1507.  I will first tabulate the results as to the restraining power of the gases over discharge.  The balls A and C (fig. 131.) were thrown out of action by distance, and the effects at B and D, or the interval n in the gas, compared with those at the interval p in the air, between E and F (fig. 132.).  The Table sufficiently explains itself.  It will be understood that all discharge was in the air, when the interval there was less than that expressed in the first or third columns of figures; and all the discharge in the gas, when the interval in air was greater than that in the second or fourth column of figures.  At intermediate distances the discharge was occasionally at both places, i.e. sometimes in the air, sometimes in the gas.

_______________________________________________________

______________
|                 |                                                   |
|                 |      Interval p in parts of an inch             |
|_________________|_________________________________________

__________|
|                 |                         |                         |
|                 | When the small ball B   | When the small ball B   |
| Constant inter- |   was inductric and     |   was inductric and     |
| val n between |    positive the       |    negative the       |
| B and D = 1     |   discharge was all     |   discharge was all     |
| inch            | at p in    at n in  | at p in    at n in  |
|                 | air before    the gas   | air before    the gas   |
|                 |                after    |                after    |
|_________________|_________________________|_______________

__________|
|                 |    p =   |    p =   |    p =   |    p =   |
|In Air           |    0.10    |    0.50    |    0.28    |    0.33    |
|In Nitrogen      |    0.30    |    0.65    |    0.31    |    0.40    |
|In Oxygen        |    0.33    |    0.52    |    0.27    |    0.30    |
|In Hydrogen      |    0.20    |    0.10    |    0.22    |    0.24    |
|In Coal Gas      |    0.20    |    0.90    |    0.20    |    0.27    |
|In Carbonic Acid |    0.61    |    1.30    |    0.30    |    0.15    |
|_________________|____________|____________|____________|__

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1508.  These results are the same generally, as far as they go, as those of the like nature in the last series (1388.), and confirm the conclusion that different gases restrain discharge in very different proportions.  They are probably not so good as the former ones, for the glass jar not being varnished, acted irregularly, sometimes taking a certain degree of charge as a non-conductor, and at other times acting as a conductor in the conveyance and derangement of that charge.  Another cause of difference in the ratios is, no doubt, the relative sizes of the discharge balls in air; in the former case they were of very different size, here they were alike.