1289.  I compared damp and dry air together, but could find no difference in the results.

* * * * *

1290. Gases.—­A very long series of experiments was then undertaken for the purpose of comparing different gases one with another.  They were all found to insulate well, except such as acted on the shell-lac of the supporting stem; these were chlorine, ammonia, and muriatic acid.  They were all dried by appropriate means before being introduced into the apparatus.  It would have been sufficient to have compared each with air; but, in consequence of the striking result which came out, namely, that all had the same power of or capacity for, sustaining induction through them, (which perhaps might have been expected after it was found that no variation of density or pressure produced any effect,) I was induced to compare them, experimentally, two and two in various ways, that no difference might escape me, and that the sameness of result might stand in full opposition to the contrast of property, composition, and condition which the gases themselves presented.

1291.  The experiments were made upon the following pairs of gases.

 1.  Nitrogen and Oxygen.
 2.  Oxygen Air.
 3.  Hydrogen Air.
 4.  Muriatic acid gas Air.
 5.  Oxygen Hydrogen.
 5.  Oxygen Carbonic acid.
 7.  Oxygen Olefiant gas.
 8.  Oxygen Nitrous gas.
 9.  Oxygen Sulphurous acid.
10.  Oxygen Ammonia.
11.  Hydrogen Carbonic acid.
12 Hydrogen Olefiant gas.
13.  Hydrogen Sulphurous acid.
14.  Hydrogen Fluo-silicic acid.
15.  Hydrogen Ammonia.
16, Hydrogen Arseniuretted hydrogen.
17.  Hydrogen Sulphuretted hydrogen.
18, Nitrogen Olefiant gas.
19.  Nitrogen Nitrous gas.
20.  Nitrogen Nitrous oxide.
21.  Nitrogen Ammonia.
22.  Carbonic oxide Carbonic acid.
23.  Carbonic oxide Olefiant gas.
24.  Nitrous oxide Nitrous gas.
25.  Ammonia Sulphurous acid.

1292.  Notwithstanding the striking contrasts of all kinds which these gases present of property, of density, whether simple or compound, anions or cations (665.), of high or low pressure (1284. 1286.), hot or cold (1288.), not the least difference in their capacity to favour or admit electrical induction through them could be perceived.  Considering the point established, that in all these gases induction takes place by an action of contiguous particles, this is the more important, and adds one to the many striking relations which hold between bodies having the gaseous condition and form.  Another equally important electrical relation, which will be examined in the next paper[A], is that which the different gases have