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discovered just at the spot where the diamond should have 
been, but not a vestige of the precious stone remained. 
The only explanation of its departure that seems feasible 
is, that the soda carbonate, causticised by the lime hydrate, 
had by its affinity for carbonic acid assisted the oxygen of 
the atmosphere getting through cracks in the clay, to 
oxidise the pure carbon of which the diamond is composed 
.at a vastly lower temperature than would in ordinary 
circumstances have been required — at all events this gem 
was entirely volatilised at a very low red heat. 
