of the familiar principle that opposite electricities attract one
another. When compounds are decomposed by the battery, this
mutual attraction is overcome by the stronger attraction of the
poles of the battery itself.

This theory of binary composition of all chemical compounds,
through the union of electro-positive and electro-negative atoms
or molecules, was extended by Berzelius, and made the basis of
his famous system of theoretical chemistry. This theory held
that all inorganic compounds, however complex their composition,
are essentially composed of such binary combinations. For many
years this view enjoyed almost undisputed sway. It received what
seemed strong confirmation when Faraday showed the definite
connection between the amount of electricity employed and the
amount of decomposition produced in the so-called electrolyte.
But its claims were really much too comprehensive, as subsequent
discoveries proved.


ORGANIC CHEMISTRY AND THE IDEA OF THE MOLECULE

When Berzelius first promulgated his binary theory he was careful
to restrict its unmodified application to the compounds of the
inorganic world. At that time, and for a long time thereafter,
it was supposed that substances of organic nature had some
properties that kept them aloof from the domain of inorganic
chemistry. It was little doubted that a so-called "vital force"
operated here, replacing or modifying the action of ordinary
"chemical affinity." It was, indeed, admitted that organic
compounds are composed of familiar elements--chiefly carbon,