The book's ancient pages were so brittle, he feared they would crumble before he finished.
The barrier that separated the Arabs from the conquered nations begins to crumble away.
Towards the northern end of Malabar hill lie the Parsee Towers of Silence, where the Parsecs expose their dead till the flesh is devoured by vultures, and then cast the bones into a well where they crumble into dust.
Great care is necessary to prevent the heaps from becoming too hot, in which case the clay becomes baked into hard lumps of brick-like material which cannot be broken up. With careful management, however, the clay dries and bakes, becoming slowly converted into lumps which readily crumble into a fine powder, in which state it is spread over and worked into the land at the rate of 40 loads per acre.
The clay should be only slightly burnt, so as to make it crumble down readily; in fact, the fire should not be allowed to break through, but should be constantly repressed by the addition of material.