THE ALUMNI JOURNAL. 



:i 9 



crease the material comforts of our civili- 

 zation, but will solve some of the most 

 exasperatingly elusive puzzles that the 

 poor chemist and physicist have to deal 

 withal. 



Cleveite was investigated first by Cleve 

 of Upsala, and is a variety of uraninite. 

 It is made up chiefly of the compounds 

 of uranium (uranyl uranate and uranate 

 of lead), a somewhat rare metal about 

 eighteen times as heavy as water, having 

 the appearance of nickel. Together with 

 these compounds of uranium there were 

 discovered small quantities of rare earths 

 which, although not of economic impor- 

 tance, are some hundreds of times more 

 valuable than gold. 



Now, unfortunately, our cleveite, 

 though noteworthy as a source of these 

 ■elements, did not add to our knowledge, 

 for we knew uranium and the rare met- 

 als ; and it therefore remained for some 

 years classed with other rare minerals 

 whose names are a ' ' terror by day ' ' to 

 the unfortunate mineralogist who finds 

 it necessary to memorize them. During 

 the month of March, however, Professor 

 Ramsay, whose name is inseparably con- 

 nected with the epoch-making discovery 

 of atmospheric argon, was led to seek 

 some clew by which he could hope to 

 make his argon combine with some other 

 element. His attention was drawn to a 

 paper by Hillebrand in the United States 

 Geological Survey (No. 78, page 43) "On 

 the Occurrence of Nitrogen in Uraninite." 

 According to Hillebrand, the gas nitro- 

 gen was obtained by simply boiling the 

 mineral in dilute sulphuric acid. Now 

 this is a very astonishing thing, for 

 throughout the whole realm of nature we 

 know no mineral which gives off nitrogen 

 on being boiled with sulphuric acid, and 

 Professor Ramsay was entirely skeptical 

 as to its possibility. 



In the hope that the gas was in reality 

 argon, and with the idea of so striving to 



make argon combine with uranium, he 

 investigated the matter himself, and 

 found his incredulity justified; for the 

 gas he obtained in his receiver contained 

 no nitrogen whatever, but was a new 

 gas, which he was utterly unable to 

 identify with any known terrestrial sub- 

 stance. Now, new elements do not hang 

 on every bush in the days when keen- 

 eyed science searches through every 

 nook and cranny of creation; and so its 

 discovery, even though there was noth- 

 ing more, was a very wonderful thing. 



We have said the new gas could be 

 identified with no known terrestrial ele- 

 ment; but it was identified, and that very 

 quickly, with the mysterious element in 

 the outer layer of the sun's atmosphere 

 called helium. Before considering the 

 remarkable consequences of the discov- 

 ery, let us ask how Ramsay could know 

 that the colorless gas which he held in 

 his test tube was identical with a sub- 

 stance 93,000,000 of miles away, which 

 no man had ever seen. Briefly, it was 

 by the light which it had emitted on 

 being heated to incandescence. That 

 different substances on being heated give 

 out lights of different colors, may be seen 

 in every display of fireworks; that every 

 known substance, on being heated to an 

 incandescent condition, gives out a light 

 peculiarly and characteristically its own, 

 js a broader statement, but just as true. 

 The light may not look characteristic to 

 the unaided eye; but when it passes 

 through the triangular prisms of a spec- 

 troscope, the original ray is dispersed 

 into a broad band, or spectrum, whose 

 vari-colored lines declare in an unyield- 

 ing voice the nature of its constituents. 

 Moreover, the spectroscope's decisions 

 cannot be invalidated by distance. Its 

 jurisdiction extends to the walls of the 

 universe. 



In 1868 J. Norman Lockyer, by means 

 of this most remarkable of all instruments 



