As Martine de Bertereau languished in her cold, damp dungeon near Paris, she had plenty of time to ponder her misfortune. Martine and her husband Jean de Chastelet, the Baron de Beausoleil, were mining engineers, hired by an archduke, two emperors and a pope to rediscover long-lost mines and find new ones. In 1642, both baron and baroness were arrested and thrown into two of the most notorious gaols in France. How had things gone so badly wrong?
The couple certainly had enemies. But Martine played right into their hands. Her mistake had been to boast about her ability to pinpoint rich deposits of minerals and metals and plentiful supplies of good water, but then to lie about how she did it. Unlike the charlatans who dress up their claims with fake data and pseudoscience, Martine de Bertereau did the opposite. She got results by careful observation and experiment but claimed it was all done with divining rods and other occult instruments. She and her husband were destined to die in gaol, accused of practising forbidden arts.
MARTINE DE BERTEREAU鈥橲 deceit might never have been discovered if her son hadn鈥檛 been taken ill. In 1627 she was on her way to Burgundy to take the waters at the fashionable spa town of Pougues-les-Eaux when her eldest son Hercule was stricken with a 鈥渇laming heat in the intestines鈥�. They spent the next few weeks in the town of Chateau-Thierry while he recovered.
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Before they left, Martine told the doctor treating her son that she had discovered a spring in the town whose healing waters were every bit as good as those at Pougues. Investigation proved her right, and within a few years the town was attracting wealthy visitors in search of a cure for their aches, pains and constipation. Now, more than 350 years later, this incident has provided geological historian Martina K枚lbl-Ebert with proof of a very peculiar case of scientific fraud.
Martine de Bertereau was adept at pinpointing 鈥渂uried treasure鈥� in the form of minerals and metals. She came from a family expert in the 鈥渁rt of mines鈥� and in 1610 she had married Jean de Chastelet, the Baron de Beausoleil, prospector, engineer and alchemist. After they married, they spent the next 16 years travelling around Europe, commissioned by the cream of the European aristocracy to find ores worth mining. Finding good supplies of water was a vital part of the job, says K枚lbl-Ebert, director of the Jura Museum in Eichst盲tt, Germany. Miners needed lots of it to work their machines and to process ore. And of course, they needed wholesome drinking water.
In 1626, the couple returned to France at the request of the superintendent of mines. Mining was in poor shape in France. Many old mines had been lost, and mines that had been profitable a century earlier no longer made money. Only those nobles who operated covert mines seemed to benefit from the mineral wealth of France. The baron鈥檚 task was to find the vanished mines, search for new deposits and denounce any illegal operations he encountered. Confident that the enterprise would make them wealthy, the Beausoleils ploughed much of their own money into it.
鈥淭he local bailiff accused them of witchcraft. How else could anyone know what lay beneath the ground?鈥�
Not everyone welcomed their investigations. The next year, while they were prospecting in Brittany, a local bailiff raided their lodgings and seized their instruments, papers and samples. He accused them of witchcraft: how else could anyone know what lay beneath the ground? The magistrate was not convinced and dismissed the case. The Beausoleils were shaken enough to flee to Hungary, but after five years the desire to recoup their losses got the better of them and they returned.
This time, Martine wanted some guarantees. She wrote to the king, Louis XIII, asking permission to develop the mines they found. Her letter was less of a humble petition than a business plan, making much of their past successes and the astrological methods they used to achieve them. There was no reply.
Eight years later, with their money fast running out, she tried again. This time she wrote to Cardinal Richelieu, the king鈥檚 chief minister. Aware that she had to convince him they could deliver, Martine wrote what amounted to a manual for finding metals, minerals and water. Divining rods and other occult instruments featured prominently. There was no reply. Two years later, Richelieu ordered their arrest. Martine was incarcerated in the Chateau de Vincennes; the baron was sent to the Bastille. They were charged with practising astrology, casting horoscopes and chiromancy 鈥� palm-reading. Of these only chiromancy was a 鈥渇orbidden art鈥�, but that was enough to lock them away.
Despite the baroness鈥檚 tales of the occult, neither she nor her husband made use of anything more mysterious than their knowledge of the landscape, the nature of rocks and some simple chemistry, says K枚lbl-Ebert. The baroness had been indulging in the reverse of scientific fraud.
The vital clue was the incident at Chateau-Thierry. The baroness told the king she had set up her divining rods in the market place and followed where they led her. But unknown to her, Julien-Claude Galien, the doctor who had visited her son and who went on to develop the spring as a spa, had written his own account of the discovery. In his version, a 鈥渧irtuous lady鈥� detained in the town by her son鈥檚 illness had during one of her regular strolls 鈥渁dmired how the flagstones were much reddened and like painted with natural paint by virtue of our waters鈥nd she assured us that our humid element has hidden in the coldness of its substance the same properties as the waters of Pougues鈥�. No mention of divining rods, just the observation of iron oxides deposited by mineral-rich water.
If you remove all mention of astrology and divining rods from Martine de Bertereau鈥檚 letters, you are left with good advice on how to detect ores worth mining, where best to sink a well and how to test the quality of ground water, says K枚lbl-Ebert. To find water, for instance, Martine suggests looking for certain water-loving plants. Once you find a likely spot, she advises digging a hole, burying an oiled bowl and digging it up the next day. 鈥淚f you find in your vase little droplets of sweat, you are assured there is water in the place.鈥� To find out if there is enough of it to warrant digging a well, she suggests burying a woollen fleece, washed and combed to remove the grease, then measuring the amount of water you can wring out of it the next day. 鈥淭hat indicates how much water is seeping out the ground into the hole,鈥� K枚lbl-Ebert says.
The baroness also suggested experiments to test the purity of the water and ensure it was neither too acid nor too alkaline. 鈥淢ost of what she suggests makes good sense,鈥� K枚lbl-Ebert says. Water that leaves pockmarks in a lead or bronze bowl is too acid. Water that extends the cooking time of peas or beans is too alkaline. 鈥淚f water is very alkaline the lime reacts with beans and it takes longer to cook them,鈥� says K枚lbl-Ebert.
So why the deception? The Beausoleils might have imagined potential clients would be more impressed by special powers than by science. But it was more likely that the elaborate front was an attempt to hide the real tricks of their trade. In the mining regions of Germany and Hungary, where the couple had spent many years, miners had strict codes to prevent outsiders learning their secrets.
And why were the Beausoleils arrested? Someone wanted them out of the way, and their apparent dealings with unearthly powers offered a perfect pretext. Richelieu may have suspected them of spying. France had been at war with Spain since 1635, and Austria was Spain鈥檚 ally. The baron had close links with both. K枚lbl-Ebert prefers a more down-to-earth explanation: 鈥淰ery probably they got into trouble with some of the local noblemen who had run private mines for decades, possibly centuries, without paying their taxes,鈥� she says. 鈥淧erhaps it was a case of getting rid of some interfering foreigners who were poking their noses into their business.鈥�