File:The Röntgen rays in medical work (1899) (14570246149).jpg

Identifier: rntgenraysinmedi00wals (find matches)
Title: The Röntgen rays in medical work
Year: 1899 (1890s)
Authors: Walsh, David
Subjects: X-rays Radiography X-Rays Radiography
Publisher: London : Baillière, Tindall and Cox
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

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es in diameter. In one * Both these drawings are from The Induction Coil in Practical Work, byLewis Wright. Macmillan and Co., 1897. 40 THE RONTGEN RA FS IN MEDICAL WORK part of its circumference is fused a small straight tube, witha platinum wire current terminal carrying at its free end analuminium disc, which projects into the globe. The diameter ofthe disc varies from J inch to 1 inch, but the smaller is found toproduce equally penetrative rays. At the opposite side of theglobe is another small straight tube, in which is sealed a platinumwire. On the free end of the latter, and projecting into the globe,is a square piece of platinum foil, fixed at an angle of 45° to thekathode. A branch from this anode end of the tube serves as aholder, and is left open for the purpose of exhaust. The alu-minium disc is the negative ( —), or kathode; the platinum is thepositive (+), or anode. Sometimes the piece of platinum is notused as the anode, which is attached to another terminal, forming
Text Appearing After Image:
Fig. 19. the bianodal form of tube (Fig. 19). In any case, the platinumtarget is often spoken of as the anti-kathode. For exhaustion the tube is attached to a pump, and the airwithdrawn to something less than the millionth of an atmo-sphere. With a good pump and with an operator who under-stands high exhausts, a moderate-sized tube may be prepared inhalf an hour. A special tube is required for use with an alter-nating current; it has two kathodes (A and B, Fig. 18), and theanode or anti-kathode (C) is placed midway between the two. The tube is a most important part of the Eontgen outfit, andwhen suited to the coil and of good definition will yield satisfac-tory results to the worker; but otherwise his time will be wasted.Unfortunately, it is not possible to say what are the exact condi-tions that make a good tube, so that another like it can be pro-duced at will, although, on the other hand, the excellences of atube, its definition and penetration, can always be tested before ELECTRIC

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