Dr. Meade’s Localities of Minerats 51 
the Macle or Chiastolite of Stirling and the staurotide 
at Northampton and Winthrop, where fine Crystals can on- 
ly be procured by long exposure of the Matrix to the action 
of the Atmosphere. 
Though Vesuvian or Idocrase is generally found in Vol- 
eanic Rocks and has been at one time supposed to be pe- 
culiar to them, yet it is now well ascertained that it occurs 
in primitive Rocks also in Norway, Piedmont, and other 
places. There can be no question with respect to the 
primitive formation in which these specimens are found 
near Worcester, but as I believe it is the first instance 
where it has been observed in this Country it is worth no- 
tice. A mineral of a green colour has been observed at 
Franklin near Sparta, which some Mineralogists here have 
talle be 
ra 
in his admirable memoir on the mineralogy of Sparta, the 
first which has appeared on the subject, takes notice of 
this but calls it epidote though resembling Idocrase. 
Proceeding from Worcester towards Boston | was indu- 
eed to deviate from the direct road in order to visit Stir- 
The crystals which are some inches in length, are im- 
bedded in a dark bluish argillite, and would escape notice, 
except where the terminations of them appear on the sur- 
face where the schist has been weathered. It is only by 
dividing the slate across its natural fracture or cleay- 
age that the real structure of the Prism can be demon- 
strated. When a transverse section of the schist is thus 
