Arginine. Arginine, or L-arginine as it is called with its L-structure, is a semi-essential amino acid. Arginine is involved in many metabolic processes and important in the treatment of heart diseases and high blood pressure.
Layman's explanation: Nitric acid was first discovered in 1648 by a German chemist, Johann Rudolf. However, in 1901 Wilhelm Ostwald developed the Ostwald Process, which became the principle way of producing nitric acid.
Nuclear Fission. The process of nuclear fission was discovered in 1938 by Otto Hahn and Fritz Strassmann and was explained in early 1939 by Lise Meitner and Otto Frisch.