Sodium amalgam sodium metal in mercury or the reverse. Sodium amalgams can be purchased from chemical supply houses. Since its introduction in the 1880s by students of Robert Bunsen, Julius Tafel and Hans Goldschmidt, sodium amalgam has also been used in organic chemistry as a powerful reducing agent, which is safer to handle than sodium itself. An example of its use is in the Emde degradation. A sodium amalgam is used in the design of the high pressure sodium lamp providing sodium to produce the proper color, and mercury to tailor the electrical characteristics of the lamp. Sodium amalgam is a by-product
What Is History? to suit their facts, and takes part in a dialogue between past and present. Summing up his argument, Carr puts forward his own answer to the question of "what is history?", remarking that "it is a continuous process of interaction between the historian and his facts, an unending dialogue between the past and the present." it is precisely for matters of this kind that the historian is entitled to rely on what have been called the auxiliary sciences of history In his second chapter, Carr focuses on the influence that society plays on forming the approach of the historian and