The wise student will try to visualize the figure
from the diagram. Thus the two triangles of hydrogen are not in one plane;
the circles are spheres, and the atoms within them, while preserving to
each other their relative positions, are in swift movement in
three-dimensional space. Where five atoms are seen, as in bromine and
iodine, they are generally arranged with the central atom above the four,
and their motion indicates lines which erect four plane triangles--meeting
at their apices--on a square base, forming a square-based four-sided
pyramid. Each dot represents a single ultimate atom. The enclosing lines
indicate the impression of form made on the observer, and the groupings of
the atoms; the groups will divide along these lines, when the element is
broken up, so that the lines have significance, but they do not exist as
stable walls or enclosing films, but rather mark limits, not lines, of
vibrations. It should be noted that it is not possible to show five of the
prisms in the five intersecting tetrahedra of prisms, and 30 atoms must,
therefore, be added in counting.
The diagrams are not drawn to scale, as such drawing would be impossible;
the dot representing the atom is enormously too large compared with the
enclosures, which are absurdly too small; a scale drawing would mean an
almost invisible dot on a sheet of many yards square.
Pages:
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63