ion: PLATE XVI.]

SILICON (Plate XVI, 1) is at the head of the group which corresponds to
carbon on the opposite turn of the lemniscate. It has the usual eight
funnels, containing four ovoids in a circle, and a truncated "cigar" but no
central body of any kind. All the funnels are alike.

SILICON: 8 funnels of 65 atoms 520
Atomic weight 28.18
Number weight 520/18 28.88
GERMANIUM (Plate XVI, 2) shows the eight funnels, containing each four
segments (XVI, 4), within which are three ovoids and a "cigar." In this
case the funnels radiate from a central globe, formed of two intersecting
tetrahedra, with "cigars" at each point enclosing a four-atomed globe.

GERMANIUM: 8 funnels of 156 atoms 1248
Central globe 52
----
Total 1300
----
Atomic weight 71.93
Number weight 1300/18 72.22
TIN (Plate XVI, 3) repeats the funnel of germanium, and the central globe
we met with in titanium, of five intersecting tetrahedra, carrying twenty
"cigars"; the latter, however, omits the eight-atomed centre of the globe
that was found in titanium, and hence has one hundred and twenty atoms
therein instead of one hundred and twenty-eight. Tin, to make room for the
necessary increase of atoms, adopts the system of spikes, which we met with
in zinc (see Plate IX, 2); these spikes, like the funnels, radiate from the
central globe, but are only six in number. The twenty-one-atomed cone at
the head of the spike we have already seen in silver, and we shall again
find it in iridium and platinum; the pillars are new in detail though not
in principle, the contained globes yielding a series of a triplet, quintet,
sextet, septet, sextet, quintet, triplet.

TIN: 8 funnels of 156 atoms 1248
6 spikes of 126 " 756
Central globe 120
----
Total 2124
----
Atomic weight 118.10
Number weight 2124/18 118.00
V.--THE BARS GROUPS.

[Illustration: PLATE XVII.]

Here, for the first time, we find ourselves a little at issue with the
accepted system of chemistry. Fluorine stands at the head of a
group--called the inter-periodic--whereof the remai