again
to | inch current was again turned on. This was repeated three or four
times, finally current was applied for 30 seconds and the vacuum again
fell to 3 inches. The gas was drawn off and collected, it amounted to a
total of 1/2 gallon at atmospheric pressure and consisted of 95
per cent, carbon monoxide, 1 per cent, hydrogen, 2 per cent,
hydrocarbon, 2 per cent, nitrogen.
The
carbon which formed the crucible and cover contained a large
percentage of sihca, but the carbon monoxide was produced chiefly by
the action of sand (of which there was a thick layer on the bottom of
the container to protect the insulating joint from iron spilled from
the crucible) on the carbon of the stem of the crucible. About one half
of the iron had been evaporated, and there remained an ingot about the
size and shape of a broad bean. It contained rather large graphite
crystals and was easily broken. The analysis gave the largest residue
of diamond in proportion
