"Crushed rock" Quotes from Famous Books
 ... material to a considerable depth are constantly being supplied with organic matter, which, along with the mineral material, constitutes that part of the earth which can support vegetation. Experiment will readily show that neither crushed rock nor pure vegetable mould will of itself serve to maintain any but the lowliest vegetation. It requires that the two materials be mixed in order that the earth may yield food for ordinary plants, particularly for those which are of use to man, as crops. ...
— Outlines of the Earth's History - A Popular Study in Physiography • Nathaniel Southgate Shaler |
