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Presentation Speech by Professor J.E. Cederblom, President of the Royal Swedish Academy of Sciences, on December 10, 1904
Your Majesty, Your Royal Highnesses, Ladies
and Gentlemen.
One of the most prominent features of natural science research in
our day is the reciprocal action characterizing physics and
chemistry, causing an important discovery in one of these
sciences almost invariably to affect the sister science. Thus
Lord Rayleigh's investigations concerning the physical properties
of certain gases that have just received award gave rise to a
whole series of surprising and important discoveries in the
department of pure chemistry.
Lord Rayleigh having proved the remarkable difference in density
existing between atmospheric nitrogen and chemically prepared
nitrogen, another British scientist, already well-known as an
eminent chemist, received permission to co-operate in the
continued investigations with the intention of discovering, if
possible, the cause of the peculiar state of things previously
mentioned. The result of this co-operation was the discovery
(published in 1894) that the air contains a gaseous component,
previously unknown, of nearly one-and-a-half the density of
nitrogen, which explains the higher specific weight of the
atmospheric nitrogen. A careful study of the properties of the
new gas soon proved beyond all doubt that a new chemical element
had been discovered, which owing to its disinclination to enter
into chemical association with other elements was called
argon ("the inactive one").
Not content with having proved the presence of argon in the
gaseous envelope of the globe, Lord Rayleigh's chemical
co-operator, on his own initiative, devoted himself to searching
for the occurrence of argon in the solid crust of the earth. This
led him to a new discovery, scarcely less surprising than the
preceding. He succeeded in isolating from certain uranium
minerals a gas, which in the spectroscope proved identical, not
to argon, but to the long sought-for solar element helium
hitherto undiscovered on earth, the existence of which had first
been demonstrated by Janssen, the French astronomer, during a
spectroscopic examination of the solar chromosphere in 1868,
while making observations on an eclipse of the sun in India. It
has subsequently been found that helium is also present in the
water of some mineral springs, in certain meteorites, and that
like argon, only in a far less degree, it forms a component of
the atmosphere of the earth.
As soon as the atomic weight of the two new gases had been
approximately determined - as 4 for helium and 40 for argon- the
energetic scientist was led, by theoretical reasoning, to search
for yet another elementary gas, the atomic weight of which should
lie between the two preceding gases and should probably be about
20. Having made a great number of fruitless attempts in various
directions, he at last obtained an active agent when the problem
of making liquid air on a large scale was practically solved.
With the assistance of the low temperature which occurs when
liquid air evaporates (-200°C and lower) he was able to
obtain considerable quantities of liquid argon without any great
difficulty, and both by fractional distillation thereof and by
direct fractionation of liquid air, he succeeded in demonstrating
in the more freely volatile fractions the sought-for element
which was called by him neon ("the new one"). Not was this all:
in the less freely diffused fractions of the air he almost
simultaneously discovered two new elements, both gaseous at
ordinary temperature, of greater density than argon, the
existence of which he had predicted - though with rather less
certainty - and for which he proposed the denominations krypton
("the hidden one") and xenon ("the strange one").
These gases occur in the air but sparingly as a rule, for while
argon forms nearly 1 hundredth of the volume of the air, neon
occurs only as 1 to 2 hundred-thousandth, helium as 1 to 2
millionth, krypton as 1 millionth and xenon only as about 1
twenty-millionth part per volume. This more than anything else
will enable us to form an idea of the vast difficulties which
attend these investigations. In spite of all obstacles, however,
it has not only been found possible to isolate the new elements
but also to study their peculiarities with an accuracy which
enabled their place to be determined in the periodic system of
the elements. It has been demonstrated that the five new gases,
or "noble gases" as they are often called, form a natural family
of elements which by the absence of electric polarity is strictly
differentiated from all elements previously known, filling a void
in the periodic system hitherto existing between the highly
negative halogens and the highly positive alkali metals.
The discovery of an entirely new group of elements, of which no
single representative had been known with any certainty, is
something utterly unique in the history of chemistry, being
intrinsically an advance in science of peculiar significance. The
more remarkable is this advance when we recollect that all these
elements are components of the atmosphere of the earth, and that,
though apparently so accessible for scientific research, they
have for so long a time baffled the acumen of eminent scientists,
who from the time of Scheele, Priestley, and Lavoisier to our own
day have been occupied in determining the chemical and physical
properties of the air. The discovery, however, signifies far more
than the simple addition of five new elements to the seventy odd
that are already known. This to no slight degree owing to the
inert character of the new gases, which certainly renders their
study very difficult, but at the same time places them in a very
peculiar position among the other elements. In spite of repeated
and indefatigable endeavours it has been found impossible in any
authenticated case to induce chemical combination either with
each other or with other known elements. Such a total inertness
among elements was previously unknown; indeed it was almost
generally believed that the power of entering into chemical
reaction was a fundamental attribute which- though in a higher or
lower degree - characterized all the elements. The discovery of
the noble gases has removed this impediment to our knowledge,
widened our far too narrow view of the nature of the elements,
and for this reason, from a theoretical aspect, is of special
interest.
This interest has of late been still further heightened by the
observation that the spectral lines of helium appear in the
emanations from radium, that very puzzling element, an
observation which may bear fruit in results for science, the full
extent of which it is now impossible to foresee.
The scientific triumphs gained by the discovery of the noble
gases are easily described, though they have not been acquired
without great toil, being not merely a combination of fortunate
circumstances but the result of a well-planned, persevering, and
tiresome work. The man who has opened these new realms of nature
to science, and to whom the Royal Swedish Academy of Sciences has
decided to award the Nobel Prize in Chemistry for the present
year is Sir William Ramsay, Professor at University College,
London.
From Nobel Lectures, Chemistry 1901-1921, Elsevier Publishing Company, Amsterdam, 1966
Copyright © The Nobel Foundation 1904