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CAVERNS AND THEIR CONTENTS. 
BY D. T. ANSTED, F.R.S. 
CHAPTER II. 
CONTENTS OE THE CAVERNS, AND THEIR MEANING. 
I N an article on “ Caverns/ 5 in No. II. of the Popular 
Science Review, something has been said concerning’ 
the history of these curious and interesting natural pheno- 
mena, and also of those remarkable columns, curtains, and 
fantastic structures of stone that are constantly growing and 
becoming modified in them by the action of water. It is also 
well known that occasionally caverns are the channels by 
which concealed rivers pass along out of sight from one part of 
the earth 5 s surface to another; that sometimes the sea washes 
through them during a part of every tide ; that some have, in 
ancient as well as modern times, served as the habitations of 
men or the dens of wild beasts ; while others, only accessible 
from above, and only entered accidentally by any of the larger 
animals, are filled with stones and rubbish, with which valuable 
minerals and metallic ores are now and then associated. 
The contents of caverns, then, is a part of the subject as 
varied as the history of the caverns, and capable of yielding 
quite as much matter of interest and information. We may 
consider in succession the mineral, the vegetable, and the 
animal contents, ranking among the latter those specimens of 
human art that have lately been found buried with the bones of 
animals. 
Limestone caverns are not unfrequently mineral veins. The 
gaping crevices, partly filled with angular blocks fallen in from 
above, and partly with fine mud, have the interstices between 
the stones often occupied by glittering lead ore ; or -perhaps 
the floor consists of that stony ore of zinc called calamine, 
which seems to have been known only to the ancients as 
useful to convert copper into brass, and was not recognized by 
them as containing a specific and somewhat remarkable metal. 
Exposed to great heat, this stone-like mineral disappears as a 
white cloud (oxide of zinc), passing away into thin air. So 
