“…The histological features of the oil pneumonias are well known. They have been fully investigated by Pinkerton (1927 and1928), Ikeda (1937), Paterson (1938), andGraef (1939) in human necropsies and animal experients. The lung responds to the inhalation of oil by a foreign body reaction, with an outpouring of macrophages into the alveoli, and by the later formation of giant cells and septal fibrosis.…”