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LETTER XLII. 
VARIETIES OF PETRIFIED WOODS CONTINUED THOSE PROCEEDING 
from the OPERATIONS OF INSECTS STARRY STONE OF CHEMNITZ 
teredo marina. 
Among the numerous subjects of the mineral kingdom, which 
manifest traces of having derived their original forms from the 
energies of vegetable life, there are none whose ambiguous appear- 
ances occasion more perplexity, than the substances to which the 
present Letter is chiefly appropriated, the starry stone (staaren- 
stein) OF chemnitz. • 
These stones, representations of which will be found m Plate 
VIII Fig. Ij 2, 3, See. are chiefly found in the neighbourhood of 
Chemnitz, and particularly near to Hillersdorf. Specimens of this 
kind of stone have been said to have been also found near Belgrade : 
and, in particular, one specimen has been mentioned, which was 
reported to be one of the piles belonging to the bridge, which the 
Romans had erected over the Danube. The general appearance of 
most specimens of this stone convey the idea of its being fossil 
wood • but those marks which dispose to this opinion, although most 
evident in some, are, however, hardly, if at all, discoverable in 
others. The hardness of these stones, in general, appears to be 
nearly that of jasper, whilst in others it even seems to approach to 
that of agate. The general colour of their ground is mostly of a 
dark brown, sometimes inclining to a brick-dust red ; but, in d' - 
ferent specimens, most of the common colours of fossil wood wi 
be found to form that of their several grounds. The circumstances, 
however, which constitute the difference between these substances, 
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