Amalgam (chemistry) inorganic chemistry. With water, it decomposes into concentrated sodium hydroxide solution, hydrogen and mercury, which can then return to the chloralkali process anew. If absolutely water-free alcohol is used instead of water, an alkoxide of sodium is produced instead of the alkali solution. Aluminium can form an amalgam through a reaction with mercury. Aluminium amalgam may be prepared by either grinding aluminium pellets or wire in mercury, or by allowing aluminium wire or foil to react with a solution of mercuric chloride. This amalgam is used as a reagent to reduce compounds, such as the reduction of imines to amines.
Dental amalgam controversy condoned the use of dental amalgam. In 1855, Dr. J. Foster Flagg, a professor of dental pathology in Philadelphia, experimented with new mixtures of amalgam. In 1861, he presented his findings to the Pennsylvania Association of Dental Surgeons and, in 1881, he published his book, Plastic and Plastic Fillings (Figure 4). (Amalgam fillings were often called "plastic fillings" at the time.) The inevitable result of this affair was that silver amalgam was proven to be, "an excellent filling material," and expanded dentistry's, "ability to save teeth." Around the same time, John and Charles Tomes in England conducted research on the