The Evolution of the Sciences 



neither helium nor neon is formed, but exclusively 

 argon, a gas still heavier than either, and belong- 

 ing to the same family; in addition to the 

 unaltered copper salt the liquid is found to 

 contain a perceptible quantity of sodium salts 

 and very distinct traces of lithium, 1 the experi- 

 ment repeated four times gave identical results, 

 and Ramsay checked it further by treating a 

 solution of copper nitrate in exactly the same 

 manner, with the single exception that it had 

 not been placed in contact with the emanation. 

 Under these new conditions no trace of lithium was 

 obtained, and only half the quantity of the sodium 

 in the previous case was ascertained to be present. 

 The presence of sodium is a normal phenome- 

 non; the glass of the bottles contains soda and 

 always communicates traces of this substance to 

 a liquid with which it has been in contact. On the 

 other hand, nothing short of a transmutation can 

 explain the presence of lithium. Further ex- 

 periments, thrice repeated, at six months' 

 intervals, manifest another phenomenon of the 



1 The weight of the lithium formed, estimated from the 

 intensity of the spectrum lines observed, would be about one 

 twenty thousandth of a milligramme. 



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