Das Element Stickstoff in der Welt der Briefmarken: Schmuckstücke für die Wissenschaft

The element nitrogen has manifold effects on life. Animals, plants and microorganisms contain the element in the reduced form in many cell components. In the biological nitrogen cycle, mainly microorganisms convert nitrogen into the different oxidation states. The element is a main contributor to the pollution of soil, water and air. Heterocyclic compounds with N as constituent can be toxic or beneficial to mankind. Many aspects of the subject nitrogen can adequately be documented by stamps issued world‐wide. The author can only present a percentage of the large amount of material available.