johann hartmann beyer (1563 - 1625)
Johann Hartmann Beyer was a German physician, mathematician and statesman.
He earned a master's degree in liberal arts at the University of Strasbourg, and then graduated from the University of Tübingen with a doctorate in medicine. In 1588 Beyer returned to his native Frankfurt and began working as a physician; a year later he was appointed Physicus ordinarius - his duties included overseeing the city's health care and pharmacy system.
In 1614 Beyer took up the position of senior burgomaster of Frankfurt, but during the Fetmilch Rebellion he became involved in conflict, was forced to resign and returned to science.
He had the richest library of scientific books, numbering about 2500 volumes, wrote scientific works on astronomy and mathematics, engaged in medical activity, having invented the famous Frankfurt pills. Beyer carried on a lively correspondence with scientists, including mathematician Johannes Kepler, dealing with decimal fractions. Beyer bequeathed his rich inheritance to the city and to charity.