Observations upon the Loudness Recruitment Phenomenon, with Especial Reference to the Differential Diagnosis of Disorders of the Internal Ear and VIII Nerve

anteroposterior, true lateral and right and left obliques. Each of these may be taken on 8+-in. by 6+-in. films. A Potter-Bucky or Lysholm fixed grid should be used for all projections, otherwise the pictures will not be of good quality. It is desirable to take all but the frontal picture with the patient standing or sitting, so that the shoulders may drop to the maximum. The frontal picture should be taken last when one has examined the lateral view. One can then judge how much the central ray must be tilted in order that it passes along the plane of the intervertebral discs of the last three cervical vertebrT. These discs slope forwards and downwards quite considerably. If the straight X-rays are normal, then a cervical disc is not present and there is no arthritis of the small joints. If there is a diminution in the intervertebral disc spaces-and this is common from middle age onwards in the lowest three cervical vertebre-the radiological conclusions are more difficult. The presence of arthritis of the small joints, even with considerable osteophyte proliferation invading the exit foramen, does not necessarily mean pressure on the nerve. Conversely, the absence of osteophytes does not rule out pressure on the nerve, for the periarticular tissues may be swollen and be pressing on the nerve but they may not cast a shadow on the X-ray film. (2) Myelography. Owing to shortage of space this section of Dr. Bull's paper is omitted.