In recent years medical men's attention has been called to a syndrome that might aptly be called Hamman's syndrome, since he was the first to describe it. 1 He reported his observations in 1937 and more fully in 1939. 2 His cases had been seen over a period of five years. Scott 3 later in 1937 reported 2 cases with similar signs and sypmptoms. Since that time others have added to this series—Faulkner and Wagner 4 as well as Morey and Sosman. 5 Because of the importance of the subject I wish to add another case to those already published. Hamman's explanation for the cause of this condition is that, owing to some weakness in an alveolar wall, it ruptures and the released air dissects its way through the fibrous tissue about the blood vessels into the hilus of the lung and thence into the mediastinal tissue. If the amount