than stations' capsules or shuttles and since they still use pure O2, an acclimation period is common in the airlock to remove nitrogen and other gases from the bloodstream. Etymology The term "space ebullism" was introduced by Captain Julian E. Ward in his paper "The True Nature of the Boiling of Body Fluids in Space", published in Aviation Medicine in October 1956. It was suggested "because the word ebullism does not connote the addition of heat to produce vapor." It comes from Latin ebullire, meaning "to bubble out, or to boil up." See also References Medical terminology Space medicine