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Description: | Chem.33.16 (entry number in white paint, removed). G (trade mark with scales acid etched on the glass) 454 (serial number acid etched on the glass) MANU E. Gundelach. circa 1904 Gehlberg, Germany. DES after RONTGEN,Wilhelm,Conrad,von. 1895 Wurzburg, Germany. DES after CROOKES,William,Sir. 1870 London, England DES after HITTORF,Johann,Wilhelm,Professor. 1869 Munster University, Munster, Germany. This is a three electrode gas tube or cold X-ray tube which has a charcoal regenerator. Early X-ray tubes were of the soft vacuum type and the vacuum increased with use, or hardened, so that the efficiency of the source increased. Coupled with the fact that the current in these tubes could not be controlled with the voltage, a property not appreciated by early users and experimentors. Since soft tissues required much lower intensities than bone etc. Most operators were forced to keep a large range of tubes of varying "hardness".
Several methods of regenerating the tubes were invented; Crookes' invented the potassium hydroxide side arm for his discharge tubes in 1874. When heated the gases given off reduced the "hardness" of the vacuum in the tube. Other methods included simply heating an empty side arm ie softening the glass and allowing osmosis of gas through the glass. This method was destructive and reduced the life of the tube. A method invented by E. Harrison Glew involved small pieces of iron coated in sealing wax. One of these was isolated by a magnet and heated until sufficient gas had been produced. Success was finally achieved with the acclusion process or automatic Glew process in 1906 . it relied on the increasing electrical resistance of the tube as it "hardened" to trigger sparks to pass to the side arm.
The anticathode of this tube is probably platinum in the form of a thin strip of foil held on a glass stem at the centre of the spherical bulb. The undished aluminium cathode lies at 45 degrees to the anticathode. The anode and cathode are in side arms. The lead in wires are platinum. The tube has a brass end cap and is mounted on a simple wooden stand with two ?silver terminals. Because of the thickness of the platinum anticathode the tube could not be used at any great power rating or there would be the risk of burning it out.
On show in the Healing Passion display from 2006. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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