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522 THE POPULAR SCIENCE MONTHLY. 



ARGON. 



THE NEW CONSTITUENT OF TIIE AIE. 

 Br Dr. JOHN TAPPAN STODDARD, 



PROFESSOR OF CHEMISTRY IN SMITH COLLEGE. 



ON the 31st of January last the Royal Society of England 

 held a special meeting in Burlington Gardens. Formal 

 invitation to this meeting had been extended to the members of 

 two other scientific bodies, and an audience of at least eight hun- 

 dred, which included the most distinguished scientific men of 

 England, assembled to listen to the account of the discovery of a 

 new substance in our atmosphere. This discovery, made by Lord 

 Rayleigh and Prof. Ramsay, had been announced at the Oxford 

 meeting of the British Association last August ; but five months 

 of patient and strenuous work proved necessary before the inves- 

 tigators felt prepared to publish the detailed results of their re- 

 search. 



Our atmosphere consists essentially of a mixture of oxygen 

 and nitrogen. To the oxygen it owes its power of supporting 

 respiration and combustion ; while the nitrogen, inert and inca- 

 pable of chemical union under ordinary conditions, acts as a dilu- 

 ent, tempering the fierceness of the chemical activity which un- 

 mixed oxygen possesses. Both of these gases were discovered 

 more than one hundred and twenty years ago ; they have long 

 been recognized as elementary substances, and innumerable analy- 

 ses have established the proportion in which they occur in air. 



When a measured quantity of air, carefully freed from the 

 moisture and carbon dioxide which it always contains, is passed 

 through a tube filled with red-hot copper, the oxygen is fixed by 

 the copper, and the residual gas, amounting to four fifths of the 

 original volume, is found to be incapable of supporting combus- 

 tion. It is, in fact, what all chemists have considered, up to the 

 time of this brilliant discovery, pure nitrogen. 



It is now proved beyond all possible doubt or question that 

 this atmospheric nitrogen is not a single substance, but contains, 

 mixed with it to the amount of about one per cent, another 

 heavier gas, whose existence was previously unknown and un- 

 suspected. To this new substance, which out-nitrogens nitrogen 

 in its chemical inertness, its discoverers give the name of argon* 



Besides its occurrence in the free state in air, nitrogen is found 

 in combination in animal and vegetable substanees, in saltpeter 

 or niter (from which its name is derived), and is a constituent of 



* Argon is derived from alpha privative, and tpyov, and means not working, idle. 



