140 
long splintery varieties; among these are the re- 
_ v ’ markable pseudomorphous crystals from Schnee- 
berg in Saxony, derived from various modifi¬ 
cations of calcareous spar ; also beautiful speci¬ 
mens of wood converted into hornstone, being 
the wood-stone of Werner; hornstone balls from 
Haunstadt in Bavaria*—Of jiint , a well known 
substance, several interesting varieties are de¬ 
posited. The remainder of this and the whole 
of the following case are occupied by calcedonic 
substances* Among the specimens of common 
calcedony the most remarkable are, the smalt 
blue variety from Felsobanya in Transylvania, 
crystallized in cubes ; the branched and stalac- 
tical calcedony from Iceland, &c.; the bo- 
try oi dal from Ferroe ; nodules, including water 
(enhydrites) from Monte Berico, near Vicenza, 
where they occur in volcanic rocks. 
Case 22. Calcedonic substances continued: 
cut and polished pieces of calcedony with red 
and black dendritic and other figures, called 
Mocha stones; varieties with white, brown, and 
black, straight or curved lines, some of which 
were probably among the substances of which 
the costly msa murrhina. of the ancients were 
made ; red and yellowish varieties of calcedony 
called carnelian .— Plasma .— Heliotrope , an inti¬ 
mate mixture of calcedony and green earth, 
which, when containing disseminated particles 
of red jasper, is commonly termed blood-stone. 
—The 
