X-ray photography has labored under the disadvantage of demanding long exposure, while, for practical purposes, instantaneous pictures were required. Pro fesser Rieder and Dr. Joseph Rosenthal, of Munich, have attained the desired end, reports Richard Guen-ther, U. S. Consul at Frankfort, Germany. After laborious experiments they have succeeded in obtaining in less than a second, X-ray photographs of the human chest, the patient ceasing to breathe meanwhile. Strong electric currents, especially good X-ray tubes, very sensitive photographic films and intensifying screens were used.

They have worked on unremittingly after their first success, and have now published in the "Medical Week " of Munich, a report concerning their further experiments. They find that high-priced and easily perishable films can be dispensed with, as less sensitive photographic plates will produce as good a picture in not more than a few seconds. It is, however, of the greatest importance that the time of exposure be shortened as much as possible for certain X-ray photographs, for instance, when it is desired to show the structure of the lungs.

While they formerly had taken a photograph during one intermission of breathing, they tried to reduce the time of exposure to the time between the beatings of the heart, as the heart beats impair the exactness of the picture. It was evident that for X-ray pictures of the heart such an accomplishment would be of great value. The first difficulty was to get a precise and reliable measurement of the length or time necessary to apply the rays for photographic purposes. This they accomplshed by a contrivance consisting principally of a wooden disk covered with lead, the diameter of which is about 39 inches. From this disk a sector was cut, amounting to about one-seventh of its total surface. The object to be photographed and the sensitive plate were placed behind the disk and the X-ray apparatus in front. The X-rays were passed through the opening in the disk while it revolved on its center once in a second, the exposure of the plate to the ray thus lasting one-seventh of a second. By changing the speed of the revolution of the disk the time of utilizing the X-rays could of course be either increased or decreased. The X-ray apparatus was supplied with a tube of very thin glass. In addition, the most sensitive films and especially strong X-rays were used. Good X-ray photographs were secured in one-tenth of a second. The outlines of the heart and of large portions of the lungs can be photographed with much greater success than was possible heretofore.