*The most well-known is urea, a white crystalline substance, made up of 46% nitrogen.

In 1727, while experimenting with animal urine, Dutch Scientist, Herman Boerhaave, isolated the primary component of urine. He discovered a colourless, odourless solid, which we now know as Urea or Carbamide. The discovery is often attributed to French Chemist, Hilaire Rouelle as well, who isolated it in 1773.

Urea is a major component found in mammal urine. It is produced by various chemical reactions involved in metabolising food. Amino acids, simpler form of proteins, are metabolised and converted to ammonia, CO2, water and energy in the liver. Ammonia, however, is toxic to cells and needs to be excreted from the body. The liver converts ammonia to urea, which is non-toxic and can be safely carried in the bloodstream to the kidneys. From there, it is eliminated as a part of urine. Nitrogen is an important element found in urea which provides nutrients to the soil, essential for good crop production. However, since urea was known to be found in animal urine and bladders, it was quite cumbersome to produce it.