They are not, however, to be used in the disinfection of instruments, nor where any large abraded surface would favour absorption.
A closer investigation of the numerous long, narrow banks which lie off the Flemish coast and the Thames estuary shows that they are composed of fragments of rock abraded and transported by tidal currents and storms in the same way that the chalk and limestone worn off from the eastern continuation of the island of Heligoland during the last two centuries has been reduced to the coarse gravel of the off-lying Dune.
Trunk or abraded mountains.