Boron is isolated in 1808 by Joseph-Louis Gay-Lussac and Louis-Jacques Thénard.

In the same year, the two French chemisst devise a chemical method for production of large quantities of potassium and sodium, a process which involves the reaction of the fused alkali with red-hot iron turnings in a clay-clad gun barrel.

The metal vapor thus liberated is condensed and collected.

In this year also, Gay-Lussac discovers the “law of combining volumes” by measuring the relative volume of gases involved in chemical reactions.

The law states that “when measured at the same temperature and pressure volumes of gaseous reactants and products of chemical reactions are always in simple ratio of whole numbers”.

Gay-Lussac and Thénard first obtain impure silicon in 1811 by passing silicon fluoride over heated potassium, but they fail to identity it as an element.

This same year, Bernard Courtois, a manufacturer of saltpeter from seaweeds, observes an unknown element when he obtains a violet vapor by heating seaweed ashes with sulfuric acid, a process used as a source of sodium and potassium salts.

This vapor condenses to a black crystalline substance with a metallic luster, which he calls “substance X”.

It will later be named iodine.

Jöns Jacob Berzelius, in discussing the work of Davy, Gay-Lussac, and Thénard in 1824, identifies boron as an element.

Berzelius is in this year the first to prepare a pure form of amorphous silicon; he names it silicium.

The same year, Berzelius isolates zirconium metal in impure form, which, even when ninety-nine percent pure, is hard and brittle.