John Jacob Abel to successfully isolate the neutral base of epinephrine by adding ammonium to highly concentrated extract, a method Abel himself tried but failed due to the use of low concentration of extract. After Takamine's success, Abel himself remarked, with great candor, "The efforts of years on my part in this once mysterious field of suprarenal, medullary biochemistry, marred by blunders as they were, eventuated, then, in the isolation of the hormone not in the form of the free base but in that of its monobenzoyl derivative." Together with L.G. Rowntree and B.B. Turner, Abel devised what they called a "vividiffusion" apparatus,
John Jacob Abel his Ph.D., but instead decided to receive an M.D. in 1888 from the University of Strasbourg. After his doctorate, Abel worked mostly in clinical studies and took clinical courses, focusing on biochemistry and pharmacology. He traveled around Europe, mostly in Germany and central Europe, conducting research in biochemistry. During this time, Abel had a number of mentors that inspired his work and exposed him to a number of disciplines that eventually prompted him to work in biochemistry and pharmacology. Starting in 1884, Abel worked with doctors Ludwig von Frey in physiology and histology, Rudolf Boehm in pharmacology, Adolph Strümpell in