198 
CHEMISTRY: J. STIEGLITZ 
questionably present as the specific hydrogen chloride radicle CI: the 
compounds are prepared from hydrogen chloride or its derivatives 
(PCI3, etc.); they form hydrochloric acid by hydrolysis, by treatment 
with ammonia and a variety of other reagents; the chlorine can be 
readily replaced by a great number of negative radicles; and in these 
chlorides, the chlorine has no oxidizing power. 
There is, evidently, a fundamental difference in the condition of the 
halogen in these organic compounds, the rearranging chloroamines and 
the (non-rearranging) alkyl and acyl chlorides. This difference is sharply 
and precisely expressed in terms of Thomson's original theory of electron 
valences by the electron structure (C1+) for the hypochlorous acid radicle,^ 
the positive charge indicating that the atom has lost an electron, and 
by the structure Cl~ for the hydrochloric acid radicle, the negative 
charge being due to an electron captured by the atom. The chloro- 
amines then have the structure R2N~+C1, the alkyl and acyl chlorides, 
the structures R3C+-CI and R.0C+-C1. (Here and throughout these 
articles only the valences in question are indicated.) These electronic 
structures give a complete and exact history of all the striking charac- 
teristics of the two groups of compounds, as just enumerated. 
According to the more recent suggestions of J. J. Thomson,^ the val- 
ences holding atoms in molecules, especially in the case of non-electro- 
lytes, may be formed, not only in the fashion assumed in his original 
theory (called now 'intramolecular ionization'), but also by the electrical 
attraction between the normal electrons of one atom and the 'positive 
core' of the other, each atom remaining, as a whole, electrically neutral. 
Practically the same suggestion (following one made by A. A. Noyes^ in 
1907 that we might have two kinds of molecules of one and the same 
compound, as, for instance, HCl and H+C1~ for hydrogen chloride) had 
previously been made by Bray and Branch^^ and by G. N. Lewis,^^ who 
speak both of 'non-polar' valences as uniting atoms, especially in non- 
electrolytes, and of 'polar' valences, of the type assumed in Thomson's 
original theory. Thomson defined and elaborated more precisely than 
did the American chemists the nature of 'non-polar' valences. Both 
Lewis and Thomson consider that the valences may be polar in one 
part, non-polar in another part of the same molecule. (The terms non- 
polar and polar will here be used as signifying the two kinds of valence 
postulated also by Thomson's later theory, inasmuch, as they are much 
more convenient than the terms 'intra-molecularly ionized' and 'non- 
ionized' valences.) 
It is evident, from the development given above, that even according 
to these newer views of valence, the electronic structure ofthechloro- 
