Berzelius, Jöns Jakob

Swedish chemist. He accurately determined more than 2,000 relative atomic and molecular masses. In 1813–14, he devised the system of chemical symbols and formulae now in use and proposed oxygen as a reference standard for atomic masses. His discoveries include the elements cerium in 1804, selenium in 1817, and thorium in 1828; he was the first to prepare silicon in its amorphous form and to isolate zirconium. The words ‘isomerism’, ‘allotropy’, and ‘protein’ were coined by him.

Berzelius noted that some reactions appeared to work faster in the presence of another substance which itself did not appear to change, and postulated that such a substance contained a catalytic force. Platinum, for example, was capable of speeding up reactions between gases. Although he appreciated the nature of catalysis, he was unable to give any real explanation of the mechanism.