In 1868 Sir Norman Lockyer detected a light coming from the prominences
of the sun which was not given by any substance known on earth, and
attributed this to an unknown gas which he called helium, from the Greek
_helios_, the sun. _In 1895 Sir William Ramsay discovered in certain
minerals the same gas identified by the spectroscope._ We can say,
therefore, that this gas was discovered in the sun nearly thirty years
before it was found on earth; this discovery of the long-lost heir is as
thrilling a chapter in the detective story of science as any in the
sensational stories of the day, and makes us feel quite certain that our
methods really tell us of what elements sun and stars are built up. The
light from the corona of the sun, as we have mentioned indicates a gas
still unknown on earth, which has been christened Coronium.