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How did Sir Humphry Davy isolate potassium and sodium in 1807?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — alkali metal Modern version of the periodic table of the elements (printable).

In October 1807, the English chemist Sir Humphry Davy successfully isolated potassium and sodium by utilizing the process of electrolysis.12

Davy had theorized that chemical compounds were held together by electrical forces of opposite charges and concluded that applying an electric current could decompose these substances into their constituent elements. To achieve this, he used a powerful voltaic battery to decompose molten compounds. Specifically, he obtained potassium by applying this electrical current to molten potassium hydroxide. Following this success, he applied the same method to isolate sodium from its compounds.2431

This achievement marked a significant milestone in electrochemistry, demonstrating that electricity could be used to isolate highly active metals that had previously resisted chemical separation.4