Samples of ammonium cyanate and urea

Two specimens to illustrate 'Isomierism':- urea and ammonium cyanate

In 1828, Friedrich Wöhler (1800-1882) wrote to Berzelius to say he had prepared urea 'without a kidney or living creature, be it man or dog'.

Wöhler treated silver cyanate with ammonia expecting to prepare ammonium cyanate. After purification the product he obtained was the organic compound, urea. It is popularly believed that this experiment refuted the theory of vitalism which maintains that organic compounds contain a vital force and cannot be synthesized from inorganic compounds. However, Wöhler himself does not claim to have carried out a true synthesis of urea since his cyanates were derived from organic matter such as dried blood, hoofs, etc.