, 2) resembles aluminium in having eight internal sub-divisions in a funnel, and the ovoids which form the top ring are identical, save for a minute difference that in aluminium the ovoids stand the reverse way from those in arsenic. It will be noted that in the former the top and bottom triangles of atoms have the apices upwards, and the middle one has its apex downwards. In arsenic, the top and bottom ones point downwards, and the middle one upwards. Arsenic inserts sixteen spheres between the ovoids and globe shown in aluminium, and thus adds no less than one hundred and forty-four atoms to each funnel.
ARSENIC: 6 funnels of 225 atoms 1350
Atomic weight 74.45
Number weight 1350/18 75.00
Antimony
(
, 3) is a close copy of indium, and the arrangement of types A and B in the funnels is identical. In the middle rings of both A and B a triplet is substituted for a unit at the centre of the larger globe. In the lowest body of type A the "cigar" has vanished, and is represented by a seven-atomed crystalline form.
ANTIMONY: Segment A 128 atoms
Segment B 113 atoms
3 funnels of 2 A and 1 B ([256 + 113]3) 1107
3 " " 2 B and 1 A ([226 + 128]3) 1056
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Total 2163
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Atomic weight 119.34
Number weight 120.16
VII.
Boron ([Plate III], 4, and Plate [XI], 1).