Sir Humphrey Davy was born in 1778 and became a self-taught chemist. At 20 years old, he was invited by the Pneumatic Institution of Bristol to research the medical uses of gases. He enjoyed experimenting with laughing gas—nitrous oxide—but most of his work was serious, including his experiments with electrolysis: “Through electrolysis, he was able to isolate for the first time a number of elements, including, in 1807, sodium, the seventh most common element on earth” (293). It would now be possible to study the true nature of salt.

For hundreds of years, salt had been differentiated only by color, texture, and taste. It wasn’t until the end of the 17th century that chemistry was seen as an independent science. Without sophisticated tools to analyze its compound, “there was little definition of salt other than something made of white crystals” (295).

Johann Rudolf Glauber, a German chemist, extracted salt from a spring in Vienna. It was hydrated sodium sulphate, although this would not be known until Davy’s experiments. Glauber began selling the salt as a miracle cure to use in baths.

Nehemiah Grew studied health spring water at Epsom, a spring in Surrey, England. He isolated a salt that would be known as Epsom, which is now used “not only mechanically, but in the textile industry, for explosives, in match heads, and in fireproofing” (295).