438 Prof, W. Ramsay and Mr. M. W. Travers. 



surface of the liquid. After about 13 or 14 litres of the argon had 

 been condensed, the stopcock was closed, and the temperature was 

 kept low for some minutes in order to establish a condition of equi- 

 librium between the liquid and vapour. In the meantime, the con- 

 necting tubes were exhausted and two fractions of gas were taken 

 off by lowering the mercury reservoirs, each fraction consisting of 

 about 50 or 60 cubic cm. These fractions should contain 

 the light gas. In a previous experiment of the same kind, a small 

 fraction of the light gas had been separated, and was found to have 

 the density 17*2. The pressure of the air was now allowed to 

 rise, and the argon disbilled away into a separate gas-holder. The 

 white solid which had condensed in the upper portion of the bulb 

 did not appear to evaporate quickly, and that portion which had 

 separated in the liquid did not perceptibly diminish in amount. 

 Towards the end, when almost all the air had boiled away, the 

 last portions of the liquid evaporated slowly, and when the remaining 

 liquid was only sufficient to cover the solid, the bulb was placed in 

 connection with the Topler pump, and the exhaustion continued 

 until the liquid had entirely disappeared. Only the solid now 

 remained, and the pressure of the gas in the apparatus was only a 

 few millimetres. The bulb was now placed in connection with mer- 

 cury gas-holders, and the reservoirs were lowered. The solid vola- 

 tilised very slowly, and was collected in two fractions, each of about 

 70 or 80 cubic cm. Before the second fraction had been taken 

 off, the air had entirely boiled away, and the jacketing tube had 

 been removed. After about a minute, on wiping off the coating of 

 snow with the finger, the solid was seen to melt, and volatilise into 

 the gas-holder. 



The first fraction of gas was mixed with oxygen, and sparked over 

 soda. After removal of the oxygen with phosphorus it was intro- 

 duced into a vacuum-tube, and the spectrum examined. It was 

 characterised by a number of bright red lines, among which one was 

 particularly brilliant, and a brilliant yellow line, while the green and 

 the blue lines were numerous, but comparatively inconspicuous. The 

 wave-length of the yellow line, measured by Mr. Baly, was 5849*6, with 

 a second-order grating spectrum. It is, therefore, not identical 

 with sodium, helium, or krypton, all of which equal it in intensity. 

 The wave-lengths of these lines are as follows : 



Na (DO 5895-0 



Na(D 2 ) 5889-0 



He (D 3 ) 5875-9 



Kr(D 4 ) 5866-5 



Ne (D s ) 5849-6 



The density of this gas, which we propose to name " neon 



