Nathan Zuntz (1847-1920)--a German pioneer in high altitude physiology and aviation medicine, Part II: Scientific work.

For over 52 years, the work of Nathan Zuntz (1847-1920) covered an amazingly wide spectrum of research fields; metabolism, nutrition, respiration, blood gases, exercise, and high altitude physiology were the main themes. Zuntz achieved fame for his invention of the Zuntz-Geppert respiratory apparatus in 1886 and the first Laufband (treadmill) in 1889. To this experimental setup Zuntz later added an X-ray apparatus in 1914 to determine the changes in heart volume during exercise. Moreover, he constructed a climate chamber to study exercise under varying and sometimes extreme climates. For field studies Zuntz invented a transportable Gasuhr (dry gas measuring device). Zuntz was the first to describe the difference between laboratory data gained in a hypobaric chamber and the measurements at high altitude. He found that the barometric formula is not applicable in the field. Two balloon expeditions in 1902 by Zuntz and his pupil, v. Schroetter, marked the step from terrestrial physiology towards aviation medicine. An outline of the development of scientific aviation in Berlin from 1880-1918 elucidates how closely the aviation union, army, and scientific departments were connected with and dependent upon each other. In cooperation with these institutions Zuntz and v. Schroetter constructed an oxygen supply system and planned a pressure cabin for extreme altitudes above 10,000 m, a forerunner of modern systems in aviation and astronautics. In 1912, Zuntz and v. Schroetter each published papers on aviation medicine, both publications internationally unique in style and extent. Zuntz's work in its empirical approach was the counterpart to the established formal mathematical-physical reductionism of the German Physiological Society.(ABSTRACT TRUNCATED AT 250 WORDS)