SNAPSHOTS OF THE ATOM

Evening Star, Issue 20670, 18 December 1930, Page 17

SNAPSHOTS OF THE ATOM

A NEW X-RAY TUBE The invention of tho new X-ray tube which takes “snapshots of atoms ” was announced at a meeting of the New York section of tho American Chemical Society. “It opens an almost unbelievably wide field in industrial development,” said Dr George L. Clark, professor of chemistry of the University of Illinois, wliero the tube was perfected a few days ago. The now_ tube takes in one minute difficult pictures that formerly required 100 hours, and in one-fifth of a second “simple” pictures that took two hours. These pictures are not tho familiar shadow pictures, such as taking the bones of a human hand, but a newer branch of X-ray photography known as diffraction patterns. These are pictures which show tho arrangement of atoms in crystals. “ In studying, for example, how cellulose is made synthetically into artificial silks, wo formerly,” said Dr Clark, “ had to give an exposure of 100 hours, which only showed ns the completed process, leaving us in ignorance of many of the intermediate stops that we needed to know most.” “This tube has taken a diffraction picture of cellulose in one minute. Then the next step, addition of sodium hydroxide to start mercerisation, has been taken in the next minute. We now can stop tho process at any phase and find out what is going on. “Tho pictures open an almost unbelievably wide field in industrial development. They are useful in every chemical process, except those changes which take place instantaneously. They are the rext thipg to motion pictures of atoms.” It is no larger than tho present tubes, and uses no higher voltages, but takes a greater current in millamperes. The tube was produced in the university X-ray laboratory. The speaker sketched other X-ray developments, showing tho new diffraction pictures of bone cancer compared with normal bones, and pointing out in the cancerous bouo “ the enormous molecular structural changes ” as revealed .by the photos. “Tiiis.” he said, “ points out a now method of medical and biological approach and diagnosis.” Hemps of cotton grown in ancient Egypt and in pre-Inca South America were analysed by the diffraction pictures, which, Dr Clark said, showed that these ancient fibres were stronger than any cotton now known on earth. They had about the strength of flax.