Ammonia

Ammonia was present in the primordial atmosphere of Earth, and may have been the source of nitrogen for the earliest forms of life, although much controversy exists over the details. In ancient Egypt, ammonium compounds were used in rites honoring the god Ammon, from which came the name we still use for the gas and its compounds. Early chemists learned to generate ammonia from animal parts such as deerhorn, and obtained ammonial preparations (spirits of hartshorn, etc.), but Joseph Priestley (1733-1804) first collected and experimented with the pure substance. C. L. Berthollet (1748-1822) proved that ammonia is composed of nitrogen and hydrogen.

In the nineteenth century, ammonia was sometimes manufactured by the action of steam on calcium cyanamide, called the cyanamide process, which in turn was made by reacting calcium carbide with nitrogen at high temperatures. In the early twentieth century, German chemists Fritz Haber and Carl Bosch learned how to make ammonia in large quantities by high-pressure catalytic reactions of nitrogen (from air) with hydrogen. Both men were awarded Nobel prizes—Haber in 1918 and Bosch in 1931. The Haber-Bosch process is the basis for modern ammonia production, although many improvements have been made in the details of the technology.