As a rule, the density increases with the amount of carbon, but in some instances a very high specific gravity is due to intermixed earthy matters, which are always denser than even the densest form of coal substance.
Its history is intermixed with that of columbium.
But when there is much small duff, with intermixed shale, more elaborate sizing and washing plant becomes necessary.
It may be situated in different counties or hundreds, and in many instances it contains, in addition to its principal district, several outlying portions intermixed with the lands in other parishes.
Oil obtained from heated meal is usually more highly coloured and harsher to the taste than cold drawn oil, more of the extractive substances being dissolved and intermixed with the oil.