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Encyclopaedia Britannica, 11th Edition, "Liquid Gases" to "Logar": Volume 16, Slice 7Various

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Encyclopaedia Britannica, 11th Edition, "Liquid Gases" to "Logar": Volume 16, Slice 7

Name: Encyclopaedia Britannica, 11th Edition, "Liquid Gases" to "Logar": Volume 16, Slice 7
Author: Various

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hydrogen or the helium absorption, it is a legitimate inference that at
a temperature of 5° to 6° abs. helium would be as freely absorbed by
charcoal as hydrogen is at its boiling-point and that the boiling-point
of helium lies at about 5° abs.

  TABLE IV.--_Gas Absorption by Charcoal at Low Temperatures._

  +--------------------------------------------+--------+----------+
  |                                            | Helium.| Hydrogen.|
  |                 Temperature.               |Vols. of| Vols. of |
  |                                            |Carbon. |  Carbon. |
  +--------------------------------------------+--------+----------+
  | -185° C. (boiling-point of liquid air)     |    2½  |    137   |
  | -210° C. (liquid air under exhaustion)     |    5   |    180   |
  | -252° C. (boiling-point of liquid hydrogen)|  160   |    258   |
  | -258° C. (solid hydrogen)                  |  195   |    ..    |
  +--------------------------------------------+--------+----------+

The rapidity with which air is absorbed by charcoal at -185° C. and
under small pressures is illustrated by table V., which shows the
reductions of pressure effected in a tube of 2000 cc. capacity by means
of 20 grammes of charcoal cooled in liquid air.

  TABLE V.--_Velocity of Absorption._

  +-----------+--------+-----------+---------+
  |  Time of  |Pressure|  Time of  |Pressure |
  |Exhaustion.| in mm. |Exhaustion.| in mm.  |
  +-----------+--------+-----------+---------+
  |   0  sec. |  2.190 |   60 sec. | 0.347   |
  |  10   "   |  1.271 |    2 min. | 0.153   |
  |  20   "   |  0.869 |    5  "   | 0.0274  |
  |  30   "   |  0.632 |   10  "   | 0.00205 |
  |  40   "   |  0.543 |   19  "   | 0.00025 |
  |  50   "   |  0.435 |     ..    |    ..   |
  +-----------+--------+-----------+---------+

  TABLE VI.

  +----------+----------+-----------+
  |  Volume  | Occlusion| Occlusion |
  |  of Gas  | Hydrogen | Nitrogen  |
  | absorbed.| Pressure.| Pressure. |
  +----------+----------+-----------+
  |    cc.   |    mm.   |    mm.    |
  |     0    |  0.00003 |  0.00005  |
  |     5    |  0.0228  |    ..     |
  |    10    |  0.0455  |    ..     |
  |    15    |  0.0645  |    ..     |
  |    20    |  0.0861  |    ..     |
  |    25    |  0.1105  |    ..     |
  |    30    |  0.1339  |  0.00031  |
  |    35    |  0.1623  |    ..     |
  |    40    |  0.1870  |    ..     |
  |   130    |    ..    |  0.00110  |
  |   500    |    ..    |  0.00314  |
  |  1000    |    ..    |  0.01756  |
  |  1500    |    ..    |  0.02920  |
  |  2500    |    ..    |  0.06172  |
  +----------+----------+-----------+

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Encyclopaedia Britannica, 11th Edition, "Liquid Gases" to "Logar": Volume 16, Slice 7

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