The Chemical History of a Candle by Michael Faraday — Summary & Review

Michael Faraday’s The Chemical History of a Candle is a captivating exploration of chemistry through the humble candle flame. Faraday transforms a familiar object into a gateway to understanding fundamental chemical principles and natural philosophy. He begins by describing various types of candles—from tallow and beeswax to paraffin and Japanese wax—and their production methods, grounding the discussion in everyday materials. The core of the lectures unpacks the candle flame’s structure: how melted wax travels up the wick, vaporizes, and combusts to produce light and heat. Faraday’s experiments reveal how air currents shape the flame, and why the bright glow comes from tiny solid carbon particles glowing within it.

He distinguishes between different kinds of combustion, showing that bright flames owe their light to solid particles, while pure gas flames can burn hot but dim. Using phosphorus, gunpowder, and iron filings, Faraday illustrates the interplay of fuel, air, heat, and light. The surprising production of water from burning hydrogen in oxygen highlights chemical transformation and conservation of matter. Faraday then broadens the scope to explore the gases involved in combustion and atmospheric air’s composition, demonstrating hydrogen’s lightness and combustibility, oxygen’s role in supporting flame, and nitrogen’s inertness. Hands-on experiments reveal atmospheric pressure and elasticity, making abstract concepts tangible.

Further lectures focus on carbonic acid gas (carbon dioxide), produced by candle combustion and respiration. Faraday shows its properties—heavier than air, non-combustible, reactive with lime-water—and draws a compelling analogy between combustion and animal respiration. This connection underscores the chemical interdependence of living organisms and plants, linking breathing and burning as complementary processes.

The final parts delve into metals like platinum, covering their properties, refining, and unique behaviors under heat and electric discharge. Faraday’s demonstrations of metal vapors and light emissions add a fascinating dimension to the chemical story.

Throughout, Faraday’s warm, engaging style encourages curiosity and careful observation. He speaks directly to his audience, balancing scientific rigor with accessible explanations and occasional humor. Footnotes provide deeper chemical and physical context, while his reflective remarks reveal his affection for the subject and learners. The lectures illuminate not just the chemistry behind a candle’s flame but the broader chemical principles that connect everyday phenomena to the natural world.