Worth one's salt - the Bex mines

Salt crystals form after brine seeps through a mine wall swissinfo.ch

The salt mines in Bex kept the population well supplied for over three centuries and were once a symbol of power and wealth.

This content was published on July 25, 2002 - 15:23

The 60-kilometre-long labyrinth in Bex lies under the hamlets of Villars, Chesières and Arveyes.

A trip into the bowels of the earth gives one a view of the hardships associated, long before the invention of modern drills, with the production of salt and its association with power and wealth, when the region was ruled by a series of French nobles.

Bex was already known to have saline springs when it was ruled by French aristocrats before the 15th century. However, Bernese invaders drove out the duke of Burgundy by 1474, and began excavations into the area's rocks to exploit the reservoir of brine several metres below the ground.

According to a local myth, the springs were first discovered at a point known as Le Fondement by a poor farmer, Jean du Bouillet, who had left his goats to pasture in the area. He found that the goats drank from two springs in the area but when he tasted the water, it was salty.

Bouillet - after whom the mines are named - then boiled the brine from the springs in a cauldron, only to find a layer of salt covering the bottom of the pot when the water evaporated.

Brine reservoir

Some of the brine produced in Bex can still be seen surrounding the reservoir at the mines' entrance, which now serves as an exhibition hall. The walls surrounding the reservoir hall are still encrusted with a brown and white carpet of gypsum and salt crystals.

There is also a foot of water between the walls and the main seating area for spectators.

Some of the visitors on this day, particularly the children, took sips of the water only to find themselves wincing with the shock of the salt on their tongues. Oddly, the Bex mines are known for being 'low density' in that the brine has just 300 grams of salt per litre of water.

Water or rats?

Even while I was watching the short film which prepares visitors for a train ride deep into the mines, I was distinctly aware, over the English translation in my headphones, of the constant sound of rushing water.

It sounded at times like rats shuffling by. However, the tour guide, Anita Ruegg, told me that this is the sound of brine being produced after water seeps through at least 400 metres of salt rock, out of our sight.

On the way to the train stop within the mine, we passed through a series of galleries whose walls had a dark, evenly mottled appearance, which Ruegg said came from the almost two centuries of hammering by local miners - long before the invention of dynamite, which was used to blast open the rest of the underground galleries.

Claustrophobic therapy

I have never regarded myself as claustrophobic but I found myself saying several Hail Marys while hurtling along in the last, open-air wagon of the train, which covers 1,500 metres and descends 400 metres into the bowels of the earth.

The subsequent feeling of being unsettled could also be attributed to the fact that the noisy locomotive snakes its way through a narrow tube of rock, peppered with dim lights and filled with a mild scent of sulphur.

It stopped at the Gare de St Pierre, which dates back to 1821, according to a plaque on the wall. Then came a precarious climb up 70 steps through a passage in the rock, once used by miners with wooden boxes strapped on to their backs to carry salt rocks up and down.

However, despite the damp feeling - with 80 per cent humidity inside the salt galleries - the temperature deep down is a pleasant 18 degrees centigrade all year round.

Subterranean lake

After a short walk through a descending maze of galleries - one of which includes a cache of hundreds of bottles of wines from the Vinicole de Bex locked behind heavy iron gates - we came upon a subterranean lake in the underground museum, the Salon du Talon.

Ruegg said that the lake, which lies several metres below the St Pierre train stop, is about 3,000 square metres in width and a hundred metres deep. It is estimated to contain over 50,000 tonnes of salt in suspension.

The Salon du Talon also contains an exhibition of tools and forge equipment used by miners through the centuries. In one corner, across from the lake, is a bone-coloured wall fountain, still oozing brine.

The guide also gave us a detailed explanation next to a water turbine dating back to 1900s about how salt extraction takes place today. Modern drills are operated at the push of a button, Ruegg said, every day, all year round.

A minimum of 40,000 tonnes is being extracted daily at the salt mines. However, according to the mines' director, Bruno Kemm, only a small proportion of this salt ends up on our tables.

"Around half goes directly to the chemical industry, mainly the company Novartis, and that is the starting point for raw materials for a lot of their products. About 1,500 tonnes is used for human consumption - a very small part of what we extract from the mine, only about three to five per cent."

Symbolic pit lamps

Another interesting feature of the exhibition area is a series of salt blocks, weighing 30 kilograms each, used as covers for lights marking our way out of the underground gallery. Ruegg says each block represents the amount of salt that a human being consumes on average over a period of 30 years.

Some of the children visiting the mines also took advantage of a small patch on the mines' wall to which visitors are allowed to take a hammer, and pocket the fruits - or salt - of their labour as souvenirs.

Salle des Fêtes

At the end of the exhibition hall, is the platform from which we took the train back to surface - and the Salle de Fêtes or banquet hall.

The hall is often booked for weddings or conferences. When I asked Ruegg why anyone would want to go into the salty entrails of the earth to celebrate a marriage, she said that it had something to do with the age-old superstitions about salt and luck.

As we rattled our way back to the entrance, I thought that, as a city-dweller with little interest in speleology and geology, I had finally understood the deeper (literally) meaning of the salt of the earth.

by MaryAnn Mathew

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