entirely composed, contain hydrogen, helium, and carbonic oxide, and
about the only imaginable way in which these gases could have become
absorbed in the iron would be through the immersion of the latter
while in a molten or vaporized state in a hot and dense atmosphere
composed of them, a condition which we know to exist only in the
envelopes of the sun and the stars.

The existence of carbon in the Canyon Diablo iron meteorites is
attended by a circumstance of the most singular character -- a very
``fairy tale of science.'' In some cases the carbon has become
diamond! These meteoric diamonds are very small; nevertheless, they
are true diamonds, resembling in many ways the little black gems
produced by Moissan's method with the aid of the electric furnace. The
fact that they are found embedded in these iron meteorites is another
argument in favor of the hypothesis of the solar or stellar origin of
the latter. To appreciate this it is necessary to recall the way in
which Moissan made his diamonds. It was by a combination of the
effects of great heat, great pressure, and sudden or rapid superficial
cooling on a mass of iron containing carbon. When he finally broke
open his iron he found it a pudding stuffed with miniature black
diamonds. When a fragment of the Canyon Diablo meteoric iron was
polished in Philadelphia over fifteen years ago it cut the emery-wheel
to pieces, and examination showed that the damage had been effected by
microscopic diamonds peppered through the mass. How were those
diamonds formed? If the sun or Sirius was the laboratory that prepared
them, we can get a glimpse at the process of their formation. There is
plenty of heat, plenty of pressure, and an abundance of vaporized iron
in the sun and the stars. When a great solar eruption takes place,
masses of iron which have absorbed carbon may be shot out with a
velocity which forbids their return. Plunged into the frightful cold