alkali Act, a precursor to many of the emissions rules to come. But what really put those Leblanc plants out of business was the march of technology

In 1861 a Belgian man called Ernest Solvay came up with a much cleaner way of turning salt (in the form of brine) into soda ash. Today the vast majority of the world’s soda ash (we still use enormous quantities) is made using the Solvay process. Not America, which, due to a geological quirk, happens to have staggering quantities of mineral soda ash buried in the ground in Wyoming, though that’s a story for another day.

But while Leblanc might seem a footnote in history, the episode is perhaps a helpful reminder that throughout history technological advances haven’t come out of nowhere. Leblanc didn’t suddenly, accidentally discover that salt could be turned into soda ash. It was a widely-understood and oft-discussed goal. But actually making it happen took time and money. It took Leblanc and that prize to make it happen.

Something similar goes for all sorts of breakthroughs during what we call the Industrial Revolution. In the 19th century aluminium was among the most precious substances in the world because no one had yet worked out a way to refine it in large quantities. Everyone know about “the aluminium problem”. But it took decades (and the advent of electricity in large quantities) until someone worked out how to refine it.

That’s worth remembering because a lot of people assume when the Industrial Revolution happened it just… happened - that there was no architect determining or influencing it from top down. But this isn’t quite true. There were loads of challenges/prizes like Leblanc’s. It is thanks to a series of French scientific prizes that we have tinned food, turbines and, for better or worse, margarine.

Indeed, since we have charged ourselves with doing the industrial revolution all over again, perhaps modern policymakers could take a leaf out of 18/19th century France and introduce a few more grand prizes to help encourage innovation today.

After all, there are plenty of modern equivalent challenges to turning salt into soda ash: How to make zero carbon concrete. Nuclear fusion. Solid state batteries. More efficient electrolysis of water. Cheap fossil fuel free ammonia production. Higher temperature superconductors. Affordable, zero carbon steel. The list goes on.

Time to learn from the forgotten story of Nicolas Leblanc, and to recapture some of the spirit of the enlightenment. Just try not to make the mistakes Leblanc himself made…

Needless to say, Leblanc features briefly in Material World and needless to say if you enjoyed this blog you should really pick up a copy. Out in paperback in the UK now!

1. My favourite other example of this, mentioned in passing in the book, was William Vernon Harcourt, an English parson who came up with all sorts of novel recipes for types of glass - but as an enthusiastic amateur, never actually turned them into the optical products which could change the world. That was only happened when Otto Schott and Carl Zeiss carried out similar experiments in Jena (now the east of Germany) decades later