Michael Faraday’s Famous Discourse on the Candle, Its Impact on Chemistry, and How Modern Eco-Friendly Candles Are Revolutionizing the Industry

By Marco Arezio

In the heart of Victorian London, in December 1848, Michael Faraday stood before an audience of young students at the Royal Institution. The renowned scientist, famous for his discoveries in electromagnetism and chemistry, was about to deliver one of his most remarkable scientific outreach lectures: "The Chemical History of a Candle."

With his unique ability to make complex concepts accessible, Faraday chose a simple and familiar object—the candle—to illustrate fundamental principles of chemistry and physics. Over the course of six lectures, he demonstrated how the flickering flame concealed significant chemical phenomena, from combustion to the formation of carbon dioxide, from capillarity to the role of oxygen in energy processes.

At the time, these lessons were revolutionary in their educational approach, and they remain a brilliant example of scientific communication today. Beyond being a masterpiece of dissemination, Faraday’s discourse serves as a bridge for reflecting on the evolution of candles up to the present day, when sustainability has become a priority. In a world increasingly concerned with environmental impact, candles have transformed from a mere source of light into a product that must now address the need to reduce emissions and use renewable materials.

Michael Faraday: Scientist and Pioneer of Chemistry and Electricity

Michael Faraday’s figure stands out with extraordinary prominence in the scientific landscape of the 19th century. Born in 1791 in Newington Butts, a suburb of London, into a humble family, young Faraday had no access to advanced formal education. However, thanks to his insatiable curiosity and passion for reading, he educated himself while working as an apprentice bookbinder.

The opportunity of a lifetime came when he managed to attend a series of lectures by the great chemist Humphry Davy at the Royal Institution. Enthralled by the wonders of science, Faraday took meticulous notes and sent Davy a detailed report of the lessons, earning himself a position as his assistant. From that moment on, his scientific career took off, leading to a series of discoveries that would change the world.

Faraday was a pioneer in several fields: from electromagnetic induction, which laid the groundwork for the development of electricity generation, to the discovery of benzene, still crucial in the chemical industry today, to his studies on electrolysis, which revolutionized our understanding of electrical conduction in liquids. However, beyond his scientific contributions, what made him truly exceptional was his remarkable ability to disseminate knowledge—an ability that found its highest expression in his lectures on the candle.

The Chemical History of a Candle: Faraday’s Lecture

The Experimental Method

Faraday opened his lecture with a seemingly simple yet profoundly scientific question: "What is a candle?" By encouraging his audience to observe critically, he demonstrated that a whole universe of chemical and physical phenomena lay hidden behind the flame. According to Faraday, the experimental method does not require sophisticated instruments—even an everyday object can reveal fundamental laws of nature.

The Composition of the Candle

One of his first observations concerned the material of the candle. At the time, the most common candles were made from tallow, an animal fat, or beeswax.

The Combustion Process

Faraday explained that a candle flame is divided into different regions: the dark inner zone, where the wax vaporizes; the bright middle zone, where incandescent carbon particles emit light; and the blue outer zone, where complete combustion occurs. Through simple experiments, he demonstrated how each phase of the process was governed by precise chemical laws.

The Role of Oxygen

To illustrate the importance of oxygen in combustion, Faraday extinguished a candle under a glass dome. This simple experiment was revolutionary for the audience at the time, as it helped reinforce Lavoisier’s theory of combustion, which established the crucial role of oxygen in burning processes.

The Production of Water and Carbon Dioxide

One of the most surprising experiments involved collecting the combustion products: Faraday demonstrated that a burning candle produces water and carbon dioxide—a concept not widely understood at the time but essential to modern chemistry.

From Traditional Candles to Sustainable Candles

In the 19th century, candles were an essential source of light, but their role has since evolved. Today, they are primarily decorative and used for relaxation and aromatherapy. However, the industrial production of candles presents significant environmental challenges.

Environmental Issues with Traditional Candles

Most commercially available candles today are made from paraffin, a petroleum byproduct. When burned, paraffin candles can release volatile organic compounds (VOCs), which may be harmful to air quality. Additionally, wicks containing lead and other toxic substances can pose health risks.

Eco-Friendly Alternatives

To address these concerns, more sustainable alternatives have been developed:

- Soy wax candles, made from a renewable resource and ensuring cleaner combustion.

- Beeswax candles, biodegradable and capable of purifying the air by releasing negative ions.

- Coconut wax candles, a natural solution with slower, more efficient burning.

- Eco-friendly wicks, made from cotton or wood, eliminating the release of heavy metals.

The shift toward sustainable candles aligns with the broader philosophy of circular economy, aiming to minimize the environmental impact of consumer products.

Conclusions

Faraday’s lesson on the candle was not only a brilliant demonstration of applied chemistry but also an invitation to observe the world with curiosity and scientific rigor. Even today, his teaching method serves as a model for science communication.

In our time, the candle has become a symbol of well-being and ambiance, yet its production must contend with the need to reduce environmental impact. From the flames illuminated by Faraday in the 19th century to today’s eco-friendly candles, science and sustainability continue to intersect to deepen our understanding of the world and lessen our footprint on it.

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Photo: Wikimedia