A manual of practical medical electricity - the Röntgen rays and Finsen light (1902) (14780564631)

Identifier: manualofpractica00turn (find matches)
Title: A manual of practical medical electricity : the Röntgen rays and Finsen light
Year: 1902 (1900s)
Authors: Turner, Dawson
Subjects: X-Rays Electrophysiology Electrosurgery Electric Stimulation Therapy Electrotherapeutics X-rays Electrophysiology Electrosurgery
Publisher: New York : William Wood & Company
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School



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which shouldfrom time to time be passed through the tube, and by theresistance offered to the passage of the electricity. Atthe proper degree of exhaustion, that part of the wall ofthe tube which is opposite the free surface of the anodewill be bathed with a greenish-yellow phosphorescence, 21—2 324 A Manual of Practical Medical Electricity and the bluish-white Hght in the body of the tube willhave disappeared. The resistance of the tube to thepassage of the electricity at first diniinishes until itreaches a minimum, and then rapidly augments again.The pumping process should not be considered completeuntil the resistance has been brought up to about thatof a 3-inch alternative air spark gap. Much, however,depends upon the size of tube exhausted and upon itstemperature. A fluorescent screen can also be used to determine thepresence and amount of X radiatioiL It is prudent tocarry the exhaustion a little further than is necessary togive the best results while on the pump, because the
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Fig. 141.—Diagram of Watsons Penetrator Tube. vacuum is liable to be slightly impaired during the processof sealing. Good makers of tubes are Miieller of Hamburg andHirschmann of Berlin ; the gold medal of the RontgenSociety was awarded to the former, and I have had someof the latter for more than a year in fairly constant use.Cox, of 10, Cursitor Street, or Miller, of 93, Hatton Garden,can supply these tubes. A large tube has the advantage of containing a greaterresidual store of air, which can be drawn on when desiredby slightly warming the tube. With a small tube, thevacuum increases so rapidly with use that it soon becomesdifficult, on account of the resistance, to pass the dischargethrough it. The tube should be held in a tube-holder, and the RoNTGEN X Rays 325 electrodes connected with the secondary terminals of theinduction coil by fine copper wire. The platinum anodeof the tube must be attached to the positive terminal ofthe coil, and the concave kathode of the tube to thene