In 1903 he obtained a scholarship to Birmingham University (as it
had now become) to work on the properties of the Crookes Dark Space
in discharge tubes. Within a short time he had discovered the phenomenon
which is known as the Aston Dark Space. At the end of 1909 he accepted
the invitation of Sir J.J.Thomson to work as his assistant at the
Cavendish Laboratory, Cambridge, on studies of positive rays. It
was during this period that he obtained definite evidence for the
existence of two isotopes of the inert gas neon.
This research was interrupted by the War of 1914-1918, during which
time Aston worked at the Royal Aircraft Establishment, Farnborough,
where he studied the effect of atmospheric conditions on aeroplane
fabrics and dopes (i.e. synthetic coatings).
Returning to the Cavendish Laboratory in 1919, he again attacked
the problem of the separation of the isotopes of neon. He quickly
achieved success in this by his invention of the mass spectrograph,
an apparatus in which the ingenious use of electromagnetic focusing
enabled him to utilize the very slight differences in mass of the
two isotopes to effect their separation. Extending this principle
to other chemical elements, he discovered, in a series of measurements,
no less than 212 of the naturally occurring isotopes. From the results
of this work he was able to formulate the so-called Whole Number
Rule which states that, the mass of the oxygen isotope being defined,
all the other isotopes have masses that are very nearly whole numbers.
Aston continued to make measurements, using an improved instrument,
with ever-increasing refinement and precision. He observed and was
able to measure those deviations from the Whole Number Rule which
were to become so important in the field of atomic energy.
The results of his work were published in the Proceedirngs of the
Royal Society and in the Philosophical Magazine. He was also the
author of the books Isotopes (1922; revised edition 1941) and of
Structural Units of the Material Uriverse (1923).
Aston was elected to a Fellowship at Trinity College in 1920, in
which year he also received the Mackenzie Davidson Medal of the
Röntgen Society. In 1921 he was made a Fellow of the Royal
Society and was awarded the Society's Hughes Medal the following
year, the same year that he received the Nobel Prize. The John Scott
and the Paterno medals were given to him in 1923, the Royal medal
in 1938, and he was Duddell medalist of the Physical Society in
He was an honorary member of the Russian Academy of Sciences and
of the Accademia dei Lincei, and held honorary doctorates ofthe
Universities of Birmingham and Dublin.
Aston, a bachelor, was an enthusiastic sportsman; skiing, rockclimbing,
tennis and swimming were among the sports in which he excelled.
He was also keen musician, playing the piano, violin and the cello.
He died at Cambridge on November 20, 1945.
From Nobel Lectures , Chemistry 1922-1941.