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 research on extracting insulin, on November 1925, Abel finally was able to witness one of the most beautiful sights of his life, "glistening crystals of insulin forming on the sides of a test tube". While at the California Institute of Technology, Abel completed an article in the proceedings of the National Academy of Sciences entitled "Crystalline Insulin" in 1926. Although Abel's work received great compliments from the media and the science community, some doubted the purity of his crystals as preliminary tests revealed that they were in fact proteins. The test result was contrary to the dominant view at the