Henry Edward Armstrong
- 6 May 1848 - 13 July 1937
- Ph.D. Leipzig University 1867
- Professor of Chemistry at the London Institution
Finsbury Circus 1871
- Fellow of the Royal Society 1876
Henry Edward Armstrong was born in Lewisham on May 6th
1848. In 1865, at the age of 17, he joined the Royal
College of Chemistry as a research assistant to Sir
Edward Frankland. During his two years at the Royal
College, he devised with Sir Frankland a way to detect
impurities in drinking water making typhoid a preventable
From 1867 to 1870, Armstrong studied in Germany, at the
University of Leipzig. There he studied under Hermann
Kolbe who introduced him to aromatic chemistry. He was
awarded a Ph.D. for his thesis entitled "Contributions
to the history of the acids of the sulphur series, I. On
the action of sulphuric anhydride on several chlorine and
In 1874 he published a book, "Introduction to
Organic Chemistry", which is still available in
certain libraries for viewing.
In 1876, at the age of 28, he was elected as a fellow to
the Royal Society and served the Chemical Society in
London as secretary, vice-president and president (1893-1895).
Armstrong was not content with the work of Kekkule
believing that one carbon in the benzene ring directly
affected the other five through a central bonding system.
As you will see further on; Armstrong actually made an
important discovery with his naphthalene structure.
Armstrong acknowledged Kekulé’s structure as "being
superior to all other symbolic expressions in almost
every respect." However he did not agree with it
because apparently two meta and two ortho derivatives
existed and that it represented benzene as having three
pairs of carbon-atoms in "the condition of ethylene".
So Armstrong came up with the centric formula.
Later Revised To
The importance of the bonds not touching in the middle is
very significant. Armstrong believed that there were
forces acting towards the centre of the molecule. These
"affinities" played a part in the ring. With
hindsight, what he was talking about was the
delocalisation and resonance effect. His formula was
almost right but it was not till he expanded his theory
to naphthalene (see below) that he made a truly important
The fact that the two bonds in the middle of the molecule
cross is of a very big importance. This shows that
Armstrong is not sure of how the centric force works but
he does know that his "affinities" have
something to do with the molecule’s reactivity.
Let us look a little close at the last line in the
excerpt. "It becomes possible in this hypothesis, in
a measure, to understand that a radicle in the one
nucleus should, as is known to be the case, exercise an
influence on a radicle in the other nucleus."
What this is essentially saying is that for some reason,
the "radicle" attached to one of the nuclei (carbon
atom in benzene) must affect the other "radical"
on the other carbon atom. Now let us use modern day terms
and re-write that quote and you will get:
"It becomes possible in this hypothesis, in a
measure, to understand that a side group (R group) on a
carbon, should, as is known to be the case, exercise an
influence on the R group on the other carbon atom."
Tie that up with "An affinity can act in two
directions" and you get the first signs of some
quantum mechanics! Of course this is a theory with a few
assumptions made. But could it be that Professor
Armstrong just did not see that electrons follow a wave
pattern? Up to you to decide!!