Archives of Physiological Therapy Volume 1-2

Archives of Physiological Therapy Volume 1-2

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 edition. Excerpt: ...spite of this long exposure and consequent movement he was partial to the low vacuum tube on account of the great detail obtained, and it was here that he discovered that better work could be done with an old than a new tube, and that an old high or low vacuum tube gave off under certain conditions a ray not obtainable under any condition from a new tube, giving clear outline and great detail with short exposure. This he called the ray of selective absorption. This he has discarded for the more expressive terms Roentgen ray direct, indirect, and secondary. He does not believe the Roentgen ray to be homogeneous, but that the discharge from an X-ray tube consists of two distinctive classes of rays, their qualities dependent upon conditions to be described, and their combined action on a photographic plate is so detrimental to success as to render their separation a matter of importance. He assumes that the rays proceed from the focal point of the anode, whence they radiate in direct lines to the walls of the tube, here to be separated into the two classes to be described, the extent of this sepa ration varying in different tubes under different conditions. Roentgen recognized the occurrence of secondary radiation in substances outside the walls of the tube, but no effort has been made to demonstrate the occurrence of this process in the walls of the tube itself. The writer is convinced that two classes of rays emanate from the walls of the tube. The lines of flight of the direct rays being a continuation of their original lines of projection and the indirect rays being at various angles therefrom. The indirect rays possess to a marked degree the power of setting up secondary radiation in any object with which they come in contact. more

Product details

  • Paperback | 342 pages
  • 189 x 246 x 18mm | 612g
  • United States
  • English
  • black & white illustrations
  • 1236908740
  • 9781236908742