ASSIMILA'TION, noun

1. The act of bringing to a resemblance.

2. The act or process by which bodies convert other bodies into their own nature and substance; as, flame assimilates oil, and the food of animals is by assimilation converted into the substances which compose their bodies.

Mineral assimilation is the property which substances possess, in the earth, of appropriating and assimilating to themselves other substances with which they are in contact; a property which seems to be the basis of the natural history of the earth.