INTEREST IN ELECTRICITY SPARKED DISCOVERIES
Michael Faraday’s pioneering work helped change the course of history
For anyone in the business of science communication, the Royal Institution of Great Britain is a holy place. Founded in London in 1799 by the leading British scientists of the era, the institution aimed to promote scientific education and research with an emphasis on public lectures focusing on the application of science to everyday life. Perhaps the most famous lecturer to grace the institution’s hallowed amphitheatre was Michael Faraday, who enthralled audiences in the mid-19th century with lectures based on his numerous discoveries.
Before Faraday, electricity was essentially a curiosity. The ancient Greeks were undoubtedly amazed when they accidentally discovered static electricity by noting that rubbing a piece of amber with a cat’s fur allowed it to attract feathers. They gave us the word electricity, deriving from the Greek “electron” for amber.
Benjamin Franklin with his famous kite experiment showed that lightning was a form of electricity, and in 1800, Alessandro Volta generated electricity by chemical action. His “voltaic pile” consisted of a pile of alternating zinc and silver discs separated by pieces of cardboard soaked in salt water. A wire connecting the bottom zinc disc to the top silver disc produced sparks.
Volta’s invention had no immediate practical application but did prove to have entertainment value. Countryman Giovanni Aldini travelled around Europe sparking interest in electricity by “animating ” corpses with electric shocks. Young Mary Shelley witnessed one of these demonstrations, which is thought to have implanted the idea that eventually blossomed into one of the most famous science fiction stories of all time, Frankenstein.
Sir Humphry Davy, Michael Faraday’s mentor, put electricity to practical use, managing to isolate the element sodium for the first time by attaching the leads of a voltaic pile to two electrodes immersed in a salt solution. The positively charged sodium ions were attracted to the negative electrode where they picked up electrons to form neutral sodium atoms. Davy went on to isolate potassium, calcium, strontium, barium, magnesium, boron, chlorine and iodine through “electrolysis.” Davy’s work ignited Faraday’s curiosity about electricity eventually leading to his major discovery that placing a conductor in a changing magnetic field produces a current in the conductor. This was the key to Faraday’s conceiving the electric motor, transformer and generator, inventions that changed the course of history.
Faraday’s interests encompassed more than just electricity. Sitting on a shelf in the Faraday Museum in the basement of the Royal Institution of Great Britain is a small vial labelled “bicarburet of hydrogen,” a liquid that Faraday had isolated from of all things, whale oil! Today we know the colourless, sweetsmelling liquid as benzene, one of the world’s most important industrial chemicals, used in the production of plastics, pesticides, detergents, rubbers, drugs and explosives.
In the early 19th century, whale oil was used for lighting, either by directly burning it in lamps or by subjecting it to heat in a furnace to yield a gas that could be compressed to a transportable liquid for later combustion. Particularly favoured was the oil from the nose of the sperm whale because it burned with less odour and smoke than other fuels. The popularity of whale oil took a toll on whales and would probably have forced the creatures into extinction had the clean-burning kerosene lamp not been invented in 1857. Kerosene was distilled from petroleum and was cheaper, did not spoil like animal fats, and burned cleaner. Eventually, benzene would also be found to be a component of petroleum from where it was isolated by fractional distillation for use as a solvent in the printing, leatherworking, metal degreasing, paint stripping and particularly rubber manufacturing industries. It was even used as an aftershave lotion because of its pleasant smell.
Since benzene was found to dissolve caffeine readily, it was the solvent used in the original process to decaffeinate coffee beans. That was the invention of German coffee merchant Ludwig Roselius, back in 1905. Although advertised as “always harmless, always wholesome,” the decaffeinated coffee had traces of benzene. It seems Roselius was either not concerned with, or was unaware of the toxicity of benzene. By the time that he introduced his process, there had been reports of deaths among workers in tire factories where benzene was widely used because of its ability to dissolve rubber. Years later, benzene was found to cause leukemia and still represents an occupational hazard in the rubber and plastic manufacturing industries.
Lost in the accolades heaped on Michael Faraday for his great discoveries, is his campaign against pseudo-science, which was rampant at the time. Mediums were commonly using trickery during seances to convince the gullible of the presence of spirits and Faraday felt it was his duty to unmask these deceptions through public lectures. Were he with us today, he would be dismayed with the plethora of pseudo-science permeating the internet but would surely be thrilled by the wonders that his experiments in electricity germinated.