Account of some new Vesuvian Minerals. 255 
ular if the fusion is suspended before the eflerveseence ter- 
minates. The splinters washed in nitric acid, i. e. free of 
calcareous laminz, melt more easily, and with more efter- 
cence. 
Varieties. 1. Primitive. 2. Peri-hexahedral. 3. Peri« 
octahedral. 4. Peri-dodecahedral. a. same shortened. 
Also, cylindrical, and in form of a compact, opaque mass, 
of asparagus colour 
imensions. . The largest crystals of the primitive variety 
are 14 millimetres long, 12 broad, and 7 igh The other 
varieties, particularly the 4th, are 21 by 15 
ee is perfectly analagous to that of the umboldilite. 
bservations. 'The crystals of zurlite have generally the 
ian SE “of grés, or sandstone. ‘The superficies rough 
and granular, of a green colour, more or less dirty. The 
angles of the crystals are more or less rounded, so aot the 
prisms pass easily into cylinders. Some crystals oc 
bedded in a whitish carb. of lime, which is spread thinly over 
the surface, like a varnish. 
The crystals of zurlite have a eS ETICHNTS, ave 
appear as if composed of umboldilite, pyrox 
lime, in mechanical combination, the f POREEEE 
and giving the primitive form. There are some crystals 
~ exhibit, in some spots, particles of pure umboldilite, and 
others a mixture of the three species. is shows 
Seis that the zurlite appertains to the umboldilite, of which 
seems a sub-specie 
The zurlite = varies d by Ramondini, who published 
a notice of it in the Neapolitan Encyclopedia. 
Davina. (Davyne.)* 
cific characters. jiige 
Ble dtase Characters. Primitive form, a regular-exa- 
“The height of the prism is greater than the breadth. 
The natural joints are very visible. 
* In honor of Sir Humphrey Davy. 
