PRESIDENT’S ADDRESS. 29 
SOME NEW CHEMICAL ELEMENTS. 
Argon and helium are two of the latest additions to the 
list of chemical elements, and Sir J. Norman Lockyer has 
recently named a third, asterium. 
Argon and helium have been captured, bottled, and 
examined pretty thoroughly as far as their physical propor- 
tions are concerned, but up to the present no chemical 
properties have yet been detected as belonging to them, so 
that although elements (i.e., they are not compound) it 
seems paradoxical to speak of them as chemical elements— 
yet it is convenient and quite right that they should be so 
regarded. 
You will all recollect that argon was discovered about 
three years ago by Lord Rayleigh and Professor Ramsay ; 
it is a constituent of the atmosphere to the extent of about 
1 per cent.; it was almost discovered by Cavendish about 
100 years previously, and had the spectroscope been known 
in his time he certainly would have discovered it. 
For some time it was thought that argon, although 
clearly not a compound body, might be a mixture, but the 
later experiments of Professors Ramsay and Norman Collie 
have practically proved that argon is not a mixture, but a 
simple substance, 7.e., an element, with a probable atomic 
weight of 40. 
The name helium was given by Professors Lockyer and 
Frankland some thirty years ago to a supposed element in 
the sun, the existence of which was indicated by a yellow 
line (D3, wave length 5,875°982) in the solar spectrum. 
In his search for argon, in the gases given off by certain 
minerals when strongly heated, especially some containing 
uranium, yttrium, and thorium, Professor Ramsay obtained 
gases, which in the spectroscope gave certain characteristic 
lines, especially the remarkably brilliant yellow helium line, 
previously noticed by Professors Lockyer and Frankland in 
1868 in the sun’s chromosphere. 
