d
niobium, and we have again to note that nitrogen, like hydrogen and oxygen,
departs from its group type. Two other triad groups, the positive
aluminium, gallium and indium (the fourth unexamined) and the negative
phosphorus, arsenic and antimony (the fourth unexamined), have also six
funnels opening on the faces of a cube.

IV. _The Octahedron._--The simplest example of this is carbon (5 on Plate
III). We have again the funnel with its ovoids, but now there are eight
funnels opening on the eight faces of the octahedron. In titanium (6 on
Plate III) the form is masked by the protruding arms, which give the
appearance of the old Rosicrucian Cross and Rose, but when we look into the
details later, the carbon type comes out clearly. Zirconium is exactly like
titanium in form, but contains a large number of atoms. We did not examine
the remaining two members of this group. The group is tetratomic and
positive. Its negative pendant shows the same form in silicon, germanium
and tin; again, the fourth was unexamined.

[Illustration: PLATE IV.]

V. _The Bars._--These characterise a set of closely allied groups, termed
"inter-periodic." Fourteen bars (or seven crossed) radiate from a centre,
as in iron (1 on Plate IV), and the members of each group--iron, nickel,
cobalt; ruthenium, rhodium, palladium; osmium, iridium, platinum--differ
from each other by the weight of each bar, increasing in orderly
succession; the details will be given later. Manganese is often grouped
with iron, nickel, and cobalt (_see_ Crookes' lemniscates), but its
fourteen protruding bodies repeat the "lithium spike" (proto-element 5) and
are grouped round a central ovoid. This would appear to connect it with
lithium (2 on Plate IV) rather than with fluorine (3 in Plate IV), with
which it is often classed. The "lithium spike" re-appears in potassium and
rubidium. These details, again, will come out more clearly later.

VI. _The Star._--A flat star, with five interpenetrating tetrahedra in the
centre, is the characteristic of neon and its allies (4 on Plate IV)
leaving apart helium, which, as may be seen by referring to 3, Plate IV,
has an entirely different form.

There are thus six clearly defined forms, typical of classes, with
two--lithium and fluorine--of doubtful affinities. It is worthy of notice
that in diatomic elements _four_ funnels open on the faces of tetrahedra;
in triatomic, _six_ funnels on the faces of cubes; in tetratomic, _eight_
fun