Young of Princeton, Professor Langley of Washington,
and Professor Pickering of Harvard), and more
than half the known terrestrial elements have been
definitely located in the sun, while fresh discoveries
are in prospect.

It is true the sun also contains some seeming elements
that are unknown on the earth, but this is no
matter for surprise. The modern chemist makes no
claim for his elements except that they have thus far
resisted all human efforts to dissociate them; it would
be nothing strange if some of them, when subjected to
the crucible of the sun, which is seen to vaporize iron,
nickel, silicon, should fail to withstand the test. But
again, chemistry has by no means exhausted the resources
of the earth's supply of raw material, and the
substance which sends its message from a star may
exist undiscovered in the dust we tread or in the air
we breathe. In the year 1895 two new terrestrial elements
were discovered; but one of these had for years
been known to the astronomer as a solar and suspected
as a stellar element, and named helium because of its
abundance in the sun. The spectroscope had reached
out millions of miles into space and brought back this
new element, and it took the chemist a score of years
to discover that he had all along had samples of the
same substance unrecognized in his sublunary laboratory.
There is hardly a more picturesque fact than
that in the entire history of science.