fourth dimension, it would be easy to understand why they differ.
Certain snails present the same characteristics as these two forms
of sugar. Some are coiled to the right and others to the left; and
it is remarkable that, like dextrose and levulose, their juices are
optically the reverse of each other when studied by polarized light.

Revolution in the fourth dimension would also explain the change in
a body from producing a right-handed, to producing a left-handed,
polarization of light.


ISOMERISM

In chemistry the molecules of a compound are assumed to consist of
the atoms of the elements contained in the compound. These atoms are
supposed to be at certain distances from one another. It sometimes
happens that two compound substances differ in their chemical or
physical properties, or both, even though they have like chemical
elements in the same proportion. This phenomenon is called isomerism,
and the generally accepted explanation is that the atoms in isomeric
molecules are differently arranged, or grouped, in space. It is
difficult to imagine how atoms, alike in number, nature, and
relative proportion, can be so grouped as somehow to produce
compounds with different properties, particularly as in
three-dimensional space four is the greatest number of points whose
mutual distances, six in number, are all independent of each other.
In four-dimensional space, however, the _ten_ equal distances
between any two of _five_ points are geometrically independent, thus
greatly augmenting the number and variety of possible arrangements
of atoms.