The diagnosis of the presence of an enlarged thymus by percussion, I believe, has been considered by most physicians to be a difficult and uncertain performance.. Therefore, the advent of roentgen ray was hailed and is generally still believed to be a safe and dependable diagnostic method as applied to the thymus.
An experience during the past winter has convinced me that the diagnosis of an enlarged thymus with the aid of the roentgen ray is also liable frequently to be very uncertain and to be a source of erroneous interpretations and findings.
A brief recapitulation of this experience will bring out the interesting points.
REPORT OF CASE
In July, 1919, in the absence of the family physician in the army, I was called to atttend the child of a colleague, whose skin was scaly and itchy and who was breathing with difficulty. The boy, 12 months old, was quite