The Pernod Accident

Doubs Sinks near Pontarlier

Useful Information

Location: Morteau.
(46.899023, 6.359682)
Open: no restrictions.
Only visible during AUG in some years.
Fee: free.
Classification: KarstLosing Stream
Light: n/a
Guided tours: self guided
Photography: allowed
Accessibility: no
Address: $CaveName$, Tel: +33-.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1790s Dr. Pierre Ordinaire creates a distilled patent medicine.
1797 Major Daniel-Henri Dubied buys the recipe and opens the first absinthe distillery in Couvet, Switzerland, with his son-in-law Henri Louis Pernod.
1805 Pernod builds a larger distillery in Pontarlier, France.
11-AUG-1901 day of the fire.
13-AUG-1901 André Berthelot visits the Luoe Spring.
1910 the father of speleology, E.A. Martel finds a swallow hole in the bed of the river Doubs and carries out a dye tracing experiment.
1976 Doubs River disappears completely underground during a severe draught.
AUG-2018 Doubs River disappears completely underground.


Fire at the Pernod Factory on 11-AUG-1901 after 1:30 hours.
Fire at the Pernod Factory on 11-AUG-1901 after 2 hours.
Fire at the Pernod Factory on 11-AUG-1901 after 3 hours.
L'Illustration of 17-AUG-1901 about the fire.
Bottles were melting by the heat of the fire.

This is not a page about a place, but it is one about the funniest accident we know of, which is based on karst geology.

During the 19th and the beginning of the 20th century a drink called absinthe was very famous in France. It was produced at the Pernod Fils factory from 1805 until 1938. Like all those anise liquors (e.g. Ouzo, Raki,...) it is a clear liquid until it is mixed with water, then it becomes milky.

Absinthe was quite similar to today's Pernod, which contains star anise, fennel, coriander, mint and 12 other herbs. But the original version, absinthe, included also the flowers and leaves of grand wormwood (Artemisia absinthium) making it bitter. It was actually named absinthe after this ingredient, but was also called la fée verte ("the green fairy") because of the green colour. Wormwood was rumoured of being poisonous, destroying the brain, making impotent, and being an aphrodisiac. The poisonous touch was part of the Absinth myth and was probably one of the reasons why it was popular. Unfortunately those peculiarities where also the base of public accusations and a campaign by social conservatives and prohibitionists. They chose this drink partly due to its association with bohemian culture, which they despised, the whole campaign was political and not based on facts. The chemical compound thujone, which is present in the spirit in trace amounts, was blamed for being a dangerously addictive psychoactive drug and hallucinogen. It would have been hard to get a lethal dose, or even hallucinations, without being killed by the alcohol much earlier, but the discussion was not based on facts. This was the era of prohibition and grumpy killjoys were the order of the day, not objectivity.

As a result absinthe was outlawed in France and subsequently in many other countries of the world until 1915. The Pernod liqueur of today was created as a replacement in 1938, avoiding all the "unhealthy" stuff, which fortunately did not include anise and alcohol. A revival of absinthe began in the 1990s, following the adoption of modern European Union food and beverage laws that removed long-standing barriers to its production and sale. A reformulated absinthe based on the original recipe was released by Pernod in 2005. But back to the story, it happened almost 15 years before absinthe was outlawed.

On 11-AUG-1901 a lightning hit the plant of the Pernod company in Pontarlier. It was set on fire, and the high temperature made the huge tanks with alcohol explode. About one Million litres of Absinth poured across the plant, down the sewer system and straight into the river Doubs. The river turned white and smelled of anise.

Two days later, André Berthelot visited the SpringSource de la Loue more than 15 km from Pontarlier, on the other side of a high mountain ridge. While enjoying the romantic atmosphere at the clear spring, he suddenly noticed a change. The water turned milky, and a smell of anise filled the air. He knew this smell from the pub, but he had to take a mouthfull, to believe it: The water of the big spring turned into a free apéritiv! It is not handed down, if he filled his water-bottle...

This story was heard by the founder of modern speleology, ExplainE. A. Martel, and nine years later he made a dye tracing experiment. He found a swallow hole in the bed of river Doubs and added a strong, non-toxic, green colour. 64 hours later, the Source de la Loue turned green. The connection of the Loue and the Doubs across the mountain ridge was proven and the dye tracing of groundwater invented.

But now the next act in this play started: the owners of some small mills along the Doubs had problems with a strange lack of water for many years now. When the water level was low there was not enough water to operate the mills, although the river had enough water above Pontarlier. And the situation worsened every year. But as they learned of the KarstPonors, they had an idea. They searched for the swallow holes at low water and simply filled them with concrete. So they blocked them successfully and the water stayed in the Doubs.

But now the residents along the Loue had problems with missing water. And so the case came before the court and a Solomonic decision was made: The already sealed ponors may remain as they are, but new changes to the water course will be penalised. Obviously a fair solution because both parties were equally unhappy with it.

The result is, it took a few decades, but since the 1970s the river falls dry again. The most spectacular event was in 2018, when the river fell completely dry for about 1 km near Morteau, also around the Saut du Doubs waterfall and at the Swiss border. It seems there were flood in winter which opened formerly sealed ponors in the river. And to make one thing clear: this is not related with global warming or climate changes, as some newspapers "guessed". Its simply karst development, the drainage is relocated underground. This is a completely basic thing in any karst area, though it is difficult to observe and this makes these events so extraordinary.

This kind of story happened in many karst areas all over the world. Another famous one is the KarstDonauversickerung (Danube Sink), where the water of the young Danube sinks to reappear in the SpringAachtopf (Aach spring). But Pernod liquor was never used for dye tracing experiments again!

If you want to visit the sites of this story, the possibilities are limited. Of course, there is still the factory of Pernod in Pontarlier, but the company is today a multinational group which owns for example half of the Scottish Whisky distilleries. They have visitor centers, distillery tours, and museum all over the world, but there is no possibility to visit the distillery at Pontarlier. Then there are the sinkholes in the river, unfortunately they are underwater and invisible. Only in very dry years its possible to get an idea where they are. There are more sinks at Morteau which swallow the Doubs in dry years and are worth a visit at that time. And finally there is the Source du Lison, where the water reappears, which is definitely worth a visit year round.