—Gershon-Cohen630 describes roentgenographic technic. for observation of the soft tissue of the knee. Anteroposterior, lateral, oblique, longitudinal and intercondylar roentgenographic views of both knees should be made routinely. By strong traction, abduction or adduction of the leg, a transient vacuum can be created in the articular space and the outline of the meniscuses will be revealed in the roentgenogram. More than 8 to 10 cc. of synovial fluid, however, interferes with such a vacuum and prevents visualization of the meniscuses. The author feels that loose bodies, sprain of the tibial collateral ligaments, periarticular bursitis, cysts of the meniscuses, neoplasms and miscellaneous lesions of soft tissue can be diagnosed if this technic is used.McGaw and Weckesser631 discuss the use of pneumarthrography in 508 examinations of the knee among army personnel. They describe the technic when oxygen is used and outline a method of interpreting the findings.