University of Iowa Studies in Physics
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...that could have been left was not more than one tenth of what was originally on the part of the cell considered. These experiments indicate the following facts: 1. That filing changes the properties of the selenium so as to increase its conductivity, and that this at first lowered the relative sensibility to light. 2. By continued filing the relative sensibility, 1'. e., the ratio of the conductivity in the light to that in the dark, increases. 3. All the selenium on the Giltay cell is conducting, and light-sensitive. 4. That further experiments must be carried on by carefully weighing the selenium removed by each filing in order to determine whether the filing produces a surface action or whether it is more deep seated. The results that have just been stated were checked with a third sample of the cell, by filing away the selenium in three instalments. The following Table II. gives the results of the observations. In these the light intensity was kept quite constant in the comparative observations, although its value was not determined. TABLE II. Time of Observntion.'I?: o'A%5M_' 12:05 P. M. 1:: 24. 1:25. i 10.30.;Dec. 17.. Dec. 18. Conductivity in I l., I l dark.......... 4.2 9.0 10. 7.0 1 3 I 4 0.7 Conductivity with 1 I 1 faint light..... 62. 1 100. 90. 75. i 90. I By intense illumi-' 1 nation........ 85. 135. 118. 98. l 130. 135. 20. Comments....... Some sele-Probably After ' After I, nium 11100 011 11.111 resting i ' filing, of entire of the since away a surface. selenium 12:30 ' least-1-9-5 removed. ' of selenium. If it is a fact, as the table indicates, that the conductivity did not change by separate filings very much after the first filing until nearly all the selenium was removed, then it is certain...
- 189 x 246 x 7mm | 254g
- 13 Sep 2013
- United States
- black & white illustrations