Journal of Applied Physiology, Vol 57, Issue 3 635-639, Copyright © 1984 by American Physiological Society
Stephen Hales: neglected respiratory physiologist
J. B. West
Stephen Hales was an eminent early 18th century scientist and minister of
the parish of Teddington near London. He is well known for his early work
on blood pressure. However, he made many contributions to respiratory
physiology. He clarified the nature of the respiratory gases,
distinguishing between their free (gaseous) and fixed (chemically combined)
forms, demonstrated that rebreathing from a closed circuit could be
extended if suitable gas absorbers were included (to remove carbon
dioxide), suggested a similar device as a respirator for noxious
atmospheres, invented the pneumatic trough for collecting gases, measured
the size of the alveoli, calculated the surface area of the interior of the
lung, calculated the time spent by the blood in a pulmonary capillary,
invented the U-tube manometer, and measured intrathoracic pressures during
normal and forced breathing. Hale's work is remarkable for its emphasis on
the "statical" method, i.e., meticulous attention to detail in measurement
and careful calculations. In his later life he made important contributions
in the area of public health. He was a trustee of the new colony of Georgia
and willed his own library of books to the colony though their whereabouts
is unknown. He deserves more recognition in the history of respiratory
physiology.
