File:Practical radiography - a handbook for physicians, surgeons, and other users of X-rays (1901) (14571330067).jpg

Identifier: practicalradiogr00isen (find matches)
Title: Practical radiography : a handbook for physicians, surgeons, and other users of X-rays
Year: 1901 (1900s)
Authors: Isenthal, A. W Ward, H. Snowden (Henry Snowden), 1865-1911
Subjects: Radiography X-rays X-rays Radiography X-Rays
Publisher: London : Published for The Photogram, Ltd. by Dawbarn and Ward, Ltd.
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

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onnecting the tinfoil ring through asmall gap with the cathode terminal. On the other handthis arrangement facilitates the passage of sparks roundthe tube and increases the risk or perforation ; Berlinertherefore replaced the tinfoil by a semi-conductor, pushinga wooden cylinder, moistened with glycerine, over thecathode neck of his tubes. A still better and simpler planis to wrap a piece of oiled linen, or of American cloth,round the cathode neck, connecting it to the cathodeterminal by means of copper wire, which also serves tofasten the wrapper round the tube. According to thedistance to which the wrapping is pushed beyond thecathode edge, the resistance of the tube may be varied. 102 Practical Radiography Recently Hirschmann has patented a method providingfor the arrangement of a metallic screen above the anti-cathode, but outside the tube and connected to the anode(Fig. 49). The latest and most promising method of regeneratinga tube is based upon the phenomenon of osmosis. Plati-
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ng. 49. num, when at red heat, becomes permeable by hydrogen.If we thus provide a tube with a branch terminating in asmall narrow tube of platinum or a platinum alloy, and ifwe carefully heat this narrow tube in a Bunsen or spirit-flame until red heat is attained, then the hydrogen fromthe flame passes into the bulb and reduces the exhaustion.It is obvious that this method is far superior to all othermeans of regeneration, since there is no limit to the supply Tubes for the Generation of X-Rays 103 of hydrogen as in the case of absorbent substances intro-duced into an auxiliary vessel and heated either electricallyor from the outside. The joint between glass and plati-num, however, requires to be effected with very great careso as to prevent any tendency to leakage. It must, however, be borne in mind that all thesevarious means of regenerating will only serve temporarily,and that a time will come when the only remedy lies inthe complete re-exhaustion of the tube. This again pre-suppos

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