continued, after the force was removed, diminished as the specific gravity increased; as for instance, in
| Carbonic acid | it continued | 6 | seconds. |
| Common air | „ | 8 | „ |
| Coal-gas | „ | 10 | „ |
| Hydrogen gas | „ | 17 | „ |
There is therefore every reason to believe, that the actual relative mobilities of the gases are inversely as their specific gravities.
These experiments have been carried much further, in consequence of some peculiar results obtained at low pressures; but as I have not been able to satisfy myself respecting the causes, and have probably taken a wrong view of the phenomena, I shall refrain from detailing them, and merely observe, that there is no apparent connexion between the passage of gases through small tubes and their densities at low pressures. Olefiant gas then passes as readily as hydrogen, and twice as rapidly as either carbonic oxide or common air, and carbonic acid escapes far more readily than much lighter gases. Similar results are also obtained by diminishing the bore of the tube, and then even at considerable pressures, the effect produced by mobility alone is interfered with by other causes, and different times are obtained. These anomalies depend, probably, upon some peculiar loss or compensation of forces in the tube, and offer interesting matter of discussion to mathematicians.
Experimental Observations on the Passage of Gases through Tubes[1].
In a previous communication I have noticed briefly some curious effects which take place when gases are passed through tubes at low pressures. They consist in an apparent inversion of the velocities; those which traverse quickest when the pressure is high, moving more tardily as it is diminished, until they are among those which require the longest time in passing the tube; thus with equal high pressures equal volumes of hydrogen gas and olefiant gas passed through the same tube in the following times:—
- ↑ Quarterly Journal of Science, vii. 106.
