Atomic weight 69.50
Number weight 1260/18 70.00
INDIUM (Plate XIII, 3) repeats the segments of gallium exactly, save in the
substitution of a sixteen-atomed body for the seven-atomed cone of the
left-hand segment, and a fourteen-atomed body for the five-atomed
corresponding one in gallium. But each funnel now has three segments
instead of two; three funnels out of the six contain two segments of type A
and one of type B; the remaining three contain two of type B, and one of
type A.

INDIUM: Segment A 121 atoms
Segment B 107 "
3 funnels of 2 A and 1 B ([242 + 107] 3) 1047
3 " " 2 B and 1 A ([214 + 121] 3) 1005
----
Total 2052
----
Atomic weight 114.05
Number weight 2052/18 114.00
The corresponding negative group, phosphorus, arsenic, and antimony, run on
very similar lines to those we have just examined.

[Illustration: PLATE XIV.]

PHOSPHORUS (Plate XIV, 1) offers us a very curious arrangement of atoms,
which will give some new forms in breaking up. Two segments are in each
funnel, in fact the only two of group III _a_ which do not show this
arrangement, or a modification thereof, are aluminium and arsenic.

PHOSPHORUS: Left segment 50 atoms