re identical;
in the upper sections, iron has a cone of twenty-eight atoms, while cobalt
and nickel have each three ovoids, and of these the middle ones alone
differ, and that only in their upper globes, this globe being four-atomed
in cobalt and six-atomed in nickel.

The long ovoids within each bar revolve round the central axis of the bar,
remaining parallel with it, while each spins on its own axis; the iron cone
spins round as though impaled on the axis.

14 bars of 72 atoms 1008
Atomic weight 55.47
Number weight 1008/18 56.00
IRON (Plate IV, 1, and XVII, 3):

14 bars of 74 atoms 1036
Atomic weight 57.70
Number weight 1036/18 57.55
COBALT (Plate XVII, 4):

14 bars of 76 atoms 1064
Atomic weight 58.30
Number weight 1064/18 59.11
NICKEL (Plate XVII, 4):

(The weight of cobalt, as given in Erdmann's _Lehrbuch_, is 58.55, but
Messrs. Parker and Sexton, in _Nature_, August 1, 1907, give the weight, as
the result of their experiments, as 57.7.)

[Illustration: PLATE XVIII.]

The next sub-group, ruthenium, rhodium, and palladium, has nothing to
detain us. It will be observed that each bar contains eight segments,
instead of the six of cobalt and nickel; that ruthenium and palladium have
the same number of atoms in their upper ovoids, although in ruthenium a
triplet and quartet represent the septet of palladium; and that in
ruthenium and rhodium the lower ovoids are identical, though one has the
order: sixteen, fourteen, sixteen, fourteen; and the other: fourteen,
sixteen, fourteen, sixteen. One constantly asks oneself: What is the
significance of these minute changes? Further investigators will probably
discover the answer.

14 bars of 132 atoms 1848
Atomic weight 100.91
Number weight 1848/18 102.66
RUTHENIUM (Plate XVIII, 1):

14 bars of 134 atoms 1876
Atomic weight 102.23
Number weight 1876/18 104.22
RHODIUM (Plate XVII, 2):

14 bars of 136 atoms 1904
Atomic weight 105.74
Number weight 1904/18 105.77
PALLADIUM (XVIII, 3):

The third sub-group, osmium, iridium and platinum, is, of course, more
complicated in its composition, but its builders succeed