differ by the addition of a triplet.

RHODIUM (Plate XVIII, 2).

Rhodium has a septet, which is to be seen in the _c_ of titanium (see _k_
in the titanium diagram) and differs only in this from its group.

PALLADIUM (Plate XVIII, 3).

In palladium this septet appears as the upper sphere in every ovoid of the
upper ring.

OSMIUM (Plate XVIII, 4).

We have here no new constituents; the ovoids are set free on the proto
level and the contained globes on the meta, all being of familiar forms.
The cigars, as usual, break free on the proto level, and leave their ovoid
with only four contained spheres, which unite into two nine-atomed bodies
as in silicon (see above).

IRIDIUM (Plate XVIII, 5.)

The twenty-one-atomed cone of silver here reappears, and its proceedings
may be followed under that metal (see diagram, p. 729, May). The remaining
bodies call for no remark.

PLATINUM (Plate XVIII, 6).

Again the silver cone is with us. The remaining bodies are set free on the
proto level, and their contained spheres on the meta.