Can you tell the difference between these two molecules of urea? Image credit The urea on the left can be isolated from cattle urine (urea is the principal nitrogenous waste product of amphibians and mammals). The urea on the right can be produced via the Wohler process. They are, of course, exactly the same molecule. Subscribers to organic farming methods, however, believe that the urea on the left is an acceptable nitrogen source, while the urea on the right is not. Once upon a time, many years ago, people who considered such things believed that there were substances that could only be synthesized by living organisms. This dichotomy between living (organic) and non-living (inorganic) is the basis of today’s chemistry sub disciplines. It was understood that life arose from and involved “life forces” that were apart from the purely physical and chemical realm. In other words, all "living organisms are fundamentally different from non-living entities because they contain some non-...