THE GASES OF THE ATMOSPHERE

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STEPHEN HALES.

THE GASES

OF

THE ATMOSPHERE

THE
HISTORY OF THEIR DISCOVERY

BY
WILLIAM RAMSAY, F.R.S.
PROFESSOR OF CHEMISTRY IN UNIVERSITY COLLEGE, LONDON

WITH PORTRAITS

London

MACMILLAN AND CO., Ltd.
NEW YORK: THE MACMILLAN CO.
1896

All rights reserved

“Modern discoveries have not been made by largecollections of facts, with subsequent discussion, separation, andresulting deduction of a truth thus rendered perceptible. A few factshave suggested an hypothesis, which means a supposition proper toexplain them. The necessary results of this supposition are worked out,and then, and not till then, other facts are examined to see if theirulterior results are found in Nature.”—DeMorgan, A Budget of Paradoxes, ed. 1872, p. 55.

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PREFACE

The discovery of new elementary gas in the atmosphere in 1894 arousedmuch interest, and public attention has again been directed to theair, which was, for many centuries, a fruitful field for speculationand conjecture. The account of this discovery, communicated to theRoyal Society in January 1895, was, however, necessarily couched inscientific language; and many matters of interest to the chemist andphysicist were written in an abbreviated style, in the knowledge thatthe passages describing them would be easily understood by the expertsto whom the communication was primarily addressed. But persons withoutany special scientific training have frequently expressed to me thehope that an account of the discovery would be published, in which the[Pg vi]conclusions drawn from the physical behaviour of argon should beaccompanied by a full account of the reasoning on which they are based.An endeavour to fulfil this request is to be found in the followingpages. And as the history of the discovery of the better knownconstituents of the atmosphere is of itself of great interest, andleads up to an acquaintance with the new stranger, who has so long beenwith us incognito, an effort has here been made to tell the tale of theair in popular language.

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CONTENTS