PRESIDENTIAL ADDRESS. 12) 
yelume was verified. Other methods were devised and 
adopted in further refinement and confirmation, ending 
(1894) in the isolation of a new gaseous element of such 
phenomenal chemical indifference as to earn the name of 
argon. Conservative members opposed its acceptance, but 
all opposition was overcome, and its existence in the air 
to the extent of about ome per cent. is now an accepted 
truth. It is interesting to remind ourselves that Cavendish 
had this very gas isolated and under his observation more 
than 100 years before (1785). 
It was natural to search for any further habitats of this 
“new stranger, who has been with us so long imcognito.”’ 
Tt was soon found that gases from mineral waters and 
springs contained it, a meteorite, and certain minerals; but 
# was not found as constituting a portion of either vegetable 
er animal tissue. 
The next new element discovered in the atmosphere was 
heiwwim, which has a story of fascmating interest. An un- 
known orange line first observed in thespectrum of the sun’s 
eorona in 1868, and afterwards in stars and nebule, was 
attributed by Lockyer and Frankland to an unknown ele- 
ment, which they named helium. 
Ramsay, in 1895, when looking for argon in the nitrogen 
gas (which Dr. Hildebrand had obtained from a crystal of 
wraninite in 1888), detected not simply the spectrum of 
argon, but the orange line that had given the spectroscopists 
so much trouble during the previous 26 years. Once helium 
had been isolated, Lockyer soon found that it accounted for 
many of the unidentified spectral lines of sun and star and 
nebula. 
And just here important assistance comes from a rather 
wnexpected source. The liquefaction of gases, beginning 
with Faraday’s, at first, simple experiments, had developed 
through the assistance of Pictet, Cailletet, and others, until, 
in the hands of Dewar and Hampson and Triplet, it has 
reached such a state of perfection that the liquefaction of air 
itself has become as simple an operation as was ice-making 
but a few years ago. 
Liquid air seems destined in the early future to play a 
most important part in the industrial world. As a possibly 
éonvenient motive-power in certain cases, as an explosive 
agent, as a ventilating agent, as a fuel, are some of the 
many directions m which it is confidently hoped by many 
that liquid air will find useful and extensive application. 
The price of production, which must so largely govern its 
uses, has been reduced from many pounds an ounce (£600) 
