Page:The Liquefaction of Gases.djvu/58

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54
Faraday.

certain results with a portion of liquid which exerted a pressure of six atmospheres at -106° Fahr.

Fahr. Atmospheres. Atmospheres.
°
-40 · · 10.20 · ·
-35 · · 10.95 · ·
-30 · · 11.80 · ·
-25 · · 12.75 · ·
-20 · · 13.80 · ·
-15 · · 14.95 · ·
-10 · · 16.20 · ·
-5 · · 17.55 · ·
0 · · 19.05 · · 24.40
5 · · 22.50 · · 26.08
10 · · 24.45 · · 27.84
15 · · 26.55 · · 29.68
20 · · 28.85 · · 31.62
25 · · · · 33.66
30 · · · · 35.82
35 · · · · 38.10

The second column expresses the pressures given as the fluid was raised from low to higher temperatures. The third column shows the pressures given the next day with the same tube after it had attained to and continued at the atmospheric temperature for some hours. There is a difference of four or five atmospheres between the two, showing that in the first instance the previous low temperature had caused the solution of a more volatile part in the less volatile and liquid portion, and that the prolonged application of a higher temperature during the night had gradually raised it again in vapour. This result occurred again and again with the same specimen.[1]

Cyanogen.—This substance becomes a solid trans-

  1. This substance is one of those which I liquefied in 1823 (see Philosophical Transactions). Since writing the above I perceive that M. Natterer has condensed it into the liquid state by the use of pumps only (see Comptes Rendus, 1844, 18th Nov. p. 1111), and obtained the liquid in considerable quantities. The non-solidification of it by exposure to the air perfectly accords with my own results.