Selenium : its electrical qualities, and the effect of light thereon : being a paper read before the Society of Telegraph Engineers, 28th November, 1877 / by Willoughby Smith.

  • Smith, Willoughby, 1828-1891.
Date:
[1877]
Catalogue details

Licence: Public Domain Mark

Credit: Selenium : its electrical qualities, and the effect of light thereon : being a paper read before the Society of Telegraph Engineers, 28th November, 1877 / by Willoughby Smith. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    No. 3. Mark. A B C D E F G H I K L M N O P o R A Megohms. 373-1 4719 283-1 5175 633*3 320-9 654-9 42-97 31-67 48-62 687-6 92-56 65-04 123-4 11-19 •1449 -003105 356-5 Megohms. 183-4 4-185 152-8 33'i9 287-4 163-7 237-7 26-59 24-81 35-65 377-5 46-06 33*78 78-9 8-997 -1318 -003156 162-6 During the test while the light was excluded, the temperature gradually increased from 97° to 100 Fahr., and the resistance of bar A decreased from 373-1 to 356-5. During the test while the light was admitted, the temperature increased from 98-5° to 99°, and the resistance of bar A decreased from 183 4 to 162-6 megohms. Seven days intervened before the following- test was made, the box having been kept closed during that time. The arrangements were the same as in the previous test, with the exception that the bottom of the iron case was kept standing in a freezing mixture. The temperature was kept at 44° Fahr. for one hour before commencing the test. The results are given in Table 4.