With the application of the more accurate means of clinical investigation in the past decade, some of the views previously held concerning pathologic processes necessarily have needed revision. This has been true particularly with regard to the disturbed mechanism of the heart beat ever since the recent interest in cardiographic work. There must take place also a similar revision of our views concerning cardiac dilatation when one applies, as a check to findings from percussion and palpation, measurements determined by roentgen-ray examination. Any clinician, who has confirmed the results as to the size of the heart determined by percussion and palpation, with roentgen-ray measurements, must feel somewhat doubtful in detecting changes in the heart size of less than 1 cm., and not infrequently he will find that his bedside figures are at a considerably greater variance from the roentgenogram.
A further point that seems rather hazy in the minds of