From DNA to Beer

An inaugural dissertation, on the phenomena, causes and effects of fermentation; submitted to the examination of the Revd. William Smith, S.T.P. provost; the trustees and medical professors, of the College of Philadelphia; for the degree of Doctor of Medicine; on the second day of June A.D. 1790

Over a half century before Louis Pasteur’s work, which proved that microorganisms are the agents of fermentation, a medical student reports on his experiments, keeping in mind that temperature and volume changes may reveal something about the nature of fermentation. He concluded that something in the air—implied as chemical—causes fermentation.