Genre:

Miscellaneous

Subjects:

Geology, Mineralogy, Vulcanology

    Gives a description of Sourther, the largest cavern in Iceland. States: 'The sides, or partitions of the cavern, produce the greatest effect, as they are covered with a sort of varnish in horizontal squares, separated by borders in-relief. This varnish is formed of a very fine vitreous, but opaque matter: in some parts it is black, but it is generally of a greenish colour, and similar to that employed in the manufactories of earthenware. This varnish as well as the stalactites just mentioned, affords a certain proof of the operation of subterraneous fires, and that the lava, in a state of fusion, has passed, like a rivulet through this channel, while it began to cool on the sides and top of the cavern. The flux of lava must have given to the cavern its present form; while the same fusion must have covered the sides of the cavern with a metallic alkaline varnish, by melting the interior crust of the cavern in those parts where the heat was strongest. The same cause must also have produced the stalactites.' (591)