The ions, therefore, seem to be formed by an agglomeration of neutral molecules maintained round an electrified centre by electrostatic attraction.

If the temperature rises, the thermal agitation will become great enough to prevent the molecules from remaining linked to the centre.

By measurements effected on the gases of flames, we arrive at very different values of the masses from those found for ordinary ions, and above all, very different ones for ions of contrary sign.

The negative ions have much more considerable velocities than the positive ones.
The latter also seem to be of the same size as atoms; and the first-named must, consequently, be considered as very much smaller, and probably about a thousand times less.
Thus, for the first time in science, the idea appears that the atom is not the smallest fraction of matter to be considered.

Fragments a thousand times smaller may exist which possess, however, a negative charge.