For the International Day of Light, we invite you to reflect (pun intended) on this charming juvenile biography of the scientist Sir Humphry Davy (1778-1829).
Sir Humphry Davy was a Cornish chemist and inventor with quite the record of scientific achievement:
Developed electrolysis (the process of using electricity to isolate elements)
Discovered the elements barium, boron, calcium, magnesium, potassium, and sodium as well as the compounds hydrogen telluride and hydrogen phosphide
Studied and wrote about the anesthetic effects of nitrous oxide (aka “laughing gas,” a term he also coined)
Proved that diamonds are made of carbon
Served as president of the British Royal Society; inaugural chairman of the Athenaeum Club; and co-founder of the Zoological Society of London
Davy was such a formidable player in the European realm of scientific learning that despite the fact that England and France were at war at the time, Napoleon gave the Englishman special permission to visit France’s leading scientists and have an audience with Empress Marie Louise in 1813.
So what, you may ask, does Sir Humphry Davy have to do with light? In the foregoing summary of the scientist’s life, we have left out his most famous accomplishment: the Davy safety lamp.
Naturally, coal miners working in the dark depths of the earth need artificial lighting by which to do their work. The problem was in early nineteenth-century northern England, the flame of the miners’ candles kept mixing with a natural flammable gas found in the mines, known as “firedamp,” causing a series of devastating explosions that claimed the lives of hundreds of miners. Moved by the suffering of working-class families in northern England, Robert Gray, the rector of Bishopwearmouth, appealed to Davy in a letter in 1815 to develop a method of lighting mines safely. Over the next several months following this charge from the clergyman, Davy developed his famous safety lamp. The safety lamp works by enclosing a flame in a wire mesh cylinder. This cylinder disseminates the heat that would otherwise cause the flame to explode upon contact with a flammable gas.
Henry Mayhew’s semi-fictionalized biography (featured here) of a young Humphry Davy uses a narrative of the chemist’s life to teach readers about the scientific properties of two things that are essential to Davy’s famous invention: heat and light. Along the way, Humphry teaches his younger sister, Kitty, about refraction and reflection and how these light phenomena can be used to trick the eye:
Humphry explains the role that light refraction plays in producing superior mirages. Superior mirages of ships at sea, which make vessels look like they are floating in midair, may be the origin of flying boat legends, such as the Flying Dutchman.
Humphry explains to Kitty the principles of reflection in mirrors.
Humphry debunks a popular trick to play on people looking for a paranormal encounter:
“It is a favourite experiment to place a skull, strongly illuminated, in the outer apartment, and to reflect an image of it amid the smoke, so as to be visible to the spectators in the inner room.”
Mayhew, Henry. The Wonders of Science, or, Young Humphry Davy. New York: Harper & Brothers, 1856.
Catalog record: https://bit.ly/3Pdk2F7
