names of bioröntgenography, or kinematoradiography."
Kennedy was holding his little audience breathless as he proceeded. I fancied I could see Anginette Phelps give a little shudder at the prospect of looking into the very interior of a human body. But she was pale with the fascination of it. Neither Forden nor the nurse looked to the right or to the left. Dana Phelps was open-eyed with wonder.
"In one X-ray photograph, or even in several," continued Kennedy, "it is difficult to discover slight motions. Not so in a moving picture. For instance, here I have a picture which will show you a living body in all its moving details."
On the screen before us was projected a huge shadowgraph of a chest and abdomen. We could see the vertebræ of the spinal column, the ribs, and the various organs.
"It is difficult to get a series of photographs directly from a fluorescent screen," Kennedy went on. "I overcome the difficulty by having lenses of sufficient rapidity to photograph even faint images on that screen. It is better than the so-called serial method, by which a number of separate X-ray pictures are taken and then pieced together and rephotographed to make the film. I can focus the X-rays first on the screen by means of a special quartz objective which I have devised. Then I take the pictures.
"Here, you see, are the lungs in slow or rapid respiration. There is the rhythmically beating heart, distinctly pulsating in perfect outline. There is the liver, moving up and down with the diaphragm, the
