Sieverts' law, in physical metallurgy and in chemistry, is a rule to predict the solubility of gases in metals. It is named after German chemist Adolf Sieverts (1874–1947).[1] The law states that the solubility of a diatomic gas in metal is proportional to the square root of the partial pressure of the gas in thermodynamic equilibrium.[2] Hydrogen, oxygen and nitrogen are examples of dissolved diatomic gases of frequent interest in metallurgy.