Before becoming president, Herbert Hoover was an engineer who made a fortune mining in Australia and China. As a humanitarian, he was renown for organizing aid to Belgium during World War I. Perhaps unexpectedly, he was also a translator: in 1912, he and his wife Lou translated Georgius Agricola’s 1556 De Re Metallica, a foundational text in geology, into English. In a footnote to their translation, the Hoovers said that the word “petroleum” was originally coined by Agricola in another one of his works, De Natura Fossilium.

Grantley McDonald begs to differ, saying Agricola certainly talked about petroleum, but he was neither the first nor the only one. Others, like Pliny, were aware of mineral oil and bitumen. But Agricola, who was born Georg Bauer in Saxony in 1494, also didn’t coin the word.

“Petroleum” is a Latinization of the Byzantine Greek and means “rock oil,” a straightforward description of the syrup of hydrocarbons found between layers of rock. Before being tapped and processed to power the modern world (this month marks the 150 anniversary of the first successful oil pipeline, built in Pennsylvania), petroleum seeped and dribbled into other human uses, such as medicine, for centuries.

It’s the cataloging in ancient medicine that gives us the first known recorded use of the word “petroleum.” The Persian polymath Ibn Sina (c.980-1037), who was known in the West as Avicenna, discussed medicinal petroleum in his enormously influential encyclopedia of medicine. Its translation into Latin spread that knowledge into Europe, where it reached Constantinus Africanus (c.1020-1087), whom McDonald cites as the first Latin writer to “employ the word petroleum, nearly five hundred years before Agricola.”

What McDonald calls “a rich tradition of employing petroleum in medicine” included concoctions recommended for eye diseases, reptile bites, respiratory problems, hysteria, epilepsy, uterine prolapse, and bringing on menstruation. Mixing petroleum and the ashes of cabbage stalks was good for scabies. A preparation of petroleum was prescribed to warm the brain by applying it to the forehead.

Petroleum today is so intimately tied up with our world that it may seem strange to consider how it was once thought to be a rare and perhaps magical medicine. Not every word’s history is so rich and strange, but then few words have been so important.