Page:The evolution of worlds - Lowell.djvu/67

Rh their present separate state. This parent mass must have been much larger and more massive than the Earth, as the great amount of occluded hydrogen,

sometimes one-third the volume at 500° C., of the meteorite seems to testify.

The two classes of meteorites, the stone and the iron, show this further by the very differences they exhibit between themselves. For both the amount and the proportions of the occluded gases in the two prove to be quite distinct. In the stones the quantity of gas is greater and the composition is diverse. In the stones carbonic acid gas is common, carbon monoxide rare; in the irons the ratio is just the other way. Thus Wright found in nine specimens of the iron meteorites:—

in ten of stone:—