Abstract: An overview is presented of photosynthesis and the problems involved in attempting to study and understand this process. The study of the order of appearance of the compounds in time and the methods of separation and analysis are discussed. About twenty compounds in the process of photosynthesis have been identified. Additional information was obtained which is more crucial in defining the path of carbon in photosynthesis. Degradative methods were devised which not only determined the compounds containing the radioactive carbon atoms, but also determined which atoms in the compounds are the radioactive ones.