spherical or ovoid forms, the atoms within each re-arranging themselves,
more or less, within the new "hole" or "wall." The figures are, of course,
three-dimensional, and often remind one of crystals; tetrahedral,
octagonal, and other like forms being of constant occurrence. In the
diagrams of the proto-compounds, the constituent atoms are shown by dots.
In the diagrams of the meta-compounds the dot becomes a heart, in order to
show the resultants of the lines of force. In the diagrams of the
hyper-compounds the same plan is followed. The letters _a_, _b_, _c_, &c.,
enable the student to follow the breaking up of each group through its
successive stages.

HYDROGEN (Plate V, 1).

[Illustration]

The six bodies contained in the gaseous atom instantaneously re-arrange
themselves within two spheres; the two linear triplets unite with one
triangular triplet, holding to each other relative positions which, if
connected by three right lines, would form a triangle with a triplet at
each angle; the remaining three triangular triplets similarly arrange
themselves in the second sphere. These form the proto-compounds of
hydrogen.

In the dissociation of these, each group breaks up into two, the two linear
triplets joining each other and setting free their triangular comrade,
while two of the triangular triplets similarly remain together, casting out
the third, so that hydrogen yields four meta-compounds.

In the hyper-condition, the connexion between the double triplets is
broken, and they become four independent groups, two like ix, in the