He was named emeritus professor of pathology at the University of Pennsylvania and was the director of the Henry Phipps Institute for the Study, Treatment and Prevention of Tuberculosis from 1935 until 1955.
Long served in the United States Army Medical Corps during World War II as director of the tuberculosis program.
[2][3] Long completed his secondary education at Morgan Park Academy in 1906, then spent a year receiving private tutelage in chemistry from his father and others.
[4] Long received his Ph.D. in 1918[4] with a thesis titled, Some Phases of Normal and Abnormal Purine Metabolism in Man and Domestic Animals.
[4] They were married on June 17, 1922, and would have a daughter, Judith Baird,[1] and a son, Esmond R. Long Jr.[2] Marian was a skilled pianist and taught piano students.
[10] The couple would honeymoon in Vienna, Austria, where Long performed post-graduate research at the University of Prague under the Austrian pathologist Anton Ghon.
[2] In 1932, Long moved to Philadelphia with his family, where he became professor of pathology at the University of Pennsylvania and a researcher at the Henry Phipps Institute for the Study, Treatment and Prevention of Tuberculosis, bringing with him Florence Seibert.
In time, she was able to crystallize and purify the substance that served as basis of the PPD skin test used for TB screening to the present day.
[13] With World War II under way, in 1940 the National Research Council asked Long to chair the tuberculosis subcommittee of the Division of Medical Sciences.
In 1945, he traveled to the Europe theater where he visited the Army medical personnel treating former prisoners at the Buchenwald and Dachau concentration camps.