VI. Argon, a New Constituent of the Atmosphere. 
By Lord Rayuricn, Sec. RS., and Professor WitttAM Ramsay, F.B.S. 
Received and Read January 31, 1895. 
“Modern discoveries have not been made by large collections of facts, with subsequent discussion, 
separation, and resulting deduction of a truth thus rendered perceptible. A few facts have suggested an 
hypothesis, which means a supposition, proper to explain them. The necessary results of this supposition 
are worked out, and then, and not till then, other facts are examined to see if their ulterior results are 
found in Nature.” —De Morean, “ A Budget of Paradoxes,” ed. 1872, p. 55. 
1. Density of Nitrogen from Various Sources. 
Iy a former paper* it has been shown that nitrogen extracted from chemical 
compounds is about one-half per cent. lighter than “atmospheric nitrogen.” 
The mean numbers for the weights of gas contained in the globe used were as 
follows :— 
grams. 
Hromepnitrichoxid ce eens ono OO 
From nitrous oxide . .. . . 2°2990 
From ammonium nitrite. . . . 2'2987 
while for “ atmospheric” nitrogen there was found— 
iByahomeopper, S920 ae cial O38 
lany loon ure, WSO 6 5 1 6 A BIOO 
‘By ferrous hydrate, 1894... -2°3102 
At the suggestion of Professor THORPE, experiments were subsequently tried with 
nitrogen liberated from wrea by the action of sodium hypobromite. The carbon and 
hydrogen of the urea are supposed to be oxidized by the reaction to CO, and H,0, 
the former of which would be retained by the large excess of alkali employed. It 
was accordingly hoped that the gas would require no further purification than drying. 
If it proved to be light, it would at any rate be free from the suspicion of containing 
hydrogen. 
* RayueicH, “On an Anomaly encountered in Determinations of the Density of Nitrogen Gas,” 
‘Proc. Roy. Soc.,’ vol. 55, p. 340, 1894. 
MDCCCXCV.—A. 2 BZ 27.6.95. 
