Elements Discovered by the Electrochemical Method Sodium and Potassium

Lavoisier included lime and magnesia into The Table of Simple Bodies but excluded potassium and sodium hydroxides believing that they had complex composition and their nature had to be further studied. One might say that history was unjust to these elements, for barium, for instance, was isolated in a metallic state simultaneously with them, but had been discovered mnch earlier. However, history is a wayward lady. The discovery of sodium, potassium, magnesium, and calcinm is interesting in that it was made possible by electric cnrrent being successfully used for the first time. This marked the birth of the electrochemical method, a subsidiary to the chemical analysis. Subsequently, electrolysis of melted compounds made it possible to obtain other metals discovered earlier in their compounds. 

That is why we considered it justified to devote a separate chapter to the history of sodium, potassium, magnesium, and calcium. The time span in question is two years and H. Davy, one of the founders of electrochemistry, is the main character. 

Man had known sodium and potassium compounds for a very long time. Carbonates of these metals were used in Egypt for laundry. Common salt, one of the most widespread 

Although chemists had suspected for a long time that alkali earths were oxides of metals, the nature of soda and potash had not been studied up to the early 19th century. Even Lavoisier had no definite idea on this subject. He did not know what the basic constituents of soda and potash were and assumed that nitrogen could be a constituent. This confusion seems to stem from the similarity between the properties of sodium, potassium, and ammonium salts. 

Credit for determining these constituents belongs to H. Davy. At first he was dogged by failures he could not separate metals from soda and potash with the aid of a galvanic battery. However, soon the scientist understood his error—he used saturated aqueous solutions but the presence of water hinders decomposition. In October, 1807, Davy decided to melt anhydrous potash, and as soon as he started electrolysis of the alkali hydroxide melt, small balls resembling mercury with bright metallic lustre appeared on 

---