The Right Chemistry: The Scientific Story Behind Lampe Berger

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A few years ago, I received a gift after speaking at a cosmetics conference. It was a handsome china item, about the size of a large coffee cup, decorated with artwork and described in an accompanying brochure as “Lampe Berger”. From a quick read, I understood that it was to be filled with the fragrant alcohol that was also provided and then lit at the top. I assumed it was similar to a scented candle and put it away. But now its status has been elevated and it’s on display in my little office museum along with other memorabilia and scientific curiosities.

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My interest in the Lampe Berger was revived by a comment by Sir Humphry Davy that I came across while researching the history of the “Davy safety lamp”. I have always been interested in Davy, the first real popularizer of chemistry. In the early years of the 19th century, the public flocked to Davy’s lectures at the Royal Institution in London to be entertained and educated by his chemical demonstrations and accounts of discoveries. The comment that caught my attention was his description of an observation of his as “more like magic than anything he’s ever seen; depends on a perfectly new principle in combustion. Being interested in magic and combustion, I had to investigate this further.

In 1815, Davy became concerned about the dangers coal miners faced from explosions of “fire moisture,” or methane as we know it today. It is a highly combustible gas released from coal seams during mining, and in the days before electric lights, miners’ use of candles or kerosene lamps posed the risk of igniting the methane and causing an explosion. Could a lamp be produced that would reduce the risk of igniting the gas? After much experimentation, Davy discovered that a fine mesh made of metal absorbed the heat of a flame and prevented it from passing through. The Davy safety lamp was born with a metal shade that surrounds a kerosene-fueled flame.

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It was during his experimentation with metals that Davy made his “magical” observation while experimenting with “fiery moisture” and a platinum wire. Held next to a flame, the wire began to glow as it heated up, which was no surprise. The surprise came when the flame was extinguished and the platinum thread continued to shine! Somehow, the methane burning around the cable continued, heating the cable even though no flame was visible. This was the new type of combustion that Davy had referred to. It was his younger cousin, Edmund Davy, who continued to investigate this phenomenon. A heated platinum wire exposed to ethanol remained red hot until all the alcohol was consumed. None of the Davys realized that they had been experimenting with one of the most important phenomena in chemistry, catalysis. The platinum wire had provided a surface on which combustion could take place without requiring the high temperature of a flame.

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In 1821, a German translation of Edmund Davy’s account caught the attention of Johann Wolfgang Döbereiner, professor of chemistry and technology at the University of Jena. He repeated the experiment and found that the ethanol was oxidized to acetic acid and noted that the platinum wire was not consumed in the process. Then, in 1823, a pivotal experiment occurred. Döbereiner directed a fine stream of hydrogen gas at a platinum thread a few centimeters away, allowing it to mix with air before hitting its target. The platinum quickly became red hot and ignited the hydrogen.

When the Swedish chemist Jons Jacob Berzelius learned of this discovery, he wrote that “From any point of view, the most important and, if I may use the expression, the most brilliant discovery of the past year is undoubtedly the one made by Döbereiner.” . It would be Berzelius who in 1835 would go on to coin the term “catalysis” for the phenomenon, defining it as the “ability of substances to awaken affinities, which are dormant at a certain temperature, by their mere presence and not by their own affinity”. .” Today, we define catalysis as the ability of a substance to increase the rate of a chemical reaction without undergoing any permanent chemical change.

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Döbereiner managed to capitalize on his discovery. By 1827 he had created the world’s first lighter. In those days, if you wanted to light a candle or a kerosene lamp, you needed tinder and a flint. Döbereiner designed a device in which hydrogen gas, generated by a reaction between zinc and sulfuric acid, was thrown at a piece of spongy platinum where it ignited. The flame would then be used to light a candle.

It was the surprising catalytic property of the platinum in the Döbereiner lighter that seems to have sparked an idea in the mind of Maurice Berger, a Frenchman with some training in chemistry who was interested in curbing the unpleasant odors that plagued morgues and hospitals. As early as 1856, there was a report of the smell of ozone on a heated platinum wire, and there were also reports of odor removal by ozone. Therefore, Berger began experimenting with a flameless alcohol burner in hopes of eliminating odors. He discovered that his Lampe Berger worked and suggested that ozone was the active agent, although its formation has never been confirmed. Foul-smelling compounds in the air are more likely to come into contact with hot platinum and oxidize. “Berger” lamps still exist and are produced in numerous artistic models and have indeed become collector’s items. They are powered by isopropyl alcohol which is combined with a variety of pleasant fragrances.

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While there is anecdotal evidence of the lamp’s ability to eliminate odors, proper scientific studies are lacking. However, there is no doubt that Lampes Berger is a very attractive collectible. And to me, they represent a fascinating glimpse into history. I also appreciate Döbereiner’s refusal to patent his invention, stating “I love science more than money, and knowing that I have been useful with it makes me happy.”

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Joe Schwarcz is director of the Office of Science and Society at McGill University (mcgill.ca/oss). He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3-4 p.m.