This section is from the book "Cassell's Cyclopaedia Of Mechanics", by Paul N. Hasluck. Also available from Amazon: Cassell's Cyclopaedia Of Mechanics.
Coral that has become very dusty may be cleaned in this manner. In a large pan full of soapsuds hang the coral in a net so that it is submerged but does not touch either the sides or bottom of the pan' and place the pan on the fire and boil. Then take it off' throw away the water, wash the coral in clean water' replace it in the net, and put it back in the pan as before; fill up with clean water and again bring to the boil .Remove coral, rinse in clean water, and allow to drain.
 
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