326 - 1836: “urila” the theory of the radicals in the study of the urine components

The work of an obscure author published in 1836 on an Italian chemistry and medicine journal is helpful in understanding a singular attempt to explain the constitution of urine components and, particularly, of urea, using the theory of radicals. The author, after several chemical experiments, hypothesizes that urine does not contain urea but a body called “urila” that nitric acid transforms into urea and that can be considered the radical of urea. The hypothesis of the radical, as a group of atoms which moves unchanged from a molecule to another during a reaction, presented by Lavoisier in 1789 and approved by Berzelius and Liebig in 1833, is rapidly accepted by the researchers in the first half of ‘800. Dumas and Liebig report in a paper published in 1838 that chemists discovered, investigated and characterized the different radicals in the past and will be engaged to the subject in the future. The chemists will continue to investigate all the known organic substances in order to understand “the sort of radical” to which they are connected elucidating the characteristic reactions and properties of each compound.