1276.  Then the sulphur apparatus was charged first, thus: 

        . . . . 0 deg.
    0 deg. . . . .
        . . . . 395
        . . . . 388
      Charge divided.
  237 . . . .
        . . . . 238
    0 . . . . after discharge.
        . . . . 0 after discharge.

Here app. ii. retained 238 deg., and gave up 150 deg. in communicating a charge of 237 deg. to app. i., and the capacity of the air apparatus is to that of the sulphur apparatus as 1 to 1.58.  These results are very near to each other, and we may take the mean 1.62 as representing the specific inductive capacity of the sulphur apparatus; in which case the specific inductive capacity of sulphur itself as compared to air = 1 (1270.) will be about or above 2.24.

1277.  This result with sulphur I consider as one of the most unexceptionable.  The substance when fused was perfectly clear, pellucid, and free from particles of dirt (1267.), so that no interference of small conducting bodies confused the result.  The substance when solid is an excellent insulator, and by experiment was found to take up, with great slowness, that state (1244. 1242.) which alone seemed likely to disturb the conclusion.  The experiments themselves, also, were free from any need of correction.  Yet notwithstanding these circumstances, so favourable to the exclusion of error, the result is a higher specific inductive capacity for sulphur than for any other body as yet tried; and though this may in part be clue to the sulphur being in a better shape, i.e. filling up more completely the space o, o, (fig. 104.) than the cups of shell-lac and glass, still I feel satisfied that the experiments altogether fully prove the existence of a difference between dielectrics as to their power of favouring an inductive action through them; which difference may, for the present, be expressed by the term specific inductive capacity.

1278.  Having thus established the point in the most favourable cases that I could anticipate, I proceeded to examine other bodies amongst solids, liquids, and gases.  These results I shall give with all convenient brevity.

* * * * *

1279. Spermaceti.—­A good hemisphere of spermaceti being tried as to conducting power whilst its two surfaces were still in contact with the tinfoil moulds used in forming it, was found to conduct sensibly even whilst warm.  On removing it from the moulds and using it in one of the apparatus, it gave results indicating a specific inductive capacity between 1.3 and 1.6 for the apparatus containing it.  But as the only mode of operation was to charge the air apparatus, and then after a quick contact with the spermaceti apparatus, ascertain what was left in the former (1281.), no great confidence can be placed in the results.  They are not in opposition to the general conclusion, but cannot be brought forward as argument in favour of it.