ere are no lines, but
the appearance of lines is caused by the rapid motion of the costituents up
and down, or along them backwards and forwards. The dots represent atoms,
or groups of atoms, within the proto-elements. 1 is found in C; 2 and 3 in
He; 4 in Fl; 5 in Li; 6 in N; 7 in Ru; 8 in Na; 9 and 10 in Co; 11 in Fe;
12 in Se. We shall return to these when analysing the elements, and shall
meet many other proto-elemental groupings.

The first thing which is noticed by the observer, when he turns his
attention to the chemical atoms, is that they show certain definite forms,
and that within these forms, modified in various ways, sub-groupings are
observable which recur in connexion with the same modified form. The main
types are not very numerous, and we found that, when we arranged the atoms
we had observed, according to their external forms, they fell into natural
classes; when these, in turn, were compared with Sir William Crookes'
classification, they proved to be singularly alike. Here is his arrangement
of the elements, as it appeared in the _Proceedings of the Royal Society_,
in a paper read on June 9th, 1898.

[Illustration]

This is to be read, following the lines of the "figures of eight": H, He,
Li, Gl, B, C, N, and so on, each successive element being heavier than the
one preceding it in order. The disks which fall immediately below each
other form a class; thus: H, Cl, Br, I; these resemble each other in
various ways, and, as we shall presently see, the same forms and groupings
re-appear.

Another chart--taken from Erdmann's _Lehrbuch_--arranges the elements on a
curved line, which curiously resembles the curves within the shell of a
nautilus. The radiating lines show the classes, the whole diameter building
up a family; it will be observed that there is an empty radius between
hydrogen and helium, and we have placed occultum there; on the opposite
radius, iron, rubidium and osmium are seen.

[Illustration]

The external forms may be classified as follows; the internal details will
be dealt with later :--

[Illustration: PLATE III.]

1. _The Dumb-bell._--The characteristics of this are a higher and lower
group, each showing 12 projecting funnels, grouped round a central body,
and a connecting rod. It appears in sodium, copper, silver, and gold,[17]
and gold is given (1 on Plate III) as the most extremely modified example
of this form. The 12 almond-like projections, above and below, are
severally