He studied to be a mechanical engineer, but Thomas Midgley Jr's great successes — and failures — came as a chemist. It's been said that he may have killed more people accidentally than anyone else who ever lived.

Working at Delco, a subsidiary of General Motors, Midgley was assigned to solve the mystery of engine knock, a persistent ping or putt-putt sound that characterized and damaged early internal-combustion engines.

He figured out that the knocking sound was caused by an increase in pressure and temperature within the engine cylinders, and solved the problem not by changing the engine's design but by altering the chemical make-up of gasoline, adding a mix of tetraethyl lead and bromine extracted from sea water to invent "no-knock" or Ethyl gasoline in 1921.

Problem solved! Except lead is poisonous, and Midgley knew it. Any chemist knew it, even then, and that’s why Midgley’s Ethel Corporation rarely mentioned lead in its promotional materials.

Midgley himself took an extended medical leave in 1924 due to lead poisoning, and he authored a paper on lead poison hazards in 1925. Lead additives in ethyl gasoline were subsequently shown to be a major pollutant, causing brain and blood disorders, chronic illness, and elevated mortality. It hits children especially hard, causing lowered IQ and increased antisocial behavior.

There’s no reliable estimate of how many people were injured and killed by leaded gasoline, but — lots. Midgley's ethyl compounds were removed from gasoline beginning in the 1970s, as ‘unleaded’ gasoline became the standard. Worldwide, the last leaded gasoline for automobiles was discontinued earlier this year.

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In 1928, Midgley was transferred to Frigidaire (another subsidiary of General Motors), where he was tasked with finding a safer yet affordable replacement for the refrigerants then being used, all of which were either toxic, flammable, or both.

He came up with dichlorodifluoromethane, a mixture of primarily chlorine, fluorine and carbon. Called chlorofluorocarbons, or CFCs, this compound was trademarked as Freon, and became a common component in air conditioning, insect repellents, and refrigeration systems.

Problem solved! Except, evidence later showed that CFCs caused large-scale destruction of the planet's ozone layer, reducing humanity's protection from skin cancers and eye damage caused by ultraviolet radiation, and causing mutations in human DNA, weakening of the immune system, and other environmental damage. Freon leaks can also cause asphyxiation and death at higher concentrations, because its molecular structure displaces oxygen.

Most CFCs were phased out by the 1980s, but Freon is still in use. Again, good luck finding an accurate count of the deaths and damage, but it's estimated that a few hundred people are still killed annually by huffing Freon.

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When he played baseball on his high school team, circa 1905, Midgley experimented with numerous elements that could be applied to the ball to yield an increased curving effect — the spitball, it’s called. He certainly didn’t invent the spitter, but his bio at the National Academy of Sciences suggests that Midgley discovered bark from slippery elm trees, when chewed and mixed with saliva, works great for that intended effect. Slippery elm is still used by pitchers looking for an illegal advantage.

Late in life Midgley contracted polio, and as the disease progressed he was confined to his home, where he designed a series of pulley mechanisms that allowed him to get from his bed to the bathroom or his home office without assistance. Like his more famous inventions, however, this also presented an unexpected danger. On a November morning in 1944, Migley slipped and became tangled in the device's ropes, accidentally strangling himself.

10/29/2021