Rotten wood, when crumbled into powder, and dry, is also collected.

A mummy had reposed in the overturned cartonnage and the brittle bindings had crumbled into powder.

The moss beneath them, that had been softer to the tread than a Persian rug, crumbled into powder under the foot.

In one trouser pocket she found the remains of a dried flower that crumbled into powder when she took it out.